glibc/sysdeps/unix
Adhemerval Zanella b4a5d26d88 linux: Consolidate sigaction implementation
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.
2018-04-05 17:09:50 -03:00
..
alpha Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
arm Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
bsd hurd: Avoid some PLTs in libc and librt 2018-04-02 19:07:52 +00:00
i386 Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
inet Remove add-ons mechanism. 2017-10-05 15:58:13 +00:00
mips Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
powerpc Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
sh Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
sysv/linux linux: Consolidate sigaction implementation 2018-04-05 17:09:50 -03:00
x86_64 Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
clock_gettime.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
clock_nanosleep.c hurd: Avoid some PLTs in libc and librt 2018-04-02 19:07:52 +00:00
clock_settime.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
confstr.h
get_child_max.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
getlogin_r.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
getlogin.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
getpagesize.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
grantpt.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
ifreq.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
Implies
make-syscalls.sh Fix make-syscalls.sh VDSO support for GCC 8. 2017-09-26 21:21:01 +00:00
Makefile Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s-proto-cancel.S
s-proto.S
setxid.h Update. 2004-11-12 01:27:04 +00:00
sockatmark.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
stime.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
syscall-template.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
syscall.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
syscalls.list posix: Consolidate Linux fsync syscall 2017-05-18 18:06:47 -03:00
sysdep.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00