Re: issue with SIGPROF signal handler on ARM

["Arvind Ayyangar" <arvind dot ayyangar at gmail dot com>]

> I assume you also had to change the signal handler to set SA_SIGINFO;

Yes, I did .


> if you didn't I'm not sure why it worked.  Here's what I checked
> in to fix this.

Thanks..

-Arvind





> --
> Daniel Jacobowitz
> CodeSourcery
>
> 2007-12-21  Daniel Jacobowitz  <dan@codesourcery.com>
>
>         * sysdeps/unix/sysv/linux/arm/profil-counter.h: Use the i386 version.
>         * sysdeps/unix/sysv/linux/arm/register-dump.h (register_dump): Update
>         to use ucontext.
>         (REGISTER_DUMP): Likewise.
>         * sysdeps/unix/sysv/linux/arm/sigcontextinfo.h (SIGCONTEXT,
>         SIGCONTEXT_EXTRA_ARGS, GET_PC, GET_FRAME, GET_STACK): Likewise.
>         (sigaction, __sigaction): Define.
>         * sysdeps/unix/sysv/linux/arm/bits/armsigctx.h: Delete.
>
> Index: sysdeps/unix/sysv/linux/arm/profil-counter.h
> ===================================================================
> RCS file: /cvs/glibc/ports/sysdeps/unix/sysv/linux/arm/profil-counter.h,v
> retrieving revision 1.8
> diff -u -p -r1.8 profil-counter.h
> --- sysdeps/unix/sysv/linux/arm/profil-counter.h        14 Oct 2002 17:26:14 -0000      1.8
> +++ sysdeps/unix/sysv/linux/arm/profil-counter.h        21 Dec 2007 16:29:19 -0000
> @@ -1,37 +1,2 @@
> -/* Low-level statistical profiling support function.  Linux/ARM version.
> -   Copyright (C) 1996, 1997, 1998, 2002 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, write to the Free
> -   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
> -   02111-1307 USA.  */
> -
> -#include <signal.h>
> -#include <bits/armsigctx.h>
> -
> -void
> -profil_counter (int signo, int _a2, int _a3, int _a4, union k_sigcontext sc)
> -{
> -  void *pc;
> -  if (sc.v20.magic == SIGCONTEXT_2_0_MAGIC)
> -    pc = (void *) sc.v20.reg.ARM_pc;
> -  else
> -    pc = (void *) sc.v21.arm_pc;
> -  profil_count (pc);
> -
> -  /* This is a hack to prevent the compiler from implementing the
> -     above function call as a sibcall.  The sibcall would overwrite
> -     the signal context.  */
> -  asm volatile ("");
> -}
> +/* We can use the ix86 version.  */
> +#include <sysdeps/unix/sysv/linux/i386/profil-counter.h>
> Index: sysdeps/unix/sysv/linux/arm/register-dump.h
> ===================================================================
> RCS file: /cvs/glibc/ports/sysdeps/unix/sysv/linux/arm/register-dump.h,v
> retrieving revision 1.5
> diff -u -p -r1.5 register-dump.h
> --- sysdeps/unix/sysv/linux/arm/register-dump.h 6 Jul 2001 04:56:13 -0000       1.5
> +++ sysdeps/unix/sysv/linux/arm/register-dump.h 21 Dec 2007 16:29:19 -0000
> @@ -20,7 +20,7 @@
>
>  #include <sys/uio.h>
>  #include <stdio-common/_itoa.h>
> -#include <bits/armsigctx.h>
> +#include <sys/ucontext.h>
>
>  /* We will print the register dump in this format:
>
> @@ -45,7 +45,7 @@ hexvalue (unsigned long int value, char
>  }
>
>  static void
> -register_dump (int fd, union k_sigcontext *ctx)
> +register_dump (int fd, const struct ucontext *ctx)
