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b4a5d26d88
This patch consolidates all Linux sigaction implementations on the default
sysdeps/unix/sysv/linux/sigaction.c. The idea is remove redundant code
and simplify new ports addition by following the current generic
Linux User API (UAPI).
The UAPI for new ports defines a generic extensible sigaction struct as:
struct sigaction
{
__sighandler_t sa_handler;
unsigned long sa_flags;
#ifdef SA_RESTORER
void (*sa_restorer) (void);
#endif
sigset_t sa_mask;
};
Where SA_RESTORER is just placed for compatibility reasons (news ports
should not add it). A similar definition is used on generic
kernel_sigaction.h.
The user exported sigaction definition is not changed, so for most
architectures it requires an adjustment to kernel expected one for the
syscall.
The main changes are:
- All architectures now define and use a kernel_sigaction struct meant
for the syscall, even for the architectures where the user sigaction
has the same layout of the kernel expected one (s390-64 and ia64).
Although it requires more work for these architectures, it simplifies
the generic implementation. Also, sigaction is hardly a hotspot where
micro optimization would play an important role.
- The generic kernel_sigaction definition is now aligned with expected
UAPI one for newer ports, where SA_RESTORER and sa_restorer are not
expected to be defined. This means adding kernel_sigaction for
current architectures that does define it (m68k, nios2, powerpc, s390,
sh, sparc, and tile) and which rely on previous generic definition.
- Remove old MIPS usage of sa_restorer. This was removed since 2.6.27
(2957c9e61ee9c - "[MIPS] IRIX: Goodbye and thanks for all the fish").
- The remaining arch-specific sigaction.c are to handle ABI idiosyncrasies
(like SPARC kernel ABI for rt_sigaction that requires an additional
stub argument).
So for new ports the generic implementation should work if its uses
Linux UAPI. If SA_RESTORER is still required (due some architecture
limitation), it should define its own kernel_sigaction.h, define it and
include generic header (assuming it still uses the default generic kernel
layout).
Checked on x86_64-linux-gnu, i686-linux-gnu, arm-linux-gnueabihf,
aarch64-linux-gnu, sparc64-linux-gnu, sparcv9-linux-gnu, powerpc-linux-gnu,
powerpc64-linux-gnu, ia64-linux-gnu and alpha-linux-gnu. I also checked the
build on all remaining affected ABIs.
* sysdeps/unix/sysv/linux/aarch64/sigaction.c: Use default Linux version
as base implementation.
* sysdeps/unix/sysv/linux/arm/sigaction.c: Likewise.
* sysdeps/unix/sysv/linux/i386/sigaction.c: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/sigaction.c: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/sigaction.c: Likewise.
* sysdeps/unix/sysv/linux/x86_64/sigaction.c: Likewise.
* sysdeps/unix/sysv/linux/alpha/kernel_sigaction.h: Add include guards,
remove unrequired definitions and update comments.
* sysdeps/unix/sysv/linux/kernel_sigaction.h: Likewise.
* sysdeps/unix/sysv/linux/mips/kernel_sigaction.h: Likewise.
* sysdeps/unix/sysv/linux/ia64/kernel_sigaction.h: New file.
* sysdeps/unix/sysv/linux/m68k/kernel_sigaction.h: Likewise.
* sysdeps/unix/sysv/linux/nios2/kernel_sigaction.h: Likewise.
* sysdeps/unix/sysv/linux/powerpc/kernel_sigaction: Likewise.
* sysdeps/unix/sysv/linux/s390/kernel_sigaction.h: Likewise.
* sysdeps/unix/sysv/linux/sh/kernel_sigaction.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/kernel_sigaction.h: Likewise.
* sysdeps/unix/sysv/linux/tile/kernel_sigaction.h: Likewise.
* sysdeps/unix/sysv/linux/ia64/sigaction.c: Remove file.
* sysdeps/unix/sysv/linux/mips/sigaction.c: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/sigaction.c: Likewise.
* sysdeps/unix/sysv/linux/sigaction.c: Add STUB, SET_SA_RESTORER,
and RESET_SA_RESTORER hooks.
80 lines
2.5 KiB
C
80 lines
2.5 KiB
C
/* POSIX.1 `sigaction' call for Linux/i386.
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Copyright (C) 1991-2018 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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<http://www.gnu.org/licenses/>. */
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#include <signal.h>
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#include <ldsodefs.h>
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#define SA_RESTORER 0x04000000
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extern void restore_rt (void) asm ("__restore_rt") attribute_hidden;
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extern void restore (void) asm ("__restore") attribute_hidden;
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#define SET_SA_RESTORER(kact, act) \
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({ \
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if (GLRO(dl_sysinfo_dso) == NULL) \
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{ \
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(kact)->sa_flags |= SA_RESTORER; \
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(kact)->sa_restorer = (((act)->sa_flags & SA_SIGINFO) \
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? &restore_rt : &restore); \
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} \
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else \
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(kact)->sa_restorer = NULL; \
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})
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#define RESET_SA_RESTORER(act, kact) \
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(act)->sa_restorer = (kact)->sa_restorer
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#include <sysdeps/unix/sysv/linux/sigaction.c>
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/* NOTE: Please think twice before making any changes to the bits of
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code below. GDB needs some intimate knowledge about it to
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recognize them as signal trampolines, and make backtraces through
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signal handlers work right. Important are both the names
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(__restore and __restore_rt) and the exact instruction sequence.
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If you ever feel the need to make any changes, please notify the
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appropriate GDB maintainer. */
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#define RESTORE(name, syscall) RESTORE2 (name, syscall)
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#define RESTORE2(name, syscall) \
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asm \
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( \
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".text\n" \
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" .align 16\n" \
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"__" #name ":\n" \
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" movl $" #syscall ", %eax\n" \
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" int $0x80" \
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);
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/* The return code for realtime-signals. */
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RESTORE (restore_rt, __NR_rt_sigreturn)
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/* For the boring old signals. */
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#undef RESTORE2
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#define RESTORE2(name, syscall) \
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asm \
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( \
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".text\n" \
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" .align 8\n" \
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"__" #name ":\n" \
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" popl %eax\n" \
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" movl $" #syscall ", %eax\n" \
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" int $0x80" \
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);
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RESTORE (restore, __NR_sigreturn)
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