12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485868788899091929394959697989910010110210310410510610710810911011111211311411511611711811912012112212312412512612712812913013113213313413513613713813914014114214314414514614714814915015115215315415515615715815916016116216316416516616716816917017117217317417517617717817918018118218318418518618718818919019119219319419519619719819920020120220320420520620720820921021121221321421521621721821922022122222322422522622722822923023123223323423523623723823924024124224324424524624724824925025125225325425525625725825926026126226326426526626726826927027127227327427527627727827928028128228328428528628728828929029129229329429529629729829930030130230330430530630730830931031131231331431531631731831932032132232332432532632732832933033133233333433533633733833934034134234334434534634734834935035135235335435535635735835936036136236336436536636736836937037137237337437537637737837938038138238338438538638738838939039139239339439539639739839940040140240340440540640740840941041141241341441541641741841942042142242342442542642742842943043143243343443543643743843944044144244344444544644744844945045145245345445545645745845946046146246346446546646746846947047147247347447547647747847948048148248348448548648748848949049149249349449549649749849950050150250350450550650750850951051151251351451551651751851952052152252352452552652752852953053153253353453553653753853954054154254354454554654754854955055155255355455555655755855956056156256356456556656756856957057157257357457557657757857958058158258358458558658758858959059159259359459559659759859960060160260360460560660760860961061161261361461561661761861962062162262362462562662762862963063163263363463563663763863964064164264364464564664764864965065165265365465565665765865966066166266366466566666766866967067167267367467567667767867968068168268368468568668768868969069169269369469569669769869970070170270370470570670770870971071171271371471571671771871972072172272372472572672772872973073173273373473573673773873974074174274374474574674774874975075175275375475575675775875976076176276376476576676776876977077177277377477577677777877978078178278378478578678778878979079179279379479579679779879980080180280380480580680780880981081181281381481581681781881982082182282382482582682782882983083183283383483583683783883984084184284384484584684784884985085185285385485585685785885986086186286386486586686786886987087187287387487587687787887988088188288388488588688788888989089189289389489589689789889990090190290390490590690790890991091191291391491591691791891992092192292392492592692792892993093193293393493593693793893994094194294394494594694794894995095195295395495595695795895996096196296396496596696796896997097197297397497597697797897998098198298398498598698798898999099199299399499599699799899910001001100210031004100510061007100810091010101110121013101410151016101710181019102010211022102310241025102610271028102910301031103210331034103510361037103810391040104110421043104410451046104710481049105010511052105310541055105610571058105910601061106210631064106510661067106810691070107110721073107410751076107710781079108010811082108310841085108610871088108910901091109210931094109510961097109810991100110111021103110411051106110711081109111011111112111311141115111611171118111911201121112211231124112511261127112811291130113111321133113411351136113711381139114011411142114311441145114611471148114911501151115211531154115511561157115811591160116111621163116411651166116711681169117011711172117311741175117611771178117911801181118211831184118511861187118811891190119111921193119411951196119711981199120012011202120312041205120612071208120912101211121212131214121512161217121812191220122112221223122412251226122712281229123012311232123312341235123612371238123912401241124212431244124512461247124812491250125112521253125412551256125712581259126012611262126312641265126612671268126912701271127212731274127512761277127812791280128112821283128412851286128712881289129012911292129312941295129612971298129913001301130213031304130513061307130813091310131113121313131413151316131713181319132013211322132313241325132613271328132913301331133213331334133513361337133813391340134113421343134413451346134713481349135013511352135313541355135613571358135913601361136213631364136513661367136813691370137113721373137413751376137713781379138013811382138313841385138613871388138913901391139213931394139513961397139813991400140114021403140414051406140714081409141014111412141314141415141614171418141914201421142214231424142514261427142814291430143114321433143414351436143714381439144014411442144314441445144614471448144914501451145214531454145514561457145814591460146114621463146414651466146714681469147014711472147314741475147614771478147914801481148214831484148514861487148814891490149114921493149414951496149714981499150015011502150315041505150615071508150915101511151215131514151515161517151815191520152115221523152415251526152715281529153015311532153315341535153615371538153915401541154215431544154515461547154815491550155115521553155415551556155715581559156015611562156315641565156615671568156915701571157215731574157515761577157815791580158115821583158415851586158715881589159015911592159315941595159615971598159916001601160216031604160516061607160816091610161116121613161416151616161716181619162016211622162316241625162616271628162916301631163216331634163516361637163816391640164116421643164416451646164716481649165016511652165316541655165616571658165916601661166216631664166516661667166816691670167116721673167416751676167716781679168016811682168316841685168616871688168916901691169216931694169516961697169816991700170117021703170417051706170717081709171017111712171317141715171617171718171917201721172217231724172517261727172817291730173117321733173417351736173717381739174017411742174317441745174617471748174917501751175217531754175517561757175817591760176117621763176417651766176717681769177017711772177317741775177617771778177917801781178217831784178517861787178817891790179117921793179417951796179717981799180018011802180318041805180618071808180918101811181218131814181518161817181818191820182118221823182418251826182718281829183018311832183318341835183618371838183918401841184218431844184518461847184818491850185118521853185418551856185718581859186018611862186318641865186618671868186918701871187218731874187518761877187818791880188118821883188418851886188718881889189018911892189318941895189618971898189919001901190219031904190519061907190819091910191119121913191419151916191719181919192019211922192319241925192619271928192919301931193219331934193519361937193819391940194119421943194419451946194719481949195019511952195319541955195619571958195919601961196219631964196519661967196819691970197119721973197419751976197719781979198019811982198319841985198619871988198919901991199219931994199519961997199819992000200120022003200420052006200720082009201020112012201320142015201620172018201920202021202220232024202520262027202820292030203120322033203420352036203720382039204020412042204320442045204620472048204920502051205220532054205520562057205820592060206120622063206420652066206720682069207020712072207320742075207620772078207920802081208220832084208520862087208820892090209120922093209420952096209720982099210021012102210321042105210621072108210921102111211221132114211521162117211821192120212121222123212421252126212721282129213021312132213321342135213621372138213921402141214221432144214521462147214821492150215121522153215421552156215721582159216021612162216321642165216621672168216921702171217221732174217521762177217821792180218121822183218421852186218721882189219021912192219321942195219621972198219922002201220222032204220522062207220822092210221122122213221422152216221722182219222022212222222322242225222622272228222922302231223222332234223522362237223822392240224122422243224422452246224722482249225022512252225322542255225622572258225922602261226222632264226522662267226822692270227122722273227422752276227722782279228022812282228322842285228622872288228922902291229222932294229522962297229822992300230123022303230423052306230723082309231023112312231323142315231623172318231923202321232223232324232523262327232823292330233123322333233423352336233723382339234023412342234323442345234623472348234923502351235223532354235523562357235823592360236123622363236423652366236723682369237023712372237323742375237623772378237923802381238223832384238523862387238823892390239123922393239423952396239723982399240024012402240324042405240624072408240924102411241224132414241524162417241824192420242124222423242424252426242724282429243024312432243324342435243624372438243924402441244224432444244524462447244824492450245124522453245424552456245724582459246024612462246324642465246624672468246924702471247224732474247524762477247824792480248124822483248424852486248724882489249024912492249324942495249624972498249925002501250225032504250525062507250825092510251125122513251425152516251725182519252025212522252325242525252625272528252925302531253225332534253525362537253825392540254125422543254425452546254725482549255025512552255325542555255625572558255925602561256225632564256525662567256825692570257125722573257425752576257725782579258025812582258325842585258625872588258925902591259225932594259525962597259825992600260126022603260426052606260726082609261026112612261326142615261626172618261926202621262226232624262526262627262826292630263126322633263426352636263726382639264026412642264326442645264626472648264926502651265226532654265526562657265826592660266126622663266426652666266726682669267026712672267326742675267626772678267926802681268226832684268526862687268826892690269126922693269426952696269726982699270027012702270327042705270627072708270927102711271227132714271527162717271827192720272127222723272427252726272727282729273027312732273327342735273627372738273927402741274227432744274527462747274827492750275127522753275427552756275727582759276027612762276327642765276627672768276927702771277227732774277527762777277827792780278127822783278427852786278727882789279027912792279327942795279627972798279928002801280228032804280528062807280828092810281128122813281428152816281728182819282028212822282328242825282628272828282928302831283228332834283528362837283828392840284128422843284428452846284728482849285028512852285328542855285628572858285928602861286228632864286528662867286828692870287128722873287428752876287728782879288028812882288328842885288628872888288928902891289228932894289528962897289828992900290129022903290429052906290729082909291029112912291329142915291629172918291929202921292229232924292529262927292829292930293129322933293429352936293729382939294029412942294329442945294629472948294929502951295229532954295529562957295829592960296129622963296429652966296729682969297029712972297329742975297629772978297929802981298229832984298529862987298829892990299129922993299429952996299729982999300030013002300330043005300630073008300930103011301230133014301530163017301830193020302130223023302430253026302730283029303030313032303330343035303630373038303930403041304230433044304530463047304830493050305130523053305430553056305730583059306030613062306330643065306630673068306930703071307230733074307530763077307830793080308130823083308430853086308730883089309030913092309330943095309630973098309931003101310231033104310531063107310831093110311131123113311431153116311731183119312031213122312331243125312631273128312931303131313231333134313531363137313831393140314131423143314431453146314731483149315031513152315331543155315631573158315931603161316231633164316531663167316831693170317131723173317431753176317731783179318031813182318331843185318631873188318931903191319231933194319531963197319831993200320132023203320432053206320732083209321032113212321332143215321632173218321932203221322232233224322532263227322832293230323132323233323432353236323732383239324032413242324332443245324632473248324932503251325232533254325532563257325832593260326132623263326432653266326732683269327032713272327332743275327632773278327932803281328232833284328532863287328832893290329132923293329432953296329732983299330033013302330333043305330633073308330933103311331233133314331533163317331833193320332133223323332433253326332733283329333033313332333333343335333633373338333933403341334233433344334533463347334833493350335133523353335433553356335733583359336033613362336333643365336633673368336933703371337233733374337533763377337833793380338133823383338433853386338733883389339033913392339333943395339633973398339934003401340234033404340534063407340834093410341134123413341434153416341734183419342034213422342334243425342634273428342934303431343234333434343534363437343834393440344134423443344434453446344734483449345034513452345334543455345634573458345934603461346234633464346534663467346834693470347134723473347434753476347734783479348034813482348334843485348634873488348934903491349234933494349534963497349834993500350135023503350435053506350735083509351035113512351335143515351635173518351935203521352235233524352535263527352835293530353135323533353435353536353735383539354035413542354335443545354635473548354935503551355235533554355535563557355835593560356135623563356435653566356735683569357035713572357335743575357635773578357935803581358235833584358535863587358835893590359135923593359435953596359735983599360036013602360336043605360636073608360936103611361236133614361536163617361836193620362136223623362436253626362736283629363036313632363336343635363636373638363936403641364236433644364536463647364836493650365136523653365436553656365736583659366036613662366336643665366636673668366936703671367236733674367536763677367836793680368136823683368436853686368736883689369036913692369336943695369636973698369937003701370237033704370537063707370837093710371137123713371437153716371737183719372037213722372337243725372637273728372937303731373237333734373537363737373837393740374137423743374437453746374737483749375037513752375337543755375637573758375937603761376237633764376537663767376837693770377137723773377437753776377737783779378037813782378337843785378637873788378937903791379237933794379537963797379837993800380138023803380438053806380738083809381038113812381338143815381638173818381938203821382238233824382538263827382838293830383138323833383438353836383738383839384038413842384338443845384638473848384938503851385238533854385538563857385838593860386138623863386438653866386738683869387038713872387338743875387638773878387938803881388238833884388538863887388838893890389138923893389438953896389738983899390039013902390339043905390639073908390939103911391239133914391539163917391839193920392139223923392439253926392739283929393039313932393339343935393639373938393939403941394239433944394539463947394839493950395139523953395439553956395739583959396039613962396339643965396639673968396939703971397239733974397539763977397839793980398139823983398439853986398739883989399039913992399339943995399639973998399940004001400240034004400540064007400840094010401140124013401440154016401740184019402040214022402340244025402640274028402940304031403240334034403540364037403840394040404140424043404440454046404740484049405040514052405340544055405640574058405940604061406240634064406540664067406840694070407140724073407440754076407740784079408040814082408340844085408640874088408940904091409240934094409540964097409840994100410141024103410441054106410741084109411041114112411341144115411641174118411941204121412241234124412541264127412841294130413141324133413441354136413741384139414041414142414341444145414641474148414941504151415241534154415541564157415841594160416141624163416441654166416741684169417041714172417341744175417641774178417941804181418241834184418541864187418841894190419141924193419441954196419741984199420042014202420342044205420642074208420942104211421242134214421542164217421842194220422142224223422442254226422742284229423042314232423342344235423642374238423942404241424242434244424542464247424842494250425142524253425442554256425742584259426042614262426342644265426642674268426942704271427242734274427542764277427842794280428142824283428442854286428742884289429042914292429342944295429642974298429943004301430243034304430543064307430843094310431143124313431443154316431743184319432043214322432343244325432643274328432943304331433243334334433543364337433843394340434143424343434443454346434743484349435043514352435343544355435643574358435943604361436243634364436543664367436843694370437143724373437443754376437743784379438043814382438343844385438643874388438943904391439243934394439543964397439843994400440144024403440444054406440744084409441044114412441344144415441644174418441944204421442244234424442544264427442844294430443144324433443444354436443744384439444044414442444344444445444644474448444944504451445244534454445544564457445844594460446144624463446444654466446744684469447044714472447344744475447644774478447944804481448244834484448544864487448844894490449144924493449444954496449744984499450045014502450345044505450645074508450945104511451245134514451545164517451845194520452145224523452445254526452745284529453045314532453345344535453645374538453945404541454245434544454545464547454845494550455145524553455445554556455745584559456045614562456345644565456645674568456945704571457245734574457545764577457845794580458145824583458445854586458745884589459045914592459345944595459645974598459946004601460246034604460546064607460846094610461146124613461446154616461746184619462046214622462346244625462646274628462946304631463246334634463546364637463846394640464146424643464446454646464746484649465046514652465346544655465646574658465946604661466246634664466546664667466846694670467146724673467446754676467746784679468046814682468346844685468646874688468946904691469246934694469546964697469846994700470147024703470447054706470747084709471047114712471347144715471647174718471947204721472247234724472547264727472847294730473147324733473447354736473747384739474047414742474347444745474647474748474947504751475247534754475547564757475847594760476147624763476447654766476747684769477047714772477347744775477647774778477947804781478247834784478547864787478847894790479147924793479447954796479747984799480048014802480348044805480648074808480948104811481248134814481548164817481848194820482148224823482448254826482748284829483048314832483348344835483648374838483948404841484248434844484548464847484848494850485148524853485448554856485748584859486048614862486348644865486648674868486948704871487248734874487548764877487848794880488148824883488448854886488748884889489048914892489348944895489648974898489949004901490249034904490549064907490849094910491149124913491449154916491749184919492049214922492349244925492649274928492949304931493249334934493549364937493849394940494149424943494449454946494749484949495049514952495349544955495649574958495949604961496249634964496549664967496849694970497149724973497449754976497749784979498049814982498349844985498649874988498949904991499249934994499549964997499849995000500150025003500450055006500750085009501050115012501350145015501650175018501950205021502250235024502550265027502850295030503150325033503450355036503750385039504050415042504350445045504650475048504950505051505250535054505550565057505850595060506150625063506450655066506750685069507050715072507350745075507650775078507950805081508250835084508550865087508850895090509150925093509450955096509750985099510051015102510351045105510651075108510951105111511251135114511551165117511851195120512151225123512451255126512751285129513051315132513351345135513651375138513951405141514251435144514551465147514851495150515151525153515451555156515751585159516051615162516351645165516651675168516951705171517251735174517551765177517851795180518151825183518451855186518751885189519051915192519351945195519651975198519952005201520252035204520552065207520852095210521152125213521452155216521752185219522052215222522352245225522652275228522952305231523252335234523552365237523852395240524152425243524452455246524752485249525052515252525352545255525652575258525952605261526252635264526552665267526852695270527152725273527452755276527752785279528052815282528352845285528652875288528952905291529252935294529552965297529852995300530153025303530453055306530753085309531053115312531353145315531653175318531953205321532253235324532553265327532853295330533153325333533453355336533753385339534053415342534353445345534653475348534953505351535253535354535553565357535853595360536153625363536453655366536753685369537053715372537353745375537653775378537953805381538253835384538553865387538853895390539153925393539453955396539753985399540054015402540354045405540654075408540954105411541254135414541554165417541854195420542154225423542454255426542754285429543054315432543354345435543654375438543954405441544254435444544554465447544854495450545154525453545454555456545754585459546054615462546354645465546654675468546954705471547254735474547554765477547854795480548154825483548454855486548754885489549054915492549354945495549654975498549955005501550255035504550555065507550855095510551155125513551455155516551755185519552055215522552355245525552655275528552955305531553255335534553555365537553855395540554155425543554455455546554755485549555055515552555355545555555655575558555955605561 |
- /* SPDX-License-Identifier: GPL-2.0 */
- /* Copyright (c) 2018 Facebook */
- #include <uapi/linux/btf.h>
- #include <uapi/linux/bpf.h>
- #include <uapi/linux/bpf_perf_event.h>
- #include <uapi/linux/types.h>
- #include <linux/seq_file.h>
- #include <linux/compiler.h>
- #include <linux/ctype.h>
- #include <linux/errno.h>
- #include <linux/slab.h>
- #include <linux/anon_inodes.h>
- #include <linux/file.h>
- #include <linux/uaccess.h>
- #include <linux/kernel.h>
- #include <linux/idr.h>
- #include <linux/sort.h>
- #include <linux/bpf_verifier.h>
- #include <linux/btf.h>
- #include <linux/btf_ids.h>
- #include <linux/skmsg.h>
- #include <linux/perf_event.h>
- #include <linux/bsearch.h>
- #include <linux/btf_ids.h>
- #include <net/sock.h>
- /* BTF (BPF Type Format) is the meta data format which describes
- * the data types of BPF program/map. Hence, it basically focus
- * on the C programming language which the modern BPF is primary
- * using.
- *
- * ELF Section:
- * ~~~~~~~~~~~
- * The BTF data is stored under the ".BTF" ELF section
- *
- * struct btf_type:
- * ~~~~~~~~~~~~~~~
- * Each 'struct btf_type' object describes a C data type.
- * Depending on the type it is describing, a 'struct btf_type'
- * object may be followed by more data. F.e.
- * To describe an array, 'struct btf_type' is followed by
- * 'struct btf_array'.
- *
- * 'struct btf_type' and any extra data following it are
- * 4 bytes aligned.
- *
- * Type section:
- * ~~~~~~~~~~~~~
- * The BTF type section contains a list of 'struct btf_type' objects.
- * Each one describes a C type. Recall from the above section
- * that a 'struct btf_type' object could be immediately followed by extra
- * data in order to desribe some particular C types.
- *
- * type_id:
- * ~~~~~~~
- * Each btf_type object is identified by a type_id. The type_id
- * is implicitly implied by the location of the btf_type object in
- * the BTF type section. The first one has type_id 1. The second
- * one has type_id 2...etc. Hence, an earlier btf_type has
- * a smaller type_id.
- *
- * A btf_type object may refer to another btf_type object by using
- * type_id (i.e. the "type" in the "struct btf_type").
- *
- * NOTE that we cannot assume any reference-order.
- * A btf_type object can refer to an earlier btf_type object
- * but it can also refer to a later btf_type object.
- *
- * For example, to describe "const void *". A btf_type
- * object describing "const" may refer to another btf_type
- * object describing "void *". This type-reference is done
- * by specifying type_id:
- *
- * [1] CONST (anon) type_id=2
- * [2] PTR (anon) type_id=0
- *
- * The above is the btf_verifier debug log:
- * - Each line started with "[?]" is a btf_type object
- * - [?] is the type_id of the btf_type object.
- * - CONST/PTR is the BTF_KIND_XXX
- * - "(anon)" is the name of the type. It just
- * happens that CONST and PTR has no name.
- * - type_id=XXX is the 'u32 type' in btf_type
- *
- * NOTE: "void" has type_id 0
- *
- * String section:
- * ~~~~~~~~~~~~~~
- * The BTF string section contains the names used by the type section.
- * Each string is referred by an "offset" from the beginning of the
- * string section.
- *
- * Each string is '\0' terminated.
- *
- * The first character in the string section must be '\0'
- * which is used to mean 'anonymous'. Some btf_type may not
- * have a name.
- */
- /* BTF verification:
- *
- * To verify BTF data, two passes are needed.
- *
- * Pass #1
- * ~~~~~~~
- * The first pass is to collect all btf_type objects to
- * an array: "btf->types".
- *
- * Depending on the C type that a btf_type is describing,
- * a btf_type may be followed by extra data. We don't know
- * how many btf_type is there, and more importantly we don't
- * know where each btf_type is located in the type section.
- *
- * Without knowing the location of each type_id, most verifications
- * cannot be done. e.g. an earlier btf_type may refer to a later
- * btf_type (recall the "const void *" above), so we cannot
- * check this type-reference in the first pass.
- *
- * In the first pass, it still does some verifications (e.g.
- * checking the name is a valid offset to the string section).
- *
- * Pass #2
- * ~~~~~~~
- * The main focus is to resolve a btf_type that is referring
- * to another type.
- *
- * We have to ensure the referring type:
- * 1) does exist in the BTF (i.e. in btf->types[])
- * 2) does not cause a loop:
- * struct A {
- * struct B b;
- * };
- *
- * struct B {
- * struct A a;
- * };
- *
- * btf_type_needs_resolve() decides if a btf_type needs
- * to be resolved.
- *
- * The needs_resolve type implements the "resolve()" ops which
- * essentially does a DFS and detects backedge.
- *
- * During resolve (or DFS), different C types have different
- * "RESOLVED" conditions.