>  {
>    char regs[21][8];
>    struct iovec iov[97];
> @@ -61,53 +61,27 @@ register_dump (int fd, union k_sigcontex
>    ++nr
>
>    /* Generate strings of register contents.  */
> -  if (ctx->v20.magic == SIGCONTEXT_2_0_MAGIC)
> -    {
> -      hexvalue (ctx->v20.reg.ARM_r0, regs[0], 8);
> -      hexvalue (ctx->v20.reg.ARM_r1, regs[1], 8);
> -      hexvalue (ctx->v20.reg.ARM_r2, regs[2], 8);
> -      hexvalue (ctx->v20.reg.ARM_r3, regs[3], 8);
> -      hexvalue (ctx->v20.reg.ARM_r4, regs[4], 8);
> -      hexvalue (ctx->v20.reg.ARM_r5, regs[5], 8);
> -      hexvalue (ctx->v20.reg.ARM_r6, regs[6], 8);
> -      hexvalue (ctx->v20.reg.ARM_r7, regs[7], 8);
> -      hexvalue (ctx->v20.reg.ARM_r8, regs[8], 8);
> -      hexvalue (ctx->v20.reg.ARM_r9, regs[9], 8);
> -      hexvalue (ctx->v20.reg.ARM_r10, regs[10], 8);
> -      hexvalue (ctx->v20.reg.ARM_fp, regs[11], 8);
> -      hexvalue (ctx->v20.reg.ARM_ip, regs[12], 8);
> -      hexvalue (ctx->v20.reg.ARM_sp, regs[13], 8);
> -      hexvalue (ctx->v20.reg.ARM_lr, regs[14], 8);
> -      hexvalue (ctx->v20.reg.ARM_pc, regs[15], 8);
> -      hexvalue (ctx->v20.reg.ARM_cpsr, regs[16], 8);
> -      hexvalue (ctx->v20.trap_no, regs[17], 8);
> -      hexvalue (ctx->v20.error_code, regs[18], 8);
> -      hexvalue (ctx->v20.oldmask, regs[19], 8);
> -    }
> -  else
> -    {
> -      hexvalue (ctx->v21.arm_r0, regs[0], 8);
> -      hexvalue (ctx->v21.arm_r1, regs[1], 8);
> -      hexvalue (ctx->v21.arm_r2, regs[2], 8);
> -      hexvalue (ctx->v21.arm_r3, regs[3], 8);
> -      hexvalue (ctx->v21.arm_r4, regs[4], 8);
> -      hexvalue (ctx->v21.arm_r5, regs[5], 8);
> -      hexvalue (ctx->v21.arm_r6, regs[6], 8);
> -      hexvalue (ctx->v21.arm_r7, regs[7], 8);
> -      hexvalue (ctx->v21.arm_r8, regs[8], 8);
> -      hexvalue (ctx->v21.arm_r9, regs[9], 8);
> -      hexvalue (ctx->v21.arm_r10, regs[10], 8);
> -      hexvalue (ctx->v21.arm_fp, regs[11], 8);
> -      hexvalue (ctx->v21.arm_ip, regs[12], 8);
> -      hexvalue (ctx->v21.arm_sp, regs[13], 8);
> -      hexvalue (ctx->v21.arm_lr, regs[14], 8);
> -      hexvalue (ctx->v21.arm_pc, regs[15], 8);
> -      hexvalue (ctx->v21.arm_cpsr, regs[16], 8);
> -      hexvalue (ctx->v21.trap_no, regs[17], 8);
> -      hexvalue (ctx->v21.error_code, regs[18], 8);
> -      hexvalue (ctx->v21.oldmask, regs[19], 8);
> -      hexvalue (ctx->v21.fault_address, regs[20], 8);
> -    }
> +  hexvalue (ctx->uc_mcontext.arm_r0, regs[0], 8);
> +  hexvalue (ctx->uc_mcontext.arm_r1, regs[1], 8);
> +  hexvalue (ctx->uc_mcontext.arm_r2, regs[2], 8);
> +  hexvalue (ctx->uc_mcontext.arm_r3, regs[3], 8);
> +  hexvalue (ctx->uc_mcontext.arm_r4, regs[4], 8);
> +  hexvalue (ctx->uc_mcontext.arm_r5, regs[5], 8);
> +  hexvalue (ctx->uc_mcontext.arm_r6, regs[6], 8);
> +  hexvalue (ctx->uc_mcontext.arm_r7, regs[7], 8);
> +  hexvalue (ctx->uc_mcontext.arm_r8, regs[8], 8);
> +  hexvalue (ctx->uc_mcontext.arm_r9, regs[9], 8);
> +  hexvalue (ctx->uc_mcontext.arm_r10, regs[10], 8);
> +  hexvalue (ctx->uc_mcontext.arm_fp, regs[11], 8);
