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-rw-r--r--debug/backtrace.c94
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diff --git a/debug/backtrace.c b/debug/backtrace.c
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+/* Return backtrace of current program state. Generic version.
+ Copyright (C) 1998, 2000, 2002, 2004, 2005 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
+
+ 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 <signal.h>
+#include <frame.h>
+#include <sigcontextinfo.h>
+#include <bp-checks.h>
+#include <ldsodefs.h>
+
+/* This implementation assumes a stack layout that matches the defaults
+ used by gcc's `__builtin_frame_address' and `__builtin_return_address'
+ (FP is the frame pointer register):
+
+ +-----------------+ +-----------------+
+ FP -> | previous FP --------> | previous FP ------>...
+ | | | |
+ | return address | | return address |
+ +-----------------+ +-----------------+
+
+ */
+
+/* Get some notion of the current stack. Need not be exactly the top
+ of the stack, just something somewhere in the current frame. */
+#ifndef CURRENT_STACK_FRAME
+# define CURRENT_STACK_FRAME ({ char __csf; &__csf; })
+#endif
+
+/* By default we assume that the stack grows downward. */
+#ifndef INNER_THAN
+# define INNER_THAN <
+#endif
+
+/* By default assume the `next' pointer in struct layout points to the
+ next struct layout. */
+#ifndef ADVANCE_STACK_FRAME
+# define ADVANCE_STACK_FRAME(next) BOUNDED_1 ((struct layout *) (next))
+#endif
+
+/* By default, the frame pointer is just what we get from gcc. */
+#ifndef FIRST_FRAME_POINTER
+# define FIRST_FRAME_POINTER __builtin_frame_address (0)
+#endif
+
+int
+__backtrace (array, size)
+ void **array;
+ int size;
+{
+ struct layout *current;
+ void *__unbounded top_frame;
+ void *__unbounded top_stack;
+ int cnt = 0;
+
+ top_frame = FIRST_FRAME_POINTER;
+ top_stack = CURRENT_STACK_FRAME;
+
+ /* We skip the call to this function, it makes no sense to record it. */
+ current = BOUNDED_1 ((struct layout *) top_frame);
+ while (cnt < size)
+ {
+ if ((void *) current INNER_THAN top_stack
+ || !((void *) current INNER_THAN __libc_stack_end))
+ /* This means the address is out of range. Note that for the
+ toplevel we see a frame pointer with value NULL which clearly is
+ out of range. */
+ break;
+
+ array[cnt++] = current->return_address;
+
+ current = ADVANCE_STACK_FRAME (current->next);
+ }
+
+ return cnt;
+}
+weak_alias (__backtrace, backtrace)
+libc_hidden_def (__backtrace)