- *
- * When resolving a BTF_KIND_STRUCT, we need to resolve all its
- * members because a member is always referring to another
- * type. A struct's member can be treated as "RESOLVED" if
- * it is referring to a BTF_KIND_PTR. Otherwise, the
- * following valid C struct would be rejected:
- *
- * struct A {
- * int m;
- * struct A *a;
- * };
- *
- * When resolving a BTF_KIND_PTR, it needs to keep resolving if
- * it is referring to another BTF_KIND_PTR. Otherwise, we cannot
- * detect a pointer loop, e.g.:
- * BTF_KIND_CONST -> BTF_KIND_PTR -> BTF_KIND_CONST -> BTF_KIND_PTR +
- * ^ |
- * +-----------------------------------------+
- *
- */
- #define BITS_PER_U128 (sizeof(u64) * BITS_PER_BYTE * 2)
- #define BITS_PER_BYTE_MASK (BITS_PER_BYTE - 1)
- #define BITS_PER_BYTE_MASKED(bits) ((bits) & BITS_PER_BYTE_MASK)
- #define BITS_ROUNDDOWN_BYTES(bits) ((bits) >> 3)
- #define BITS_ROUNDUP_BYTES(bits) \
- (BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits))
- #define BTF_INFO_MASK 0x8f00ffff
- #define BTF_INT_MASK 0x0fffffff
- #define BTF_TYPE_ID_VALID(type_id) ((type_id) <= BTF_MAX_TYPE)
- #define BTF_STR_OFFSET_VALID(name_off) ((name_off) <= BTF_MAX_NAME_OFFSET)
- /* 16MB for 64k structs and each has 16 members and
- * a few MB spaces for the string section.
- * The hard limit is S32_MAX.
- */
- #define BTF_MAX_SIZE (16 * 1024 * 1024)
- #define for_each_member_from(i, from, struct_type, member) \
- for (i = from, member = btf_type_member(struct_type) + from; \
- i < btf_type_vlen(struct_type); \
- i++, member++)
- #define for_each_vsi_from(i, from, struct_type, member) \
- for (i = from, member = btf_type_var_secinfo(struct_type) + from; \
- i < btf_type_vlen(struct_type); \
- i++, member++)
- DEFINE_IDR(btf_idr);
- DEFINE_SPINLOCK(btf_idr_lock);
- struct btf {
- void *data;
- struct btf_type **types;
- u32 *resolved_ids;
- u32 *resolved_sizes;
- const char *strings;
- void *nohdr_data;
- struct btf_header hdr;
- u32 nr_types;
- u32 types_size;
- u32 data_size;
- refcount_t refcnt;
- u32 id;
- struct rcu_head rcu;
- };
- enum verifier_phase {
- CHECK_META,
- CHECK_TYPE,
- };
- struct resolve_vertex {
- const struct btf_type *t;
- u32 type_id;
- u16 next_member;
- };
- enum visit_state {
- NOT_VISITED,
- VISITED,
- RESOLVED,
- };
- enum resolve_mode {
- RESOLVE_TBD, /* To Be Determined */
- RESOLVE_PTR, /* Resolving for Pointer */
- RESOLVE_STRUCT_OR_ARRAY, /* Resolving for struct/union
- * or array
- */
- };
- #define MAX_RESOLVE_DEPTH 32
- struct btf_sec_info {
- u32 off;
- u32 len;
- };
- struct btf_verifier_env {
- struct btf *btf;
- u8 *visit_states;
- struct resolve_vertex stack[MAX_RESOLVE_DEPTH];
- struct bpf_verifier_log log;
- u32 log_type_id;
- u32 top_stack;
- enum verifier_phase phase;
- enum resolve_mode resolve_mode;
- };
- static const char * const btf_kind_str[NR_BTF_KINDS] = {
- [BTF_KIND_UNKN] = "UNKNOWN",
- [BTF_KIND_INT] = "INT",
- [BTF_KIND_PTR] = "PTR",
- [BTF_KIND_ARRAY] = "ARRAY",
- [BTF_KIND_STRUCT] = "STRUCT",
- [BTF_KIND_UNION] = "UNION",
- [BTF_KIND_ENUM] = "ENUM",
- [BTF_KIND_FWD] = "FWD",
- [BTF_KIND_TYPEDEF] = "TYPEDEF",
- [BTF_KIND_VOLATILE] = "VOLATILE",
- [BTF_KIND_CONST] = "CONST",
- [BTF_KIND_RESTRICT] = "RESTRICT",
- [BTF_KIND_FUNC] = "FUNC",
- [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO",
- [BTF_KIND_VAR] = "VAR",
- [BTF_KIND_DATASEC] = "DATASEC",
- };
- static const char *btf_type_str(const struct btf_type *t)
- {
- return btf_kind_str[BTF_INFO_KIND(t->info)];
- }
- /* Chunk size we use in safe copy of data to be shown. */
- #define BTF_SHOW_OBJ_SAFE_SIZE 32
- /*
- * This is the maximum size of a base type value (equivalent to a
- * 128-bit int); if we are at the end of our safe buffer and have
- * less than 16 bytes space we can't be assured of being able
- * to copy the next type safely, so in such cases we will initiate
- * a new copy.
- */
- #define BTF_SHOW_OBJ_BASE_TYPE_SIZE 16
- /* Type name size */
- #define BTF_SHOW_NAME_SIZE 80
- /*
- * Common data to all BTF show operations. Private show functions can add
- * their own data to a structure containing a struct btf_show and consult it
- * in the show callback. See btf_type_show() below.
- *
- * One challenge with showing nested data is we want to skip 0-valued
- * data, but in order to figure out whether a nested object is all zeros
- * we need to walk through it. As a result, we need to make two passes
- * when handling structs, unions and arrays; the first path simply looks
- * for nonzero data, while the second actually does the display. The first
- * pass is signalled by show->state.depth_check being set, and if we
- * encounter a non-zero value we set show->state.depth_to_show to
- * the depth at which we encountered it. When we have completed the
- * first pass, we will know if anything needs to be displayed if
- * depth_to_show > depth. See btf_[struct,array]_show() for the
- * implementation of this.
- *
- * Another problem is we want to ensure the data for display is safe to
- * access. To support this, the anonymous "struct {} obj" tracks the data
- * object and our safe copy of it. We copy portions of the data needed
- * to the object "copy" buffer, but because its size is limited to
- * BTF_SHOW_OBJ_COPY_LEN bytes, multiple copies may be required as we
- * traverse larger objects for display.
- *
- * The various data type show functions all start with a call to
- * btf_show_start_type() which returns a pointer to the safe copy
- * of the data needed (or if BTF_SHOW_UNSAFE is specified, to the
- * raw data itself). btf_show_obj_safe() is responsible for
- * using copy_from_kernel_nofault() to update the safe data if necessary
- * as we traverse the object's data. skbuff-like semantics are
- * used:
- *
- * - obj.head points to the start of the toplevel object for display
- * - obj.size is the size of the toplevel object
- * - obj.data points to the current point in the original data at
- * which our safe data starts. obj.data will advance as we copy
- * portions of the data.
- *
- * In most cases a single copy will suffice, but larger data structures
- * such as "struct task_struct" will require many copies. The logic in
- * btf_show_obj_safe() handles the logic that determines if a new
- * copy_from_kernel_nofault() is needed.
- */
- struct btf_show {
- u64 flags;
- void *target; /* target of show operation (seq file, buffer) */
- void (*showfn)(struct btf_show *show, const char *fmt, va_list args);
- const struct btf *btf;
- /* below are used during iteration */
- struct {
- u8 depth;
- u8 depth_to_show;
- u8 depth_check;
- u8 array_member:1,
- array_terminated:1;
- u16 array_encoding;
- u32 type_id;
- int status; /* non-zero for error */
- const struct btf_type *type;
- const struct btf_member *member;
- char name[BTF_SHOW_NAME_SIZE]; /* space for member name/type */
- } state;
- struct {
- u32 size;
- void *head;
- void *data;
- u8 safe[BTF_SHOW_OBJ_SAFE_SIZE];
- } obj;
- };
- struct btf_kind_operations {
- s32 (*check_meta)(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left);
- int (*resolve)(struct btf_verifier_env *env,
- const struct resolve_vertex *v);
- int (*check_member)(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type);
- int (*check_kflag_member)(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type);
- void (*log_details)(struct btf_verifier_env *env,
- const struct btf_type *t);
- void (*show)(const struct btf *btf, const struct btf_type *t,
- u32 type_id, void *data, u8 bits_offsets,
- struct btf_show *show);
- };
- static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS];
- static struct btf_type btf_void;
- static int btf_resolve(struct btf_verifier_env *env,
- const struct btf_type *t, u32 type_id);
- static bool btf_type_is_modifier(const struct btf_type *t)
- {
- /* Some of them is not strictly a C modifier
- * but they are grouped into the same bucket
- * for BTF concern:
- * A type (t) that refers to another
- * type through t->type AND its size cannot
- * be determined without following the t->type.
- *
- * ptr does not fall into this bucket
- * because its size is always sizeof(void *).
- */
- switch (BTF_INFO_KIND(t->info)) {
- case BTF_KIND_TYPEDEF:
- case BTF_KIND_VOLATILE:
- case BTF_KIND_CONST:
- case BTF_KIND_RESTRICT:
- return true;
- }
- return false;
- }
- bool btf_type_is_void(const struct btf_type *t)
- {
- return t == &btf_void;
- }
- static bool btf_type_is_fwd(const struct btf_type *t)
- {
- return BTF_INFO_KIND(t->info) == BTF_KIND_FWD;
- }
- static bool btf_type_nosize(const struct btf_type *t)
- {
- return btf_type_is_void(t) || btf_type_is_fwd(t) ||
- btf_type_is_func(t) || btf_type_is_func_proto(t);
- }
- static bool btf_type_nosize_or_null(const struct btf_type *t)
- {
- return !t || btf_type_nosize(t);
- }
- static bool __btf_type_is_struct(const struct btf_type *t)
- {
- return BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT;
- }
- static bool btf_type_is_array(const struct btf_type *t)
- {
- return BTF_INFO_KIND(t->info) == BTF_KIND_ARRAY;
- }
- static bool btf_type_is_datasec(const struct btf_type *t)
- {
- return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC;
- }
- s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind)
- {
- const struct btf_type *t;
- const char *tname;
- u32 i;
- for (i = 1; i <= btf->nr_types; i++) {
- t = btf->types[i];
- if (BTF_INFO_KIND(t->info) != kind)
- continue;
- tname = btf_name_by_offset(btf, t->name_off);
- if (!strcmp(tname, name))
- return i;
- }
- return -ENOENT;
- }
- const struct btf_type *btf_type_skip_modifiers(const struct btf *btf,
- u32 id, u32 *res_id)
- {
- const struct btf_type *t = btf_type_by_id(btf, id);
- while (btf_type_is_modifier(t)) {
- id = t->type;
- t = btf_type_by_id(btf, t->type);
- }
- if (res_id)
- *res_id = id;
- return t;
- }
- const struct btf_type *btf_type_resolve_ptr(const struct btf *btf,
- u32 id, u32 *res_id)
- {
- const struct btf_type *t;
- t = btf_type_skip_modifiers(btf, id, NULL);
- if (!btf_type_is_ptr(t))
- return NULL;
- return btf_type_skip_modifiers(btf, t->type, res_id);
- }
- const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf,
- u32 id, u32 *res_id)
- {
- const struct btf_type *ptype;
- ptype = btf_type_resolve_ptr(btf, id, res_id);
- if (ptype && btf_type_is_func_proto(ptype))
- return ptype;
- return NULL;
- }
- /* Types that act only as a source, not sink or intermediate
- * type when resolving.
- */
- static bool btf_type_is_resolve_source_only(const struct btf_type *t)
- {
- return btf_type_is_var(t) ||
- btf_type_is_datasec(t);
- }
- /* What types need to be resolved?
- *
- * btf_type_is_modifier() is an obvious one.
- *
- * btf_type_is_struct() because its member refers to
- * another type (through member->type).
- *
- * btf_type_is_var() because the variable refers to
- * another type. btf_type_is_datasec() holds multiple
- * btf_type_is_var() types that need resolving.
- *
- * btf_type_is_array() because its element (array->type)
- * refers to another type. Array can be thought of a
- * special case of struct while array just has the same
- * member-type repeated by array->nelems of times.
- */
- static bool btf_type_needs_resolve(const struct btf_type *t)
- {
- return btf_type_is_modifier(t) ||
- btf_type_is_ptr(t) ||
- btf_type_is_struct(t) ||
- btf_type_is_array(t) ||
- btf_type_is_var(t) ||
- btf_type_is_datasec(t);
- }
- /* t->size can be used */
- static bool btf_type_has_size(const struct btf_type *t)
- {
- switch (BTF_INFO_KIND(t->info)) {
- case BTF_KIND_INT:
- case BTF_KIND_STRUCT:
- case BTF_KIND_UNION:
- case BTF_KIND_ENUM:
- case BTF_KIND_DATASEC:
- return true;
- }
- return false;
- }
- static const char *btf_int_encoding_str(u8 encoding)
- {
- if (encoding == 0)
- return "(none)";
- else if (encoding == BTF_INT_SIGNED)
- return "SIGNED";
- else if (encoding == BTF_INT_CHAR)
- return "CHAR";
- else if (encoding == BTF_INT_BOOL)
- return "BOOL";
- else
- return "UNKN";
- }
- static u32 btf_type_int(const struct btf_type *t)
- {
- return *(u32 *)(t + 1);
- }
- static const struct btf_array *btf_type_array(const struct btf_type *t)
- {
- return (const struct btf_array *)(t + 1);
- }
- static const struct btf_enum *btf_type_enum(const struct btf_type *t)
- {
- return (const struct btf_enum *)(t + 1);
- }
- static const struct btf_var *btf_type_var(const struct btf_type *t)
- {
- return (const struct btf_var *)(t + 1);
- }
- static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t)
- {
- return kind_ops[BTF_INFO_KIND(t->info)];
- }
- static bool btf_name_offset_valid(const struct btf *btf, u32 offset)
- {
- return BTF_STR_OFFSET_VALID(offset) &&
- offset < btf->hdr.str_len;
- }
- static bool __btf_name_char_ok(char c, bool first, bool dot_ok)
- {
- if ((first ? !isalpha(c) :
- !isalnum(c)) &&
- c != '_' &&
- ((c == '.' && !dot_ok) ||
- c != '.'))
- return false;
- return true;
- }
- static bool __btf_name_valid(const struct btf *btf, u32 offset, bool dot_ok)
- {
- /* offset must be valid */
- const char *src = &btf->strings[offset];
- const char *src_limit;
- if (!__btf_name_char_ok(*src, true, dot_ok))
- return false;
- /* set a limit on identifier length */
- src_limit = src + KSYM_NAME_LEN;
- src++;
- while (*src && src < src_limit) {
- if (!__btf_name_char_ok(*src, false, dot_ok))
- return false;
- src++;
- }
- return !*src;
- }
- /* Only C-style identifier is permitted. This can be relaxed if
- * necessary.
- */
- static bool btf_name_valid_identifier(const struct btf *btf, u32 offset)
- {
- return __btf_name_valid(btf, offset, false);
- }
- static bool btf_name_valid_section(const struct btf *btf, u32 offset)
- {
- return __btf_name_valid(btf, offset, true);
- }
- static const char *__btf_name_by_offset(const struct btf *btf, u32 offset)
- {
- if (!offset)
- return "(anon)";
- else if (offset < btf->hdr.str_len)
- return &btf->strings[offset];
- else
- return "(invalid-name-offset)";
- }
- const char *btf_name_by_offset(const struct btf *btf, u32 offset)
- {
- if (offset < btf->hdr.str_len)
- return &btf->strings[offset];
- return NULL;
- }
- const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id)
- {
- if (type_id > btf->nr_types)
- return NULL;
- return btf->types[type_id];
- }
- /*
- * Regular int is not a bit field and it must be either
- * u8/u16/u32/u64 or __int128.
- */
- static bool btf_type_int_is_regular(const struct btf_type *t)
- {
- u8 nr_bits, nr_bytes;
- u32 int_data;
- int_data = btf_type_int(t);
- nr_bits = BTF_INT_BITS(int_data);
- nr_bytes = BITS_ROUNDUP_BYTES(nr_bits);
- if (BITS_PER_BYTE_MASKED(nr_bits) ||
- BTF_INT_OFFSET(int_data) ||
- (nr_bytes != sizeof(u8) && nr_bytes != sizeof(u16) &&
- nr_bytes != sizeof(u32) && nr_bytes != sizeof(u64) &&
- nr_bytes != (2 * sizeof(u64)))) {
- return false;
- }
- return true;
- }
- /*
- * Check that given struct member is a regular int with expected
- * offset and size.
- */
- bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,
- const struct btf_member *m,
- u32 expected_offset, u32 expected_size)
- {
- const struct btf_type *t;
- u32 id, int_data;
- u8 nr_bits;
- id = m->type;
- t = btf_type_id_size(btf, &id, NULL);
- if (!t || !btf_type_is_int(t))
- return false;
- int_data = btf_type_int(t);
- nr_bits = BTF_INT_BITS(int_data);
- if (btf_type_kflag(s)) {
- u32 bitfield_size = BTF_MEMBER_BITFIELD_SIZE(m->offset);
- u32 bit_offset = BTF_MEMBER_BIT_OFFSET(m->offset);
- /* if kflag set, int should be a regular int and
- * bit offset should be at byte boundary.
- */
- return !bitfield_size &&
- BITS_ROUNDUP_BYTES(bit_offset) == expected_offset &&
- BITS_ROUNDUP_BYTES(nr_bits) == expected_size;
- }
- if (BTF_INT_OFFSET(int_data) ||
- BITS_PER_BYTE_MASKED(m->offset) ||
- BITS_ROUNDUP_BYTES(m->offset) != expected_offset ||
- BITS_PER_BYTE_MASKED(nr_bits) ||
- BITS_ROUNDUP_BYTES(nr_bits) != expected_size)
- return false;
- return true;
- }
- /* Similar to btf_type_skip_modifiers() but does not skip typedefs. */
- static const struct btf_type *btf_type_skip_qualifiers(const struct btf *btf,
- u32 id)
- {
- const struct btf_type *t = btf_type_by_id(btf, id);
- while (btf_type_is_modifier(t) &&
- BTF_INFO_KIND(t->info) != BTF_KIND_TYPEDEF) {
- id = t->type;
- t = btf_type_by_id(btf, t->type);
- }
- return t;
- }
- #define BTF_SHOW_MAX_ITER 10
- #define BTF_KIND_BIT(kind) (1ULL << kind)
- /*
- * Populate show->state.name with type name information.
- * Format of type name is
- *
- * [.member_name = ] (type_name)
- */
- static const char *btf_show_name(struct btf_show *show)
- {
- /* BTF_MAX_ITER array suffixes "[]" */
- const char *array_suffixes = "[][][][][][][][][][]";
- const char *array_suffix = &array_suffixes[strlen(array_suffixes)];
- /* BTF_MAX_ITER pointer suffixes "*" */
- const char *ptr_suffixes = "**********";
- const char *ptr_suffix = &ptr_suffixes[strlen(ptr_suffixes)];
- const char *name = NULL, *prefix = "", *parens = "";
- const struct btf_member *m = show->state.member;
- const struct btf_type *t = show->state.type;
- const struct btf_array *array;
- u32 id = show->state.type_id;
- const char *member = NULL;
- bool show_member = false;
- u64 kinds = 0;
- int i;
- show->state.name[0] = '\0';
- /*
- * Don't show type name if we're showing an array member;
- * in that case we show the array type so don't need to repeat
- * ourselves for each member.
- */
- if (show->state.array_member)
- return "";
- /* Retrieve member name, if any. */
- if (m) {
- member = btf_name_by_offset(show->btf, m->name_off);
- show_member = strlen(member) > 0;
- id = m->type;
- }
- /*
- * Start with type_id, as we have resolved the struct btf_type *
- * via btf_modifier_show() past the parent typedef to the child
- * struct, int etc it is defined as. In such cases, the type_id
- * still represents the starting type while the struct btf_type *
- * in our show->state points at the resolved type of the typedef.
- */
- t = btf_type_by_id(show->btf, id);
- if (!t)
- return "";
- /*
- * The goal here is to build up the right number of pointer and
- * array suffixes while ensuring the type name for a typedef
- * is represented. Along the way we accumulate a list of
- * BTF kinds we have encountered, since these will inform later
- * display; for example, pointer types will not require an
- * opening "{" for struct, we will just display the pointer value.
- *
- * We also want to accumulate the right number of pointer or array
- * indices in the format string while iterating until we get to
- * the typedef/pointee/array member target type.
- *
- * We start by pointing at the end of pointer and array suffix
- * strings; as we accumulate pointers and arrays we move the pointer
- * or array string backwards so it will show the expected number of
- * '*' or '[]' for the type. BTF_SHOW_MAX_ITER of nesting of pointers
- * and/or arrays and typedefs are supported as a precaution.
- *
- * We also want to get typedef name while proceeding to resolve
- * type it points to so that we can add parentheses if it is a
- * "typedef struct" etc.
- */
- for (i = 0; i < BTF_SHOW_MAX_ITER; i++) {
- switch (BTF_INFO_KIND(t->info)) {
- case BTF_KIND_TYPEDEF:
- if (!name)
- name = btf_name_by_offset(show->btf,
- t->name_off);
- kinds |= BTF_KIND_BIT(BTF_KIND_TYPEDEF);
- id = t->type;
- break;
- case BTF_KIND_ARRAY:
- kinds |= BTF_KIND_BIT(BTF_KIND_ARRAY);
- parens = "[";
- if (!t)
- return "";
- array = btf_type_array(t);
- if (array_suffix > array_suffixes)
- array_suffix -= 2;
- id = array->type;
- break;
- case BTF_KIND_PTR:
- kinds |= BTF_KIND_BIT(BTF_KIND_PTR);
- if (ptr_suffix > ptr_suffixes)
- ptr_suffix -= 1;
- id = t->type;
- break;
- default:
- id = 0;
- break;
- }
- if (!id)
- break;
- t = btf_type_skip_qualifiers(show->btf, id);
- }
- /* We may not be able to represent this type; bail to be safe */
- if (i == BTF_SHOW_MAX_ITER)
- return "";
- if (!name)
- name = btf_name_by_offset(show->btf, t->name_off);
- switch (BTF_INFO_KIND(t->info)) {
- case BTF_KIND_STRUCT:
- case BTF_KIND_UNION:
- prefix = BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT ?
