diff options
| -rw-r--r-- | ChangeLog | 9 | ||||
| -rw-r--r-- | nptl/pt-fork.c | 43 |
2 files changed, 19 insertions, 33 deletions
diff --git a/ChangeLog b/ChangeLog index d1a3489658..7dfe5752a7 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,12 @@ +2016-06-01 Florian Weimer <fweimer@redhat.com> + + [BZ #19861] + Do not use IFUNC resolver with potentially unrelocated symbol. + * nptl/pt-fork.c [HAVE_IFUNC]: Remove. + (DEFINE_FORK): Remove macro and inline definition. + (fork_alias): Renamed from fork_ifunc. + (__fork_alias): Renamed from __fork_ifunc. + 2016-05-30 Paul Pluzhnikov <ppluzhnikov@google.com> [BZ 19653] diff --git a/nptl/pt-fork.c b/nptl/pt-fork.c index b65d6b4edd..db9b61d9aa 100644 --- a/nptl/pt-fork.c +++ b/nptl/pt-fork.c @@ -25,33 +25,14 @@ 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. */ + libpthread.so. -#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_22) - -# if HAVE_IFUNC - -static __typeof (fork) * -__attribute__ ((used)) -fork_resolve (void) -{ - return &__libc_fork; -} + With an IFUNC resolver, it would be possible to avoid the + indirection, but the IFUNC resolver might run before the + __libc_fork symbol has been relocated, in which case the IFUNC + resolver would not be able to provide the correct address. */ -# 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 */ +#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_22) static pid_t __attribute__ ((used)) fork_compat (void) @@ -59,14 +40,10 @@ fork_compat (void) return __libc_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); +strong_alias (fork_compat, fork_alias) +compat_symbol (libpthread, fork_alias, fork, GLIBC_2_0); -DEFINE_FORK (__fork_ifunc) -compat_symbol (libpthread, __fork_ifunc, __fork, GLIBC_2_0); +strong_alias (fork_compat, __fork_alias) +compat_symbol (libpthread, __fork_alias, __fork, GLIBC_2_0); #endif |