1 files changed, 139 insertions, 0 deletions
diff --git a/libc/ports/sysdeps/microblaze/backtrace.c b/libc/ports/sysdeps/microblaze/backtrace.c
new file mode 100644
index 000000000..97a5fdbea
--- /dev/null
+++ b/libc/ports/sysdeps/microblaze/backtrace.c
@@ -0,0 +1,139 @@
+/* Copyright (C) 2005-2013 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, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <stdio.h>
+#include <string.h>
+#include <sysdep.h>
+#include <signal.h>
+#include <execinfo.h>
+
+extern int
+_identify_sighandler (unsigned long fp, unsigned long pc,
+                      unsigned long *pprev_fp, unsigned long *pprev_pc,
+                      unsigned long *retaddr);
+
+inline long
+get_frame_size (unsigned long instr)
+{
+  return abs ((short signed) (instr & 0xFFFF));
+}
+
+static unsigned long *
+find_frame_creation (unsigned long *pc)
+{
+  int i;
+
+  /* NOTE: Distance to search is arbitrary.
+     250 works well for most things,
+     750 picks up things like tcp_recvmsg,
+     1000 needed for fat_fill_super.  */
+  for (i = 0; i < 1000; i++, pc--)
+    {
+      unsigned long instr;
+      unsigned long frame_size;
+
+      instr = *pc;
+
+      /* Is the instruction of the form
+         addik r1, r1, foo ? */
+      if ((instr & 0xFFFF0000) != 0x30210000)
+        continue;
+
+      frame_size = get_frame_size (instr);
+
+      if ((frame_size < 8) || (frame_size & 3))
+        return NULL;
+
+      return pc;
+    }
+  return NULL;
+}
+
+static int
+lookup_prev_stack_frame (unsigned long fp, unsigned long pc,
+                         unsigned long *pprev_fp, unsigned long *pprev_pc,
+                         unsigned long *retaddr)
+{
+  unsigned long *prologue = NULL;
+
+  int is_signalhandler = _identify_sighandler (fp, pc, pprev_fp,
+                                               pprev_pc, retaddr);
+
+  if (!is_signalhandler)
+    {
+      prologue = find_frame_creation ((unsigned long *) pc);
+
+      if (prologue)
+        {
+          long frame_size = get_frame_size (*prologue);
+          *pprev_fp = fp + frame_size;
+          if (*retaddr != 0)
+            *pprev_pc = *retaddr;
+          else
+            *pprev_pc = *(unsigned long *) fp;
+
+          *retaddr = 0;
+          if (!*pprev_pc || (*pprev_pc & 3))
+            prologue=0;
+        }
+      else
+        {
+          *pprev_pc = 0;
+          *pprev_fp = fp;
+          *retaddr = 0;
+        }
+    }
+    return (!*pprev_pc || (*pprev_pc & 3)) ? -1 : 0;
+}
+
+int
+__backtrace (void **array, int size)
+{
+  unsigned long pc, fp;
+  unsigned long ppc, pfp;
+  /* Return address(r15) is required in the signal handler case, since the
+     return address of the function which causes the signal may not be
+     recorded in the stack.  */
+  unsigned long retaddr;
+
+  int count;
+  int rc = 0;
+
+  __asm__ __volatile__ ("mfs %0, rpc"
+                        : "=r"(pc));
+
+  __asm__ __volatile__ ("add %0, r1, r0"
+                        : "=r"(fp));
+
+  array[0] = (void *) pc;
+  retaddr = 0;
+  for (count = 1; count < size; count++)
+    {
+      rc = lookup_prev_stack_frame (fp, pc, &pfp, &ppc, &retaddr);
+
+      fp = pfp;
+      pc = ppc;
+      array[count] = (void *) pc;
+      if (rc)
+        return count;
+    }
+  return count;
+}
+
+weak_alias (__backtrace, backtrace)
+libc_hidden_def (__backtrace)