- "struct" : "union";
- /* if it's an array of struct/union, parens is already set */
- if (!(kinds & (BTF_KIND_BIT(BTF_KIND_ARRAY))))
- parens = "{";
- break;
- case BTF_KIND_ENUM:
- prefix = "enum";
- break;
- default:
- break;
- }
- /* pointer does not require parens */
- if (kinds & BTF_KIND_BIT(BTF_KIND_PTR))
- parens = "";
- /* typedef does not require struct/union/enum prefix */
- if (kinds & BTF_KIND_BIT(BTF_KIND_TYPEDEF))
- prefix = "";
- if (!name)
- name = "";
- /* Even if we don't want type name info, we want parentheses etc */
- if (show->flags & BTF_SHOW_NONAME)
- snprintf(show->state.name, sizeof(show->state.name), "%s",
- parens);
- else
- snprintf(show->state.name, sizeof(show->state.name),
- "%s%s%s(%s%s%s%s%s%s)%s",
- /* first 3 strings comprise ".member = " */
- show_member ? "." : "",
- show_member ? member : "",
- show_member ? " = " : "",
- /* ...next is our prefix (struct, enum, etc) */
- prefix,
- strlen(prefix) > 0 && strlen(name) > 0 ? " " : "",
- /* ...this is the type name itself */
- name,
- /* ...suffixed by the appropriate '*', '[]' suffixes */
- strlen(ptr_suffix) > 0 ? " " : "", ptr_suffix,
- array_suffix, parens);
- return show->state.name;
- }
- static const char *__btf_show_indent(struct btf_show *show)
- {
- const char *indents = " ";
- const char *indent = &indents[strlen(indents)];
- if ((indent - show->state.depth) >= indents)
- return indent - show->state.depth;
- return indents;
- }
- static const char *btf_show_indent(struct btf_show *show)
- {
- return show->flags & BTF_SHOW_COMPACT ? "" : __btf_show_indent(show);
- }
- static const char *btf_show_newline(struct btf_show *show)
- {
- return show->flags & BTF_SHOW_COMPACT ? "" : "\n";
- }
- static const char *btf_show_delim(struct btf_show *show)
- {
- if (show->state.depth == 0)
- return "";
- if ((show->flags & BTF_SHOW_COMPACT) && show->state.type &&
- BTF_INFO_KIND(show->state.type->info) == BTF_KIND_UNION)
- return "|";
- return ",";
- }
- __printf(2, 3) static void btf_show(struct btf_show *show, const char *fmt, ...)
- {
- va_list args;
- if (!show->state.depth_check) {
- va_start(args, fmt);
- show->showfn(show, fmt, args);
- va_end(args);
- }
- }
- /* Macros are used here as btf_show_type_value[s]() prepends and appends
- * format specifiers to the format specifier passed in; these do the work of
- * adding indentation, delimiters etc while the caller simply has to specify
- * the type value(s) in the format specifier + value(s).
- */
- #define btf_show_type_value(show, fmt, value) \
- do { \
- if ((value) != 0 || (show->flags & BTF_SHOW_ZERO) || \
- show->state.depth == 0) { \
- btf_show(show, "%s%s" fmt "%s%s", \
- btf_show_indent(show), \
- btf_show_name(show), \
- value, btf_show_delim(show), \
- btf_show_newline(show)); \
- if (show->state.depth > show->state.depth_to_show) \
- show->state.depth_to_show = show->state.depth; \
- } \
- } while (0)
- #define btf_show_type_values(show, fmt, ...) \
- do { \
- btf_show(show, "%s%s" fmt "%s%s", btf_show_indent(show), \
- btf_show_name(show), \
- __VA_ARGS__, btf_show_delim(show), \
- btf_show_newline(show)); \
- if (show->state.depth > show->state.depth_to_show) \
- show->state.depth_to_show = show->state.depth; \
- } while (0)
- /* How much is left to copy to safe buffer after @data? */
- static int btf_show_obj_size_left(struct btf_show *show, void *data)
- {
- return show->obj.head + show->obj.size - data;
- }
- /* Is object pointed to by @data of @size already copied to our safe buffer? */
- static bool btf_show_obj_is_safe(struct btf_show *show, void *data, int size)
- {
- return data >= show->obj.data &&
- (data + size) < (show->obj.data + BTF_SHOW_OBJ_SAFE_SIZE);
- }
- /*
- * If object pointed to by @data of @size falls within our safe buffer, return
- * the equivalent pointer to the same safe data. Assumes
- * copy_from_kernel_nofault() has already happened and our safe buffer is
- * populated.
- */
- static void *__btf_show_obj_safe(struct btf_show *show, void *data, int size)
- {
- if (btf_show_obj_is_safe(show, data, size))
- return show->obj.safe + (data - show->obj.data);
- return NULL;
- }
- /*
- * Return a safe-to-access version of data pointed to by @data.
- * We do this by copying the relevant amount of information
- * to the struct btf_show obj.safe buffer using copy_from_kernel_nofault().
- *
- * If BTF_SHOW_UNSAFE is specified, just return data as-is; no
- * safe copy is needed.
- *
- * Otherwise we need to determine if we have the required amount
- * of data (determined by the @data pointer and the size of the
- * largest base type we can encounter (represented by
- * BTF_SHOW_OBJ_BASE_TYPE_SIZE). Having that much data ensures
- * that we will be able to print some of the current object,
- * and if more is needed a copy will be triggered.
- * Some objects such as structs will not fit into the buffer;
- * in such cases additional copies when we iterate over their
- * members may be needed.
- *
- * btf_show_obj_safe() is used to return a safe buffer for
- * btf_show_start_type(); this ensures that as we recurse into
- * nested types we always have safe data for the given type.
- * This approach is somewhat wasteful; it's possible for example
- * that when iterating over a large union we'll end up copying the
- * same data repeatedly, but the goal is safety not performance.
- * We use stack data as opposed to per-CPU buffers because the
- * iteration over a type can take some time, and preemption handling
- * would greatly complicate use of the safe buffer.
- */
- static void *btf_show_obj_safe(struct btf_show *show,
- const struct btf_type *t,
- void *data)
- {
- const struct btf_type *rt;
- int size_left, size;
- void *safe = NULL;
- if (show->flags & BTF_SHOW_UNSAFE)
- return data;
- rt = btf_resolve_size(show->btf, t, &size);
- if (IS_ERR(rt)) {
- show->state.status = PTR_ERR(rt);
- return NULL;
- }
- /*
- * Is this toplevel object? If so, set total object size and
- * initialize pointers. Otherwise check if we still fall within
- * our safe object data.
- */
- if (show->state.depth == 0) {
- show->obj.size = size;
- show->obj.head = data;
- } else {
- /*
- * If the size of the current object is > our remaining
- * safe buffer we _may_ need to do a new copy. However
- * consider the case of a nested struct; it's size pushes
- * us over the safe buffer limit, but showing any individual
- * struct members does not. In such cases, we don't need
- * to initiate a fresh copy yet; however we definitely need
- * at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes left
- * in our buffer, regardless of the current object size.
- * The logic here is that as we resolve types we will
- * hit a base type at some point, and we need to be sure
- * the next chunk of data is safely available to display
- * that type info safely. We cannot rely on the size of
- * the current object here because it may be much larger
- * than our current buffer (e.g. task_struct is 8k).
- * All we want to do here is ensure that we can print the
- * next basic type, which we can if either
- * - the current type size is within the safe buffer; or
- * - at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes are left in
- * the safe buffer.
- */
- safe = __btf_show_obj_safe(show, data,
- min(size,
- BTF_SHOW_OBJ_BASE_TYPE_SIZE));
- }
- /*
- * We need a new copy to our safe object, either because we haven't
- * yet copied and are intializing safe data, or because the data
- * we want falls outside the boundaries of the safe object.
- */
- if (!safe) {
- size_left = btf_show_obj_size_left(show, data);
- if (size_left > BTF_SHOW_OBJ_SAFE_SIZE)
- size_left = BTF_SHOW_OBJ_SAFE_SIZE;
- show->state.status = copy_from_kernel_nofault(show->obj.safe,
- data, size_left);
- if (!show->state.status) {
- show->obj.data = data;
- safe = show->obj.safe;
- }
- }
- return safe;
- }
- /*
- * Set the type we are starting to show and return a safe data pointer
- * to be used for showing the associated data.
- */
- static void *btf_show_start_type(struct btf_show *show,
- const struct btf_type *t,
- u32 type_id, void *data)
- {
- show->state.type = t;
- show->state.type_id = type_id;
- show->state.name[0] = '\0';
- return btf_show_obj_safe(show, t, data);
- }
- static void btf_show_end_type(struct btf_show *show)
- {
- show->state.type = NULL;
- show->state.type_id = 0;
- show->state.name[0] = '\0';
- }
- static void *btf_show_start_aggr_type(struct btf_show *show,
- const struct btf_type *t,
- u32 type_id, void *data)
- {
- void *safe_data = btf_show_start_type(show, t, type_id, data);
- if (!safe_data)
- return safe_data;
- btf_show(show, "%s%s%s", btf_show_indent(show),
- btf_show_name(show),
- btf_show_newline(show));
- show->state.depth++;
- return safe_data;
- }
- static void btf_show_end_aggr_type(struct btf_show *show,
- const char *suffix)
- {
- show->state.depth--;
- btf_show(show, "%s%s%s%s", btf_show_indent(show), suffix,
- btf_show_delim(show), btf_show_newline(show));
- btf_show_end_type(show);
- }
- static void btf_show_start_member(struct btf_show *show,
- const struct btf_member *m)
- {
- show->state.member = m;
- }
- static void btf_show_start_array_member(struct btf_show *show)
- {
- show->state.array_member = 1;
- btf_show_start_member(show, NULL);
- }
- static void btf_show_end_member(struct btf_show *show)
- {
- show->state.member = NULL;
- }
- static void btf_show_end_array_member(struct btf_show *show)
- {
- show->state.array_member = 0;
- btf_show_end_member(show);
- }
- static void *btf_show_start_array_type(struct btf_show *show,
- const struct btf_type *t,
- u32 type_id,
- u16 array_encoding,
- void *data)
- {
- show->state.array_encoding = array_encoding;
- show->state.array_terminated = 0;
- return btf_show_start_aggr_type(show, t, type_id, data);
- }
- static void btf_show_end_array_type(struct btf_show *show)
- {
- show->state.array_encoding = 0;
- show->state.array_terminated = 0;
- btf_show_end_aggr_type(show, "]");
- }
- static void *btf_show_start_struct_type(struct btf_show *show,
- const struct btf_type *t,
- u32 type_id,
- void *data)
- {
- return btf_show_start_aggr_type(show, t, type_id, data);
- }
- static void btf_show_end_struct_type(struct btf_show *show)
- {
- btf_show_end_aggr_type(show, "}");
- }
- __printf(2, 3) static void __btf_verifier_log(struct bpf_verifier_log *log,
- const char *fmt, ...)
- {
- va_list args;
- va_start(args, fmt);
- bpf_verifier_vlog(log, fmt, args);
- va_end(args);
- }
- __printf(2, 3) static void btf_verifier_log(struct btf_verifier_env *env,
- const char *fmt, ...)
- {
- struct bpf_verifier_log *log = &env->log;
- va_list args;
- if (!bpf_verifier_log_needed(log))
- return;
- va_start(args, fmt);
- bpf_verifier_vlog(log, fmt, args);
- va_end(args);
- }
- __printf(4, 5) static void __btf_verifier_log_type(struct btf_verifier_env *env,
- const struct btf_type *t,
- bool log_details,
- const char *fmt, ...)
- {
- struct bpf_verifier_log *log = &env->log;
- u8 kind = BTF_INFO_KIND(t->info);
- struct btf *btf = env->btf;
- va_list args;
- if (!bpf_verifier_log_needed(log))
- return;
- /* btf verifier prints all types it is processing via
- * btf_verifier_log_type(..., fmt = NULL).
- * Skip those prints for in-kernel BTF verification.
- */
- if (log->level == BPF_LOG_KERNEL && !fmt)
- return;
- __btf_verifier_log(log, "[%u] %s %s%s",
- env->log_type_id,
- btf_kind_str[kind],
- __btf_name_by_offset(btf, t->name_off),
- log_details ? " " : "");
- if (log_details)
- btf_type_ops(t)->log_details(env, t);
- if (fmt && *fmt) {
- __btf_verifier_log(log, " ");
- va_start(args, fmt);
- bpf_verifier_vlog(log, fmt, args);
- va_end(args);
- }
- __btf_verifier_log(log, "\n");
- }
- #define btf_verifier_log_type(env, t, ...) \
- __btf_verifier_log_type((env), (t), true, __VA_ARGS__)
- #define btf_verifier_log_basic(env, t, ...) \
- __btf_verifier_log_type((env), (t), false, __VA_ARGS__)
- __printf(4, 5)
- static void btf_verifier_log_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const char *fmt, ...)
- {
- struct bpf_verifier_log *log = &env->log;
- struct btf *btf = env->btf;
- va_list args;
- if (!bpf_verifier_log_needed(log))
- return;
- if (log->level == BPF_LOG_KERNEL && !fmt)
- return;
- /* The CHECK_META phase already did a btf dump.
- *
- * If member is logged again, it must hit an error in
- * parsing this member. It is useful to print out which
- * struct this member belongs to.
- */
- if (env->phase != CHECK_META)
- btf_verifier_log_type(env, struct_type, NULL);
- if (btf_type_kflag(struct_type))
- __btf_verifier_log(log,
- "\t%s type_id=%u bitfield_size=%u bits_offset=%u",
- __btf_name_by_offset(btf, member->name_off),
- member->type,
- BTF_MEMBER_BITFIELD_SIZE(member->offset),
- BTF_MEMBER_BIT_OFFSET(member->offset));
- else
- __btf_verifier_log(log, "\t%s type_id=%u bits_offset=%u",
- __btf_name_by_offset(btf, member->name_off),
- member->type, member->offset);
- if (fmt && *fmt) {
- __btf_verifier_log(log, " ");
- va_start(args, fmt);
- bpf_verifier_vlog(log, fmt, args);
- va_end(args);
- }
- __btf_verifier_log(log, "\n");
- }
- __printf(4, 5)
- static void btf_verifier_log_vsi(struct btf_verifier_env *env,
- const struct btf_type *datasec_type,
- const struct btf_var_secinfo *vsi,
- const char *fmt, ...)
- {
- struct bpf_verifier_log *log = &env->log;
- va_list args;
- if (!bpf_verifier_log_needed(log))
- return;
- if (log->level == BPF_LOG_KERNEL && !fmt)
- return;
- if (env->phase != CHECK_META)
- btf_verifier_log_type(env, datasec_type, NULL);
- __btf_verifier_log(log, "\t type_id=%u offset=%u size=%u",
- vsi->type, vsi->offset, vsi->size);
- if (fmt && *fmt) {
- __btf_verifier_log(log, " ");
- va_start(args, fmt);
- bpf_verifier_vlog(log, fmt, args);
- va_end(args);
- }
- __btf_verifier_log(log, "\n");
- }
- static void btf_verifier_log_hdr(struct btf_verifier_env *env,
- u32 btf_data_size)
- {
- struct bpf_verifier_log *log = &env->log;
- const struct btf *btf = env->btf;
- const struct btf_header *hdr;
- if (!bpf_verifier_log_needed(log))
- return;
- if (log->level == BPF_LOG_KERNEL)
- return;
- hdr = &btf->hdr;
- __btf_verifier_log(log, "magic: 0x%x\n", hdr->magic);
- __btf_verifier_log(log, "version: %u\n", hdr->version);
- __btf_verifier_log(log, "flags: 0x%x\n", hdr->flags);
- __btf_verifier_log(log, "hdr_len: %u\n", hdr->hdr_len);
- __btf_verifier_log(log, "type_off: %u\n", hdr->type_off);
- __btf_verifier_log(log, "type_len: %u\n", hdr->type_len);
- __btf_verifier_log(log, "str_off: %u\n", hdr->str_off);
- __btf_verifier_log(log, "str_len: %u\n", hdr->str_len);
- __btf_verifier_log(log, "btf_total_size: %u\n", btf_data_size);
- }
- static int btf_add_type(struct btf_verifier_env *env, struct btf_type *t)
- {
- struct btf *btf = env->btf;
- /* < 2 because +1 for btf_void which is always in btf->types[0].
- * btf_void is not accounted in btf->nr_types because btf_void
- * does not come from the BTF file.
- */
- if (btf->types_size - btf->nr_types < 2) {
- /* Expand 'types' array */
- struct btf_type **new_types;
- u32 expand_by, new_size;
- if (btf->types_size == BTF_MAX_TYPE) {
- btf_verifier_log(env, "Exceeded max num of types");
- return -E2BIG;
- }
- expand_by = max_t(u32, btf->types_size >> 2, 16);
- new_size = min_t(u32, BTF_MAX_TYPE,
- btf->types_size + expand_by);
- new_types = kvcalloc(new_size, sizeof(*new_types),
- GFP_KERNEL | __GFP_NOWARN);
- if (!new_types)
- return -ENOMEM;
- if (btf->nr_types == 0)
- new_types[0] = &btf_void;
- else
- memcpy(new_types, btf->types,
- sizeof(*btf->types) * (btf->nr_types + 1));
- kvfree(btf->types);
- btf->types = new_types;
- btf->types_size = new_size;
- }
- btf->types[++(btf->nr_types)] = t;
- return 0;
- }
- static int btf_alloc_id(struct btf *btf)
- {
- int id;
- idr_preload(GFP_KERNEL);
- spin_lock_bh(&btf_idr_lock);
- id = idr_alloc_cyclic(&btf_idr, btf, 1, INT_MAX, GFP_ATOMIC);
- if (id > 0)
- btf->id = id;
- spin_unlock_bh(&btf_idr_lock);
- idr_preload_end();
- if (WARN_ON_ONCE(!id))
- return -ENOSPC;
- return id > 0 ? 0 : id;
- }
- static void btf_free_id(struct btf *btf)
- {
- unsigned long flags;
- /*
- * In map-in-map, calling map_delete_elem() on outer
- * map will call bpf_map_put on the inner map.
- * It will then eventually call btf_free_id()
- * on the inner map. Some of the map_delete_elem()
- * implementation may have irq disabled, so
- * we need to use the _irqsave() version instead
- * of the _bh() version.
- */
- spin_lock_irqsave(&btf_idr_lock, flags);
- idr_remove(&btf_idr, btf->id);
- spin_unlock_irqrestore(&btf_idr_lock, flags);
- }
- static void btf_free(struct btf *btf)
- {
- kvfree(btf->types);
- kvfree(btf->resolved_sizes);
- kvfree(btf->resolved_ids);
- kvfree(btf->data);
- kfree(btf);
- }
- static void btf_free_rcu(struct rcu_head *rcu)
- {
- struct btf *btf = container_of(rcu, struct btf, rcu);
- btf_free(btf);
- }
- void btf_put(struct btf *btf)
- {
- if (btf && refcount_dec_and_test(&btf->refcnt)) {
- btf_free_id(btf);
- call_rcu(&btf->rcu, btf_free_rcu);
- }
- }
- static int env_resolve_init(struct btf_verifier_env *env)
- {
- struct btf *btf = env->btf;
- u32 nr_types = btf->nr_types;
- u32 *resolved_sizes = NULL;
- u32 *resolved_ids = NULL;
- u8 *visit_states = NULL;
- /* +1 for btf_void */
- resolved_sizes = kvcalloc(nr_types + 1, sizeof(*resolved_sizes),
- GFP_KERNEL | __GFP_NOWARN);
- if (!resolved_sizes)
- goto nomem;
- resolved_ids = kvcalloc(nr_types + 1, sizeof(*resolved_ids),
- GFP_KERNEL | __GFP_NOWARN);
- if (!resolved_ids)
- goto nomem;
- visit_states = kvcalloc(nr_types + 1, sizeof(*visit_states),
- GFP_KERNEL | __GFP_NOWARN);
- if (!visit_states)
- goto nomem;
- btf->resolved_sizes = resolved_sizes;
- btf->resolved_ids = resolved_ids;
- env->visit_states = visit_states;
- return 0;
- nomem:
- kvfree(resolved_sizes);
- kvfree(resolved_ids);
- kvfree(visit_states);
- return -ENOMEM;
- }
- static void btf_verifier_env_free(struct btf_verifier_env *env)
- {
- kvfree(env->visit_states);
- kfree(env);
- }
- static bool env_type_is_resolve_sink(const struct btf_verifier_env *env,
- const struct btf_type *next_type)
- {
- switch (env->resolve_mode) {
- case RESOLVE_TBD:
- /* int, enum or void is a sink */
- return !btf_type_needs_resolve(next_type);
- case RESOLVE_PTR:
- /* int, enum, void, struct, array, func or func_proto is a sink
- * for ptr
- */
- return !btf_type_is_modifier(next_type) &&
- !btf_type_is_ptr(next_type);
- case RESOLVE_STRUCT_OR_ARRAY:
- /* int, enum, void, ptr, func or func_proto is a sink
- * for struct and array
- */
- return !btf_type_is_modifier(next_type) &&
- !btf_type_is_array(next_type) &&
- !btf_type_is_struct(next_type);
- default:
- BUG();
- }
- }
- static bool env_type_is_resolved(const struct btf_verifier_env *env,
- u32 type_id)
- {
- return env->visit_states[type_id] == RESOLVED;
- }
- static int env_stack_push(struct btf_verifier_env *env,
- const struct btf_type *t, u32 type_id)
- {
- struct resolve_vertex *v;
- if (env->top_stack == MAX_RESOLVE_DEPTH)
- return -E2BIG;
- if (env->visit_states[type_id] != NOT_VISITED)
- return -EEXIST;
- env->visit_states[type_id] = VISITED;
- v = &env->stack[env->top_stack++];
- v->t = t;
- v->type_id = type_id;
- v->next_member = 0;
- if (env->resolve_mode == RESOLVE_TBD) {
- if (btf_type_is_ptr(t))
- env->resolve_mode = RESOLVE_PTR;
- else if (btf_type_is_struct(t) || btf_type_is_array(t))
- env->resolve_mode = RESOLVE_STRUCT_OR_ARRAY;
- }
- return 0;
- }
- static void env_stack_set_next_member(struct btf_verifier_env *env,
- u16 next_member)
- {
- env->stack[env->top_stack - 1].next_member = next_member;
- }
- static void env_stack_pop_resolved(struct btf_verifier_env *env,
- u32 resolved_type_id,
- u32 resolved_size)
- {
- u32 type_id = env->stack[--(env->top_stack)].type_id;
- struct btf *btf = env->btf;
- btf->resolved_sizes[type_id] = resolved_size;
- btf->resolved_ids[type_id] = resolved_type_id;
- env->visit_states[type_id] = RESOLVED;
- }
- static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env)
- {
- return env->top_stack ? &env->stack[env->top_stack - 1] : NULL;
- }
- /* Resolve the size of a passed-in "type"
- *
- * type: is an array (e.g. u32 array[x][y])
- * return type: type "u32[x][y]", i.e. BTF_KIND_ARRAY,
- * *type_size: (x * y * sizeof(u32)). Hence, *type_size always
- * corresponds to the return type.
