mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-02 09:40:13 +00:00
b8a7c7da4e
Linux vDSO initialization code the internal function pointers require a
lot of duplicated boilerplate over different architectures. This patch
aims to simplify not only the code but the required definition to enable
a vDSO symbol.
The changes are:
1. Consolidate all init-first.c on only one implementation and enable
the symbol based on HAVE_*_VSYSCALL existence.
2. Set the HAVE_*_VSYSCALL to the architecture expected names string.
3. Add a new internal implementation, get_vdso_mangle_symbol, which
returns a mangled function pointer.
Currently the clock_gettime, clock_getres, gettimeofday, getcpu, and time
are handled in an arch-independent way, powerpc still uses some
arch-specific vDSO symbol handled in a specific init-first implementation.
Checked on aarch64-linux-gnu, arm-linux-gnueabihf, i386-linux-gnu,
mips64-linux-gnu, powerpc64le-linux-gnu, s390x-linux-gnu,
sparc64-linux-gnu, and x86_64-linux-gnu.
* sysdeps/powerpc/powerpc32/backtrace.c (is_sigtramp_address,
is_sigtramp_address_rt): Use HAVE_SIGTRAMP_{RT}32 instead of SHARED.
* sysdeps/powerpc/powerpc64/backtrace.c (is_sigtramp_address):
Likewise.
* sysdeps/unix/sysv/linux/aarch64/init-first.c: Remove file.
* sysdeps/unix/sysv/linux/aarch64/libc-vdso.h: Likewise.
* sysdeps/unix/sysv/linux/arm/init-first.c: Likewise.
* sysdeps/unix/sysv/linux/arm/libc-vdso.h: Likewise.
* sysdeps/unix/sysv/linux/mips/init-first.c: Likewise.
* sysdeps/unix/sysv/linux/mips/libc-vdso.h: Likewise.
* sysdeps/unix/sysv/linux/i386/init-first.c: Likewise.
* sysdeps/unix/sysv/linux/riscv/init-first.c: Likewise.
* sysdeps/unix/sysv/linux/riscv/libc-vdso.h: Likewise.
* sysdeps/unix/sysv/linux/s390/init-first.c: Likewise.
* sysdeps/unix/sysv/linux/s390/libc-vdso.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/init-first.c: Likewise.
* sysdeps/unix/sysv/linux/sparc/libc-vdso.h: Likewise.
* sysdeps/unix/sysv/linux/x86/libc-vdso.h: Likewise.
* sysdeps/unix/sysv/linux/x86_64/init-first.c: Likewise.
* sysdeps/unix/sysv/linux/aarch64/sysdep.h
(HAVE_CLOCK_GETRES_VSYSCALL, HAVE_CLOCK_GETTIME_VSYSCALL,
HAVE_GETTIMEOFDAY_VSYSCALL): Define value based on kernel exported
name.
* sysdeps/unix/sysv/linux/arm/sysdep.h (HAVE_CLOCK_GETTIME_VSYSCALL,
HAVE_GETTIMEOFDAY_VSYSCALL): Likewise.
* sysdeps/unix/sysv/linux/i386/sysdep.h (HAVE_CLOCK_GETTIME_VSYSCALL,
HAVE_GETTIMEOFDAY_VSYSCALL): Likewise.
* sysdeps/unix/sysv/linux/mips/sysdep.h (HAVE_CLOCK_GETTIME_VSYSCALL,
HAVE_GETTIMEOFDAY_VSYSCALL): Likewise.
* sysdeps/unix/sysv/linux/powerpc/sysdep.h
(HAVE_CLOCK_GETRES_VSYSCALL, HAVE_CLOCK_GETTIME_VSYSCALL,
HAVE_GETCPU_VSYSCALL, HAVE_TIME_VSYSCALL, HAVE_GET_TBFREQ,
HAVE_SIGTRAMP_RT64, HAVE_SIGTRAMP_32, HAVE_SIGTRAMP_RT32i,
HAVE_GETTIMEOFDAY_VSYSCALL): Likewise.
* sysdeps/unix/sysv/linux/riscv/sysdep.h (HAVE_CLOCK_GETRES_VSYSCALL,
HAVE_CLOCK_GETTIME_VSYSCALL, HAVE_GETTIMEOFDAY_VSYSCALL,
HAVE_GETCPU_VSYSCALL): Likewise.
* sysdeps/unix/sysv/linux/s390/sysdep.h (HAVE_CLOCK_GETRES_VSYSCALL,
HAVE_CLOCK_GETTIME_VSYSCALL, HAVE_GETTIMEOFDAY_VSYSCALL,
HAVE_GETCPU_VSYSCALL): Likewise.
