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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.
57 lines
1.7 KiB
C
57 lines
1.7 KiB
C
/* ELF symbol resolve functions for VDSO objects.
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Copyright (C) 2005-2019 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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#ifndef _DL_VDSO_H
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#define _DL_VDSO_H 1
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#include <ldsodefs.h>
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#include <dl-hash.h>
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/* Functions for resolving symbols in the VDSO link map. */
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extern void *_dl_vdso_vsym (const char *name,
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const struct r_found_version *version)
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attribute_hidden;
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/* If the architecture support vDSO it should define which is the expected
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kernel version and hash value through both VDSO_NAME and VDSO_HASH
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(usually defined at architecture sysdep.h). */
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#ifndef VDSO_NAME
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# define VDSO_NAME "LINUX_0.0"
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#endif
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#ifndef VDSO_HASH
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# define VDSO_HASH 0
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#endif
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static inline void *
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get_vdso_symbol (const char *symbol)
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{
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struct r_found_version rfv = { VDSO_NAME, VDSO_HASH, 1, NULL };
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return _dl_vdso_vsym (symbol, &rfv);
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}
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static inline void *
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get_vdso_mangle_symbol (const char *symbol)
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{
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void *vdsop = get_vdso_symbol (symbol);
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PTR_MANGLE (vdsop);
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return vdsop;
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}
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#endif /* dl-vdso.h */
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