- * *elem_type: u32
- * *elem_id: id of u32
- * *total_nelems: (x * y). Hence, individual elem size is
- * (*type_size / *total_nelems)
- * *type_id: id of type if it's changed within the function, 0 if not
- *
- * type: is not an array (e.g. const struct X)
- * return type: type "struct X"
- * *type_size: sizeof(struct X)
- * *elem_type: same as return type ("struct X")
- * *elem_id: 0
- * *total_nelems: 1
- * *type_id: id of type if it's changed within the function, 0 if not
- */
- static const struct btf_type *
- __btf_resolve_size(const struct btf *btf, const struct btf_type *type,
- u32 *type_size, const struct btf_type **elem_type,
- u32 *elem_id, u32 *total_nelems, u32 *type_id)
- {
- const struct btf_type *array_type = NULL;
- const struct btf_array *array = NULL;
- u32 i, size, nelems = 1, id = 0;
- for (i = 0; i < MAX_RESOLVE_DEPTH; i++) {
- switch (BTF_INFO_KIND(type->info)) {
- /* type->size can be used */
- case BTF_KIND_INT:
- case BTF_KIND_STRUCT:
- case BTF_KIND_UNION:
- case BTF_KIND_ENUM:
- size = type->size;
- goto resolved;
- case BTF_KIND_PTR:
- size = sizeof(void *);
- goto resolved;
- /* Modifiers */
- case BTF_KIND_TYPEDEF:
- case BTF_KIND_VOLATILE:
- case BTF_KIND_CONST:
- case BTF_KIND_RESTRICT:
- id = type->type;
- type = btf_type_by_id(btf, type->type);
- break;
- case BTF_KIND_ARRAY:
- if (!array_type)
- array_type = type;
- array = btf_type_array(type);
- if (nelems && array->nelems > U32_MAX / nelems)
- return ERR_PTR(-EINVAL);
- nelems *= array->nelems;
- type = btf_type_by_id(btf, array->type);
- break;
- /* type without size */
- default:
- return ERR_PTR(-EINVAL);
- }
- }
- return ERR_PTR(-EINVAL);
- resolved:
- if (nelems && size > U32_MAX / nelems)
- return ERR_PTR(-EINVAL);
- *type_size = nelems * size;
- if (total_nelems)
- *total_nelems = nelems;
- if (elem_type)
- *elem_type = type;
- if (elem_id)
- *elem_id = array ? array->type : 0;
- if (type_id && id)
- *type_id = id;
- return array_type ? : type;
- }
- const struct btf_type *
- btf_resolve_size(const struct btf *btf, const struct btf_type *type,
- u32 *type_size)
- {
- return __btf_resolve_size(btf, type, type_size, NULL, NULL, NULL, NULL);
- }
- /* The input param "type_id" must point to a needs_resolve type */
- static const struct btf_type *btf_type_id_resolve(const struct btf *btf,
- u32 *type_id)
- {
- *type_id = btf->resolved_ids[*type_id];
- return btf_type_by_id(btf, *type_id);
- }
- const struct btf_type *btf_type_id_size(const struct btf *btf,
- u32 *type_id, u32 *ret_size)
- {
- const struct btf_type *size_type;
- u32 size_type_id = *type_id;
- u32 size = 0;
- size_type = btf_type_by_id(btf, size_type_id);
- if (btf_type_nosize_or_null(size_type))
- return NULL;
- if (btf_type_has_size(size_type)) {
- size = size_type->size;
- } else if (btf_type_is_array(size_type)) {
- size = btf->resolved_sizes[size_type_id];
- } else if (btf_type_is_ptr(size_type)) {
- size = sizeof(void *);
- } else {
- if (WARN_ON_ONCE(!btf_type_is_modifier(size_type) &&
- !btf_type_is_var(size_type)))
- return NULL;
- size_type_id = btf->resolved_ids[size_type_id];
- size_type = btf_type_by_id(btf, size_type_id);
- if (btf_type_nosize_or_null(size_type))
- return NULL;
- else if (btf_type_has_size(size_type))
- size = size_type->size;
- else if (btf_type_is_array(size_type))
- size = btf->resolved_sizes[size_type_id];
- else if (btf_type_is_ptr(size_type))
- size = sizeof(void *);
- else
- return NULL;
- }
- *type_id = size_type_id;
- if (ret_size)
- *ret_size = size;
- return size_type;
- }
- static int btf_df_check_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
- {
- btf_verifier_log_basic(env, struct_type,
- "Unsupported check_member");
- return -EINVAL;
- }
- static int btf_df_check_kflag_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
- {
- btf_verifier_log_basic(env, struct_type,
- "Unsupported check_kflag_member");
- return -EINVAL;
- }
- /* Used for ptr, array and struct/union type members.
- * int, enum and modifier types have their specific callback functions.
- */
- static int btf_generic_check_kflag_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
- {
- if (BTF_MEMBER_BITFIELD_SIZE(member->offset)) {
- btf_verifier_log_member(env, struct_type, member,
- "Invalid member bitfield_size");
- return -EINVAL;
- }
- /* bitfield size is 0, so member->offset represents bit offset only.
- * It is safe to call non kflag check_member variants.
- */
- return btf_type_ops(member_type)->check_member(env, struct_type,
- member,
- member_type);
- }
- static int btf_df_resolve(struct btf_verifier_env *env,
- const struct resolve_vertex *v)
- {
- btf_verifier_log_basic(env, v->t, "Unsupported resolve");
- return -EINVAL;
- }
- static void btf_df_show(const struct btf *btf, const struct btf_type *t,
- u32 type_id, void *data, u8 bits_offsets,
- struct btf_show *show)
- {
- btf_show(show, "<unsupported kind:%u>", BTF_INFO_KIND(t->info));
- }
- static int btf_int_check_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
- {
- u32 int_data = btf_type_int(member_type);
- u32 struct_bits_off = member->offset;
- u32 struct_size = struct_type->size;
- u32 nr_copy_bits;
- u32 bytes_offset;
- if (U32_MAX - struct_bits_off < BTF_INT_OFFSET(int_data)) {
- btf_verifier_log_member(env, struct_type, member,
- "bits_offset exceeds U32_MAX");
- return -EINVAL;
- }
- struct_bits_off += BTF_INT_OFFSET(int_data);
- bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
- nr_copy_bits = BTF_INT_BITS(int_data) +
- BITS_PER_BYTE_MASKED(struct_bits_off);
- if (nr_copy_bits > BITS_PER_U128) {
- btf_verifier_log_member(env, struct_type, member,
- "nr_copy_bits exceeds 128");
- return -EINVAL;
- }
- if (struct_size < bytes_offset ||
- struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) {
- btf_verifier_log_member(env, struct_type, member,
- "Member exceeds struct_size");
- return -EINVAL;
- }
- return 0;
- }
- static int btf_int_check_kflag_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
- {
- u32 struct_bits_off, nr_bits, nr_int_data_bits, bytes_offset;
- u32 int_data = btf_type_int(member_type);
- u32 struct_size = struct_type->size;
- u32 nr_copy_bits;
- /* a regular int type is required for the kflag int member */
- if (!btf_type_int_is_regular(member_type)) {
- btf_verifier_log_member(env, struct_type, member,
- "Invalid member base type");
- return -EINVAL;
- }
- /* check sanity of bitfield size */
- nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset);
- struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset);
- nr_int_data_bits = BTF_INT_BITS(int_data);
- if (!nr_bits) {
- /* Not a bitfield member, member offset must be at byte
- * boundary.
- */
- if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
- btf_verifier_log_member(env, struct_type, member,
- "Invalid member offset");
- return -EINVAL;
- }
- nr_bits = nr_int_data_bits;
- } else if (nr_bits > nr_int_data_bits) {
- btf_verifier_log_member(env, struct_type, member,
- "Invalid member bitfield_size");
- return -EINVAL;
- }
- bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
- nr_copy_bits = nr_bits + BITS_PER_BYTE_MASKED(struct_bits_off);
- if (nr_copy_bits > BITS_PER_U128) {
- btf_verifier_log_member(env, struct_type, member,
- "nr_copy_bits exceeds 128");
- return -EINVAL;
- }
- if (struct_size < bytes_offset ||
- struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) {
- btf_verifier_log_member(env, struct_type, member,
- "Member exceeds struct_size");
- return -EINVAL;
- }
- return 0;
- }
- static s32 btf_int_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
- {
- u32 int_data, nr_bits, meta_needed = sizeof(int_data);
- u16 encoding;
- if (meta_left < meta_needed) {
- btf_verifier_log_basic(env, t,
- "meta_left:%u meta_needed:%u",
- meta_left, meta_needed);
- return -EINVAL;
- }
- if (btf_type_vlen(t)) {
- btf_verifier_log_type(env, t, "vlen != 0");
- return -EINVAL;
- }
- if (btf_type_kflag(t)) {
- btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
- return -EINVAL;
- }
- int_data = btf_type_int(t);
- if (int_data & ~BTF_INT_MASK) {
- btf_verifier_log_basic(env, t, "Invalid int_data:%x",
- int_data);
- return -EINVAL;
- }
- nr_bits = BTF_INT_BITS(int_data) + BTF_INT_OFFSET(int_data);
- if (nr_bits > BITS_PER_U128) {
- btf_verifier_log_type(env, t, "nr_bits exceeds %zu",
- BITS_PER_U128);
- return -EINVAL;
- }
- if (BITS_ROUNDUP_BYTES(nr_bits) > t->size) {
- btf_verifier_log_type(env, t, "nr_bits exceeds type_size");
- return -EINVAL;
- }
- /*
- * Only one of the encoding bits is allowed and it
- * should be sufficient for the pretty print purpose (i.e. decoding).
- * Multiple bits can be allowed later if it is found
- * to be insufficient.
- */
- encoding = BTF_INT_ENCODING(int_data);
- if (encoding &&
- encoding != BTF_INT_SIGNED &&
- encoding != BTF_INT_CHAR &&
- encoding != BTF_INT_BOOL) {
- btf_verifier_log_type(env, t, "Unsupported encoding");
- return -ENOTSUPP;
- }
- btf_verifier_log_type(env, t, NULL);
- return meta_needed;
- }
- static void btf_int_log(struct btf_verifier_env *env,
- const struct btf_type *t)
- {
- int int_data = btf_type_int(t);
- btf_verifier_log(env,
- "size=%u bits_offset=%u nr_bits=%u encoding=%s",
- t->size, BTF_INT_OFFSET(int_data),
- BTF_INT_BITS(int_data),
- btf_int_encoding_str(BTF_INT_ENCODING(int_data)));
- }
- static void btf_int128_print(struct btf_show *show, void *data)
- {
- /* data points to a __int128 number.
- * Suppose
- * int128_num = *(__int128 *)data;
- * The below formulas shows what upper_num and lower_num represents:
- * upper_num = int128_num >> 64;
- * lower_num = int128_num & 0xffffffffFFFFFFFFULL;
- */
- u64 upper_num, lower_num;
- #ifdef __BIG_ENDIAN_BITFIELD
- upper_num = *(u64 *)data;
- lower_num = *(u64 *)(data + 8);
- #else
- upper_num = *(u64 *)(data + 8);
- lower_num = *(u64 *)data;
- #endif
- if (upper_num == 0)
- btf_show_type_value(show, "0x%llx", lower_num);
- else
- btf_show_type_values(show, "0x%llx%016llx", upper_num,
- lower_num);
- }
- static void btf_int128_shift(u64 *print_num, u16 left_shift_bits,
- u16 right_shift_bits)
- {
- u64 upper_num, lower_num;
- #ifdef __BIG_ENDIAN_BITFIELD
- upper_num = print_num[0];
- lower_num = print_num[1];
- #else
- upper_num = print_num[1];
- lower_num = print_num[0];
- #endif
- /* shake out un-needed bits by shift/or operations */
- if (left_shift_bits >= 64) {
- upper_num = lower_num << (left_shift_bits - 64);
- lower_num = 0;
- } else {
- upper_num = (upper_num << left_shift_bits) |
- (lower_num >> (64 - left_shift_bits));
- lower_num = lower_num << left_shift_bits;
- }
- if (right_shift_bits >= 64) {
- lower_num = upper_num >> (right_shift_bits - 64);
- upper_num = 0;
- } else {
- lower_num = (lower_num >> right_shift_bits) |
- (upper_num << (64 - right_shift_bits));
- upper_num = upper_num >> right_shift_bits;
- }
- #ifdef __BIG_ENDIAN_BITFIELD
- print_num[0] = upper_num;
- print_num[1] = lower_num;
- #else
- print_num[0] = lower_num;
- print_num[1] = upper_num;
- #endif
- }
- static void btf_bitfield_show(void *data, u8 bits_offset,
- u8 nr_bits, struct btf_show *show)
- {
- u16 left_shift_bits, right_shift_bits;
- u8 nr_copy_bytes;
- u8 nr_copy_bits;
- u64 print_num[2] = {};
- nr_copy_bits = nr_bits + bits_offset;
- nr_copy_bytes = BITS_ROUNDUP_BYTES(nr_copy_bits);
- memcpy(print_num, data, nr_copy_bytes);
- #ifdef __BIG_ENDIAN_BITFIELD
- left_shift_bits = bits_offset;
- #else
- left_shift_bits = BITS_PER_U128 - nr_copy_bits;
- #endif
- right_shift_bits = BITS_PER_U128 - nr_bits;
- btf_int128_shift(print_num, left_shift_bits, right_shift_bits);
- btf_int128_print(show, print_num);
- }
- static void btf_int_bits_show(const struct btf *btf,
- const struct btf_type *t,
- void *data, u8 bits_offset,
- struct btf_show *show)
- {
- u32 int_data = btf_type_int(t);
- u8 nr_bits = BTF_INT_BITS(int_data);
- u8 total_bits_offset;
- /*
- * bits_offset is at most 7.
- * BTF_INT_OFFSET() cannot exceed 128 bits.
- */
- total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data);
- data += BITS_ROUNDDOWN_BYTES(total_bits_offset);
- bits_offset = BITS_PER_BYTE_MASKED(total_bits_offset);
- btf_bitfield_show(data, bits_offset, nr_bits, show);
- }
- static void btf_int_show(const struct btf *btf, const struct btf_type *t,
- u32 type_id, void *data, u8 bits_offset,
- struct btf_show *show)
- {
- u32 int_data = btf_type_int(t);
- u8 encoding = BTF_INT_ENCODING(int_data);
- bool sign = encoding & BTF_INT_SIGNED;
- u8 nr_bits = BTF_INT_BITS(int_data);
- void *safe_data;
- safe_data = btf_show_start_type(show, t, type_id, data);
- if (!safe_data)
- return;
- if (bits_offset || BTF_INT_OFFSET(int_data) ||
- BITS_PER_BYTE_MASKED(nr_bits)) {
- btf_int_bits_show(btf, t, safe_data, bits_offset, show);
- goto out;
- }
- switch (nr_bits) {
- case 128:
- btf_int128_print(show, safe_data);
- break;
- case 64:
- if (sign)
- btf_show_type_value(show, "%lld", *(s64 *)safe_data);
- else
- btf_show_type_value(show, "%llu", *(u64 *)safe_data);
- break;
- case 32:
- if (sign)
- btf_show_type_value(show, "%d", *(s32 *)safe_data);
- else
- btf_show_type_value(show, "%u", *(u32 *)safe_data);
- break;
- case 16:
- if (sign)
- btf_show_type_value(show, "%d", *(s16 *)safe_data);
- else
- btf_show_type_value(show, "%u", *(u16 *)safe_data);
- break;
- case 8:
- if (show->state.array_encoding == BTF_INT_CHAR) {
- /* check for null terminator */
- if (show->state.array_terminated)
- break;
- if (*(char *)data == '\0') {
- show->state.array_terminated = 1;
- break;
- }
- if (isprint(*(char *)data)) {
- btf_show_type_value(show, "'%c'",
- *(char *)safe_data);
- break;
- }
- }
- if (sign)
- btf_show_type_value(show, "%d", *(s8 *)safe_data);
- else
- btf_show_type_value(show, "%u", *(u8 *)safe_data);
- break;
- default:
- btf_int_bits_show(btf, t, safe_data, bits_offset, show);
- break;
- }
- out:
- btf_show_end_type(show);
- }
- static const struct btf_kind_operations int_ops = {
- .check_meta = btf_int_check_meta,
- .resolve = btf_df_resolve,
- .check_member = btf_int_check_member,
- .check_kflag_member = btf_int_check_kflag_member,
- .log_details = btf_int_log,
- .show = btf_int_show,
- };
- static int btf_modifier_check_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
- {
- const struct btf_type *resolved_type;
- u32 resolved_type_id = member->type;
- struct btf_member resolved_member;
- struct btf *btf = env->btf;
- resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL);
- if (!resolved_type) {
- btf_verifier_log_member(env, struct_type, member,
- "Invalid member");
- return -EINVAL;
- }
- resolved_member = *member;
- resolved_member.type = resolved_type_id;
- return btf_type_ops(resolved_type)->check_member(env, struct_type,
- &resolved_member,
- resolved_type);
- }
- static int btf_modifier_check_kflag_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
- {
- const struct btf_type *resolved_type;
- u32 resolved_type_id = member->type;
- struct btf_member resolved_member;
- struct btf *btf = env->btf;
- resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL);
- if (!resolved_type) {
- btf_verifier_log_member(env, struct_type, member,
- "Invalid member");
- return -EINVAL;
- }
- resolved_member = *member;
- resolved_member.type = resolved_type_id;
- return btf_type_ops(resolved_type)->check_kflag_member(env, struct_type,
- &resolved_member,
- resolved_type);
- }
- static int btf_ptr_check_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
- {
- u32 struct_size, struct_bits_off, bytes_offset;
- struct_size = struct_type->size;
- struct_bits_off = member->offset;
- bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
- if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
- btf_verifier_log_member(env, struct_type, member,
- "Member is not byte aligned");
- return -EINVAL;
- }
- if (struct_size - bytes_offset < sizeof(void *)) {
- btf_verifier_log_member(env, struct_type, member,
- "Member exceeds struct_size");
- return -EINVAL;
- }
- return 0;
- }
- static int btf_ref_type_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
- {
- if (btf_type_vlen(t)) {
- btf_verifier_log_type(env, t, "vlen != 0");
- return -EINVAL;
- }
- if (btf_type_kflag(t)) {
- btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
- return -EINVAL;
- }
- if (!BTF_TYPE_ID_VALID(t->type)) {
- btf_verifier_log_type(env, t, "Invalid type_id");
- return -EINVAL;
- }
- /* typedef type must have a valid name, and other ref types,
- * volatile, const, restrict, should have a null name.
- */
- if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF) {
- if (!t->name_off ||
- !btf_name_valid_identifier(env->btf, t->name_off)) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
- } else {
- if (t->name_off) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
- }
- btf_verifier_log_type(env, t, NULL);
- return 0;
- }
- static int btf_modifier_resolve(struct btf_verifier_env *env,
- const struct resolve_vertex *v)
- {
- const struct btf_type *t = v->t;
- const struct btf_type *next_type;
- u32 next_type_id = t->type;
- struct btf *btf = env->btf;
- next_type = btf_type_by_id(btf, next_type_id);
- if (!next_type || btf_type_is_resolve_source_only(next_type)) {
- btf_verifier_log_type(env, v->t, "Invalid type_id");
- return -EINVAL;
- }
- if (!env_type_is_resolve_sink(env, next_type) &&
- !env_type_is_resolved(env, next_type_id))
- return env_stack_push(env, next_type, next_type_id);
- /* Figure out the resolved next_type_id with size.
- * They will be stored in the current modifier's
- * resolved_ids and resolved_sizes such that it can
- * save us a few type-following when we use it later (e.g. in
- * pretty print).
- */
- if (!btf_type_id_size(btf, &next_type_id, NULL)) {
- if (env_type_is_resolved(env, next_type_id))
- next_type = btf_type_id_resolve(btf, &next_type_id);
- /* "typedef void new_void", "const void"...etc */
- if (!btf_type_is_void(next_type) &&
- !btf_type_is_fwd(next_type) &&
- !btf_type_is_func_proto(next_type)) {
- btf_verifier_log_type(env, v->t, "Invalid type_id");
- return -EINVAL;
- }
- }
- env_stack_pop_resolved(env, next_type_id, 0);
- return 0;
- }
- static int btf_var_resolve(struct btf_verifier_env *env,
- const struct resolve_vertex *v)
- {
- const struct btf_type *next_type;
- const struct btf_type *t = v->t;
- u32 next_type_id = t->type;
- struct btf *btf = env->btf;
- next_type = btf_type_by_id(btf, next_type_id);
- if (!next_type || btf_type_is_resolve_source_only(next_type)) {
- btf_verifier_log_type(env, v->t, "Invalid type_id");
- return -EINVAL;
- }
- if (!env_type_is_resolve_sink(env, next_type) &&
- !env_type_is_resolved(env, next_type_id))
- return env_stack_push(env, next_type, next_type_id);
- if (btf_type_is_modifier(next_type)) {
- const struct btf_type *resolved_type;
- u32 resolved_type_id;
- resolved_type_id = next_type_id;
- resolved_type = btf_type_id_resolve(btf, &resolved_type_id);
- if (btf_type_is_ptr(resolved_type) &&
- !env_type_is_resolve_sink(env, resolved_type) &&
- !env_type_is_resolved(env, resolved_type_id))
- return env_stack_push(env, resolved_type,
- resolved_type_id);
- }
- /* We must resolve to something concrete at this point, no
- * forward types or similar that would resolve to size of
- * zero is allowed.
- */
- if (!btf_type_id_size(btf, &next_type_id, NULL)) {
- btf_verifier_log_type(env, v->t, "Invalid type_id");
- return -EINVAL;
- }
- env_stack_pop_resolved(env, next_type_id, 0);
- return 0;
- }
- static int btf_ptr_resolve(struct btf_verifier_env *env,
- const struct resolve_vertex *v)
- {
- const struct btf_type *next_type;
- const struct btf_type *t = v->t;
- u32 next_type_id = t->type;
- struct btf *btf = env->btf;
- next_type = btf_type_by_id(btf, next_type_id);
- if (!next_type || btf_type_is_resolve_source_only(next_type)) {
- btf_verifier_log_type(env, v->t, "Invalid type_id");
- return -EINVAL;
- }
- if (!env_type_is_resolve_sink(env, next_type) &&
- !env_type_is_resolved(env, next_type_id))
- return env_stack_push(env, next_type, next_type_id);
- /* If the modifier was RESOLVED during RESOLVE_STRUCT_OR_ARRAY,
- * the modifier may have stopped resolving when it was resolved
- * to a ptr (last-resolved-ptr).
- *
- * We now need to continue from the last-resolved-ptr to
- * ensure the last-resolved-ptr will not referring back to
- * the currenct ptr (t).
