signal_64.c 28 KB

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  1. // SPDX-License-Identifier: GPL-2.0-or-later
  2. /*
  3. * PowerPC version
  4. * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
  5. *
  6. * Derived from "arch/i386/kernel/signal.c"
  7. * Copyright (C) 1991, 1992 Linus Torvalds
  8. * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
  9. */
  10. #include <linux/sched.h>
  11. #include <linux/mm.h>
  12. #include <linux/smp.h>
  13. #include <linux/kernel.h>
  14. #include <linux/signal.h>
  15. #include <linux/errno.h>
  16. #include <linux/wait.h>
  17. #include <linux/unistd.h>
  18. #include <linux/stddef.h>
  19. #include <linux/elf.h>
  20. #include <linux/ptrace.h>
  21. #include <linux/ratelimit.h>
  22. #include <linux/syscalls.h>
  23. #include <linux/pagemap.h>
  24. #include <asm/sigcontext.h>
  25. #include <asm/ucontext.h>
  26. #include <linux/uaccess.h>
  27. #include <asm/unistd.h>
  28. #include <asm/cacheflush.h>
  29. #include <asm/syscalls.h>
  30. #include <asm/vdso.h>
  31. #include <asm/switch_to.h>
  32. #include <asm/tm.h>
  33. #include <asm/asm-prototypes.h>
  34. #include "signal.h"
  35. #define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
  36. #define FP_REGS_SIZE sizeof(elf_fpregset_t)
  37. #define TRAMP_TRACEBACK 4
  38. #define TRAMP_SIZE 7
  39. /*
  40. * When we have signals to deliver, we set up on the user stack,
  41. * going down from the original stack pointer:
  42. * 1) a rt_sigframe struct which contains the ucontext
  43. * 2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller
  44. * frame for the signal handler.
  45. */
  46. struct rt_sigframe {
  47. /* sys_rt_sigreturn requires the ucontext be the first field */
  48. struct ucontext uc;
  49. #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
  50. struct ucontext uc_transact;
  51. #endif
  52. unsigned long _unused[2];
  53. unsigned int tramp[TRAMP_SIZE];
  54. struct siginfo __user *pinfo;
  55. void __user *puc;
  56. struct siginfo info;
  57. /* New 64 bit little-endian ABI allows redzone of 512 bytes below sp */
  58. char abigap[USER_REDZONE_SIZE];
  59. } __attribute__ ((aligned (16)));
  60. static const char fmt32[] = KERN_INFO \
  61. "%s[%d]: bad frame in %s: %08lx nip %08lx lr %08lx\n";
  62. static const char fmt64[] = KERN_INFO \
  63. "%s[%d]: bad frame in %s: %016lx nip %016lx lr %016lx\n";
  64. /*
  65. * This computes a quad word aligned pointer inside the vmx_reserve array
  66. * element. For historical reasons sigcontext might not be quad word aligned,
  67. * but the location we write the VMX regs to must be. See the comment in
  68. * sigcontext for more detail.
  69. */
  70. #ifdef CONFIG_ALTIVEC
  71. static elf_vrreg_t __user *sigcontext_vmx_regs(struct sigcontext __user *sc)
  72. {
  73. return (elf_vrreg_t __user *) (((unsigned long)sc->vmx_reserve + 15) & ~0xful);
  74. }
  75. #endif
  76. /*
  77. * Set up the sigcontext for the signal frame.
  78. */
  79. static long setup_sigcontext(struct sigcontext __user *sc,
  80. struct task_struct *tsk, int signr, sigset_t *set,
  81. unsigned long handler, int ctx_has_vsx_region)
  82. {
  83. /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
  84. * process never used altivec yet (MSR_VEC is zero in pt_regs of
  85. * the context). This is very important because we must ensure we
  86. * don't lose the VRSAVE content that may have been set prior to
  87. * the process doing its first vector operation
  88. * Userland shall check AT_HWCAP to know whether it can rely on the
  89. * v_regs pointer or not
  90. */
  91. #ifdef CONFIG_ALTIVEC
  92. elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
  93. unsigned long vrsave;
  94. #endif
  95. struct pt_regs *regs = tsk->thread.regs;
  96. unsigned long msr = regs->msr;
  97. long err = 0;
  98. /* Force usr to alway see softe as 1 (interrupts enabled) */
  99. unsigned long softe = 0x1;
  100. BUG_ON(tsk != current);
  101. #ifdef CONFIG_ALTIVEC
  102. err |= __put_user(v_regs, &sc->v_regs);
  103. /* save altivec registers */
  104. if (tsk->thread.used_vr) {
  105. flush_altivec_to_thread(tsk);
  106. /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
  107. err |= __copy_to_user(v_regs, &tsk->thread.vr_state,
  108. 33 * sizeof(vector128));
  109. /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg)
  110. * contains valid data.
