Re: [Patches] Add more backtrace tests

["Joseph S. Myers" <joseph@xxxxxxxxxxxxxxxx>]

I've added a further backtrace test, for a noreturn leaf function 
(backtracing from noreturn functions is important - they may include error 
handlers or abort(), for example - and has been known to have problems (in 
particular there were problems on ARM for a long time because GCC didn't 
save enough registers)).

This one does fail for x86_64 (with GCC 4.6), unlike the previous ones; it 
looks like it may be a real problem with the unwind info there.

Index: ports/sysdeps/arm/eabi/Makefile
===================================================================
--- ports/sysdeps/arm/eabi/Makefile	(revision 16142)
+++ ports/sysdeps/arm/eabi/Makefile	(working copy)
@@ -25,6 +25,7 @@
 CFLAGS-tst-backtrace3.c += -funwind-tables
 CFLAGS-tst-backtrace4.c += -funwind-tables
 CFLAGS-tst-backtrace5.c += -funwind-tables
+CFLAGS-tst-backtrace6.c += -funwind-tables
 endif
 
 ifeq ($(subdir),elf)
Index: ports/ChangeLog.eglibc
===================================================================
--- ports/ChangeLog.eglibc	(revision 16142)
+++ ports/ChangeLog.eglibc	(working copy)
@@ -1,3 +1,7 @@
+2011-12-07  Joseph Myers  <joseph@xxxxxxxxxxxxxxxx>
+
+	* sysdeps/arm/eabi/Makefile (CFLAGS-tst-backtrace6.c): Define.
+
 2011-12-01  Joseph Myers  <joseph@xxxxxxxxxxxxxxxx>
 
 	* sysdeps/arm/eabi/Makefile (CFLAGS-tst-backtrace3.c)
Index: libc/debug/Makefile
===================================================================
--- libc/debug/Makefile	(revision 16142)
+++ libc/debug/Makefile	(working copy)
@@ -134,13 +134,14 @@
 LDFLAGS-tst-backtrace3 = -rdynamic
 LDFLAGS-tst-backtrace4 = -rdynamic
 LDFLAGS-tst-backtrace5 = -rdynamic
+LDFLAGS-tst-backtrace6 = -rdynamic
 
