From 7355653cfe6d16e3813889559f4762bbc8a4ea06 Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Fri, 27 Jun 2014 13:08:21 -0700 Subject: Clean up NPTL fork to be compat-only. --- ChangeLog | 6 ++++++ nptl/pt-fork.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++---- 2 files changed, 55 insertions(+), 4 deletions(-) diff --git a/ChangeLog b/ChangeLog index 5b31532e4b..74b77e28b5 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,9 @@ +2014-06-27 Roland McGrath + + * nptl/pt-fork.c: Rewritten. Put everything under + [SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_20)]. + Use IFUNC to redirect when possible. + 2014-07-07 Roland McGrath * sysdeps/nptl/lowlevellock.h: File removed. diff --git a/nptl/pt-fork.c b/nptl/pt-fork.c index 582409486e..6b7ceeafd3 100644 --- a/nptl/pt-fork.c +++ b/nptl/pt-fork.c @@ -1,4 +1,5 @@ -/* Copyright (C) 2002-2014 Free Software Foundation, Inc. +/* ABI compatibility for 'fork' symbol in libpthread ABI. + Copyright (C) 2002-2014 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper , 2002. @@ -17,11 +18,55 @@ . */ #include +#include +/* libpthread once had its own fork, though there was no apparent reason + for it. There is no use in having a separate symbol 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 __fork and fork symbols in + libpthread.so; so we define them using IFUNC to redirect to the libc + function. */ -pid_t -__fork (void) +#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_20) + +# if HAVE_IFUNC + +static __typeof (fork) * +__attribute__ ((used)) +fork_resolve (void) +{ + return &__libc_fork; +} + +# ifdef HAVE_ASM_SET_DIRECTIVE +# define DEFINE_FORK(name) \ + asm (".set " #name ", fork_resolve\n" \ + ".globl " #name "\n" \ + ".type " #name ", %gnu_indirect_function"); +# else +# define DEFINE_FORK(name) \ + asm (#name " = fork_resolve\n" \ + ".globl " #name "\n" \ + ".type " #name ", %gnu_indirect_function"); +# endif + +# else /* !HAVE_IFUNC */ + +static pid_t __attribute__ ((used)) +fork_compat (void) { return __libc_fork (); } -strong_alias (__fork, fork) + +# define DEFINE_FORK(name) strong_alias (fork_compat, name) + +# endif /* HAVE_IFUNC */ + +DEFINE_FORK (fork_ifunc) +compat_symbol (libpthread, fork_ifunc, fork, GLIBC_2_0); + +DEFINE_FORK (__fork_ifunc) +compat_symbol (libpthread, __fork_ifunc, __fork, GLIBC_2_1_2); + +#endif -- cgit v1.2.1