  111. */
  112. msr |= MSR_VEC;
  113. }
  114. /* We always copy to/from vrsave, it's 0 if we don't have or don't
  115. * use altivec.
  116. */
  117. vrsave = 0;
  118. if (cpu_has_feature(CPU_FTR_ALTIVEC)) {
  119. vrsave = mfspr(SPRN_VRSAVE);
  120. tsk->thread.vrsave = vrsave;
  121. }
  122. err |= __put_user(vrsave, (u32 __user *)&v_regs[33]);
  123. #else /* CONFIG_ALTIVEC */
  124. err |= __put_user(0, &sc->v_regs);
  125. #endif /* CONFIG_ALTIVEC */
  126. flush_fp_to_thread(tsk);
  127. /* copy fpr regs and fpscr */
  128. err |= copy_fpr_to_user(&sc->fp_regs, tsk);
  129. /*
  130. * Clear the MSR VSX bit to indicate there is no valid state attached
  131. * to this context, except in the specific case below where we set it.
  132. */
  133. msr &= ~MSR_VSX;
  134. #ifdef CONFIG_VSX
  135. /*
  136. * Copy VSX low doubleword to local buffer for formatting,
  137. * then out to userspace. Update v_regs to point after the
  138. * VMX data.
  139. */
  140. if (tsk->thread.used_vsr && ctx_has_vsx_region) {
  141. flush_vsx_to_thread(tsk);
  142. v_regs += ELF_NVRREG;
  143. err |= copy_vsx_to_user(v_regs, tsk);
  144. /* set MSR_VSX in the MSR value in the frame to
  145. * indicate that sc->vs_reg) contains valid data.
  146. */
  147. msr |= MSR_VSX;
  148. }
  149. #endif /* CONFIG_VSX */
  150. err |= __put_user(&sc->gp_regs, &sc->regs);
  151. WARN_ON(!FULL_REGS(regs));
  152. err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE);
  153. err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
  154. err |= __put_user(softe, &sc->gp_regs[PT_SOFTE]);
  155. err |= __put_user(signr, &sc->signal);
  156. err |= __put_user(handler, &sc->handler);
  157. if (set != NULL)
  158. err |= __put_user(set->sig[0], &sc->oldmask);
  159. return err;
  160. }
  161. #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
  162. /*
  163. * As above, but Transactional Memory is in use, so deliver sigcontexts
  164. * containing checkpointed and transactional register states.
  165. *
  166. * To do this, we treclaim (done before entering here) to gather both sets of
  167. * registers and set up the 'normal' sigcontext registers with rolled-back
  168. * register values such that a simple signal handler sees a correct
  169. * checkpointed register state. If interested, a TM-aware sighandler can
  170. * examine the transactional registers in the 2nd sigcontext to determine the
  171. * real origin of the signal.
  172. */
  173. static long setup_tm_sigcontexts(struct sigcontext __user *sc,
  174. struct sigcontext __user *tm_sc,
  175. struct task_struct *tsk,
  176. int signr, sigset_t *set, unsigned long handler,
  177. unsigned long msr)
  178. {
  179. /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
  180. * process never used altivec yet (MSR_VEC is zero in pt_regs of
  181. * the context). This is very important because we must ensure we
  182. * don't lose the VRSAVE content that may have been set prior to
  183. * the process doing its first vector operation
  184. * Userland shall check AT_HWCAP to know wether it can rely on the
  185. * v_regs pointer or not.
  186. */
  187. #ifdef CONFIG_ALTIVEC
  188. elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
  189. elf_vrreg_t __user *tm_v_regs = sigcontext_vmx_regs(tm_sc);
  190. #endif
  191. struct pt_regs *regs = tsk->thread.regs;
  192. long err = 0;
  193. BUG_ON(tsk != current);
  194. BUG_ON(!MSR_TM_ACTIVE(msr));
  195. WARN_ON(tm_suspend_disabled);
  196. /* Restore checkpointed FP, VEC, and VSX bits from ckpt_regs as
  197. * it contains the correct FP, VEC, VSX state after we treclaimed
  198. * the transaction and giveup_all() was called on reclaiming.
  199. */
  200. msr |= tsk->thread.ckpt_regs.msr & (MSR_FP | MSR_VEC | MSR_VSX);
  201. #ifdef CONFIG_ALTIVEC
  202. err |= __put_user(v_regs, &sc->v_regs);
  203. err |= __put_user(tm_v_regs, &tm_sc->v_regs);
  204. /* save altivec registers */
  205. if (tsk->thread.used_vr) {
  206. /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
  207. err |= __copy_to_user(v_regs, &tsk->thread.ckvr_state,
  208. 33 * sizeof(vector128));
  209. /* If VEC was enabled there are transactional VRs valid too,
  210. * else they're a copy of the checkpointed VRs.