 tests = tst-longjmp_chk test-strcpy_chk test-stpcpy_chk tst-longjmp_chk2
 tests-$(OPTION_EGLIBC_LOCALE_CODE) \
       += tst-chk1 tst-chk2 tst-chk3 tst-lfschk1 tst-lfschk2 tst-lfschk3 
 tests-$(OPTION_EGLIBC_BACKTRACE) \
       += backtrace-tst tst-backtrace2 tst-backtrace3 tst-backtrace4 \
-         tst-backtrace5
+         tst-backtrace5 tst-backtrace6
 ifeq (yy,$(OPTION_EGLIBC_LOCALE_CODE)$(OPTION_EGLIBC_CXX_TESTS))
 tests += tst-chk4 tst-chk5 tst-chk6 tst-lfschk4 tst-lfschk5 tst-lfschk6
 endif
Index: libc/debug/tst-backtrace6.c
===================================================================
--- libc/debug/tst-backtrace6.c	(revision 0)
+++ libc/debug/tst-backtrace6.c	(revision 0)
@@ -0,0 +1,152 @@
+/* Copyright (C) 2011 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by CodeSourcery.
+
+   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 <execinfo.h>
+#include <search.h>
+#include <setjmp.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <signal.h>
+#include <unistd.h>
+
+static int do_test (void);
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
+
+/* Set to a non-zero value if the test fails.  */
+volatile int ret;
+
+/* Accesses to X are used to prevent optimization.  */
+volatile int x;
+
+/* Called if the test fails.  */
+#define FAIL() \
+  do { printf ("Failure on line %d\n", __LINE__); ret = 1; } while (0)
+
+/* The backtrace should include at least handle_signal, a signal
+   trampoline, noreturn_func, 3 * fn, and do_test.  */
+#define NUM_FUNCTIONS 7
+
+/* Use this attribute to prevent inlining, so that all expected frames
+   are present.  */
+#define NO_INLINE __attribute__((noinline))
+
+jmp_buf b;
+
+void
+handle_signal (int signum)
+{
+  void *addresses[NUM_FUNCTIONS];
+  char **symbols;
+  int n;
+  int i;
+
+  /* Get the backtrace addresses.  */
+  n = backtrace (addresses, sizeof (addresses) / sizeof (addresses[0]));
+  printf ("Obtained backtrace with %d functions\n", n);
+  /*  Check that there are at least seven functions.  */
+  if (n < NUM_FUNCTIONS)
+    {
+      FAIL ();
+      longjmp (b, 1);
+    }
+  /* Convert them to symbols.  */
+  symbols = backtrace_symbols (addresses, n);
+  /* Check that symbols were obtained.  */
+  if (symbols == NULL)
+    {
+      FAIL ();
+      longjmp (b, 1);
+    }
+  for (i = 0; i < n; ++i)
+    printf ("Function %d: %s\n", i, symbols[i]);
+  /* Check that the function names obtained are accurate.  */
+  if (strstr (symbols[0], "handle_signal") == NULL)
+    {
+      FAIL ();
+      longjmp (b, 1);
+    }
+  /* Do not check name for signal trampoline.  */
+  if (strstr (symbols[2], "noreturn_func") == NULL)
+    {
+      FAIL ();
+      longjmp (b, 1);
+    }
+  for (i = 3; i < n - 1; i++)
+    if (strstr (symbols[i], "fn") == NULL)
+      {
+	FAIL ();
+	longjmp (b, 1);
+      }
+  /* Symbol names are not available for static functions, so we do not
+     check do_test.  */
+
+  longjmp (b, 1);
+}
+
+NO_INLINE __attribute__((noreturn)) void
+noreturn_func (void)
+{
+  while (1)
+    ;
+}
+
+NO_INLINE int
+fn (int c)
+{
+  pid_t parent_pid, child_pid;
+  struct sigaction act;
+
+  if (c > 0)
+    {
+      fn (c - 1);
+      return x;
+    }
+
+  memset (&act, 0, sizeof (act));
+  act.sa_handler = handle_signal;
+  sigemptyset (&act.sa_mask);
+  sigaction (SIGUSR1, &act, NULL);
+  parent_pid = getpid ();
+
+  child_pid = fork ();
+  if (child_pid == (pid_t) -1)
+    abort ();
+  else if (child_pid == 0)
+    {
+      sleep (1);
+      kill (parent_pid, SIGUSR1);
+      _exit (0);
+    }
+
+  /* In the parent.  */
+  if (setjmp (b))
+    return 0;
+  else
+    noreturn_func ();
+}
+
+NO_INLINE static int
+do_test (void)
+{
+  fn (2);
+  return ret;
+}
Index: libc/sysdeps/sh/Makefile
===================================================================
--- libc/sysdeps/sh/Makefile	(revision 16142)
+++ libc/sysdeps/sh/Makefile	(working copy)
@@ -8,4 +8,5 @@
 CFLAGS-tst-backtrace3.c += -funwind-tables
 CFLAGS-tst-backtrace4.c += -funwind-tables
 CFLAGS-tst-backtrace5.c += -funwind-tables
+CFLAGS-tst-backtrace6.c += -funwind-tables
 endif
Index: libc/ChangeLog.eglibc
===================================================================
--- libc/ChangeLog.eglibc	(revision 16142)
+++ libc/ChangeLog.eglibc	(working copy)
@@ -1,3 +1,10 @@
+2011-12-07  Joseph Myers  <joseph@xxxxxxxxxxxxxxxx>
+
+	* debug/tst-backtrace6.c: New test.
+	* debug/Makefile (LDFLAGS-tst-backtrace6): Define.
+	(tests-$(OPTION_EGLIBC_BACKTRACE)): Add new tst-backtrace6.
+	* sysdeps/sh/Makefile (CFLAGS-tst-backtrace6.c): Define.
+
 2011-12-02  Joseph Myers  <joseph@xxxxxxxxxxxxxxxx>
 
 	* sysdeps/sh/Makefile (CFLAGS-backtrace.c)

-- 
Joseph S. Myers
joseph@xxxxxxxxxxxxxxxx
_______________________________________________
Patches mailing list
Patches@xxxxxxxxxx
http://eglibc.org/cgi-bin/mailman/listinfo/patches