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Re: [PATCH 2/5] alpha: Use Linux generic sigaction implementation
I will commit this shortly if no one opposes it.
On 11/12/2018 17:55, Adhemerval Zanella wrote:
> Alpha rt_sigaction syscall uses a slight different kernel ABI than
> generic one:
>
> arch/alpha/kernel/signal.c
>
> 90 SYSCALL_DEFINE5(rt_sigaction, int, sig, const struct sigaction __user *, act,
> 91 struct sigaction __user *, oact,
> 92 size_t, sigsetsize, void __user *, restorer)
>
> Similar as sparc, the syscall expects a restorer function. However
> different than sparc, alpha defines the restorer as the 5th argument
> (sparc defines as the 4th).
>
> This patch removes the arch-specific alpha sigaction implementation,
> adapt the Linux generic one to different restore placements (through
> STUB macro), and make alpha use the Linux generic kernel_sigaction
> definition.
>
> Checked on alpha-linux-gnu and x86_64-linux-gnu (for sanity).
>
> * sysdeps/unix/sysv/linux/alpha/Makefile: Update comment about
> __syscall_rt_sigaction.
> * sysdeps/unix/sysv/linux/alpha/kernel_sigaction.h
> (kernel_sigaction): Use Linux generic defintion.
> (STUB): Define.
> (__syscall_rt_sigreturn, __syscall_sigreturn): Add prototype.
> * sysdeps/unix/sysv/linux/alpha/rt_sigaction.S
> (__syscall_rt_sigaction): Remove implementation.
> (__syscall_sigreturn, __syscall_rt_sigreturn): Define as global and
> hidden.
> * sysdeps/unix/sysv/linux/alpha/sigaction.c: Remove file.
> * sysdeps/unix/sysv/linux/alpha/sysdep.h (INLINE_SYSCALL,
> INTERNAL_SYSCALL): Remove definitions.
> * sysdeps/unix/sysv/linux/sigaction.c: Define STUB to accept both the
> action and signal set size.
> * sysdeps/unix/sysv/linux/sparc/sparc32/sigaction.c (STUB): Redefine.
> * sysdeps/unix/sysv/linux/sparc/sparc64/sigaction.c (STUB): Likewise.
> ---
> ChangeLog | 20 +++++++++
> sysdeps/unix/sysv/linux/alpha/Makefile | 2 +-
> .../unix/sysv/linux/alpha/kernel_sigaction.h | 19 ++++-----
> sysdeps/unix/sysv/linux/alpha/rt_sigaction.S | 41 ++-----------------
> sysdeps/unix/sysv/linux/alpha/sigaction.c | 38 -----------------
> sysdeps/unix/sysv/linux/alpha/sysdep.h | 23 -----------
> sysdeps/unix/sysv/linux/sigaction.c | 4 +-
> .../unix/sysv/linux/sparc/sparc32/sigaction.c | 5 ++-
> .../unix/sysv/linux/sparc/sparc64/sigaction.c | 5 ++-
> 9 files changed, 42 insertions(+), 115 deletions(-)
> delete mode 100644 sysdeps/unix/sysv/linux/alpha/sigaction.c
>
> diff --git a/sysdeps/unix/sysv/linux/alpha/Makefile b/sysdeps/unix/sysv/linux/alpha/Makefile
> index 50f4fb1183..fdd089af71 100644
> --- a/sysdeps/unix/sysv/linux/alpha/Makefile
> +++ b/sysdeps/unix/sysv/linux/alpha/Makefile
> @@ -31,7 +31,7 @@ libm-routines += multc3 divtc3
> endif # math
>
> ifeq ($(subdir),nptl)
> -# pull in __syscall_error routine, __sigprocmask, __syscall_rt_sigaction
> +# pull in __syscall_error routine, __sigprocmask, sigaction stubs.