  211. */
  212. if (msr & MSR_VEC)
  213. err |= __copy_to_user(tm_v_regs,
  214. &tsk->thread.vr_state,
  215. 33 * sizeof(vector128));
  216. else
  217. err |= __copy_to_user(tm_v_regs,
  218. &tsk->thread.ckvr_state,
  219. 33 * sizeof(vector128));
  220. /* set MSR_VEC in the MSR value in the frame to indicate
  221. * that sc->v_reg contains valid data.
  222. */
  223. msr |= MSR_VEC;
  224. }
  225. /* We always copy to/from vrsave, it's 0 if we don't have or don't
  226. * use altivec.
  227. */
  228. if (cpu_has_feature(CPU_FTR_ALTIVEC))
  229. tsk->thread.ckvrsave = mfspr(SPRN_VRSAVE);
  230. err |= __put_user(tsk->thread.ckvrsave, (u32 __user *)&v_regs[33]);
  231. if (msr & MSR_VEC)
  232. err |= __put_user(tsk->thread.vrsave,
  233. (u32 __user *)&tm_v_regs[33]);
  234. else
  235. err |= __put_user(tsk->thread.ckvrsave,
  236. (u32 __user *)&tm_v_regs[33]);
  237. #else /* CONFIG_ALTIVEC */
  238. err |= __put_user(0, &sc->v_regs);
  239. err |= __put_user(0, &tm_sc->v_regs);
  240. #endif /* CONFIG_ALTIVEC */
  241. /* copy fpr regs and fpscr */
  242. err |= copy_ckfpr_to_user(&sc->fp_regs, tsk);
  243. if (msr & MSR_FP)
  244. err |= copy_fpr_to_user(&tm_sc->fp_regs, tsk);
  245. else
  246. err |= copy_ckfpr_to_user(&tm_sc->fp_regs, tsk);
  247. #ifdef CONFIG_VSX
  248. /*
  249. * Copy VSX low doubleword to local buffer for formatting,
  250. * then out to userspace. Update v_regs to point after the
  251. * VMX data.
  252. */
  253. if (tsk->thread.used_vsr) {
  254. v_regs += ELF_NVRREG;
  255. tm_v_regs += ELF_NVRREG;
  256. err |= copy_ckvsx_to_user(v_regs, tsk);
  257. if (msr & MSR_VSX)
  258. err |= copy_vsx_to_user(tm_v_regs, tsk);
  259. else
  260. err |= copy_ckvsx_to_user(tm_v_regs, tsk);
  261. /* set MSR_VSX in the MSR value in the frame to
  262. * indicate that sc->vs_reg) contains valid data.
  263. */
  264. msr |= MSR_VSX;
  265. }
  266. #endif /* CONFIG_VSX */
  267. err |= __put_user(&sc->gp_regs, &sc->regs);
  268. err |= __put_user(&tm_sc->gp_regs, &tm_sc->regs);
  269. WARN_ON(!FULL_REGS(regs));
  270. err |= __copy_to_user(&tm_sc->gp_regs, regs, GP_REGS_SIZE);
  271. err |= __copy_to_user(&sc->gp_regs,
  272. &tsk->thread.ckpt_regs, GP_REGS_SIZE);
  273. err |= __put_user(msr, &tm_sc->gp_regs[PT_MSR]);
  274. err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
  275. err |= __put_user(signr, &sc->signal);
  276. err |= __put_user(handler, &sc->handler);
  277. if (set != NULL)
  278. err |= __put_user(set->sig[0], &sc->oldmask);
  279. return err;
  280. }
  281. #endif
  282. /*
  283. * Restore the sigcontext from the signal frame.