- */
- if (btf_type_is_modifier(next_type)) {
- const struct btf_type *resolved_type;
- u32 resolved_type_id;
- resolved_type_id = next_type_id;
- resolved_type = btf_type_id_resolve(btf, &resolved_type_id);
- if (btf_type_is_ptr(resolved_type) &&
- !env_type_is_resolve_sink(env, resolved_type) &&
- !env_type_is_resolved(env, resolved_type_id))
- return env_stack_push(env, resolved_type,
- resolved_type_id);
- }
- if (!btf_type_id_size(btf, &next_type_id, NULL)) {
- if (env_type_is_resolved(env, next_type_id))
- next_type = btf_type_id_resolve(btf, &next_type_id);
- if (!btf_type_is_void(next_type) &&
- !btf_type_is_fwd(next_type) &&
- !btf_type_is_func_proto(next_type)) {
- btf_verifier_log_type(env, v->t, "Invalid type_id");
- return -EINVAL;
- }
- }
- env_stack_pop_resolved(env, next_type_id, 0);
- return 0;
- }
- static void btf_modifier_show(const struct btf *btf,
- const struct btf_type *t,
- u32 type_id, void *data,
- u8 bits_offset, struct btf_show *show)
- {
- if (btf->resolved_ids)
- t = btf_type_id_resolve(btf, &type_id);
- else
- t = btf_type_skip_modifiers(btf, type_id, NULL);
- btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show);
- }
- static void btf_var_show(const struct btf *btf, const struct btf_type *t,
- u32 type_id, void *data, u8 bits_offset,
- struct btf_show *show)
- {
- t = btf_type_id_resolve(btf, &type_id);
- btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show);
- }
- static void btf_ptr_show(const struct btf *btf, const struct btf_type *t,
- u32 type_id, void *data, u8 bits_offset,
- struct btf_show *show)
- {
- void *safe_data;
- safe_data = btf_show_start_type(show, t, type_id, data);
- if (!safe_data)
- return;
- /* It is a hashed value unless BTF_SHOW_PTR_RAW is specified */
- if (show->flags & BTF_SHOW_PTR_RAW)
- btf_show_type_value(show, "0x%px", *(void **)safe_data);
- else
- btf_show_type_value(show, "0x%p", *(void **)safe_data);
- btf_show_end_type(show);
- }
- static void btf_ref_type_log(struct btf_verifier_env *env,
- const struct btf_type *t)
- {
- btf_verifier_log(env, "type_id=%u", t->type);
- }
- static struct btf_kind_operations modifier_ops = {
- .check_meta = btf_ref_type_check_meta,
- .resolve = btf_modifier_resolve,
- .check_member = btf_modifier_check_member,
- .check_kflag_member = btf_modifier_check_kflag_member,
- .log_details = btf_ref_type_log,
- .show = btf_modifier_show,
- };
- static struct btf_kind_operations ptr_ops = {
- .check_meta = btf_ref_type_check_meta,
- .resolve = btf_ptr_resolve,
- .check_member = btf_ptr_check_member,
- .check_kflag_member = btf_generic_check_kflag_member,
- .log_details = btf_ref_type_log,
- .show = btf_ptr_show,
- };
- static s32 btf_fwd_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
- {
- if (btf_type_vlen(t)) {
- btf_verifier_log_type(env, t, "vlen != 0");
- return -EINVAL;
- }
- if (t->type) {
- btf_verifier_log_type(env, t, "type != 0");
- return -EINVAL;
- }
- /* fwd type must have a valid name */
- if (!t->name_off ||
- !btf_name_valid_identifier(env->btf, t->name_off)) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
- btf_verifier_log_type(env, t, NULL);
- return 0;
- }
- static void btf_fwd_type_log(struct btf_verifier_env *env,
- const struct btf_type *t)
- {
- btf_verifier_log(env, "%s", btf_type_kflag(t) ? "union" : "struct");
- }
- static struct btf_kind_operations fwd_ops = {
- .check_meta = btf_fwd_check_meta,
- .resolve = btf_df_resolve,
- .check_member = btf_df_check_member,
- .check_kflag_member = btf_df_check_kflag_member,
- .log_details = btf_fwd_type_log,
- .show = btf_df_show,
- };
- static int btf_array_check_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
- {
- u32 struct_bits_off = member->offset;
- u32 struct_size, bytes_offset;
- u32 array_type_id, array_size;
- struct btf *btf = env->btf;
- if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
- btf_verifier_log_member(env, struct_type, member,
- "Member is not byte aligned");
- return -EINVAL;
- }
- array_type_id = member->type;
- btf_type_id_size(btf, &array_type_id, &array_size);
- struct_size = struct_type->size;
- bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
- if (struct_size - bytes_offset < array_size) {
- btf_verifier_log_member(env, struct_type, member,
- "Member exceeds struct_size");
- return -EINVAL;
- }
- return 0;
- }
- static s32 btf_array_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
- {
- const struct btf_array *array = btf_type_array(t);
- u32 meta_needed = sizeof(*array);
- if (meta_left < meta_needed) {
- btf_verifier_log_basic(env, t,
- "meta_left:%u meta_needed:%u",
- meta_left, meta_needed);
- return -EINVAL;
- }
- /* array type should not have a name */
- if (t->name_off) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
- if (btf_type_vlen(t)) {
- btf_verifier_log_type(env, t, "vlen != 0");
- return -EINVAL;
- }
- if (btf_type_kflag(t)) {
- btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
- return -EINVAL;
- }
- if (t->size) {
- btf_verifier_log_type(env, t, "size != 0");
- return -EINVAL;
- }
- /* Array elem type and index type cannot be in type void,
- * so !array->type and !array->index_type are not allowed.
- */
- if (!array->type || !BTF_TYPE_ID_VALID(array->type)) {
- btf_verifier_log_type(env, t, "Invalid elem");
- return -EINVAL;
- }
- if (!array->index_type || !BTF_TYPE_ID_VALID(array->index_type)) {
- btf_verifier_log_type(env, t, "Invalid index");
- return -EINVAL;
- }
- btf_verifier_log_type(env, t, NULL);
- return meta_needed;
- }
- static int btf_array_resolve(struct btf_verifier_env *env,
- const struct resolve_vertex *v)
- {
- const struct btf_array *array = btf_type_array(v->t);
- const struct btf_type *elem_type, *index_type;
- u32 elem_type_id, index_type_id;
- struct btf *btf = env->btf;
- u32 elem_size;
- /* Check array->index_type */
- index_type_id = array->index_type;
- index_type = btf_type_by_id(btf, index_type_id);
- if (btf_type_nosize_or_null(index_type) ||
- btf_type_is_resolve_source_only(index_type)) {
- btf_verifier_log_type(env, v->t, "Invalid index");
- return -EINVAL;
- }
- if (!env_type_is_resolve_sink(env, index_type) &&
- !env_type_is_resolved(env, index_type_id))
- return env_stack_push(env, index_type, index_type_id);
- index_type = btf_type_id_size(btf, &index_type_id, NULL);
- if (!index_type || !btf_type_is_int(index_type) ||
- !btf_type_int_is_regular(index_type)) {
- btf_verifier_log_type(env, v->t, "Invalid index");
- return -EINVAL;
- }
- /* Check array->type */
- elem_type_id = array->type;
- elem_type = btf_type_by_id(btf, elem_type_id);
- if (btf_type_nosize_or_null(elem_type) ||
- btf_type_is_resolve_source_only(elem_type)) {
- btf_verifier_log_type(env, v->t,
- "Invalid elem");
- return -EINVAL;
- }
- if (!env_type_is_resolve_sink(env, elem_type) &&
- !env_type_is_resolved(env, elem_type_id))
- return env_stack_push(env, elem_type, elem_type_id);
- elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size);
- if (!elem_type) {
- btf_verifier_log_type(env, v->t, "Invalid elem");
- return -EINVAL;
- }
- if (btf_type_is_int(elem_type) && !btf_type_int_is_regular(elem_type)) {
- btf_verifier_log_type(env, v->t, "Invalid array of int");
- return -EINVAL;
- }
- if (array->nelems && elem_size > U32_MAX / array->nelems) {
- btf_verifier_log_type(env, v->t,
- "Array size overflows U32_MAX");
- return -EINVAL;
- }
- env_stack_pop_resolved(env, elem_type_id, elem_size * array->nelems);
- return 0;
- }
- static void btf_array_log(struct btf_verifier_env *env,
- const struct btf_type *t)
- {
- const struct btf_array *array = btf_type_array(t);
- btf_verifier_log(env, "type_id=%u index_type_id=%u nr_elems=%u",
- array->type, array->index_type, array->nelems);
- }
- static void __btf_array_show(const struct btf *btf, const struct btf_type *t,
- u32 type_id, void *data, u8 bits_offset,
- struct btf_show *show)
- {
- const struct btf_array *array = btf_type_array(t);
- const struct btf_kind_operations *elem_ops;
- const struct btf_type *elem_type;
- u32 i, elem_size = 0, elem_type_id;
- u16 encoding = 0;
- elem_type_id = array->type;
- elem_type = btf_type_skip_modifiers(btf, elem_type_id, NULL);
- if (elem_type && btf_type_has_size(elem_type))
- elem_size = elem_type->size;
- if (elem_type && btf_type_is_int(elem_type)) {
- u32 int_type = btf_type_int(elem_type);
- encoding = BTF_INT_ENCODING(int_type);
- /*
- * BTF_INT_CHAR encoding never seems to be set for
- * char arrays, so if size is 1 and element is
- * printable as a char, we'll do that.
- */
- if (elem_size == 1)
- encoding = BTF_INT_CHAR;
- }
- if (!btf_show_start_array_type(show, t, type_id, encoding, data))
- return;
- if (!elem_type)
- goto out;
- elem_ops = btf_type_ops(elem_type);
- for (i = 0; i < array->nelems; i++) {
- btf_show_start_array_member(show);
- elem_ops->show(btf, elem_type, elem_type_id, data,
- bits_offset, show);
- data += elem_size;
- btf_show_end_array_member(show);
- if (show->state.array_terminated)
- break;
- }
- out:
- btf_show_end_array_type(show);
- }
- static void btf_array_show(const struct btf *btf, const struct btf_type *t,
- u32 type_id, void *data, u8 bits_offset,
- struct btf_show *show)
- {
- const struct btf_member *m = show->state.member;
- /*
- * First check if any members would be shown (are non-zero).
- * See comments above "struct btf_show" definition for more
- * details on how this works at a high-level.
- */
- if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) {
- if (!show->state.depth_check) {
- show->state.depth_check = show->state.depth + 1;
- show->state.depth_to_show = 0;
- }
- __btf_array_show(btf, t, type_id, data, bits_offset, show);
- show->state.member = m;
- if (show->state.depth_check != show->state.depth + 1)
- return;
- show->state.depth_check = 0;
- if (show->state.depth_to_show <= show->state.depth)
- return;
- /*
- * Reaching here indicates we have recursed and found
- * non-zero array member(s).
- */
- }
- __btf_array_show(btf, t, type_id, data, bits_offset, show);
- }
- static struct btf_kind_operations array_ops = {
- .check_meta = btf_array_check_meta,
- .resolve = btf_array_resolve,
- .check_member = btf_array_check_member,
- .check_kflag_member = btf_generic_check_kflag_member,
- .log_details = btf_array_log,
- .show = btf_array_show,
- };
- static int btf_struct_check_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
- {
- u32 struct_bits_off = member->offset;
- u32 struct_size, bytes_offset;
- if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
- btf_verifier_log_member(env, struct_type, member,
- "Member is not byte aligned");
- return -EINVAL;
- }
- struct_size = struct_type->size;
- bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
- if (struct_size - bytes_offset < member_type->size) {
- btf_verifier_log_member(env, struct_type, member,
- "Member exceeds struct_size");
- return -EINVAL;
- }
- return 0;
- }
- static s32 btf_struct_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
- {
- bool is_union = BTF_INFO_KIND(t->info) == BTF_KIND_UNION;
- const struct btf_member *member;
- u32 meta_needed, last_offset;
- struct btf *btf = env->btf;
- u32 struct_size = t->size;
- u32 offset;
- u16 i;
- meta_needed = btf_type_vlen(t) * sizeof(*member);
- if (meta_left < meta_needed) {
- btf_verifier_log_basic(env, t,
- "meta_left:%u meta_needed:%u",
- meta_left, meta_needed);
- return -EINVAL;
- }
- /* struct type either no name or a valid one */
- if (t->name_off &&
- !btf_name_valid_identifier(env->btf, t->name_off)) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
- btf_verifier_log_type(env, t, NULL);
- last_offset = 0;
- for_each_member(i, t, member) {
- if (!btf_name_offset_valid(btf, member->name_off)) {
- btf_verifier_log_member(env, t, member,
- "Invalid member name_offset:%u",
- member->name_off);
- return -EINVAL;
- }
- /* struct member either no name or a valid one */
- if (member->name_off &&
- !btf_name_valid_identifier(btf, member->name_off)) {
- btf_verifier_log_member(env, t, member, "Invalid name");
- return -EINVAL;
- }
- /* A member cannot be in type void */
- if (!member->type || !BTF_TYPE_ID_VALID(member->type)) {
- btf_verifier_log_member(env, t, member,
- "Invalid type_id");
- return -EINVAL;
- }
- offset = btf_member_bit_offset(t, member);
- if (is_union && offset) {
- btf_verifier_log_member(env, t, member,
- "Invalid member bits_offset");
- return -EINVAL;
- }
- /*
- * ">" instead of ">=" because the last member could be
- * "char a[0];"
- */
- if (last_offset > offset) {
- btf_verifier_log_member(env, t, member,
- "Invalid member bits_offset");
- return -EINVAL;
- }
- if (BITS_ROUNDUP_BYTES(offset) > struct_size) {
- btf_verifier_log_member(env, t, member,
- "Member bits_offset exceeds its struct size");
- return -EINVAL;
- }
- btf_verifier_log_member(env, t, member, NULL);
- last_offset = offset;
- }
- return meta_needed;
- }
- static int btf_struct_resolve(struct btf_verifier_env *env,
- const struct resolve_vertex *v)
- {
- const struct btf_member *member;
- int err;
- u16 i;
- /* Before continue resolving the next_member,
- * ensure the last member is indeed resolved to a
- * type with size info.
- */
- if (v->next_member) {
- const struct btf_type *last_member_type;
- const struct btf_member *last_member;
- u16 last_member_type_id;
- last_member = btf_type_member(v->t) + v->next_member - 1;
- last_member_type_id = last_member->type;
- if (WARN_ON_ONCE(!env_type_is_resolved(env,
- last_member_type_id)))
- return -EINVAL;
- last_member_type = btf_type_by_id(env->btf,
- last_member_type_id);
- if (btf_type_kflag(v->t))
- err = btf_type_ops(last_member_type)->check_kflag_member(env, v->t,
- last_member,
- last_member_type);
- else
- err = btf_type_ops(last_member_type)->check_member(env, v->t,
- last_member,
- last_member_type);
- if (err)
- return err;
- }
- for_each_member_from(i, v->next_member, v->t, member) {
- u32 member_type_id = member->type;
- const struct btf_type *member_type = btf_type_by_id(env->btf,
- member_type_id);
- if (btf_type_nosize_or_null(member_type) ||
- btf_type_is_resolve_source_only(member_type)) {
- btf_verifier_log_member(env, v->t, member,
- "Invalid member");
- return -EINVAL;
- }
- if (!env_type_is_resolve_sink(env, member_type) &&
- !env_type_is_resolved(env, member_type_id)) {
- env_stack_set_next_member(env, i + 1);
- return env_stack_push(env, member_type, member_type_id);
- }
- if (btf_type_kflag(v->t))
- err = btf_type_ops(member_type)->check_kflag_member(env, v->t,
- member,
- member_type);
- else
- err = btf_type_ops(member_type)->check_member(env, v->t,
- member,
- member_type);
- if (err)
- return err;
- }
- env_stack_pop_resolved(env, 0, 0);
- return 0;
- }
- static void btf_struct_log(struct btf_verifier_env *env,
- const struct btf_type *t)
- {
- btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
- }
- /* find 'struct bpf_spin_lock' in map value.
- * return >= 0 offset if found
- * and < 0 in case of error
- */
- int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t)
- {
- const struct btf_member *member;
- u32 i, off = -ENOENT;
- if (!__btf_type_is_struct(t))
- return -EINVAL;
- for_each_member(i, t, member) {
- const struct btf_type *member_type = btf_type_by_id(btf,
- member->type);
- if (!__btf_type_is_struct(member_type))
- continue;
- if (member_type->size != sizeof(struct bpf_spin_lock))
- continue;
- if (strcmp(__btf_name_by_offset(btf, member_type->name_off),
- "bpf_spin_lock"))
- continue;
- if (off != -ENOENT)
- /* only one 'struct bpf_spin_lock' is allowed */
- return -E2BIG;
- off = btf_member_bit_offset(t, member);
- if (off % 8)
- /* valid C code cannot generate such BTF */
- return -EINVAL;
- off /= 8;
- if (off % __alignof__(struct bpf_spin_lock))
- /* valid struct bpf_spin_lock will be 4 byte aligned */
- return -EINVAL;
- }
- return off;
- }
- static void __btf_struct_show(const struct btf *btf, const struct btf_type *t,
- u32 type_id, void *data, u8 bits_offset,
- struct btf_show *show)
- {
- const struct btf_member *member;
- void *safe_data;
- u32 i;
- safe_data = btf_show_start_struct_type(show, t, type_id, data);
- if (!safe_data)
- return;
- for_each_member(i, t, member) {
- const struct btf_type *member_type = btf_type_by_id(btf,
- member->type);
- const struct btf_kind_operations *ops;
- u32 member_offset, bitfield_size;
- u32 bytes_offset;
- u8 bits8_offset;
- btf_show_start_member(show, member);
- member_offset = btf_member_bit_offset(t, member);
- bitfield_size = btf_member_bitfield_size(t, member);
- bytes_offset = BITS_ROUNDDOWN_BYTES(member_offset);
- bits8_offset = BITS_PER_BYTE_MASKED(member_offset);
- if (bitfield_size) {
- safe_data = btf_show_start_type(show, member_type,
- member->type,
- data + bytes_offset);
- if (safe_data)
- btf_bitfield_show(safe_data,
- bits8_offset,
- bitfield_size, show);
- btf_show_end_type(show);
- } else {
- ops = btf_type_ops(member_type);
- ops->show(btf, member_type, member->type,
- data + bytes_offset, bits8_offset, show);
- }
- btf_show_end_member(show);
- }
- btf_show_end_struct_type(show);
- }
- static void btf_struct_show(const struct btf *btf, const struct btf_type *t,
- u32 type_id, void *data, u8 bits_offset,
- struct btf_show *show)
- {
- const struct btf_member *m = show->state.member;
- /*
- * First check if any members would be shown (are non-zero).
- * See comments above "struct btf_show" definition for more
- * details on how this works at a high-level.
- */
- if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) {
- if (!show->state.depth_check) {
- show->state.depth_check = show->state.depth + 1;
- show->state.depth_to_show = 0;
- }
- __btf_struct_show(btf, t, type_id, data, bits_offset, show);
- /* Restore saved member data here */
- show->state.member = m;
- if (show->state.depth_check != show->state.depth + 1)
- return;
- show->state.depth_check = 0;
- if (show->state.depth_to_show <= show->state.depth)
- return;
- /*
- * Reaching here indicates we have recursed and found
- * non-zero child values.
- */
- }
- __btf_struct_show(btf, t, type_id, data, bits_offset, show);
- }
- static struct btf_kind_operations struct_ops = {
- .check_meta = btf_struct_check_meta,
- .resolve = btf_struct_resolve,
- .check_member = btf_struct_check_member,
- .check_kflag_member = btf_generic_check_kflag_member,
- .log_details = btf_struct_log,
- .show = btf_struct_show,
- };
- static int btf_enum_check_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
- {
- u32 struct_bits_off = member->offset;
- u32 struct_size, bytes_offset;
- if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
- btf_verifier_log_member(env, struct_type, member,
- "Member is not byte aligned");
- return -EINVAL;
- }
- struct_size = struct_type->size;
- bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
- if (struct_size - bytes_offset < member_type->size) {
- btf_verifier_log_member(env, struct_type, member,
- "Member exceeds struct_size");
- return -EINVAL;
- }
- return 0;
- }
- static int btf_enum_check_kflag_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
- {
- u32 struct_bits_off, nr_bits, bytes_end, struct_size;
- u32 int_bitsize = sizeof(int) * BITS_PER_BYTE;
- struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset);
- nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset);
- if (!nr_bits) {
- if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
- btf_verifier_log_member(env, struct_type, member,
- "Member is not byte aligned");
- return -EINVAL;
- }
- nr_bits = int_bitsize;
- } else if (nr_bits > int_bitsize) {
- btf_verifier_log_member(env, struct_type, member,
- "Invalid member bitfield_size");
- return -EINVAL;
- }
- struct_size = struct_type->size;
- bytes_end = BITS_ROUNDUP_BYTES(struct_bits_off + nr_bits);
- if (struct_size < bytes_end) {
- btf_verifier_log_member(env, struct_type, member,
- "Member exceeds struct_size");
- return -EINVAL;
- }
- return 0;
- }
- static s32 btf_enum_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
- {
- const struct btf_enum *enums = btf_type_enum(t);
- struct btf *btf = env->btf;
- u16 i, nr_enums;
- u32 meta_needed;
- nr_enums = btf_type_vlen(t);
- meta_needed = nr_enums * sizeof(*enums);
- if (meta_left < meta_needed) {
- btf_verifier_log_basic(env, t,
- "meta_left:%u meta_needed:%u",
- meta_left, meta_needed);
- return -EINVAL;
- }
- if (btf_type_kflag(t)) {
- btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
- return -EINVAL;
- }
- if (t->size > 8 || !is_power_of_2(t->size)) {
- btf_verifier_log_type(env, t, "Unexpected size");
- return -EINVAL;
- }
- /* enum type either no name or a valid one */
- if (t->name_off &&
- !btf_name_valid_identifier(env->btf, t->name_off)) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
- btf_verifier_log_type(env, t, NULL);
- for (i = 0; i < nr_enums; i++) {
- if (!btf_name_offset_valid(btf, enums[i].name_off)) {
- btf_verifier_log(env, "\tInvalid name_offset:%u",
- enums[i].name_off);
- return -EINVAL;
- }
- /* enum member must have a valid name */
- if (!enums[i].name_off ||
- !btf_name_valid_identifier(btf, enums[i].name_off)) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
- if (env->log.level == BPF_LOG_KERNEL)
- continue;
- btf_verifier_log(env, "\t%s val=%d\n",
- __btf_name_by_offset(btf, enums[i].name_off),
- enums[i].val);
- }
- return meta_needed;
- }
- static void btf_enum_log(struct btf_verifier_env *env,
- const struct btf_type *t)
- {
- btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
- }
- static void btf_enum_show(const struct btf *btf, const struct btf_type *t,
- u32 type_id, void *data, u8 bits_offset,
- struct btf_show *show)
- {
- const struct btf_enum *enums = btf_type_enum(t);
- u32 i, nr_enums = btf_type_vlen(t);
- void *safe_data;
- int v;
- safe_data = btf_show_start_type(show, t, type_id, data);
- if (!safe_data)
- return;
- v = *(int *)safe_data;
- for (i = 0; i < nr_enums; i++) {
- if (v != enums[i].val)
- continue;
- btf_show_type_value(show, "%s",
- __btf_name_by_offset(btf,
- enums[i].name_off));
- btf_show_end_type(show);
- return;
- }
- btf_show_type_value(show, "%d", v);
- btf_show_end_type(show);
- }
- static struct btf_kind_operations enum_ops = {
- .check_meta = btf_enum_check_meta,
- .resolve = btf_df_resolve,
- .check_member = btf_enum_check_member,
- .check_kflag_member = btf_enum_check_kflag_member,
- .log_details = btf_enum_log,
- .show = btf_enum_show,
- };
- static s32 btf_func_proto_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
- {
- u32 meta_needed = btf_type_vlen(t) * sizeof(struct btf_param);
- if (meta_left < meta_needed) {
- btf_verifier_log_basic(env, t,
- "meta_left:%u meta_needed:%u",
- meta_left, meta_needed);
- return -EINVAL;
- }
- if (t->name_off) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
- if (btf_type_kflag(t)) {
- btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
- return -EINVAL;
- }
- btf_verifier_log_type(env, t, NULL);
- return meta_needed;
- }
- static void btf_func_proto_log(struct btf_verifier_env *env,
- const struct btf_type *t)
- {
- const struct btf_param *args = (const struct btf_param *)(t + 1);
- u16 nr_args = btf_type_vlen(t), i;
- btf_verifier_log(env, "return=%u args=(", t->type);
- if (!nr_args) {
- btf_verifier_log(env, "void");
- goto done;
- }
- if (nr_args == 1 && !args[0].type) {
- /* Only one vararg */
- btf_verifier_log(env, "vararg");
- goto done;
- }
- btf_verifier_log(env, "%u %s", args[0].type,
- __btf_name_by_offset(env->btf,
- args[0].name_off));
- for (i = 1; i < nr_args - 1; i++)
- btf_verifier_log(env, ", %u %s", args[i].type,
- __btf_name_by_offset(env->btf,
- args[i].name_off));
- if (nr_args > 1) {
- const struct btf_param *last_arg = &args[nr_args - 1];
- if (last_arg->type)
- btf_verifier_log(env, ", %u %s", last_arg->type,
- __btf_name_by_offset(env->btf,
- last_arg->name_off));
- else
- btf_verifier_log(env, ", vararg");
- }
- done:
- btf_verifier_log(env, ")");
- }
- static struct btf_kind_operations func_proto_ops = {
- .check_meta = btf_func_proto_check_meta,
- .resolve = btf_df_resolve,
- /*
- * BTF_KIND_FUNC_PROTO cannot be directly referred by
- * a struct's member.