> +  hexvalue (ctx->uc_mcontext.arm_ip, regs[12], 8);
> +  hexvalue (ctx->uc_mcontext.arm_sp, regs[13], 8);
> +  hexvalue (ctx->uc_mcontext.arm_lr, regs[14], 8);
> +  hexvalue (ctx->uc_mcontext.arm_pc, regs[15], 8);
> +  hexvalue (ctx->uc_mcontext.arm_cpsr, regs[16], 8);
> +  hexvalue (ctx->uc_mcontext.trap_no, regs[17], 8);
> +  hexvalue (ctx->uc_mcontext.error_code, regs[18], 8);
> +  hexvalue (ctx->uc_mcontext.oldmask, regs[19], 8);
> +  hexvalue (ctx->uc_mcontext.fault_address, regs[20], 8);
>
>    /* Generate the output.  */
>    ADD_STRING ("Register dump:\n\n R0: ");
> @@ -150,11 +124,8 @@ register_dump (int fd, union k_sigcontex
>    ADD_MEM (regs[18], 8);
>    ADD_STRING ("   OldMask: ");
>    ADD_MEM (regs[19], 8);
> -  if (ctx->v20.magic != SIGCONTEXT_2_0_MAGIC)
> -    {
> -      ADD_STRING ("\n Addr: ");
> -      ADD_MEM (regs[20], 8);
> -    }
> +  ADD_STRING ("\n Addr: ");
> +  ADD_MEM (regs[20], 8);
>
>    ADD_STRING ("\n");
>
> @@ -163,4 +134,4 @@ register_dump (int fd, union k_sigcontex
>  }
>
>
> -#define REGISTER_DUMP register_dump (fd, &ctx)
> +#define REGISTER_DUMP register_dump (fd, ctx)
> Index: sysdeps/unix/sysv/linux/arm/sigcontextinfo.h
> ===================================================================
> RCS file: /cvs/glibc/ports/sysdeps/unix/sysv/linux/arm/sigcontextinfo.h,v
> retrieving revision 1.8
> diff -u -p -r1.8 sigcontextinfo.h
> --- sysdeps/unix/sysv/linux/arm/sigcontextinfo.h        21 Dec 2002 18:37:16 -0000      1.8
> +++ sysdeps/unix/sysv/linux/arm/sigcontextinfo.h        21 Dec 2007 16:29:19 -0000
> @@ -17,35 +17,34 @@
>     Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
>     02111-1307 USA.  */
>
> -#include <bits/armsigctx.h>
> +#include <sys/ucontext.h>
>  #include "kernel-features.h"
>
> -#define SIGCONTEXT int _a2, int _a3, int _a4, union k_sigcontext
> -#define SIGCONTEXT_EXTRA_ARGS _a2, _a3, _a4,
> +#define SIGCONTEXT siginfo_t *_si, struct ucontext *
> +#define SIGCONTEXT_EXTRA_ARGS _si,
>
>  /* The sigcontext structure changed between 2.0 and 2.1 kernels.  On any
>     modern system we should be able to assume that the "new" format will be
>     in use.  */
> -#if __LINUX_KERNEL_VERSION > 131328
>
> -#define GET_PC(ctx)    ((void *) ctx.v21.arm_pc)
> -#define GET_FRAME(ctx) ADVANCE_STACK_FRAME ((void *) ctx.v21.arm_fp)
> -#define GET_STACK(ctx) ((void *) ctx.v21.arm_sp)
> -
> -#else
> -
> -#define GET_PC(ctx)    ((void *)((ctx.v20.magic == SIGCONTEXT_2_0_MAGIC) ? \
> -                        ctx.v20.reg.ARM_pc : ctx.v21.arm_pc))
> -#define GET_FRAME(ctx) \
> -       ADVANCE_STACK_FRAME((void *)((ctx.v20.magic == SIGCONTEXT_2_0_MAGIC) ? \
> -                        ctx.v20.reg.ARM_fp : ctx.v21.arm_fp))
> -#define GET_STACK(ctx) ((void *)((ctx.v20.magic == SIGCONTEXT_2_0_MAGIC) ? \
> -                        ctx.v20.reg.ARM_sp : ctx.v21.arm_sp))
> -
> -#endif
> +#define GET_PC(ctx)    ((void *) (ctx)->uc_mcontext.arm_pc)
> +#define GET_FRAME(ctx) ADVANCE_STACK_FRAME ((void *) ctx->uc_mcontext.arm_fp)
> +#define GET_STACK(ctx) ((void *) (ctx)->uc_mcontext.arm_sp)