  284. */
  285. static long restore_sigcontext(struct task_struct *tsk, sigset_t *set, int sig,
  286. struct sigcontext __user *sc)
  287. {
  288. #ifdef CONFIG_ALTIVEC
  289. elf_vrreg_t __user *v_regs;
  290. #endif
  291. unsigned long err = 0;
  292. unsigned long save_r13 = 0;
  293. unsigned long msr;
  294. struct pt_regs *regs = tsk->thread.regs;
  295. #ifdef CONFIG_VSX
  296. int i;
  297. #endif
  298. BUG_ON(tsk != current);
  299. /* If this is not a signal return, we preserve the TLS in r13 */
  300. if (!sig)
  301. save_r13 = regs->gpr[13];
  302. /* copy the GPRs */
  303. err |= __copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr));
  304. err |= __get_user(regs->nip, &sc->gp_regs[PT_NIP]);
  305. /* get MSR separately, transfer the LE bit if doing signal return */
  306. err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
  307. if (sig)
  308. regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
  309. err |= __get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3]);
  310. err |= __get_user(regs->ctr, &sc->gp_regs[PT_CTR]);
  311. err |= __get_user(regs->link, &sc->gp_regs[PT_LNK]);
  312. err |= __get_user(regs->xer, &sc->gp_regs[PT_XER]);
  313. err |= __get_user(regs->ccr, &sc->gp_regs[PT_CCR]);
  314. /* Don't allow userspace to set SOFTE */
  315. set_trap_norestart(regs);
  316. err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
  317. err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
  318. err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
  319. if (!sig)
  320. regs->gpr[13] = save_r13;
  321. if (set != NULL)
  322. err |= __get_user(set->sig[0], &sc->oldmask);
  323. /*
  324. * Force reload of FP/VEC.
  325. * This has to be done before copying stuff into tsk->thread.fpr/vr
  326. * for the reasons explained in the previous comment.
  327. */
  328. regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
  329. #ifdef CONFIG_ALTIVEC
  330. err |= __get_user(v_regs, &sc->v_regs);
  331. if (err)
  332. return err;
  333. if (v_regs && !access_ok(v_regs, 34 * sizeof(vector128)))
  334. return -EFAULT;
  335. /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
  336. if (v_regs != NULL && (msr & MSR_VEC) != 0) {
  337. err |= __copy_from_user(&tsk->thread.vr_state, v_regs,
  338. 33 * sizeof(vector128));
  339. tsk->thread.used_vr = true;
  340. } else if (tsk->thread.used_vr) {
  341. memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128));
  342. }
  343. /* Always get VRSAVE back */
  344. if (v_regs != NULL)
  345. err |= __get_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33]);
  346. else
  347. tsk->thread.vrsave = 0;
  348. if (cpu_has_feature(CPU_FTR_ALTIVEC))
  349. mtspr(SPRN_VRSAVE, tsk->thread.vrsave);
  350. #endif /* CONFIG_ALTIVEC */
  351. /* restore floating point */
  352. err |= copy_fpr_from_user(tsk, &sc->fp_regs);
  353. #ifdef CONFIG_VSX
  354. /*
  355. * Get additional VSX data. Update v_regs to point after the
  356. * VMX data. Copy VSX low doubleword from userspace to local
  357. * buffer for formatting, then into the taskstruct.
  358. */
  359. v_regs += ELF_NVRREG;
  360. if ((msr & MSR_VSX) != 0) {
  361. err |= copy_vsx_from_user(tsk, v_regs);
  362. tsk->thread.used_vsr = true;
  363. } else {
  364. for (i = 0; i < 32 ; i++)
  365. tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
  366. }
  367. #endif
  368. return err;
  369. }
  370. #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
  371. /*
  372. * Restore the two sigcontexts from the frame of a transactional processes.
  373. */
  374. static long restore_tm_sigcontexts(struct task_struct *tsk,
  375. struct sigcontext __user *sc,
  376. struct sigcontext __user *tm_sc)
  377. {
  378. #ifdef CONFIG_ALTIVEC
  379. elf_vrreg_t __user *v_regs, *tm_v_regs;
  380. #endif
  381. unsigned long err = 0;
  382. unsigned long msr;
  383. struct pt_regs *regs = tsk->thread.regs;
  384. #ifdef CONFIG_VSX
  385. int i;
  386. #endif
  387. BUG_ON(tsk != current);
  388. if (tm_suspend_disabled)
  389. return -EINVAL;
  390. /* copy the GPRs */
  391. err |= __copy_from_user(regs->gpr, tm_sc->gp_regs, sizeof(regs->gpr));
  392. err |= __copy_from_user(&tsk->thread.ckpt_regs, sc->gp_regs,
  393. sizeof(regs->gpr));
  394. /*
  395. * TFHAR is restored from the checkpointed 'wound-back' ucontext's NIP.
  396. * TEXASR was set by the signal delivery reclaim, as was TFIAR.
  397. * Users doing anything abhorrent like thread-switching w/ signals for
  398. * TM-Suspended code will have to back TEXASR/TFIAR up themselves.
  399. * For the case of getting a signal and simply returning from it,
  400. * we don't need to re-copy them here.
