src/patches/glibc/glibc-rh868808.patch

   1 From d6f67f7d833b4e2039f832355fb0edd65522c9f4 Mon Sep 17 00:00:00 2001
   2 From: Ulrich Drepper <drepper@gmail.com>
   3 Date: Sat, 14 May 2011 10:46:17 -0400
   4 Subject: [PATCH] Handle recursive calls in backtrace better
   5
   6 ---
   7  ChangeLog                |    7 +++++++
   8  NEWS                     |   12 ++++++------
   9  sysdeps/ia64/backtrace.c |   27 +++++++++++++++++++++++----
  10  3 files changed, 36 insertions(+), 10 deletions(-)
  11
  12  2011-05-14  Ulrich Drepper  <drepper@gmail.com>
  13
  14         [BZ #12432]
  15         * sysdeps/ia64/backtrace.c (struct trace_reg): Add cfa element.
  16         (dummy_getcfa): New function.
  17         (init): Get _Unwind_GetCFA address, use dummy if not found.
  18         (backtrace_helper): In recursion check, also check whether CFA changes.
  19         (__backtrace): Completely initialize arg.
  20
  21 diff --git a/sysdeps/ia64/backtrace.c b/sysdeps/ia64/backtrace.c
  22 index 5cefb86..d4ff291 100644
  23 --- a/sysdeps/ia64/backtrace.c
  24 +++ b/sysdeps/ia64/backtrace.c
  25 @@ -1,5 +1,5 @@
  26  /* Return backtrace of current program state.
  27 -   Copyright (C) 2003, 2004, 2005, 2007, 2009 Free Software Foundation, Inc.
  28 +   Copyright (C) 2003-2005, 2007, 2009, 2011 Free Software Foundation, Inc.
  29     This file is part of the GNU C Library.
  30     Contributed by Jakub Jelinek <jakub@redhat.com>, 2003.
  31
  32 @@ -27,14 +27,26 @@
  33  struct trace_arg
  34  {
  35    void **array;
  36 -  int cnt, size;
  37 +  _Unwind_Word cfa;
  38 +  int cnt;
  39 +  int size;
  40  };
  41
  42  #ifdef SHARED
  43  static _Unwind_Reason_Code (*unwind_backtrace) (_Unwind_Trace_Fn, void *);
  44  static _Unwind_Ptr (*unwind_getip) (struct _Unwind_Context *);
  45 +static _Unwind_Word (*unwind_getcfa) (struct _Unwind_Context *);
  46  static void *libgcc_handle;
  47
  48 +
  49 +/* Dummy version in case libgcc_s does not contain the real code.  */
  50 +static _Unwind_Word
  51 +dummy_getcfa (struct _Unwind_Context *ctx __attribute__ ((unused)))
  52 +{
  53 +  return 0;
  54 +}
  55 +
  56 +
  57  static void
  58  init (void)
  59  {
  60 @@ -47,10 +59,13 @@ init (void)
  61    unwind_getip = __libc_dlsym (libgcc_handle, "_Unwind_GetIP");
  62    if (unwind_getip == NULL)
  63      unwind_backtrace = NULL;
  64 +  unwind_getcfa = (__libc_dlsym (libgcc_handle, "_Unwind_GetCFA")
  65 +                  ?: dummy_getcfa);
  66  }
  67  #else
  68  # define unwind_backtrace _Unwind_Backtrace
  69  # define unwind_getip _Unwind_GetIP
  70 +# define unwind_getcfa _Unwind_GetCFA
  71  #endif
  72
  73  static _Unwind_Reason_Code
  74 @@ -65,8 +80,12 @@ backtrace_helper (struct _Unwind_Context *ctx, void *a)
  75        arg->array[arg->cnt] = (void *) unwind_getip (ctx);
  76
  77        /* Check whether we make any progress.  */
  78 -      if (arg->cnt > 0 && arg->array[arg->cnt - 1] == arg->array[arg->cnt])
  79 +      _Unwind_Word cfa = unwind_getcfa (ctx);
  80 +
  81 +      if (arg->cnt > 0 && arg->array[arg->cnt - 1] == arg->array[arg->cnt]
  82 +         && cfa == arg->cfa)
  83         return _URC_END_OF_STACK;
  84 +      arg->cfa = cfa;
  85      }
  86    if (++arg->cnt == arg->size)
  87      return _URC_END_OF_STACK;
  88 @@ -78,7 +97,7 @@ __backtrace (array, size)
  89       void **array;
  90       int size;
  91  {
  92 -  struct trace_arg arg = { .array = array, .size = size, .cnt = -1 };
  93 +  struct trace_arg arg = { .array = array, .cfa = 0, .size = size, .cnt = -1 };
  94  #ifdef SHARED
  95    __libc_once_define (static, once);
  96
  97 --
  98 1.7.1
  99