- *
- * It should be a funciton pointer instead.
- * (i.e. struct's member -> BTF_KIND_PTR -> BTF_KIND_FUNC_PROTO)
- *
- * Hence, there is no btf_func_check_member().
- */
- .check_member = btf_df_check_member,
- .check_kflag_member = btf_df_check_kflag_member,
- .log_details = btf_func_proto_log,
- .show = btf_df_show,
- };
- static s32 btf_func_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
- {
- if (!t->name_off ||
- !btf_name_valid_identifier(env->btf, t->name_off)) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
- if (btf_type_vlen(t) > BTF_FUNC_GLOBAL) {
- btf_verifier_log_type(env, t, "Invalid func linkage");
- return -EINVAL;
- }
- if (btf_type_kflag(t)) {
- btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
- return -EINVAL;
- }
- btf_verifier_log_type(env, t, NULL);
- return 0;
- }
- static struct btf_kind_operations func_ops = {
- .check_meta = btf_func_check_meta,
- .resolve = btf_df_resolve,
- .check_member = btf_df_check_member,
- .check_kflag_member = btf_df_check_kflag_member,
- .log_details = btf_ref_type_log,
- .show = btf_df_show,
- };
- static s32 btf_var_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
- {
- const struct btf_var *var;
- u32 meta_needed = sizeof(*var);
- if (meta_left < meta_needed) {
- btf_verifier_log_basic(env, t,
- "meta_left:%u meta_needed:%u",
- meta_left, meta_needed);
- return -EINVAL;
- }
- if (btf_type_vlen(t)) {
- btf_verifier_log_type(env, t, "vlen != 0");
- return -EINVAL;
- }
- if (btf_type_kflag(t)) {
- btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
- return -EINVAL;
- }
- if (!t->name_off ||
- !__btf_name_valid(env->btf, t->name_off, true)) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
- /* A var cannot be in type void */
- if (!t->type || !BTF_TYPE_ID_VALID(t->type)) {
- btf_verifier_log_type(env, t, "Invalid type_id");
- return -EINVAL;
- }
- var = btf_type_var(t);
- if (var->linkage != BTF_VAR_STATIC &&
- var->linkage != BTF_VAR_GLOBAL_ALLOCATED) {
- btf_verifier_log_type(env, t, "Linkage not supported");
- return -EINVAL;
- }
- btf_verifier_log_type(env, t, NULL);
- return meta_needed;
- }
- static void btf_var_log(struct btf_verifier_env *env, const struct btf_type *t)
- {
- const struct btf_var *var = btf_type_var(t);
- btf_verifier_log(env, "type_id=%u linkage=%u", t->type, var->linkage);
- }
- static const struct btf_kind_operations var_ops = {
- .check_meta = btf_var_check_meta,
- .resolve = btf_var_resolve,
- .check_member = btf_df_check_member,
- .check_kflag_member = btf_df_check_kflag_member,
- .log_details = btf_var_log,
- .show = btf_var_show,
- };
- static s32 btf_datasec_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
- {
- const struct btf_var_secinfo *vsi;
- u64 last_vsi_end_off = 0, sum = 0;
- u32 i, meta_needed;
- meta_needed = btf_type_vlen(t) * sizeof(*vsi);
- if (meta_left < meta_needed) {
- btf_verifier_log_basic(env, t,
- "meta_left:%u meta_needed:%u",
- meta_left, meta_needed);
- return -EINVAL;
- }
- if (!btf_type_vlen(t)) {
- btf_verifier_log_type(env, t, "vlen == 0");
- return -EINVAL;
- }
- if (!t->size) {
- btf_verifier_log_type(env, t, "size == 0");
- return -EINVAL;
- }
- if (btf_type_kflag(t)) {
- btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
- return -EINVAL;
- }
- if (!t->name_off ||
- !btf_name_valid_section(env->btf, t->name_off)) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
- btf_verifier_log_type(env, t, NULL);
- for_each_vsi(i, t, vsi) {
- /* A var cannot be in type void */
- if (!vsi->type || !BTF_TYPE_ID_VALID(vsi->type)) {
- btf_verifier_log_vsi(env, t, vsi,
- "Invalid type_id");
- return -EINVAL;
- }
- if (vsi->offset < last_vsi_end_off || vsi->offset >= t->size) {
- btf_verifier_log_vsi(env, t, vsi,
- "Invalid offset");
- return -EINVAL;
- }
- if (!vsi->size || vsi->size > t->size) {
- btf_verifier_log_vsi(env, t, vsi,
- "Invalid size");
- return -EINVAL;
- }
- last_vsi_end_off = vsi->offset + vsi->size;
- if (last_vsi_end_off > t->size) {
- btf_verifier_log_vsi(env, t, vsi,
- "Invalid offset+size");
- return -EINVAL;
- }
- btf_verifier_log_vsi(env, t, vsi, NULL);
- sum += vsi->size;
- }
- if (t->size < sum) {
- btf_verifier_log_type(env, t, "Invalid btf_info size");
- return -EINVAL;
- }
- return meta_needed;
- }
- static int btf_datasec_resolve(struct btf_verifier_env *env,
- const struct resolve_vertex *v)
- {
- const struct btf_var_secinfo *vsi;
- struct btf *btf = env->btf;
- u16 i;
- for_each_vsi_from(i, v->next_member, v->t, vsi) {
- u32 var_type_id = vsi->type, type_id, type_size = 0;
- const struct btf_type *var_type = btf_type_by_id(env->btf,
- var_type_id);
- if (!var_type || !btf_type_is_var(var_type)) {
- btf_verifier_log_vsi(env, v->t, vsi,
- "Not a VAR kind member");
- return -EINVAL;
- }
- if (!env_type_is_resolve_sink(env, var_type) &&
- !env_type_is_resolved(env, var_type_id)) {
- env_stack_set_next_member(env, i + 1);
- return env_stack_push(env, var_type, var_type_id);
- }
- type_id = var_type->type;
- if (!btf_type_id_size(btf, &type_id, &type_size)) {
- btf_verifier_log_vsi(env, v->t, vsi, "Invalid type");
- return -EINVAL;
- }
- if (vsi->size < type_size) {
- btf_verifier_log_vsi(env, v->t, vsi, "Invalid size");
- return -EINVAL;
- }
- }
- env_stack_pop_resolved(env, 0, 0);
- return 0;
- }
- static void btf_datasec_log(struct btf_verifier_env *env,
- const struct btf_type *t)
- {
- btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
- }
- static void btf_datasec_show(const struct btf *btf,
- const struct btf_type *t, u32 type_id,
- void *data, u8 bits_offset,
- struct btf_show *show)
- {
- const struct btf_var_secinfo *vsi;
- const struct btf_type *var;
- u32 i;
- if (!btf_show_start_type(show, t, type_id, data))
- return;
- btf_show_type_value(show, "section (\"%s\") = {",
- __btf_name_by_offset(btf, t->name_off));
- for_each_vsi(i, t, vsi) {
- var = btf_type_by_id(btf, vsi->type);
- if (i)
- btf_show(show, ",");
- btf_type_ops(var)->show(btf, var, vsi->type,
- data + vsi->offset, bits_offset, show);
- }
- btf_show_end_type(show);
- }
- static const struct btf_kind_operations datasec_ops = {
- .check_meta = btf_datasec_check_meta,
- .resolve = btf_datasec_resolve,
- .check_member = btf_df_check_member,
- .check_kflag_member = btf_df_check_kflag_member,
- .log_details = btf_datasec_log,
- .show = btf_datasec_show,
- };
- static int btf_func_proto_check(struct btf_verifier_env *env,
- const struct btf_type *t)
- {
- const struct btf_type *ret_type;
- const struct btf_param *args;
- const struct btf *btf;
- u16 nr_args, i;
- int err;
- btf = env->btf;
- args = (const struct btf_param *)(t + 1);
- nr_args = btf_type_vlen(t);
- /* Check func return type which could be "void" (t->type == 0) */
- if (t->type) {
- u32 ret_type_id = t->type;
- ret_type = btf_type_by_id(btf, ret_type_id);
- if (!ret_type) {
- btf_verifier_log_type(env, t, "Invalid return type");
- return -EINVAL;
- }
- if (btf_type_needs_resolve(ret_type) &&
- !env_type_is_resolved(env, ret_type_id)) {
- err = btf_resolve(env, ret_type, ret_type_id);
- if (err)
- return err;
- }
- /* Ensure the return type is a type that has a size */
- if (!btf_type_id_size(btf, &ret_type_id, NULL)) {
- btf_verifier_log_type(env, t, "Invalid return type");
- return -EINVAL;
- }
- }
- if (!nr_args)
- return 0;
- /* Last func arg type_id could be 0 if it is a vararg */
- if (!args[nr_args - 1].type) {
- if (args[nr_args - 1].name_off) {
- btf_verifier_log_type(env, t, "Invalid arg#%u",
- nr_args);
- return -EINVAL;
- }
- nr_args--;
- }
- err = 0;
- for (i = 0; i < nr_args; i++) {
- const struct btf_type *arg_type;
- u32 arg_type_id;
- arg_type_id = args[i].type;
- arg_type = btf_type_by_id(btf, arg_type_id);
- if (!arg_type) {
- btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
- err = -EINVAL;
- break;
- }
- if (args[i].name_off &&
- (!btf_name_offset_valid(btf, args[i].name_off) ||
- !btf_name_valid_identifier(btf, args[i].name_off))) {
- btf_verifier_log_type(env, t,
- "Invalid arg#%u", i + 1);
- err = -EINVAL;
- break;
- }
- if (btf_type_needs_resolve(arg_type) &&
- !env_type_is_resolved(env, arg_type_id)) {
- err = btf_resolve(env, arg_type, arg_type_id);
- if (err)
- break;
- }
- if (!btf_type_id_size(btf, &arg_type_id, NULL)) {
- btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
- err = -EINVAL;
- break;
- }
- }
- return err;
- }
- static int btf_func_check(struct btf_verifier_env *env,
- const struct btf_type *t)
- {
- const struct btf_type *proto_type;
- const struct btf_param *args;
- const struct btf *btf;
- u16 nr_args, i;
- btf = env->btf;
- proto_type = btf_type_by_id(btf, t->type);
- if (!proto_type || !btf_type_is_func_proto(proto_type)) {
- btf_verifier_log_type(env, t, "Invalid type_id");
- return -EINVAL;
- }
- args = (const struct btf_param *)(proto_type + 1);
- nr_args = btf_type_vlen(proto_type);
- for (i = 0; i < nr_args; i++) {
- if (!args[i].name_off && args[i].type) {
- btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
- return -EINVAL;
- }
- }
- return 0;
- }
- static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = {
- [BTF_KIND_INT] = &int_ops,
- [BTF_KIND_PTR] = &ptr_ops,
- [BTF_KIND_ARRAY] = &array_ops,
- [BTF_KIND_STRUCT] = &struct_ops,
- [BTF_KIND_UNION] = &struct_ops,
- [BTF_KIND_ENUM] = &enum_ops,
- [BTF_KIND_FWD] = &fwd_ops,
- [BTF_KIND_TYPEDEF] = &modifier_ops,
- [BTF_KIND_VOLATILE] = &modifier_ops,
- [BTF_KIND_CONST] = &modifier_ops,
- [BTF_KIND_RESTRICT] = &modifier_ops,
- [BTF_KIND_FUNC] = &func_ops,
- [BTF_KIND_FUNC_PROTO] = &func_proto_ops,
- [BTF_KIND_VAR] = &var_ops,
- [BTF_KIND_DATASEC] = &datasec_ops,
- };
- static s32 btf_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
- {
- u32 saved_meta_left = meta_left;
- s32 var_meta_size;
- if (meta_left < sizeof(*t)) {
- btf_verifier_log(env, "[%u] meta_left:%u meta_needed:%zu",
- env->log_type_id, meta_left, sizeof(*t));
- return -EINVAL;
- }
- meta_left -= sizeof(*t);
- if (t->info & ~BTF_INFO_MASK) {
- btf_verifier_log(env, "[%u] Invalid btf_info:%x",
- env->log_type_id, t->info);
- return -EINVAL;
- }
- if (BTF_INFO_KIND(t->info) > BTF_KIND_MAX ||
- BTF_INFO_KIND(t->info) == BTF_KIND_UNKN) {
- btf_verifier_log(env, "[%u] Invalid kind:%u",
- env->log_type_id, BTF_INFO_KIND(t->info));
- return -EINVAL;
- }
- if (!btf_name_offset_valid(env->btf, t->name_off)) {
- btf_verifier_log(env, "[%u] Invalid name_offset:%u",
- env->log_type_id, t->name_off);
- return -EINVAL;
- }
- var_meta_size = btf_type_ops(t)->check_meta(env, t, meta_left);
- if (var_meta_size < 0)
- return var_meta_size;
- meta_left -= var_meta_size;
- return saved_meta_left - meta_left;
- }
- static int btf_check_all_metas(struct btf_verifier_env *env)
- {
- struct btf *btf = env->btf;
- struct btf_header *hdr;
- void *cur, *end;
- hdr = &btf->hdr;
- cur = btf->nohdr_data + hdr->type_off;
- end = cur + hdr->type_len;
- env->log_type_id = 1;
- while (cur < end) {
- struct btf_type *t = cur;
- s32 meta_size;
- meta_size = btf_check_meta(env, t, end - cur);
- if (meta_size < 0)
- return meta_size;
- btf_add_type(env, t);
- cur += meta_size;
- env->log_type_id++;
- }
- return 0;
- }
- static bool btf_resolve_valid(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 type_id)
- {
- struct btf *btf = env->btf;
- if (!env_type_is_resolved(env, type_id))
- return false;
- if (btf_type_is_struct(t) || btf_type_is_datasec(t))
- return !btf->resolved_ids[type_id] &&
- !btf->resolved_sizes[type_id];
- if (btf_type_is_modifier(t) || btf_type_is_ptr(t) ||
- btf_type_is_var(t)) {
- t = btf_type_id_resolve(btf, &type_id);
- return t &&
- !btf_type_is_modifier(t) &&
- !btf_type_is_var(t) &&
- !btf_type_is_datasec(t);
- }
- if (btf_type_is_array(t)) {
- const struct btf_array *array = btf_type_array(t);
- const struct btf_type *elem_type;
- u32 elem_type_id = array->type;
- u32 elem_size;
- elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size);
- return elem_type && !btf_type_is_modifier(elem_type) &&
- (array->nelems * elem_size ==
- btf->resolved_sizes[type_id]);
- }
- return false;
- }
- static int btf_resolve(struct btf_verifier_env *env,
- const struct btf_type *t, u32 type_id)
- {
- u32 save_log_type_id = env->log_type_id;
- const struct resolve_vertex *v;
- int err = 0;
- env->resolve_mode = RESOLVE_TBD;
- env_stack_push(env, t, type_id);
- while (!err && (v = env_stack_peak(env))) {
- env->log_type_id = v->type_id;
- err = btf_type_ops(v->t)->resolve(env, v);
- }
- env->log_type_id = type_id;
- if (err == -E2BIG) {
- btf_verifier_log_type(env, t,
- "Exceeded max resolving depth:%u",
- MAX_RESOLVE_DEPTH);
- } else if (err == -EEXIST) {
- btf_verifier_log_type(env, t, "Loop detected");
- }
- /* Final sanity check */
- if (!err && !btf_resolve_valid(env, t, type_id)) {
- btf_verifier_log_type(env, t, "Invalid resolve state");
- err = -EINVAL;
- }
- env->log_type_id = save_log_type_id;
- return err;
- }
- static int btf_check_all_types(struct btf_verifier_env *env)
- {
- struct btf *btf = env->btf;
- u32 type_id;
- int err;
- err = env_resolve_init(env);
- if (err)
- return err;
- env->phase++;
- for (type_id = 1; type_id <= btf->nr_types; type_id++) {
- const struct btf_type *t = btf_type_by_id(btf, type_id);
- env->log_type_id = type_id;
- if (btf_type_needs_resolve(t) &&
- !env_type_is_resolved(env, type_id)) {
- err = btf_resolve(env, t, type_id);
- if (err)
- return err;
- }
- if (btf_type_is_func_proto(t)) {
- err = btf_func_proto_check(env, t);
- if (err)
- return err;
- }
- if (btf_type_is_func(t)) {
- err = btf_func_check(env, t);
- if (err)
- return err;
- }
- }
- return 0;
- }
- static int btf_parse_type_sec(struct btf_verifier_env *env)
- {
- const struct btf_header *hdr = &env->btf->hdr;
- int err;
- /* Type section must align to 4 bytes */
- if (hdr->type_off & (sizeof(u32) - 1)) {
- btf_verifier_log(env, "Unaligned type_off");
- return -EINVAL;
- }
- if (!hdr->type_len) {
- btf_verifier_log(env, "No type found");
- return -EINVAL;
- }
- err = btf_check_all_metas(env);
- if (err)
- return err;
- return btf_check_all_types(env);
- }
- static int btf_parse_str_sec(struct btf_verifier_env *env)
- {
- const struct btf_header *hdr;
- struct btf *btf = env->btf;
- const char *start, *end;
- hdr = &btf->hdr;
- start = btf->nohdr_data + hdr->str_off;
- end = start + hdr->str_len;
- if (end != btf->data + btf->data_size) {
- btf_verifier_log(env, "String section is not at the end");
- return -EINVAL;
- }
- if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET ||
- start[0] || end[-1]) {
- btf_verifier_log(env, "Invalid string section");
- return -EINVAL;
- }
- btf->strings = start;
- return 0;
- }
- static const size_t btf_sec_info_offset[] = {
- offsetof(struct btf_header, type_off),
- offsetof(struct btf_header, str_off),
- };
- static int btf_sec_info_cmp(const void *a, const void *b)
- {
- const struct btf_sec_info *x = a;
- const struct btf_sec_info *y = b;
- return (int)(x->off - y->off) ? : (int)(x->len - y->len);
- }
- static int btf_check_sec_info(struct btf_verifier_env *env,
- u32 btf_data_size)
- {
- struct btf_sec_info secs[ARRAY_SIZE(btf_sec_info_offset)];
- u32 total, expected_total, i;
- const struct btf_header *hdr;
- const struct btf *btf;
- btf = env->btf;
- hdr = &btf->hdr;
- /* Populate the secs from hdr */
- for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++)
- secs[i] = *(struct btf_sec_info *)((void *)hdr +
- btf_sec_info_offset[i]);
- sort(secs, ARRAY_SIZE(btf_sec_info_offset),
- sizeof(struct btf_sec_info), btf_sec_info_cmp, NULL);
- /* Check for gaps and overlap among sections */
- total = 0;
- expected_total = btf_data_size - hdr->hdr_len;
- for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) {
- if (expected_total < secs[i].off) {
- btf_verifier_log(env, "Invalid section offset");
- return -EINVAL;
- }
- if (total < secs[i].off) {
- /* gap */
- btf_verifier_log(env, "Unsupported section found");
- return -EINVAL;
- }
- if (total > secs[i].off) {
- btf_verifier_log(env, "Section overlap found");
- return -EINVAL;
- }
- if (expected_total - total < secs[i].len) {
- btf_verifier_log(env,
- "Total section length too long");
- return -EINVAL;
- }
- total += secs[i].len;
- }
- /* There is data other than hdr and known sections */
- if (expected_total != total) {
- btf_verifier_log(env, "Unsupported section found");
- return -EINVAL;
- }
- return 0;
- }
- static int btf_parse_hdr(struct btf_verifier_env *env)
- {
- u32 hdr_len, hdr_copy, btf_data_size;
- const struct btf_header *hdr;
- struct btf *btf;
- int err;
- btf = env->btf;
- btf_data_size = btf->data_size;
- if (btf_data_size <
- offsetof(struct btf_header, hdr_len) + sizeof(hdr->hdr_len)) {
- btf_verifier_log(env, "hdr_len not found");
- return -EINVAL;
- }
- hdr = btf->data;
- hdr_len = hdr->hdr_len;
- if (btf_data_size < hdr_len) {
- btf_verifier_log(env, "btf_header not found");
- return -EINVAL;
- }
- /* Ensure the unsupported header fields are zero */
- if (hdr_len > sizeof(btf->hdr)) {
- u8 *expected_zero = btf->data + sizeof(btf->hdr);
- u8 *end = btf->data + hdr_len;
- for (; expected_zero < end; expected_zero++) {
- if (*expected_zero) {
- btf_verifier_log(env, "Unsupported btf_header");
- return -E2BIG;
- }
- }
- }
- hdr_copy = min_t(u32, hdr_len, sizeof(btf->hdr));
- memcpy(&btf->hdr, btf->data, hdr_copy);
- hdr = &btf->hdr;
- btf_verifier_log_hdr(env, btf_data_size);
- if (hdr->magic != BTF_MAGIC) {
- btf_verifier_log(env, "Invalid magic");
- return -EINVAL;
- }
- if (hdr->version != BTF_VERSION) {
- btf_verifier_log(env, "Unsupported version");
- return -ENOTSUPP;
- }
- if (hdr->flags) {
- btf_verifier_log(env, "Unsupported flags");
- return -ENOTSUPP;
- }
- if (btf_data_size == hdr->hdr_len) {
- btf_verifier_log(env, "No data");
- return -EINVAL;
- }
- err = btf_check_sec_info(env, btf_data_size);
- if (err)
- return err;
- return 0;
- }
- static struct btf *btf_parse(void __user *btf_data, u32 btf_data_size,
- u32 log_level, char __user *log_ubuf, u32 log_size)
- {
- struct btf_verifier_env *env = NULL;
- struct bpf_verifier_log *log;
- struct btf *btf = NULL;
- u8 *data;
- int err;
- if (btf_data_size > BTF_MAX_SIZE)
- return ERR_PTR(-E2BIG);
- env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN);
- if (!env)
- return ERR_PTR(-ENOMEM);
- log = &env->log;
- if (log_level || log_ubuf || log_size) {
- /* user requested verbose verifier output
- * and supplied buffer to store the verification trace
- */
- log->level = log_level;
- log->ubuf = log_ubuf;
- log->len_total = log_size;
- /* log attributes have to be sane */
- if (!bpf_verifier_log_attr_valid(log)) {
- err = -EINVAL;
- goto errout;
- }
- }
- btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN);
- if (!btf) {
- err = -ENOMEM;
- goto errout;
- }
- env->btf = btf;
- data = kvmalloc(btf_data_size, GFP_KERNEL | __GFP_NOWARN);
- if (!data) {
- err = -ENOMEM;
- goto errout;
- }
- btf->data = data;
- btf->data_size = btf_data_size;
- if (copy_from_user(data, btf_data, btf_data_size)) {
- err = -EFAULT;
- goto errout;
- }
- err = btf_parse_hdr(env);
- if (err)
- goto errout;
- btf->nohdr_data = btf->data + btf->hdr.hdr_len;
- err = btf_parse_str_sec(env);
- if (err)
- goto errout;
- err = btf_parse_type_sec(env);
- if (err)
- goto errout;
- if (log->level && bpf_verifier_log_full(log)) {
- err = -ENOSPC;
- goto errout;
- }
- btf_verifier_env_free(env);
- refcount_set(&btf->refcnt, 1);
- return btf;
- errout:
- btf_verifier_env_free(env);
- if (btf)
- btf_free(btf);
- return ERR_PTR(err);
- }
- extern char __weak __start_BTF[];
- extern char __weak __stop_BTF[];
- extern struct btf *btf_vmlinux;
- #define BPF_MAP_TYPE(_id, _ops)
- #define BPF_LINK_TYPE(_id, _name)
- static union {
- struct bpf_ctx_convert {
- #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
- prog_ctx_type _id##_prog; \
- kern_ctx_type _id##_kern;
- #include <linux/bpf_types.h>
- #undef BPF_PROG_TYPE
- } *__t;
- /* 't' is written once under lock. Read many times. */
- const struct btf_type *t;
- } bpf_ctx_convert;
- enum {
- #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
- __ctx_convert##_id,
- #include <linux/bpf_types.h>
- #undef BPF_PROG_TYPE
- __ctx_convert_unused, /* to avoid empty enum in extreme .config */
- };
- static u8 bpf_ctx_convert_map[] = {
- #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
- [_id] = __ctx_convert##_id,
- #include <linux/bpf_types.h>
- #undef BPF_PROG_TYPE
- 0, /* avoid empty array */
- };
- #undef BPF_MAP_TYPE
- #undef BPF_LINK_TYPE
- static const struct btf_member *
- btf_get_prog_ctx_type(struct bpf_verifier_log *log, struct btf *btf,
- const struct btf_type *t, enum bpf_prog_type prog_type,
- int arg)
- {
- const struct btf_type *conv_struct;
- const struct btf_type *ctx_struct;
- const struct btf_member *ctx_type;
- const char *tname, *ctx_tname;
- conv_struct = bpf_ctx_convert.t;
- if (!conv_struct) {
- bpf_log(log, "btf_vmlinux is malformed\n");
- return NULL;
- }
- t = btf_type_by_id(btf, t->type);
- while (btf_type_is_modifier(t))
- t = btf_type_by_id(btf, t->type);
- if (!btf_type_is_struct(t)) {
- /* Only pointer to struct is supported for now.