>
>  #define ADVANCE_STACK_FRAME(frm)       \
>                         ((struct layout *)frm - 1)
>
>  #define CALL_SIGHANDLER(handler, signo, ctx) \
>    (handler)((signo), SIGCONTEXT_EXTRA_ARGS (ctx))
> +
> +/* There is no reliable way to get the sigcontext unless we use a
> +   three-argument signal handler.  */
> +#define __sigaction(sig, act, oact) ({ \
> +  (act)->sa_flags |= SA_SIGINFO; \
> +  (__sigaction) (sig, act, oact); \
> +})
> +
> +#define sigaction(sig, act, oact) ({ \
> +  (act)->sa_flags |= SA_SIGINFO; \
> +  (sigaction) (sig, act, oact); \
> +})
> Index: sysdeps/unix/sysv/linux/arm/bits/armsigctx.h
> ===================================================================
> RCS file: sysdeps/unix/sysv/linux/arm/bits/armsigctx.h
> diff -N sysdeps/unix/sysv/linux/arm/bits/armsigctx.h
> --- sysdeps/unix/sysv/linux/arm/bits/armsigctx.h        6 Jul 2001 04:56:13 -0000       1.5
> +++ /dev/null   1 Jan 1970 00:00:00 -0000
> @@ -1,73 +0,0 @@
> -/* Definition of `struct sigcontext' for Linux/ARM
> -   Copyright (C) 1996, 1997, 1998, 1999, 2000 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, write to the Free
> -   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
> -   02111-1307 USA.  */
> -
> -/* The format of struct sigcontext changed between 2.0 and 2.1 kernels.
> -   Fortunately 2.0 puts a magic number in the first word and this is not
> -   a legal value for `trap_no', so we can tell them apart.  */
> -
> -/* Early 2.2 and 2.3 kernels do not have the `fault_address' member in
> -   the sigcontext structure.  Unfortunately there is no reliable way
> -   to test for its presence and this word will contain garbage for too-old
> -   kernels.  Versions 2.2.14 and 2.3.35 (plus later versions) are known to
> -   include this element.  */
> -
> -#ifndef __ARMSIGCTX_H
> -#define __ARMSIGCTX_H  1
> -
> -#include <asm/ptrace.h>
> -
> -union k_sigcontext
> -  {
> -    struct
> -      {
> -       unsigned long int trap_no;
> -       unsigned long int error_code;
> -       unsigned long int oldmask;
> -       unsigned long int arm_r0;
> -       unsigned long int arm_r1;
> -       unsigned long int arm_r2;
> -       unsigned long int arm_r3;
> -       unsigned long int arm_r4;
> -       unsigned long int arm_r5;
> -       unsigned long int arm_r6;
> -       unsigned long int arm_r7;
> -       unsigned long int arm_r8;
> -       unsigned long int arm_r9;
> -       unsigned long int arm_r10;
> -       unsigned long int arm_fp;
> -       unsigned long int arm_ip;
> -       unsigned long int arm_sp;
> -       unsigned long int arm_lr;
> -       unsigned long int arm_pc;
> -       unsigned long int arm_cpsr;
> -       unsigned long fault_address;
> -      } v21;
> -    struct
> -      {
> -       unsigned long int magic;
> -       struct pt_regs reg;
> -       unsigned long int trap_no;
> -       unsigned long int error_code;
> -       unsigned long int oldmask;
> -      } v20;
> -};
> -
> -#define SIGCONTEXT_2_0_MAGIC   0x4B534154
> -
> -#endif /* bits/armsigctx.h */
>