  401. */
  402. err |= __get_user(regs->nip, &tm_sc->gp_regs[PT_NIP]);
  403. err |= __get_user(tsk->thread.tm_tfhar, &sc->gp_regs[PT_NIP]);
  404. /* get MSR separately, transfer the LE bit if doing signal return */
  405. err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
  406. /* Don't allow reserved mode. */
  407. if (MSR_TM_RESV(msr))
  408. return -EINVAL;
  409. /* pull in MSR LE from user context */
  410. regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
  411. /* The following non-GPR non-FPR non-VR state is also checkpointed: */
  412. err |= __get_user(regs->ctr, &tm_sc->gp_regs[PT_CTR]);
  413. err |= __get_user(regs->link, &tm_sc->gp_regs[PT_LNK]);
  414. err |= __get_user(regs->xer, &tm_sc->gp_regs[PT_XER]);
  415. err |= __get_user(regs->ccr, &tm_sc->gp_regs[PT_CCR]);
  416. err |= __get_user(tsk->thread.ckpt_regs.ctr,
  417. &sc->gp_regs[PT_CTR]);
  418. err |= __get_user(tsk->thread.ckpt_regs.link,
  419. &sc->gp_regs[PT_LNK]);
  420. err |= __get_user(tsk->thread.ckpt_regs.xer,
  421. &sc->gp_regs[PT_XER]);
  422. err |= __get_user(tsk->thread.ckpt_regs.ccr,
  423. &sc->gp_regs[PT_CCR]);
  424. /* Don't allow userspace to set SOFTE */
  425. set_trap_norestart(regs);
  426. /* These regs are not checkpointed; they can go in 'regs'. */
  427. err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
  428. err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
  429. err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
  430. /*
  431. * Force reload of FP/VEC.
  432. * This has to be done before copying stuff into tsk->thread.fpr/vr
  433. * for the reasons explained in the previous comment.
  434. */
  435. regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
  436. #ifdef CONFIG_ALTIVEC
  437. err |= __get_user(v_regs, &sc->v_regs);
  438. err |= __get_user(tm_v_regs, &tm_sc->v_regs);
  439. if (err)
  440. return err;
  441. if (v_regs && !access_ok(v_regs, 34 * sizeof(vector128)))
  442. return -EFAULT;
  443. if (tm_v_regs && !access_ok(tm_v_regs, 34 * sizeof(vector128)))
  444. return -EFAULT;
  445. /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
  446. if (v_regs != NULL && tm_v_regs != NULL && (msr & MSR_VEC) != 0) {
  447. err |= __copy_from_user(&tsk->thread.ckvr_state, v_regs,
  448. 33 * sizeof(vector128));
  449. err |= __copy_from_user(&tsk->thread.vr_state, tm_v_regs,
  450. 33 * sizeof(vector128));
  451. current->thread.used_vr = true;
  452. }
  453. else if (tsk->thread.used_vr) {
  454. memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128));
  455. memset(&tsk->thread.ckvr_state, 0, 33 * sizeof(vector128));
  456. }
  457. /* Always get VRSAVE back */
  458. if (v_regs != NULL && tm_v_regs != NULL) {
  459. err |= __get_user(tsk->thread.ckvrsave,
  460. (u32 __user *)&v_regs[33]);
  461. err |= __get_user(tsk->thread.vrsave,
  462. (u32 __user *)&tm_v_regs[33]);
  463. }
  464. else {
  465. tsk->thread.vrsave = 0;
  466. tsk->thread.ckvrsave = 0;
  467. }
  468. if (cpu_has_feature(CPU_FTR_ALTIVEC))
  469. mtspr(SPRN_VRSAVE, tsk->thread.vrsave);
  470. #endif /* CONFIG_ALTIVEC */
  471. /* restore floating point */
  472. err |= copy_fpr_from_user(tsk, &tm_sc->fp_regs);
  473. err |= copy_ckfpr_from_user(tsk, &sc->fp_regs);
  474. #ifdef CONFIG_VSX
  475. /*
  476. * Get additional VSX data. Update v_regs to point after the
  477. * VMX data. Copy VSX low doubleword from userspace to local
  478. * buffer for formatting, then into the taskstruct.
  479. */
  480. if (v_regs && ((msr & MSR_VSX) != 0)) {
  481. v_regs += ELF_NVRREG;
  482. tm_v_regs += ELF_NVRREG;
  483. err |= copy_vsx_from_user(tsk, tm_v_regs);
  484. err |= copy_ckvsx_from_user(tsk, v_regs);
  485. tsk->thread.used_vsr = true;
  486. } else {
  487. for (i = 0; i < 32 ; i++) {
  488. tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
  489. tsk->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
  490. }
  491. }
  492. #endif
  493. tm_enable();
  494. /* Make sure the transaction is marked as failed */
  495. tsk->thread.tm_texasr |= TEXASR_FS;
  496. /*
  497. * Disabling preemption, since it is unsafe to be preempted
  498. * with MSR[TS] set without recheckpointing.