> libpthread-routines += sysdep sigprocmask rt_sigaction
> libpthread-shared-only-routines += sysdep sigprocmask rt_sigaction
> endif
> diff --git a/sysdeps/unix/sysv/linux/alpha/kernel_sigaction.h b/sysdeps/unix/sysv/linux/alpha/kernel_sigaction.h
> index 25180ff9c9..679179b563 100644
> --- a/sysdeps/unix/sysv/linux/alpha/kernel_sigaction.h
> +++ b/sysdeps/unix/sysv/linux/alpha/kernel_sigaction.h
> @@ -1,12 +1,11 @@
> -#ifndef _KERNEL_SIGACTION_H
> -# define _KERNEL_SIGACTION_H
> +#include <sysdeps/unix/sysv/linux/kernel_sigaction.h>
>
> -/* This is the sigaction structure from the Linux 3.2 kernel. */
> -struct kernel_sigaction
> -{
> - __sighandler_t k_sa_handler;
> - unsigned int sa_flags;
> - sigset_t sa_mask;
> -};
> +void __syscall_rt_sigreturn (void) attribute_hidden;
> +void __syscall_sigreturn (void) attribute_hidden;
>
> -#endif
> +#define STUB(act, sigsetsize) \
> + (sigsetsize), \
> + (act) ? ((unsigned long)((act->sa_flags & SA_SIGINFO) \
> + ? &__syscall_rt_sigreturn \
> + : &__syscall_sigreturn)) \
> + : 0
> diff --git a/sysdeps/unix/sysv/linux/alpha/rt_sigaction.S b/sysdeps/unix/sysv/linux/alpha/rt_sigaction.S
> index ca25eee611..17e55239fe 100644
> --- a/sysdeps/unix/sysv/linux/alpha/rt_sigaction.S
> +++ b/sysdeps/unix/sysv/linux/alpha/rt_sigaction.S
> @@ -18,43 +18,6 @@
>
> #include <sysdep.h>
>
> -/* On Alpha we desparately want to avoid having to issue an imb. Ordinarily
> - the kernel would have to issue one after setting up the signal return
> - stack, but the Linux rt_sigaction syscall is prepared to accept a pointer
> - to the sigreturn syscall, instead of inlining it on the stack.
> -
> - This just about halves signal delivery time. */
> -
> - .text
> -
> -ENTRY(__syscall_rt_sigaction)
> - cfi_startproc
> - ldgp gp,0(pv)
> -#ifdef PROF
> - .set noat
> - lda AT, _mcount
> - jsr AT, (AT), _mcount
> - .set at
> -#endif
> - .prologue 1
> -
> - beq a1, 0f
> - ldl t0, 8(a1) # sa_flags
> -
> - ldah a4, __syscall_sigreturn(gp) !gprelhigh
> - ldah t1, __syscall_rt_sigreturn(gp) !gprelhigh
> - lda a4, __syscall_sigreturn(a4) !gprellow
> - lda t1, __syscall_rt_sigreturn(t1) !gprellow
> - and t0, 0x40, t0 # SA_SIGINFO
> - cmovne t0, t1, a4
> -
> -0: ldi v0, __NR_rt_sigaction
> - callsys
> - bne a3, SYSCALL_ERROR_LABEL
> - ret
> - cfi_endproc
> -PSEUDO_END(__syscall_rt_sigaction)
> -
> /* To enable unwinding through the signal frame without special hackery
> elsewhere, describe the entire struct sigcontext with unwind info.
>
> @@ -104,6 +67,8 @@ __syscall_sigreturn:
> callsys
> .size __syscall_sigreturn, .-__syscall_sigreturn
> .type __syscall_sigreturn, @function
> + .global __syscall_sigreturn;
> + .hidden __syscall_sigreturn;
>
> /* See above wrt including the nop. */
> cfi_def_cfa_offset (176 + 648)
> @@ -116,5 +81,7 @@ __syscall_rt_sigreturn:
> callsys
> .size __syscall_rt_sigreturn, .-__syscall_rt_sigreturn
> .type __syscall_rt_sigreturn, @function
> + .global __syscall_rt_sigreturn;
> + .hidden __syscall_rt_sigreturn;
>
> cfi_endproc
> diff --git a/sysdeps/unix/sysv/linux/alpha/sigaction.c b/sysdeps/unix/sysv/linux/alpha/sigaction.c
> deleted file mode 100644
> index 8051043587..0000000000
> --- a/sysdeps/unix/sysv/linux/alpha/sigaction.c
> +++ /dev/null
> @@ -1,38 +0,0 @@
> -/* Copyright (C) 2003-2018 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
> - <http://www.gnu.org/licenses/>. */
> -
> -#include <sysdep.h>
> -#include <sys/cdefs.h>
> -#include <stddef.h>
> -
> -/*
> - * In order to get the hidden arguments for rt_sigaction set up
> - * properly, we need to call the assembly version. Detect this in the
> - * INLINE_SYSCALL macro, and fail to expand inline in that case.
