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-rw-r--r--sysdeps/powerpc/powerpc32/backtrace.c66
1 files changed, 66 insertions, 0 deletions
diff --git a/sysdeps/powerpc/powerpc32/backtrace.c b/sysdeps/powerpc/powerpc32/backtrace.c
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+++ b/sysdeps/powerpc/powerpc32/backtrace.c
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+/* Return backtrace of current program state.
+   Copyright (C) 1998, 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.  */
+
+#include <execinfo.h>
+#include <stddef.h>
+#include <bp-checks.h>
+
+/* This is the stack layout we see with every stack frame.
+   Note that every routine is required by the ABI to lay out the stack
+   like this.
+
+            +----------------+        +-----------------+
+    %r1  -> | %r1 last frame--------> | %r1 last frame--->...  --> NULL
+            |                |        |                 |
+            | (unused)       |        | return address  |
+            +----------------+        +-----------------+
+*/
+struct layout
+{
+  struct layout *__unbounded next;
+  void *__unbounded return_address;
+};
+
+int
+__backtrace (void **array, int size)
+{
+  struct layout *current;
+  int count;
+
+  /* Force gcc to spill LR.  */
+  asm volatile ("" : "=l"(current));
+
+  /* Get the address on top-of-stack.  */
+  asm volatile ("lwz %0,0(1)" : "=r"(current));
+  current = BOUNDED_1 (current);
+
+  for (				count = 0;
+       current != NULL && 	count < size;
+       current = BOUNDED_1 (current->next), count++)
+    array[count] = current->return_address;
+
+  /* It's possible the second-last stack frame can't return
+     (that is, it's __libc_start_main), in which case
+     the CRT startup code will have set its LR to 'NULL'.  */
+  if (count > 0 && array[count-1] == NULL)
+    count--;
+
+  return count;
+}
+weak_alias (__backtrace, backtrace)