- * That means that BPF_PROG_TYPE_TRACEPOINT with BTF
- * is not supported yet.
- * BPF_PROG_TYPE_RAW_TRACEPOINT is fine.
- */
- if (log->level & BPF_LOG_LEVEL)
- bpf_log(log, "arg#%d type is not a struct\n", arg);
- return NULL;
- }
- tname = btf_name_by_offset(btf, t->name_off);
- if (!tname) {
- bpf_log(log, "arg#%d struct doesn't have a name\n", arg);
- return NULL;
- }
- /* prog_type is valid bpf program type. No need for bounds check. */
- ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2;
- /* ctx_struct is a pointer to prog_ctx_type in vmlinux.
- * Like 'struct __sk_buff'
- */
- ctx_struct = btf_type_by_id(btf_vmlinux, ctx_type->type);
- if (!ctx_struct)
- /* should not happen */
- return NULL;
- ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_struct->name_off);
- if (!ctx_tname) {
- /* should not happen */
- bpf_log(log, "Please fix kernel include/linux/bpf_types.h\n");
- return NULL;
- }
- /* only compare that prog's ctx type name is the same as
- * kernel expects. No need to compare field by field.
- * It's ok for bpf prog to do:
- * struct __sk_buff {};
- * int socket_filter_bpf_prog(struct __sk_buff *skb)
- * { // no fields of skb are ever used }
- */
- if (strcmp(ctx_tname, tname))
- return NULL;
- return ctx_type;
- }
- static const struct bpf_map_ops * const btf_vmlinux_map_ops[] = {
- #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
- #define BPF_LINK_TYPE(_id, _name)
- #define BPF_MAP_TYPE(_id, _ops) \
- [_id] = &_ops,
- #include <linux/bpf_types.h>
- #undef BPF_PROG_TYPE
- #undef BPF_LINK_TYPE
- #undef BPF_MAP_TYPE
- };
- static int btf_vmlinux_map_ids_init(const struct btf *btf,
- struct bpf_verifier_log *log)
- {
- const struct bpf_map_ops *ops;
- int i, btf_id;
- for (i = 0; i < ARRAY_SIZE(btf_vmlinux_map_ops); ++i) {
- ops = btf_vmlinux_map_ops[i];
- if (!ops || (!ops->map_btf_name && !ops->map_btf_id))
- continue;
- if (!ops->map_btf_name || !ops->map_btf_id) {
- bpf_log(log, "map type %d is misconfigured\n", i);
- return -EINVAL;
- }
- btf_id = btf_find_by_name_kind(btf, ops->map_btf_name,
- BTF_KIND_STRUCT);
- if (btf_id < 0)
- return btf_id;
- *ops->map_btf_id = btf_id;
- }
- return 0;
- }
- static int btf_translate_to_vmlinux(struct bpf_verifier_log *log,
- struct btf *btf,
- const struct btf_type *t,
- enum bpf_prog_type prog_type,
- int arg)
- {
- const struct btf_member *prog_ctx_type, *kern_ctx_type;
- prog_ctx_type = btf_get_prog_ctx_type(log, btf, t, prog_type, arg);
- if (!prog_ctx_type)
- return -ENOENT;
- kern_ctx_type = prog_ctx_type + 1;
- return kern_ctx_type->type;
- }
- BTF_ID_LIST(bpf_ctx_convert_btf_id)
- BTF_ID(struct, bpf_ctx_convert)
- struct btf *btf_parse_vmlinux(void)
- {
- struct btf_verifier_env *env = NULL;
- struct bpf_verifier_log *log;
- struct btf *btf = NULL;
- int err;
- env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN);
- if (!env)
- return ERR_PTR(-ENOMEM);
- log = &env->log;
- log->level = BPF_LOG_KERNEL;
- btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN);
- if (!btf) {
- err = -ENOMEM;
- goto errout;
- }
- env->btf = btf;
- btf->data = __start_BTF;
- btf->data_size = __stop_BTF - __start_BTF;
- err = btf_parse_hdr(env);
- if (err)
- goto errout;
- btf->nohdr_data = btf->data + btf->hdr.hdr_len;
- err = btf_parse_str_sec(env);
- if (err)
- goto errout;
- err = btf_check_all_metas(env);
- if (err)
- goto errout;
- /* btf_parse_vmlinux() runs under bpf_verifier_lock */
- bpf_ctx_convert.t = btf_type_by_id(btf, bpf_ctx_convert_btf_id[0]);
- /* find bpf map structs for map_ptr access checking */
- err = btf_vmlinux_map_ids_init(btf, log);
- if (err < 0)
- goto errout;
- bpf_struct_ops_init(btf, log);
- btf_verifier_env_free(env);
- refcount_set(&btf->refcnt, 1);
- return btf;
- errout:
- btf_verifier_env_free(env);
- if (btf) {
- kvfree(btf->types);
- kfree(btf);
- }
- return ERR_PTR(err);
- }
- struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog)
- {
- struct bpf_prog *tgt_prog = prog->aux->dst_prog;
- if (tgt_prog) {
- return tgt_prog->aux->btf;
- } else {
- return btf_vmlinux;
- }
- }
- static bool is_string_ptr(struct btf *btf, const struct btf_type *t)
- {
- /* t comes in already as a pointer */
- t = btf_type_by_id(btf, t->type);
- /* allow const */
- if (BTF_INFO_KIND(t->info) == BTF_KIND_CONST)
- t = btf_type_by_id(btf, t->type);
- /* char, signed char, unsigned char */
- return btf_type_is_int(t) && t->size == 1;
- }
- bool btf_ctx_access(int off, int size, enum bpf_access_type type,
- const struct bpf_prog *prog,
- struct bpf_insn_access_aux *info)
- {
- const struct btf_type *t = prog->aux->attach_func_proto;
- struct bpf_prog *tgt_prog = prog->aux->dst_prog;
- struct btf *btf = bpf_prog_get_target_btf(prog);
- const char *tname = prog->aux->attach_func_name;
- struct bpf_verifier_log *log = info->log;
- const struct btf_param *args;
- u32 nr_args, arg;
- int i, ret;
- if (off % 8) {
- bpf_log(log, "func '%s' offset %d is not multiple of 8\n",
- tname, off);
- return false;
- }
- arg = off / 8;
- args = (const struct btf_param *)(t + 1);
- /* if (t == NULL) Fall back to default BPF prog with 5 u64 arguments */
- nr_args = t ? btf_type_vlen(t) : 5;
- if (prog->aux->attach_btf_trace) {
- /* skip first 'void *__data' argument in btf_trace_##name typedef */
- args++;
- nr_args--;
- }
- if (arg > nr_args) {
- bpf_log(log, "func '%s' doesn't have %d-th argument\n",
- tname, arg + 1);
- return false;
- }
- if (arg == nr_args) {
- switch (prog->expected_attach_type) {
- case BPF_LSM_MAC:
- case BPF_TRACE_FEXIT:
- /* When LSM programs are attached to void LSM hooks
- * they use FEXIT trampolines and when attached to
- * int LSM hooks, they use MODIFY_RETURN trampolines.
- *
- * While the LSM programs are BPF_MODIFY_RETURN-like
- * the check:
- *
- * if (ret_type != 'int')
- * return -EINVAL;
- *
- * is _not_ done here. This is still safe as LSM hooks
- * have only void and int return types.
- */
- if (!t)
- return true;
- t = btf_type_by_id(btf, t->type);
- break;
- case BPF_MODIFY_RETURN:
- /* For now the BPF_MODIFY_RETURN can only be attached to
- * functions that return an int.
- */
- if (!t)
- return false;
- t = btf_type_skip_modifiers(btf, t->type, NULL);
- if (!btf_type_is_small_int(t)) {
- bpf_log(log,
- "ret type %s not allowed for fmod_ret\n",
- btf_kind_str[BTF_INFO_KIND(t->info)]);
- return false;
- }
- break;
- default:
- bpf_log(log, "func '%s' doesn't have %d-th argument\n",
- tname, arg + 1);
- return false;
- }
- } else {
- if (!t)
- /* Default prog with 5 args */
- return true;
- t = btf_type_by_id(btf, args[arg].type);
- }
- /* skip modifiers */
- while (btf_type_is_modifier(t))
- t = btf_type_by_id(btf, t->type);
- if (btf_type_is_small_int(t) || btf_type_is_enum(t))
- /* accessing a scalar */
- return true;
- if (!btf_type_is_ptr(t)) {
- bpf_log(log,
- "func '%s' arg%d '%s' has type %s. Only pointer access is allowed\n",
- tname, arg,
- __btf_name_by_offset(btf, t->name_off),
- btf_kind_str[BTF_INFO_KIND(t->info)]);
- return false;
- }
- /* check for PTR_TO_RDONLY_BUF_OR_NULL or PTR_TO_RDWR_BUF_OR_NULL */
- for (i = 0; i < prog->aux->ctx_arg_info_size; i++) {
- const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i];
- if (ctx_arg_info->offset == off &&
- (ctx_arg_info->reg_type == PTR_TO_RDONLY_BUF_OR_NULL ||
- ctx_arg_info->reg_type == PTR_TO_RDWR_BUF_OR_NULL)) {
- info->reg_type = ctx_arg_info->reg_type;
- return true;
- }
- }
- if (t->type == 0)
- /* This is a pointer to void.
- * It is the same as scalar from the verifier safety pov.
- * No further pointer walking is allowed.
- */
- return true;
- if (is_string_ptr(btf, t))
- return true;
- /* this is a pointer to another type */
- for (i = 0; i < prog->aux->ctx_arg_info_size; i++) {
- const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i];
- if (ctx_arg_info->offset == off) {
- info->reg_type = ctx_arg_info->reg_type;
- info->btf_id = ctx_arg_info->btf_id;
- return true;
- }
- }
- info->reg_type = PTR_TO_BTF_ID;
- if (tgt_prog) {
- enum bpf_prog_type tgt_type;
- if (tgt_prog->type == BPF_PROG_TYPE_EXT)
- tgt_type = tgt_prog->aux->saved_dst_prog_type;
- else
- tgt_type = tgt_prog->type;
- ret = btf_translate_to_vmlinux(log, btf, t, tgt_type, arg);
- if (ret > 0) {
- info->btf_id = ret;
- return true;
- } else {
- return false;
- }
- }
- info->btf_id = t->type;
- t = btf_type_by_id(btf, t->type);
- /* skip modifiers */
- while (btf_type_is_modifier(t)) {
- info->btf_id = t->type;
- t = btf_type_by_id(btf, t->type);
- }
- if (!btf_type_is_struct(t)) {
- bpf_log(log,
- "func '%s' arg%d type %s is not a struct\n",
- tname, arg, btf_kind_str[BTF_INFO_KIND(t->info)]);
- return false;
- }
- bpf_log(log, "func '%s' arg%d has btf_id %d type %s '%s'\n",
- tname, arg, info->btf_id, btf_kind_str[BTF_INFO_KIND(t->info)],
- __btf_name_by_offset(btf, t->name_off));
- return true;
- }
- enum bpf_struct_walk_result {
- /* < 0 error */
- WALK_SCALAR = 0,
- WALK_PTR,
- WALK_STRUCT,
- };
- static int btf_struct_walk(struct bpf_verifier_log *log,
- const struct btf_type *t, int off, int size,
- u32 *next_btf_id)
- {
- u32 i, moff, mtrue_end, msize = 0, total_nelems = 0;
- const struct btf_type *mtype, *elem_type = NULL;
- const struct btf_member *member;
- const char *tname, *mname;
- u32 vlen, elem_id, mid;
- again:
- tname = __btf_name_by_offset(btf_vmlinux, t->name_off);
- if (!btf_type_is_struct(t)) {
- bpf_log(log, "Type '%s' is not a struct\n", tname);
- return -EINVAL;
- }
- vlen = btf_type_vlen(t);
- if (off + size > t->size) {
- /* If the last element is a variable size array, we may
- * need to relax the rule.
- */
- struct btf_array *array_elem;
- if (vlen == 0)
- goto error;
- member = btf_type_member(t) + vlen - 1;
- mtype = btf_type_skip_modifiers(btf_vmlinux, member->type,
- NULL);
- if (!btf_type_is_array(mtype))
- goto error;
- array_elem = (struct btf_array *)(mtype + 1);
- if (array_elem->nelems != 0)
- goto error;
- moff = btf_member_bit_offset(t, member) / 8;
- if (off < moff)
- goto error;
- /* Only allow structure for now, can be relaxed for
- * other types later.
- */
- t = btf_type_skip_modifiers(btf_vmlinux, array_elem->type,
- NULL);
- if (!btf_type_is_struct(t))
- goto error;
- off = (off - moff) % t->size;
- goto again;
- error:
- bpf_log(log, "access beyond struct %s at off %u size %u\n",
- tname, off, size);
- return -EACCES;
- }
- for_each_member(i, t, member) {
- /* offset of the field in bytes */
- moff = btf_member_bit_offset(t, member) / 8;
- if (off + size <= moff)
- /* won't find anything, field is already too far */
- break;
- if (btf_member_bitfield_size(t, member)) {
- u32 end_bit = btf_member_bit_offset(t, member) +
- btf_member_bitfield_size(t, member);
- /* off <= moff instead of off == moff because clang
- * does not generate a BTF member for anonymous
- * bitfield like the ":16" here:
- * struct {
- * int :16;
- * int x:8;
- * };
- */
- if (off <= moff &&
- BITS_ROUNDUP_BYTES(end_bit) <= off + size)
- return WALK_SCALAR;
- /* off may be accessing a following member
- *
- * or
- *
- * Doing partial access at either end of this
- * bitfield. Continue on this case also to
- * treat it as not accessing this bitfield
- * and eventually error out as field not
- * found to keep it simple.
- * It could be relaxed if there was a legit
- * partial access case later.
- */
- continue;
- }
- /* In case of "off" is pointing to holes of a struct */
- if (off < moff)
- break;
- /* type of the field */
- mid = member->type;
- mtype = btf_type_by_id(btf_vmlinux, member->type);
- mname = __btf_name_by_offset(btf_vmlinux, member->name_off);
- mtype = __btf_resolve_size(btf_vmlinux, mtype, &msize,
- &elem_type, &elem_id, &total_nelems,
- &mid);
- if (IS_ERR(mtype)) {
- bpf_log(log, "field %s doesn't have size\n", mname);
- return -EFAULT;
- }
- mtrue_end = moff + msize;
- if (off >= mtrue_end)
- /* no overlap with member, keep iterating */
- continue;
- if (btf_type_is_array(mtype)) {
- u32 elem_idx;
- /* __btf_resolve_size() above helps to
- * linearize a multi-dimensional array.
- *
- * The logic here is treating an array
- * in a struct as the following way:
- *
- * struct outer {
- * struct inner array[2][2];
- * };
- *
- * looks like:
- *
- * struct outer {
- * struct inner array_elem0;
- * struct inner array_elem1;
- * struct inner array_elem2;
- * struct inner array_elem3;
- * };
- *
- * When accessing outer->array[1][0], it moves
- * moff to "array_elem2", set mtype to
- * "struct inner", and msize also becomes
- * sizeof(struct inner). Then most of the
- * remaining logic will fall through without
- * caring the current member is an array or
- * not.
- *
- * Unlike mtype/msize/moff, mtrue_end does not
- * change. The naming difference ("_true") tells
- * that it is not always corresponding to
- * the current mtype/msize/moff.
- * It is the true end of the current
- * member (i.e. array in this case). That
- * will allow an int array to be accessed like
- * a scratch space,
- * i.e. allow access beyond the size of
- * the array's element as long as it is
- * within the mtrue_end boundary.
- */
- /* skip empty array */
- if (moff == mtrue_end)
- continue;
- msize /= total_nelems;
- elem_idx = (off - moff) / msize;
- moff += elem_idx * msize;
- mtype = elem_type;
- mid = elem_id;
- }
- /* the 'off' we're looking for is either equal to start
- * of this field or inside of this struct
- */
- if (btf_type_is_struct(mtype)) {
- /* our field must be inside that union or struct */
- t = mtype;
- /* return if the offset matches the member offset */
- if (off == moff) {
- *next_btf_id = mid;
- return WALK_STRUCT;
- }
- /* adjust offset we're looking for */
- off -= moff;
- goto again;
- }
- if (btf_type_is_ptr(mtype)) {
- const struct btf_type *stype;
- u32 id;
- if (msize != size || off != moff) {
- bpf_log(log,
- "cannot access ptr member %s with moff %u in struct %s with off %u size %u\n",
- mname, moff, tname, off, size);
- return -EACCES;
- }
- stype = btf_type_skip_modifiers(btf_vmlinux, mtype->type, &id);
- if (btf_type_is_struct(stype)) {
- *next_btf_id = id;
- return WALK_PTR;
- }
- }
- /* Allow more flexible access within an int as long as
- * it is within mtrue_end.
- * Since mtrue_end could be the end of an array,
- * that also allows using an array of int as a scratch
- * space. e.g. skb->cb[].
- */
- if (off + size > mtrue_end) {
- bpf_log(log,
- "access beyond the end of member %s (mend:%u) in struct %s with off %u size %u\n",
- mname, mtrue_end, tname, off, size);
- return -EACCES;
- }
- return WALK_SCALAR;
- }
- bpf_log(log, "struct %s doesn't have field at offset %d\n", tname, off);
- return -EINVAL;
- }
- int btf_struct_access(struct bpf_verifier_log *log,
- const struct btf_type *t, int off, int size,
- enum bpf_access_type atype __maybe_unused,
- u32 *next_btf_id)
- {
- int err;
- u32 id;
- do {
- err = btf_struct_walk(log, t, off, size, &id);
- switch (err) {
- case WALK_PTR:
- /* If we found the pointer or scalar on t+off,
- * we're done.