> - */
> -
> -#undef INLINE_SYSCALL
> -#define INLINE_SYSCALL(name, nr, args...) \
> - (__NR_##name == __NR_rt_sigaction \
> - ? __syscall_rt_sigaction(args) \
> - : INLINE_SYSCALL1(name, nr, args))
> -
> -struct kernel_sigaction;
> -extern int __syscall_rt_sigaction (int, const struct kernel_sigaction *,
> - struct kernel_sigaction *, size_t);
> -
> -#include <sysdeps/unix/sysv/linux/sigaction.c>
> diff --git a/sysdeps/unix/sysv/linux/alpha/sysdep.h b/sysdeps/unix/sysv/linux/alpha/sysdep.h
> index 080405021f..9148b4793b 100644
> --- a/sysdeps/unix/sysv/linux/alpha/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/alpha/sysdep.h
> @@ -72,27 +72,4 @@
>
> #define SINGLE_THREAD_BY_GLOBAL 1
>
> -/*
> - * In order to get the hidden arguments for rt_sigaction set up
> - * properly, we need to call the assembly version. This shouldn't
> - * happen except for inside sigaction.c, where we handle this
> - * specially. Catch other uses and error.
> - */
> -
> -#undef INLINE_SYSCALL
> -#define INLINE_SYSCALL(name, nr, args...) \
> -({ \
> - extern char ChEcK[__NR_##name == __NR_rt_sigaction ? -1 : 1] \
> - __attribute__((unused)); \
> - INLINE_SYSCALL1(name, nr, args); \
> -})
> -
> -#undef INTERNAL_SYSCALL
> -#define INTERNAL_SYSCALL(name, err_out, nr, args...) \
> -({ \
> - extern char ChEcK[__NR_##name == __NR_rt_sigaction ? -1 : 1] \
> - __attribute__((unused)); \
> - INTERNAL_SYSCALL1(name, err_out, nr, args); \
> -})
> -
> #endif /* _LINUX_ALPHA_SYSDEP_H */
> diff --git a/sysdeps/unix/sysv/linux/sigaction.c b/sysdeps/unix/sysv/linux/sigaction.c
> index 0e6851a148..233ab1fcb5 100644
> --- a/sysdeps/unix/sysv/linux/sigaction.c
> +++ b/sysdeps/unix/sysv/linux/sigaction.c
> @@ -33,7 +33,7 @@
>
> /* SPARC passes the restore function as an argument to rt_sigaction. */
> #ifndef STUB
> -# define STUB(act)
> +# define STUB(act, sigsetsize) (sigsetsize)
> #endif
>
> /* If ACT is not NULL, change the action for SIG to *ACT.
> @@ -57,7 +57,7 @@ __libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
> real size of the user-level sigset_t. */
> result = INLINE_SYSCALL_CALL (rt_sigaction, sig,
> act ? &kact : NULL,
> - oact ? &koact : NULL, STUB(act) _NSIG / 8);
> + oact ? &koact : NULL, STUB (act, _NSIG / 8));
>
> if (oact && result >= 0)
> {
> diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/sigaction.c b/sysdeps/unix/sysv/linux/sparc/sparc32/sigaction.c
> index 191f58729e..9f1a31a3b3 100644
> --- a/sysdeps/unix/sysv/linux/sparc/sparc32/sigaction.c
> +++ b/sysdeps/unix/sysv/linux/sparc/sparc32/sigaction.c
> @@ -27,11 +27,12 @@
> static void __rt_sigreturn_stub (void);
> static void __sigreturn_stub (void);
>
> -#define STUB(act) \
> +#define STUB(act, sigsetsize) \
> (act) ? ((unsigned long)((act->sa_flags & SA_SIGINFO) \
> ? &__rt_sigreturn_stub \
> : &__sigreturn_stub) - 8) \
> - : 0,
> + : 0, \
> + (sigsetsize)
>
> #include <sysdeps/unix/sysv/linux/sigaction.c>
>
> diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/sigaction.c b/sysdeps/unix/sysv/linux/sparc/sparc64/sigaction.c
> index cfbbc6e7b4..acc76b1bf9 100644
> --- a/sysdeps/unix/sysv/linux/sparc/sparc64/sigaction.c
> +++ b/sysdeps/unix/sysv/linux/sparc/sparc64/sigaction.c
> @@ -24,8 +24,9 @@
>
> static void __rt_sigreturn_stub (void);
>
> -#define STUB(act) \
> - (((unsigned long) &__rt_sigreturn_stub) - 8),
> +#define STUB(act, sigsetsize) \
> + (((unsigned long) &__rt_sigreturn_stub) - 8), \
> + (sigsetsize)
>
> #include <sysdeps/unix/sysv/linux/sigaction.c>
>
>