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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.
84 lines
2.3 KiB
C
84 lines
2.3 KiB
C
/* time system call for Linux/PowerPC.
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Copyright (C) 2013-2019 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#ifdef SHARED
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# ifndef __powerpc64__
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# define time __redirect_time
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# else
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# define __redirect_time time
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# endif
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# include <time.h>
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# include <sysdep.h>
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# include <dl-vdso.h>
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# include <libc-vdso.h>
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# include <dl-machine.h>
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# ifndef __powerpc64__
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# undef time
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time_t
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__time_vsyscall (time_t *t)
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{
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return INLINE_VSYSCALL (time, 1, t);
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}
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/* __GI_time is defined as hidden and for ppc32 it enables the
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compiler make a local call (symbol@local) for internal GLIBC usage. It
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means the PLT won't be used and the ifunc resolver will be called directly.
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For ppc64 a call to a function in another translation unit might use a
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different toc pointer thus disallowing direct branchess and making internal
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ifuncs calls safe. */
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# undef libc_hidden_def
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# define libc_hidden_def(name) \
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__hidden_ver1 (__time_vsyscall, __GI_time, __time_vsyscall);
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# endif /* !__powerpc64__ */
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static time_t
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time_syscall (time_t *t)
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{
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struct timeval tv;
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time_t result;
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if (INLINE_VSYSCALL (gettimeofday, 2, &tv, NULL) < 0)
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result = (time_t) -1;
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else
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result = (time_t) tv.tv_sec;
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if (t != NULL)
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*t = result;
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return result;
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}
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# define INIT_ARCH() \
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void *vdso_time = get_vdso_symbol (HAVE_TIME_VSYSCALL);
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/* If the vDSO is not available we fall back to the syscall. */
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libc_ifunc_hidden (__redirect_time, time,
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vdso_time
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? VDSO_IFUNC_RET (vdso_time)
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: (void *) time_syscall);
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libc_hidden_def (time)
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#else
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#include <sysdeps/posix/time.c>
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#endif /* !SHARED */
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