From 94d71c49eb1682a73465eb162b0a059561168bb2 Mon Sep 17 00:00:00 2001 From: Marcin Niestroj Date: Fri, 20 Jul 2018 14:26:44 +0200 Subject: [PATCH] configure: Introduce --enable-symvers option Only few libc (e.g. glibc) libraries support full symbol version resolution in runtime. There are lot of standard libraries that do not support that, such as dietlibc, musl and uclibc. Hence there is no reason to generate symbol versions when compiling against them. Additionally libdevmapper.so was broken when compiled against uclibc. Runtime linker loader caused calling dm_task_get_info_base() function recursively, leading to segmentation fault. Introduce --enable-symvers[=STYLE] option, which allows to choose between gnu and disabled symbol versioning. By default gnu symbol versioning is used to provide backward compatibility. __GNUC__ check is replaced now with GNU_SYMVER, which is generated by configure script. Additionally ld version script is included only in case of gnu option, which slightly reduces output size. Providing --disable-symvers to configure script when building against uclibc library fixes segmentation fault error described above, due to lack of several versions of the same symbol in libdevmapper.so library. Signed-off-by: Marcin Niestroj --- configure | 32 ++++++++++++++++++++++++++++++-- configure.ac | 28 +++++++++++++++++++++++++--- include/configure.h.in | 3 +++ lib/misc/lib.h | 10 +++++----- libdm/datastruct/bitset.c | 5 +---- libdm/ioctl/libdm-iface.c | 2 +- libdm/libdm-deptree.c | 2 +- libdm/libdm-stats.c | 2 +- 8 files changed, 67 insertions(+), 17 deletions(-) diff --git a/configure b/configure index 7d945dfa8..94cd6b1ea 100755 --- a/configure +++ b/configure @@ -975,6 +975,7 @@ enable_fsadm enable_blkdeactivate enable_dmeventd enable_selinux +enable_symvers enable_nls with_localedir with_confdir @@ -1725,6 +1726,9 @@ Optional Features: --disable-blkdeactivate disable blkdeactivate --enable-dmeventd enable the device-mapper event daemon --disable-selinux disable selinux support + --enable-symvers[=STYLE] + enables symbol versioning of the shared library + [default=gnu] --enable-nls enable Native Language Support Optional Packages: @@ -3156,7 +3160,6 @@ if test -z "$CFLAGS"; then : fi case "$host_os" in linux*) - CLDFLAGS="$CLDFLAGS -Wl,--version-script,.export.sym" # equivalent to -rdynamic ELDFLAGS="-Wl,--export-dynamic" # FIXME Generate list and use --dynamic-list=.dlopen.sym @@ -3178,7 +3181,6 @@ case "$host_os" in ;; darwin*) CFLAGS="$CFLAGS -no-cpp-precomp -fno-common" - CLDFLAGS="$CLDFLAGS" ELDFLAGS= CLDWHOLEARCHIVE="-all_load" CLDNOWHOLEARCHIVE= @@ -14401,6 +14403,32 @@ done LIBS=$lvm_saved_libs fi +################################################################################ +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether to enable symbol versioning" >&5 +$as_echo_n "checking whether to enable symbol versioning... " >&6; } +# Check whether --enable-symvers was given. +if test "${enable_symvers+set}" = set; then : + enableval=$enable_symvers; + case "$enableval" in + gnu|no) ;; + *) as_fn_error $? "Unknown argument to enable/disable symvers" "$LINENO" 5 ;; + esac +else + enable_symvers=gnu +fi + +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $enable_symvers" >&5 +$as_echo "$enable_symvers" >&6; } + +if test x$GCC = xyes && test x$enable_symvers = xgnu ; then + +$as_echo "#define GNU_SYMVER 1" >>confdefs.h + + case "$host_os" in + linux*) CLDFLAGS="$CLDFLAGS -Wl,--version-script,.export.sym" ;; + esac +fi + ################################################################################ { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether to enable internationalisation" >&5 $as_echo_n "checking whether to enable internationalisation... " >&6; } diff --git a/configure.ac b/configure.ac index e427708cd..2e8712f92 100644 --- a/configure.ac +++ b/configure.ac @@ -30,13 +30,11 @@ AC_CANONICAL_TARGET([]) AS_IF([test -z "$CFLAGS"], [COPTIMISE_FLAG="-O2"]) case "$host_os" in linux*) - CLDFLAGS="$CLDFLAGS -Wl,--version-script,.export.sym" # equivalent to -rdynamic ELDFLAGS="-Wl,--export-dynamic" # FIXME Generate list and use --dynamic-list=.dlopen.sym CLDWHOLEARCHIVE="-Wl,-whole-archive" CLDNOWHOLEARCHIVE="-Wl,-no-whole-archive" - LDDEPS="$LDDEPS .export.sym" LIB_SUFFIX=so DEVMAPPER=yes BUILD_LVMETAD=no @@ -52,7 +50,6 @@ case "$host_os" in ;; darwin*) CFLAGS="$CFLAGS -no-cpp-precomp -fno-common" - CLDFLAGS="$CLDFLAGS" ELDFLAGS= CLDWHOLEARCHIVE="-all_load" CLDNOWHOLEARCHIVE= @@ -1656,6 +1653,31 @@ package as well (which may be called readline-devel or something similar).]) LIBS=$lvm_saved_libs fi +################################################################################ +dnl -- Symbol versioning +AC_MSG_CHECKING(whether to enable symbol versioning) +AC_ARG_ENABLE(symvers, + AC_HELP_STRING([--enable-symvers[[[=STYLE]]]], + [enables symbol versioning of the shared library [default=gnu]]), + [ + case "$enableval" in + gnu|no) ;; + *) AC_MSG_ERROR(Unknown argument to enable/disable symvers) ;; + esac], + enable_symvers=gnu) +AC_MSG_RESULT($enable_symvers) + +if test x$GCC = xyes && test x$enable_symvers = xgnu ; then + AC_DEFINE(GNU_SYMVER, 1, + [Define to use GNU versioning in the shared library.]) + case "$host_os" in + linux*) + CLDFLAGS="$CLDFLAGS -Wl,--version-script,.export.sym" + LDDEPS="$LDDEPS .export.sym" + ;; + esac +fi + ################################################################################ dnl -- Internationalisation stuff AC_MSG_CHECKING(whether to enable internationalisation) diff --git a/include/configure.h.in b/include/configure.h.in index 15fd150ed..7a07a10ef 100644 --- a/include/configure.h.in +++ b/include/configure.h.in @@ -147,6 +147,9 @@ /* Path to fsadm binary. */ #undef FSADM_PATH +/* Define to use GNU versioning in the shared library. */ +#undef GNU_SYMVER + /* Define to 1 if you have the `alarm' function. */ #undef HAVE_ALARM diff --git a/lib/misc/lib.h b/lib/misc/lib.h index d7fa5c721..7cf98f932 100644 --- a/lib/misc/lib.h +++ b/lib/misc/lib.h @@ -41,16 +41,16 @@ * macro DM_EXPORT_SYMBOL to export the function and bind it to the * specified version string. * - * Since versioning is only available when compiling with GCC the entire - * compatibility version should be enclosed in '#if defined(__GNUC__)', - * for example: + * Since versioning is only available when compiling with GCC + * and GLIBC the entire compatibility version should be enclosed + * in '#if defined(GNU_SYMVER)', for example: * * int dm_foo(int bar) * { * return bar; * } * - * #if defined(__GNUC__) + * #if defined(GNU_SYMVER) * // Backward compatible dm_foo() version 1.02.104 * int dm_foo_v1_02_104(void); * int dm_foo_v1_02_104(void) @@ -67,7 +67,7 @@ * versions of library symbols prior to the introduction of symbol * versioning: it must never be used for new symbols. */ -#if defined(__GNUC__) +#if defined(GNU_SYMVER) #define DM_EXPORT_SYMBOL(func, ver) \ __asm__(".symver " #func "_v" #ver ", " #func "@DM_" #ver ) #define DM_EXPORT_SYMBOL_BASE(func) \ diff --git a/libdm/datastruct/bitset.c b/libdm/datastruct/bitset.c index b0826e1eb..2ec3f8f84 100644 --- a/libdm/datastruct/bitset.c +++ b/libdm/datastruct/bitset.c @@ -242,7 +242,7 @@ bad: return NULL; } -#if defined(__GNUC__) +#if defined(GNU_SYMVER) /* * Maintain backward compatibility with older versions that did not * accept a 'min_num_bits' argument to dm_bitset_parse_list(). @@ -253,7 +253,4 @@ dm_bitset_t dm_bitset_parse_list_v1_02_129(const char *str, struct dm_pool *mem) return dm_bitset_parse_list(str, mem, 0); } DM_EXPORT_SYMBOL(dm_bitset_parse_list, 1_02_129); - -#else /* if defined(__GNUC__) */ - #endif diff --git a/libdm/ioctl/libdm-iface.c b/libdm/ioctl/libdm-iface.c index 769b69c1b..28e2eadee 100644 --- a/libdm/ioctl/libdm-iface.c +++ b/libdm/ioctl/libdm-iface.c @@ -2145,7 +2145,7 @@ void dm_lib_exit(void) _version_checked = 0; } -#if defined(__GNUC__) +#if defined(GNU_SYMVER) /* * Maintain binary backward compatibility. * Version script mechanism works with 'gcc' compatible compilers only. diff --git a/libdm/libdm-deptree.c b/libdm/libdm-deptree.c index ab0545659..00651c0b2 100644 --- a/libdm/libdm-deptree.c +++ b/libdm/libdm-deptree.c @@ -3797,7 +3797,7 @@ void dm_tree_node_set_callback(struct dm_tree_node *dnode, dnode->callback_data = data; } -#if defined(__GNUC__) +#if defined(GNU_SYMVER) /* * Backward compatible implementations. * diff --git a/libdm/libdm-stats.c b/libdm/libdm-stats.c index 94ad380e0..76efbbe35 100644 --- a/libdm/libdm-stats.c +++ b/libdm/libdm-stats.c @@ -5065,7 +5065,7 @@ int dm_stats_start_filemapd(int fd, uint64_t group_id, const char *path, * current dm_stats_create_region() version. */ -#if defined(__GNUC__) +#if defined(GNU_SYMVER) int dm_stats_create_region_v1_02_106(struct dm_stats *dms, uint64_t *region_id, uint64_t start, uint64_t len, int64_t step, int precise, const char *program_id, -- 2.18.0