- */
- *next_btf_id = id;
- return PTR_TO_BTF_ID;
- case WALK_SCALAR:
- return SCALAR_VALUE;
- case WALK_STRUCT:
- /* We found nested struct, so continue the search
- * by diving in it. At this point the offset is
- * aligned with the new type, so set it to 0.
- */
- t = btf_type_by_id(btf_vmlinux, id);
- off = 0;
- break;
- default:
- /* It's either error or unknown return value..
- * scream and leave.
- */
- if (WARN_ONCE(err > 0, "unknown btf_struct_walk return value"))
- return -EINVAL;
- return err;
- }
- } while (t);
- return -EINVAL;
- }
- bool btf_struct_ids_match(struct bpf_verifier_log *log,
- int off, u32 id, u32 need_type_id)
- {
- const struct btf_type *type;
- int err;
- /* Are we already done? */
- if (need_type_id == id && off == 0)
- return true;
- again:
- type = btf_type_by_id(btf_vmlinux, id);
- if (!type)
- return false;
- err = btf_struct_walk(log, type, off, 1, &id);
- if (err != WALK_STRUCT)
- return false;
- /* We found nested struct object. If it matches
- * the requested ID, we're done. Otherwise let's
- * continue the search with offset 0 in the new
- * type.
- */
- if (need_type_id != id) {
- off = 0;
- goto again;
- }
- return true;
- }
- static int __get_type_size(struct btf *btf, u32 btf_id,
- const struct btf_type **bad_type)
- {
- const struct btf_type *t;
- if (!btf_id)
- /* void */
- return 0;
- t = btf_type_by_id(btf, btf_id);
- while (t && btf_type_is_modifier(t))
- t = btf_type_by_id(btf, t->type);
- if (!t) {
- *bad_type = btf->types[0];
- return -EINVAL;
- }
- if (btf_type_is_ptr(t))
- /* kernel size of pointer. Not BPF's size of pointer*/
- return sizeof(void *);
- if (btf_type_is_int(t) || btf_type_is_enum(t))
- return t->size;
- *bad_type = t;
- return -EINVAL;
- }
- int btf_distill_func_proto(struct bpf_verifier_log *log,
- struct btf *btf,
- const struct btf_type *func,
- const char *tname,
- struct btf_func_model *m)
- {
- const struct btf_param *args;
- const struct btf_type *t;
- u32 i, nargs;
- int ret;
- if (!func) {
- /* BTF function prototype doesn't match the verifier types.
- * Fall back to 5 u64 args.
- */
- for (i = 0; i < 5; i++)
- m->arg_size[i] = 8;
- m->ret_size = 8;
- m->nr_args = 5;
- return 0;
- }
- args = (const struct btf_param *)(func + 1);
- nargs = btf_type_vlen(func);
- if (nargs >= MAX_BPF_FUNC_ARGS) {
- bpf_log(log,
- "The function %s has %d arguments. Too many.\n",
- tname, nargs);
- return -EINVAL;
- }
- ret = __get_type_size(btf, func->type, &t);
- if (ret < 0) {
- bpf_log(log,
- "The function %s return type %s is unsupported.\n",
- tname, btf_kind_str[BTF_INFO_KIND(t->info)]);
- return -EINVAL;
- }
- m->ret_size = ret;
- for (i = 0; i < nargs; i++) {
- if (i == nargs - 1 && args[i].type == 0) {
- bpf_log(log,
- "The function %s with variable args is unsupported.\n",
- tname);
- return -EINVAL;
- }
- ret = __get_type_size(btf, args[i].type, &t);
- if (ret < 0) {
- bpf_log(log,
- "The function %s arg%d type %s is unsupported.\n",
- tname, i, btf_kind_str[BTF_INFO_KIND(t->info)]);
- return -EINVAL;
- }
- if (ret == 0) {
- bpf_log(log,
- "The function %s has malformed void argument.\n",
- tname);
- return -EINVAL;
- }
- m->arg_size[i] = ret;
- }
- m->nr_args = nargs;
- return 0;
- }
- /* Compare BTFs of two functions assuming only scalars and pointers to context.
- * t1 points to BTF_KIND_FUNC in btf1
- * t2 points to BTF_KIND_FUNC in btf2
- * Returns:
- * EINVAL - function prototype mismatch
- * EFAULT - verifier bug
- * 0 - 99% match. The last 1% is validated by the verifier.
- */
- static int btf_check_func_type_match(struct bpf_verifier_log *log,
- struct btf *btf1, const struct btf_type *t1,
- struct btf *btf2, const struct btf_type *t2)
- {
- const struct btf_param *args1, *args2;
- const char *fn1, *fn2, *s1, *s2;
- u32 nargs1, nargs2, i;
- fn1 = btf_name_by_offset(btf1, t1->name_off);
- fn2 = btf_name_by_offset(btf2, t2->name_off);
- if (btf_func_linkage(t1) != BTF_FUNC_GLOBAL) {
- bpf_log(log, "%s() is not a global function\n", fn1);
- return -EINVAL;
- }
- if (btf_func_linkage(t2) != BTF_FUNC_GLOBAL) {
- bpf_log(log, "%s() is not a global function\n", fn2);
- return -EINVAL;
- }
- t1 = btf_type_by_id(btf1, t1->type);
- if (!t1 || !btf_type_is_func_proto(t1))
- return -EFAULT;
- t2 = btf_type_by_id(btf2, t2->type);
- if (!t2 || !btf_type_is_func_proto(t2))
- return -EFAULT;
- args1 = (const struct btf_param *)(t1 + 1);
- nargs1 = btf_type_vlen(t1);
- args2 = (const struct btf_param *)(t2 + 1);
- nargs2 = btf_type_vlen(t2);
- if (nargs1 != nargs2) {
- bpf_log(log, "%s() has %d args while %s() has %d args\n",
- fn1, nargs1, fn2, nargs2);
- return -EINVAL;
- }
- t1 = btf_type_skip_modifiers(btf1, t1->type, NULL);
- t2 = btf_type_skip_modifiers(btf2, t2->type, NULL);
- if (t1->info != t2->info) {
- bpf_log(log,
- "Return type %s of %s() doesn't match type %s of %s()\n",
- btf_type_str(t1), fn1,
- btf_type_str(t2), fn2);
- return -EINVAL;
- }
- for (i = 0; i < nargs1; i++) {
- t1 = btf_type_skip_modifiers(btf1, args1[i].type, NULL);
- t2 = btf_type_skip_modifiers(btf2, args2[i].type, NULL);
- if (t1->info != t2->info) {
- bpf_log(log, "arg%d in %s() is %s while %s() has %s\n",
- i, fn1, btf_type_str(t1),
- fn2, btf_type_str(t2));
- return -EINVAL;
- }
- if (btf_type_has_size(t1) && t1->size != t2->size) {
- bpf_log(log,
- "arg%d in %s() has size %d while %s() has %d\n",
- i, fn1, t1->size,
- fn2, t2->size);
- return -EINVAL;
- }
- /* global functions are validated with scalars and pointers
- * to context only. And only global functions can be replaced.
- * Hence type check only those types.
- */
- if (btf_type_is_int(t1) || btf_type_is_enum(t1))
- continue;
- if (!btf_type_is_ptr(t1)) {
- bpf_log(log,
- "arg%d in %s() has unrecognized type\n",
- i, fn1);
- return -EINVAL;
- }
- t1 = btf_type_skip_modifiers(btf1, t1->type, NULL);
- t2 = btf_type_skip_modifiers(btf2, t2->type, NULL);
- if (!btf_type_is_struct(t1)) {
- bpf_log(log,
- "arg%d in %s() is not a pointer to context\n",
- i, fn1);
- return -EINVAL;
- }
- if (!btf_type_is_struct(t2)) {
- bpf_log(log,
- "arg%d in %s() is not a pointer to context\n",
- i, fn2);
- return -EINVAL;
- }
- /* This is an optional check to make program writing easier.
- * Compare names of structs and report an error to the user.
- * btf_prepare_func_args() already checked that t2 struct
- * is a context type. btf_prepare_func_args() will check
- * later that t1 struct is a context type as well.
- */
- s1 = btf_name_by_offset(btf1, t1->name_off);
- s2 = btf_name_by_offset(btf2, t2->name_off);
- if (strcmp(s1, s2)) {
- bpf_log(log,
- "arg%d %s(struct %s *) doesn't match %s(struct %s *)\n",
- i, fn1, s1, fn2, s2);
- return -EINVAL;
- }
- }
- return 0;
- }
- /* Compare BTFs of given program with BTF of target program */
- int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *prog,
- struct btf *btf2, const struct btf_type *t2)
- {
- struct btf *btf1 = prog->aux->btf;
- const struct btf_type *t1;
- u32 btf_id = 0;
- if (!prog->aux->func_info) {
- bpf_log(log, "Program extension requires BTF\n");
- return -EINVAL;
- }
- btf_id = prog->aux->func_info[0].type_id;
- if (!btf_id)
- return -EFAULT;
- t1 = btf_type_by_id(btf1, btf_id);
- if (!t1 || !btf_type_is_func(t1))
- return -EFAULT;
- return btf_check_func_type_match(log, btf1, t1, btf2, t2);
- }
- /* Compare BTF of a function with given bpf_reg_state.
- * Returns:
- * EFAULT - there is a verifier bug. Abort verification.
- * EINVAL - there is a type mismatch or BTF is not available.
- * 0 - BTF matches with what bpf_reg_state expects.
- * Only PTR_TO_CTX and SCALAR_VALUE states are recognized.
- */
- int btf_check_func_arg_match(struct bpf_verifier_env *env, int subprog,
- struct bpf_reg_state *reg)
- {
- struct bpf_verifier_log *log = &env->log;
- struct bpf_prog *prog = env->prog;
- struct btf *btf = prog->aux->btf;
- const struct btf_param *args;
- const struct btf_type *t;
- u32 i, nargs, btf_id;
- const char *tname;
- if (!prog->aux->func_info)
- return -EINVAL;
- btf_id = prog->aux->func_info[subprog].type_id;
- if (!btf_id)
- return -EFAULT;
- if (prog->aux->func_info_aux[subprog].unreliable)
- return -EINVAL;
- t = btf_type_by_id(btf, btf_id);
- if (!t || !btf_type_is_func(t)) {
- /* These checks were already done by the verifier while loading
- * struct bpf_func_info
- */
- bpf_log(log, "BTF of func#%d doesn't point to KIND_FUNC\n",
- subprog);
- return -EFAULT;
- }
- tname = btf_name_by_offset(btf, t->name_off);
- t = btf_type_by_id(btf, t->type);
- if (!t || !btf_type_is_func_proto(t)) {
- bpf_log(log, "Invalid BTF of func %s\n", tname);
- return -EFAULT;
- }
- args = (const struct btf_param *)(t + 1);
- nargs = btf_type_vlen(t);
- if (nargs > 5) {
- bpf_log(log, "Function %s has %d > 5 args\n", tname, nargs);
- goto out;
- }
- /* check that BTF function arguments match actual types that the
- * verifier sees.
- */
- for (i = 0; i < nargs; i++) {
- t = btf_type_by_id(btf, args[i].type);
- while (btf_type_is_modifier(t))
- t = btf_type_by_id(btf, t->type);
- if (btf_type_is_int(t) || btf_type_is_enum(t)) {
- if (reg[i + 1].type == SCALAR_VALUE)
- continue;
- bpf_log(log, "R%d is not a scalar\n", i + 1);
- goto out;
- }
- if (btf_type_is_ptr(t)) {
- if (reg[i + 1].type == SCALAR_VALUE) {
- bpf_log(log, "R%d is not a pointer\n", i + 1);
- goto out;
- }
- /* If function expects ctx type in BTF check that caller
- * is passing PTR_TO_CTX.
- */
- if (btf_get_prog_ctx_type(log, btf, t, prog->type, i)) {
- if (reg[i + 1].type != PTR_TO_CTX) {
- bpf_log(log,
- "arg#%d expected pointer to ctx, but got %s\n",
- i, btf_kind_str[BTF_INFO_KIND(t->info)]);
- goto out;
- }
- if (check_ctx_reg(env, ®[i + 1], i + 1))
- goto out;
- continue;
- }
- }
- bpf_log(log, "Unrecognized arg#%d type %s\n",
- i, btf_kind_str[BTF_INFO_KIND(t->info)]);
- goto out;
- }
- return 0;
- out:
- /* Compiler optimizations can remove arguments from static functions
- * or mismatched type can be passed into a global function.
- * In such cases mark the function as unreliable from BTF point of view.
- */
- prog->aux->func_info_aux[subprog].unreliable = true;
- return -EINVAL;
- }
- /* Convert BTF of a function into bpf_reg_state if possible
- * Returns:
- * EFAULT - there is a verifier bug. Abort verification.
- * EINVAL - cannot convert BTF.
- * 0 - Successfully converted BTF into bpf_reg_state
- * (either PTR_TO_CTX or SCALAR_VALUE).
- */
- int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog,
- struct bpf_reg_state *reg)
- {
- struct bpf_verifier_log *log = &env->log;
- struct bpf_prog *prog = env->prog;
- enum bpf_prog_type prog_type = prog->type;
- struct btf *btf = prog->aux->btf;
- const struct btf_param *args;
- const struct btf_type *t;
- u32 i, nargs, btf_id;
- const char *tname;
- if (!prog->aux->func_info ||
- prog->aux->func_info_aux[subprog].linkage != BTF_FUNC_GLOBAL) {
- bpf_log(log, "Verifier bug\n");
- return -EFAULT;
- }
- btf_id = prog->aux->func_info[subprog].type_id;
- if (!btf_id) {
- bpf_log(log, "Global functions need valid BTF\n");
- return -EFAULT;
- }
- t = btf_type_by_id(btf, btf_id);
- if (!t || !btf_type_is_func(t)) {
- /* These checks were already done by the verifier while loading
- * struct bpf_func_info
- */
- bpf_log(log, "BTF of func#%d doesn't point to KIND_FUNC\n",
- subprog);
- return -EFAULT;
- }
- tname = btf_name_by_offset(btf, t->name_off);
- if (log->level & BPF_LOG_LEVEL)
- bpf_log(log, "Validating %s() func#%d...\n",
- tname, subprog);
- if (prog->aux->func_info_aux[subprog].unreliable) {
- bpf_log(log, "Verifier bug in function %s()\n", tname);
- return -EFAULT;
- }
- if (prog_type == BPF_PROG_TYPE_EXT)
- prog_type = prog->aux->dst_prog->type;
- t = btf_type_by_id(btf, t->type);
- if (!t || !btf_type_is_func_proto(t)) {
- bpf_log(log, "Invalid type of function %s()\n", tname);
- return -EFAULT;
- }
- args = (const struct btf_param *)(t + 1);
- nargs = btf_type_vlen(t);
- if (nargs > 5) {
- bpf_log(log, "Global function %s() with %d > 5 args. Buggy compiler.\n",
- tname, nargs);
- return -EINVAL;
- }
- /* check that function returns int */
- t = btf_type_by_id(btf, t->type);
- while (btf_type_is_modifier(t))
- t = btf_type_by_id(btf, t->type);
- if (!btf_type_is_int(t) && !btf_type_is_enum(t)) {
- bpf_log(log,
- "Global function %s() doesn't return scalar. Only those are supported.\n",
- tname);
- return -EINVAL;
- }
- /* Convert BTF function arguments into verifier types.
- * Only PTR_TO_CTX and SCALAR are supported atm.
- */
- for (i = 0; i < nargs; i++) {
- t = btf_type_by_id(btf, args[i].type);
- while (btf_type_is_modifier(t))
- t = btf_type_by_id(btf, t->type);
- if (btf_type_is_int(t) || btf_type_is_enum(t)) {
- reg[i + 1].type = SCALAR_VALUE;
- continue;
- }
- if (btf_type_is_ptr(t) &&
- btf_get_prog_ctx_type(log, btf, t, prog_type, i)) {
- reg[i + 1].type = PTR_TO_CTX;
- continue;
- }
- bpf_log(log, "Arg#%d type %s in %s() is not supported yet.\n",
- i, btf_kind_str[BTF_INFO_KIND(t->info)], tname);
- return -EINVAL;
- }
- return 0;
- }
- static void btf_type_show(const struct btf *btf, u32 type_id, void *obj,
- struct btf_show *show)
- {
- const struct btf_type *t = btf_type_by_id(btf, type_id);
- show->btf = btf;
- memset(&show->state, 0, sizeof(show->state));
- memset(&show->obj, 0, sizeof(show->obj));
- btf_type_ops(t)->show(btf, t, type_id, obj, 0, show);
- }
- static void btf_seq_show(struct btf_show *show, const char *fmt,
- va_list args)
- {
- seq_vprintf((struct seq_file *)show->target, fmt, args);
- }
- int btf_type_seq_show_flags(const struct btf *btf, u32 type_id,
- void *obj, struct seq_file *m, u64 flags)
- {
- struct btf_show sseq;
- sseq.target = m;
- sseq.showfn = btf_seq_show;
- sseq.flags = flags;
- btf_type_show(btf, type_id, obj, &sseq);
- return sseq.state.status;
- }
- void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj,
- struct seq_file *m)
- {
- (void) btf_type_seq_show_flags(btf, type_id, obj, m,
- BTF_SHOW_NONAME | BTF_SHOW_COMPACT |
- BTF_SHOW_ZERO | BTF_SHOW_UNSAFE);
- }
- struct btf_show_snprintf {
- struct btf_show show;
- int len_left; /* space left in string */
- int len; /* length we would have written */
- };
- static void btf_snprintf_show(struct btf_show *show, const char *fmt,
- va_list args)
- {
- struct btf_show_snprintf *ssnprintf = (struct btf_show_snprintf *)show;
- int len;
- len = vsnprintf(show->target, ssnprintf->len_left, fmt, args);
- if (len < 0) {
- ssnprintf->len_left = 0;
- ssnprintf->len = len;
- } else if (len > ssnprintf->len_left) {
- /* no space, drive on to get length we would have written */
- ssnprintf->len_left = 0;
- ssnprintf->len += len;
- } else {
- ssnprintf->len_left -= len;
- ssnprintf->len += len;
- show->target += len;
- }
- }
- int btf_type_snprintf_show(const struct btf *btf, u32 type_id, void *obj,
- char *buf, int len, u64 flags)
- {
- struct btf_show_snprintf ssnprintf;
- ssnprintf.show.target = buf;
- ssnprintf.show.flags = flags;
- ssnprintf.show.showfn = btf_snprintf_show;
- ssnprintf.len_left = len;
- ssnprintf.len = 0;
- btf_type_show(btf, type_id, obj, (struct btf_show *)&ssnprintf);
- /* If we encontered an error, return it. */
- if (ssnprintf.show.state.status)
- return ssnprintf.show.state.status;
- /* Otherwise return length we would have written */
- return ssnprintf.len;
- }
- #ifdef CONFIG_PROC_FS
- static void bpf_btf_show_fdinfo(struct seq_file *m, struct file *filp)
- {
- const struct btf *btf = filp->private_data;
- seq_printf(m, "btf_id:\t%u\n", btf->id);
- }
- #endif
- static int btf_release(struct inode *inode, struct file *filp)
- {
- btf_put(filp->private_data);
- return 0;
- }
- const struct file_operations btf_fops = {
- #ifdef CONFIG_PROC_FS
- .show_fdinfo = bpf_btf_show_fdinfo,
- #endif
- .release = btf_release,
- };
- static int __btf_new_fd(struct btf *btf)
- {
- return anon_inode_getfd("btf", &btf_fops, btf, O_RDONLY | O_CLOEXEC);
- }
- int btf_new_fd(const union bpf_attr *attr)
- {
- struct btf *btf;
- int ret;
- btf = btf_parse(u64_to_user_ptr(attr->btf),
- attr->btf_size, attr->btf_log_level,
- u64_to_user_ptr(attr->btf_log_buf),
- attr->btf_log_size);
- if (IS_ERR(btf))
- return PTR_ERR(btf);
- ret = btf_alloc_id(btf);
- if (ret) {
- btf_free(btf);
- return ret;
- }
- /*
- * The BTF ID is published to the userspace.
- * All BTF free must go through call_rcu() from
- * now on (i.e. free by calling btf_put()).
- */
- ret = __btf_new_fd(btf);
- if (ret < 0)
- btf_put(btf);
- return ret;
- }
- struct btf *btf_get_by_fd(int fd)
- {
- struct btf *btf;
- struct fd f;
- f = fdget(fd);
- if (!f.file)
- return ERR_PTR(-EBADF);
- if (f.file->f_op != &btf_fops) {
- fdput(f);
- return ERR_PTR(-EINVAL);
- }
- btf = f.file->private_data;
- refcount_inc(&btf->refcnt);
- fdput(f);
- return btf;
- }
- int btf_get_info_by_fd(const struct btf *btf,
- const union bpf_attr *attr,
- union bpf_attr __user *uattr)
- {
- struct bpf_btf_info __user *uinfo;
- struct bpf_btf_info info;
- u32 info_copy, btf_copy;
- void __user *ubtf;
- u32 uinfo_len;
- uinfo = u64_to_user_ptr(attr->info.info);
- uinfo_len = attr->info.info_len;
- info_copy = min_t(u32, uinfo_len, sizeof(info));
- memset(&info, 0, sizeof(info));
- if (copy_from_user(&info, uinfo, info_copy))
- return -EFAULT;
- info.id = btf->id;
- ubtf = u64_to_user_ptr(info.btf);
- btf_copy = min_t(u32, btf->data_size, info.btf_size);
- if (copy_to_user(ubtf, btf->data, btf_copy))
- return -EFAULT;
- info.btf_size = btf->data_size;
- if (copy_to_user(uinfo, &info, info_copy) ||
- put_user(info_copy, &uattr->info.info_len))
- return -EFAULT;
- return 0;
- }
- int btf_get_fd_by_id(u32 id)
- {
- struct btf *btf;
- int fd;
- rcu_read_lock();
- btf = idr_find(&btf_idr, id);
- if (!btf || !refcount_inc_not_zero(&btf->refcnt))
- btf = ERR_PTR(-ENOENT);
- rcu_read_unlock();
- if (IS_ERR(btf))
- return PTR_ERR(btf);
- fd = __btf_new_fd(btf);
- if (fd < 0)
- btf_put(btf);
- return fd;
- }
- u32 btf_id(const struct btf *btf)
- {
- return btf->id;
- }
- static int btf_id_cmp_func(const void *a, const void *b)
- {
- const int *pa = a, *pb = b;
- return *pa - *pb;
- }
- bool btf_id_set_contains(const struct btf_id_set *set, u32 id)
- {
- return bsearch(&id, set->ids, set->cnt, sizeof(u32), btf_id_cmp_func) != NULL;
- }
|