  499. */
  500. preempt_disable();
  501. /* pull in MSR TS bits from user context */
  502. regs->msr |= msr & MSR_TS_MASK;
  503. /*
  504. * Ensure that TM is enabled in regs->msr before we leave the signal
  505. * handler. It could be the case that (a) user disabled the TM bit
  506. * through the manipulation of the MSR bits in uc_mcontext or (b) the
  507. * TM bit was disabled because a sufficient number of context switches
  508. * happened whilst in the signal handler and load_tm overflowed,
  509. * disabling the TM bit. In either case we can end up with an illegal
  510. * TM state leading to a TM Bad Thing when we return to userspace.
  511. *
  512. * CAUTION:
  513. * After regs->MSR[TS] being updated, make sure that get_user(),
  514. * put_user() or similar functions are *not* called. These
  515. * functions can generate page faults which will cause the process
  516. * to be de-scheduled with MSR[TS] set but without calling
  517. * tm_recheckpoint(). This can cause a bug.
  518. */
  519. regs->msr |= MSR_TM;
  520. /* This loads the checkpointed FP/VEC state, if used */
  521. tm_recheckpoint(&tsk->thread);
  522. msr_check_and_set(msr & (MSR_FP | MSR_VEC));
  523. if (msr & MSR_FP) {
  524. load_fp_state(&tsk->thread.fp_state);
  525. regs->msr |= (MSR_FP | tsk->thread.fpexc_mode);
  526. }
  527. if (msr & MSR_VEC) {
  528. load_vr_state(&tsk->thread.vr_state);
  529. regs->msr |= MSR_VEC;
  530. }
  531. preempt_enable();
  532. return err;
  533. }
  534. #endif
  535. /*
  536. * Setup the trampoline code on the stack
  537. */
  538. static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp)
  539. {
  540. int i;
  541. long err = 0;
  542. /* bctrl # call the handler */
  543. err |= __put_user(PPC_INST_BCTRL, &tramp[0]);
  544. /* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */
  545. err |= __put_user(PPC_INST_ADDI | __PPC_RT(R1) | __PPC_RA(R1) |
  546. (__SIGNAL_FRAMESIZE & 0xffff), &tramp[1]);
  547. /* li r0, __NR_[rt_]sigreturn| */
  548. err |= __put_user(PPC_INST_ADDI | (syscall & 0xffff), &tramp[2]);
  549. /* sc */
  550. err |= __put_user(PPC_INST_SC, &tramp[3]);
  551. /* Minimal traceback info */
  552. for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++)
  553. err |= __put_user(0, &tramp[i]);
  554. if (!err)
  555. flush_icache_range((unsigned long) &tramp[0],
  556. (unsigned long) &tramp[TRAMP_SIZE]);
  557. return err;
  558. }
  559. /*
  560. * Userspace code may pass a ucontext which doesn't include VSX added
  561. * at the end. We need to check for this case.
  562. */
  563. #define UCONTEXTSIZEWITHOUTVSX \
  564. (sizeof(struct ucontext) - 32*sizeof(long))
  565. /*
  566. * Handle {get,set,swap}_context operations
  567. */
  568. SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
  569. struct ucontext __user *, new_ctx, long, ctx_size)
  570. {
  571. sigset_t set;
  572. unsigned long new_msr = 0;
  573. int ctx_has_vsx_region = 0;
  574. if (new_ctx &&
  575. get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR]))
  576. return -EFAULT;
  577. /*
  578. * Check that the context is not smaller than the original
  579. * size (with VMX but without VSX)
  580. */
  581. if (ctx_size < UCONTEXTSIZEWITHOUTVSX)
  582. return -EINVAL;
  583. /*
  584. * If the new context state sets the MSR VSX bits but
  585. * it doesn't provide VSX state.
  586. */
  587. if ((ctx_size < sizeof(struct ucontext)) &&
  588. (new_msr & MSR_VSX))
  589. return -EINVAL;
  590. /* Does the context have enough room to store VSX data? */
  591. if (ctx_size >= sizeof(struct ucontext))
  592. ctx_has_vsx_region = 1;
  593. if (old_ctx != NULL) {
  594. if (!access_ok(old_ctx, ctx_size)
  595. || setup_sigcontext(&old_ctx->uc_mcontext, current, 0, NULL, 0,
  596. ctx_has_vsx_region)
  597. || __copy_to_user(&old_ctx->uc_sigmask,
  598. &current->blocked, sizeof(sigset_t)))
  599. return -EFAULT;
  600. }
  601. if (new_ctx == NULL)
  602. return 0;
  603. if (!access_ok(new_ctx, ctx_size) ||
  604. fault_in_pages_readable((u8 __user *)new_ctx, ctx_size))
  605. return -EFAULT;
  606. /*
  607. * If we get a fault copying the context into the kernel's
  608. * image of the user's registers, we can't just return -EFAULT
  609. * because the user's registers will be corrupted. For instance
  610. * the NIP value may have been updated but not some of the
  611. * other registers. Given that we have done the access_ok
  612. * and successfully read the first and last bytes of the region
  613. * above, this should only happen in an out-of-memory situation
  614. * or if another thread unmaps the region containing the context.