* sysdeps/unix/sysv/linux/sparc/sysdep.h (HAVE_CLOCK_GETTIME_VSYSCALL,
HAVE_GETTIMEOFDAY_VSYSCALL): Likewise.
* sysdeps/unix/sysv/linux/x86_64/sysdep.h
(HAVE_CLOCK_GETTIME_VSYSCALL, HAVE_GETTIMEOFDAY_VSYSCALL,
HAVE_GETCPU_VSYSCALL): Likewise.
* sysdeps/unix/sysv/linux/dl-vdso.h (VDSO_NAME, VDSO_HASH): Define to
invalid names if architecture does not define them.
(get_vdso_mangle_symbol): New symbol.
* sysdeps/unix/sysv/linux/init-first.c: New file.
* sysdeps/unix/sysv/linux/libc-vdso.h: Likewise.
* sysdeps/unix/sysv/linux/powerpc/init-first.c (gettimeofday,
clock_gettime, clock_getres, getcpu, time): Remove declaration.
(__libc_vdso_platform_setup_arch): Likewise and use
get_vdso_mangle_symbol to setup vDSO symbols.
(sigtramp_rt64, sigtramp32, sigtramp_rt32, get_tbfreq): Add
attribute_hidden.
* sysdeps/unix/sysv/linux/powerpc/libc-vdso.h: Likewise.
* sysdeps/unix/sysv/linux/sysdep-vdso.h (VDSO_SYMBOL): Remove
definition.
86 lines
2.6 KiB
C
86 lines
2.6 KiB
C
/* Copyright (C) 2005-2019 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
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#if defined SHARED && !defined __powerpc64__
|
|
# define __gettimeofday __redirect___gettimeofday
|
|
#else
|
|
# define __redirect___gettimeofday __gettimeofday
|
|
#endif
|
|
|
|
#include <sys/time.h>
|
|
|
|
#ifdef SHARED
|
|
|
|
# include <dl-vdso.h>
|
|
# include <libc-vdso.h>
|
|
# include <dl-machine.h>
|
|
# include <sysdep.h>
|
|
|
|
# ifndef __powerpc64__
|
|
# undef __gettimeofday
|
|
|
|
int
|
|
__gettimeofday_vsyscall (struct timeval *tv, struct timezone *tz)
|
|
{
|
|
return INLINE_VSYSCALL (gettimeofday, 2, tv, tz);
|
|
}
|
|
|
|
/* __GI___gettimeofday is defined as hidden and for ppc32 it enables the
|
|
compiler make a local call (symbol@local) for internal GLIBC usage. It
|
|
means the PLT won't be used and the ifunc resolver will be called directly.
|
|
For ppc64 a call to a function in another translation unit might use a
|
|
different toc pointer thus disallowing direct branchess and making internal
|
|
ifuncs calls safe. */
|
|
# undef libc_hidden_def
|
|
# define libc_hidden_def(name) \
|
|
__hidden_ver1 (__gettimeofday_vsyscall, __GI___gettimeofday, \
|
|
__gettimeofday_vsyscall);
|
|
|
|
# endif /* !__powerpc64__ */
|
|
|
|
static int
|
|
__gettimeofday_syscall (struct timeval *tv, struct timezone *tz)
|
|
{
|
|
return INLINE_SYSCALL (gettimeofday, 2, tv, tz);
|
|
}
|
|
|
|
# define INIT_ARCH() \
|
|
void *vdso_gettimeofday = get_vdso_symbol (HAVE_GETTIMEOFDAY_VSYSCALL)
|
|
|
|
/* If the vDSO is not available we fall back syscall. */
|
|
libc_ifunc_hidden (__redirect___gettimeofday, __gettimeofday,
|
|
vdso_gettimeofday
|
|
? VDSO_IFUNC_RET (vdso_gettimeofday)
|
|
: (void *) __gettimeofday_syscall);
|
|
libc_hidden_def (__gettimeofday)
|
|
|
|
#else
|
|
|
|
# include <sysdep.h>
|
|
# include <errno.h>
|
|
|
|
int
|
|
__gettimeofday (struct timeval *tv, struct timezone *tz)
|
|
{
|
|
return INLINE_SYSCALL (gettimeofday, 2, tv, tz);
|
|
}
|
|
libc_hidden_def (__gettimeofday)
|
|
|
|
#endif
|
|
weak_alias (__gettimeofday, gettimeofday)
|
|
libc_hidden_weak (gettimeofday)
|