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author | Florian Weimer <fweimer@redhat.com> | 2019-07-02 15:12:20 +0200 |
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committer | Florian Weimer <fweimer@redhat.com> | 2019-07-02 16:51:13 +0200 |
commit | 41d6f74e6cb6a92ab428c11ee1e408b2a16aa1b0 (patch) | |
tree | ece03ae53e8fd589f2c493cb753c132545a49196 /sysdeps/unix/sysv/linux/aarch64 | |
parent | 27cec9aed97447dff887a88f4241604fffd8c525 (diff) | |
download | glibc-41d6f74e6cb6a92ab428c11ee1e408b2a16aa1b0.tar.gz glibc-41d6f74e6cb6a92ab428c11ee1e408b2a16aa1b0.tar.xz glibc-41d6f74e6cb6a92ab428c11ee1e408b2a16aa1b0.zip |
nptl: Remove vfork IFUNC-based forwarder from libpthread [BZ #20188]
With commit f0b2132b35248c1f4a80f62a2c38cddcc802aa8c ("ld.so: Support moving versioned symbols between sonames [BZ #24741]"), the dynamic linker will find the definition of vfork in libc and binds a vfork reference to that symbol, even if the soname in the version reference says that the symbol should be located in libpthread. As a result, the forwarder (whether it's IFUNC-based or a duplicate of the libc implementation) is no longer necessary. On older architectures, a placeholder symbol is required, to make sure that the GLIBC_2.1.2 symbol version does not go away, or is turned in to a weak symbol definition by the link editor. (The symbol version needs to preserved so that the symbol coverage check in elf/dl-version.c does not fail for old binaries.) mips32 is an outlier: It defined __vfork@@GLIBC_2.2, but the baseline is GLIBC_2.0. Since there are other @@GLIBC_2.2 symbols, the placeholder symbol is not needed there.
Diffstat (limited to 'sysdeps/unix/sysv/linux/aarch64')
-rw-r--r-- | sysdeps/unix/sysv/linux/aarch64/libpthread.abilist | 2 | ||||
-rw-r--r-- | sysdeps/unix/sysv/linux/aarch64/pt-vfork.c | 54 |
2 files changed, 0 insertions, 56 deletions
diff --git a/sysdeps/unix/sysv/linux/aarch64/libpthread.abilist b/sysdeps/unix/sysv/linux/aarch64/libpthread.abilist index 9a9e4cee85..6945b7cbe4 100644 --- a/sysdeps/unix/sysv/linux/aarch64/libpthread.abilist +++ b/sysdeps/unix/sysv/linux/aarch64/libpthread.abilist @@ -45,7 +45,6 @@ GLIBC_2.17 __read F GLIBC_2.17 __res_state F GLIBC_2.17 __send F GLIBC_2.17 __sigaction F -GLIBC_2.17 __vfork F GLIBC_2.17 __wait F GLIBC_2.17 __write F GLIBC_2.17 _pthread_cleanup_pop F @@ -216,7 +215,6 @@ GLIBC_2.17 siglongjmp F GLIBC_2.17 sigwait F GLIBC_2.17 system F GLIBC_2.17 tcdrain F -GLIBC_2.17 vfork F GLIBC_2.17 wait F GLIBC_2.17 waitpid F GLIBC_2.17 write F diff --git a/sysdeps/unix/sysv/linux/aarch64/pt-vfork.c b/sysdeps/unix/sysv/linux/aarch64/pt-vfork.c deleted file mode 100644 index 3009f8d2fd..0000000000 --- a/sysdeps/unix/sysv/linux/aarch64/pt-vfork.c +++ /dev/null @@ -1,54 +0,0 @@ -/* vfork ABI-compatibility entry points for libpthread. - Copyright (C) 2014-2019 Free Software Foundation, Inc. - This file is part of the GNU C Library. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - <http://www.gnu.org/licenses/>. */ - -#include <shlib-compat.h> - -/* libpthread used to have its own vfork implementation that differed - from libc's only in having a pointless micro-optimization. There - is no longer any use to having a separate copy in libpthread, but - the historical ABI requires it. For static linking, there is no - need to provide anything here--the libc version will be linked in. - For shared library ABI compatibility, there must be __vfork and - vfork symbols in libpthread.so. */ - -#if HAVE_IFUNC -# include <nptl/pt-vfork.c> -#elif (SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_20) \ - || SHLIB_COMPAT (libpthread, GLIBC_2_1_2, GLIBC_2_20)) - -/* Thankfully, on AArch64 we can rely on the compiler generating - a tail call here. */ - -extern void __libc_vfork (void); - -void -vfork_compat (void) -{ - __libc_vfork (); -} - -# if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_20) -compat_symbol (libpthread, vfork_compat, vfork, GLIBC_2_0); -# endif - -# if SHLIB_COMPAT (libpthread, GLIBC_2_1_2, GLIBC_2_20) -strong_alias (vfork_compat, vfork_compat2) -compat_symbol (libpthread, vfork_compat2, __vfork, GLIBC_2_1_2); -# endif - -#endif |