  615. * We kill the task with a SIGSEGV in this situation.
  616. */
  617. if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
  618. do_exit(SIGSEGV);
  619. set_current_blocked(&set);
  620. if (restore_sigcontext(current, NULL, 0, &new_ctx->uc_mcontext))
  621. do_exit(SIGSEGV);
  622. /* This returns like rt_sigreturn */
  623. set_thread_flag(TIF_RESTOREALL);
  624. return 0;
  625. }
  626. /*
  627. * Do a signal return; undo the signal stack.
  628. */
  629. SYSCALL_DEFINE0(rt_sigreturn)
  630. {
  631. struct pt_regs *regs = current_pt_regs();
  632. struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1];
  633. sigset_t set;
  634. #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
  635. unsigned long msr;
  636. #endif
  637. /* Always make any pending restarted system calls return -EINTR */
  638. current->restart_block.fn = do_no_restart_syscall;
  639. if (!access_ok(uc, sizeof(*uc)))
  640. goto badframe;
  641. if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
  642. goto badframe;
  643. set_current_blocked(&set);
  644. #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
  645. /*
  646. * If there is a transactional state then throw it away.
  647. * The purpose of a sigreturn is to destroy all traces of the
  648. * signal frame, this includes any transactional state created
  649. * within in. We only check for suspended as we can never be
  650. * active in the kernel, we are active, there is nothing better to
  651. * do than go ahead and Bad Thing later.
  652. * The cause is not important as there will never be a
  653. * recheckpoint so it's not user visible.
  654. */
  655. if (MSR_TM_SUSPENDED(mfmsr()))
  656. tm_reclaim_current(0);
  657. /*
  658. * Disable MSR[TS] bit also, so, if there is an exception in the
  659. * code below (as a page fault in copy_ckvsx_to_user()), it does
  660. * not recheckpoint this task if there was a context switch inside
  661. * the exception.
  662. *
  663. * A major page fault can indirectly call schedule(). A reschedule
  664. * process in the middle of an exception can have a side effect
  665. * (Changing the CPU MSR[TS] state), since schedule() is called
  666. * with the CPU MSR[TS] disable and returns with MSR[TS]=Suspended
  667. * (switch_to() calls tm_recheckpoint() for the 'new' process). In
  668. * this case, the process continues to be the same in the CPU, but
  669. * the CPU state just changed.
  670. *
  671. * This can cause a TM Bad Thing, since the MSR in the stack will
  672. * have the MSR[TS]=0, and this is what will be used to RFID.
  673. *
  674. * Clearing MSR[TS] state here will avoid a recheckpoint if there
  675. * is any process reschedule in kernel space. The MSR[TS] state
  676. * does not need to be saved also, since it will be replaced with
  677. * the MSR[TS] that came from user context later, at
  678. * restore_tm_sigcontexts.
  679. */
  680. regs->msr &= ~MSR_TS_MASK;
  681. if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR]))
  682. goto badframe;
  683. if (MSR_TM_ACTIVE(msr)) {
  684. /* We recheckpoint on return. */
  685. struct ucontext __user *uc_transact;
  686. /* Trying to start TM on non TM system */
  687. if (!cpu_has_feature(CPU_FTR_TM))
  688. goto badframe;
  689. if (__get_user(uc_transact, &uc->uc_link))
  690. goto badframe;
  691. if (restore_tm_sigcontexts(current, &uc->uc_mcontext,
  692. &uc_transact->uc_mcontext))
  693. goto badframe;
  694. } else
  695. #endif
  696. {
  697. /*
  698. * Fall through, for non-TM restore
  699. *
  700. * Unset MSR[TS] on the thread regs since MSR from user
  701. * context does not have MSR active, and recheckpoint was
  702. * not called since restore_tm_sigcontexts() was not called
  703. * also.
  704. *
  705. * If not unsetting it, the code can RFID to userspace with
  706. * MSR[TS] set, but without CPU in the proper state,
  707. * causing a TM bad thing.
  708. */
  709. current->thread.regs->msr &= ~MSR_TS_MASK;
  710. if (restore_sigcontext(current, NULL, 1, &uc->uc_mcontext))
  711. goto badframe;
  712. }
  713. if (restore_altstack(&uc->uc_stack))
  714. goto badframe;
  715. set_thread_flag(TIF_RESTOREALL);
  716. return 0;
  717. badframe:
  718. if (show_unhandled_signals)
  719. printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
  720. current->comm, current->pid, "rt_sigreturn",
  721. (long)uc, regs->nip, regs->link);
  722. force_sig(SIGSEGV);
  723. return 0;
  724. }
  725. int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
  726. struct task_struct *tsk)
  727. {
  728. struct rt_sigframe __user *frame;
  729. unsigned long newsp = 0;
  730. long err = 0;
  731. struct pt_regs *regs = tsk->thread.regs;
  732. #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
  733. /* Save the thread's msr before get_tm_stackpointer() changes it */
  734. unsigned long msr = regs->msr;
  735. #endif
  736. BUG_ON(tsk != current);
  737. frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 0);
  738. if (unlikely(frame == NULL))
  739. goto badframe;
  740. err |= __put_user(&frame->info, &frame->pinfo);
  741. err |= __put_user(&frame->uc, &frame->puc);
  742. err |= copy_siginfo_to_user(&frame->info, &ksig->info);
  743. if (err)
  744. goto badframe;
  745. /* Create the ucontext. */
  746. err |= __put_user(0, &frame->uc.uc_flags);
  747. err |= __save_altstack(&frame->uc.uc_stack, regs->gpr[1]);
  748. #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
  749. if (MSR_TM_ACTIVE(msr)) {
  750. /* The ucontext_t passed to userland points to the second
  751. * ucontext_t (for transactional state) with its uc_link ptr.
  752. */
  753. err |= __put_user(&frame->uc_transact, &frame->uc.uc_link);
  754. err |= setup_tm_sigcontexts(&frame->uc.uc_mcontext,
  755. &frame->uc_transact.uc_mcontext,
  756. tsk, ksig->sig, NULL,
  757. (unsigned long)ksig->ka.sa.sa_handler,
  758. msr);
  759. } else
  760. #endif
  761. {
  762. err |= __put_user(0, &frame->uc.uc_link);
  763. err |= setup_sigcontext(&frame->uc.uc_mcontext, tsk, ksig->sig,
  764. NULL, (unsigned long)ksig->ka.sa.sa_handler,
  765. 1);
  766. }
  767. err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
  768. if (err)
  769. goto badframe;
  770. /* Make sure signal handler doesn't get spurious FP exceptions */
  771. tsk->thread.fp_state.fpscr = 0;
  772. /* Set up to return from userspace. */
  773. if (vdso64_rt_sigtramp && tsk->mm->context.vdso_base) {
  774. regs->nip = tsk->mm->context.vdso_base + vdso64_rt_sigtramp;
  775. } else {
  776. err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
  777. if (err)
  778. goto badframe;
  779. regs->nip = (unsigned long) &frame->tramp[0];
  780. }
  781. /* Allocate a dummy caller frame for the signal handler. */
  782. newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
  783. err |= put_user(regs->gpr[1], (unsigned long __user *)newsp);
  784. /* Set up "regs" so we "return" to the signal handler. */
  785. if (is_elf2_task()) {
  786. regs->ctr = (unsigned long) ksig->ka.sa.sa_handler;
  787. regs->gpr[12] = regs->ctr;
  788. } else {
  789. /* Handler is *really* a pointer to the function descriptor for
  790. * the signal routine. The first entry in the function
  791. * descriptor is the entry address of signal and the second
  792. * entry is the TOC value we need to use.
  793. */
  794. func_descr_t __user *funct_desc_ptr =
  795. (func_descr_t __user *) ksig->ka.sa.sa_handler;
  796. err |= get_user(regs->ctr, &funct_desc_ptr->entry);
  797. err |= get_user(regs->gpr[2], &funct_desc_ptr->toc);
  798. }
  799. /* enter the signal handler in native-endian mode */
  800. regs->msr &= ~MSR_LE;
  801. regs->msr |= (MSR_KERNEL & MSR_LE);
  802. regs->gpr[1] = newsp;
  803. regs->gpr[3] = ksig->sig;
  804. regs->result = 0;
  805. if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
  806. err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo);
  807. err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc);
  808. regs->gpr[6] = (unsigned long) frame;
  809. } else {
  810. regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext;
  811. }
  812. if (err)
  813. goto badframe;
  814. return 0;
  815. badframe:
  816. if (show_unhandled_signals)
  817. printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
  818. tsk->comm, tsk->pid, "setup_rt_frame",
  819. (long)frame, regs->nip, regs->link);
  820. return 1;
  821. }