* sparc64obsd-tdep.c (sparc64obsd_sigreturn_offset): New variable.

(sparc64obsd_pc_in_sigtramp): Reorganize to avoid goto.

1 files changed, 19 insertions, 22 deletions

diff --git a/gdb/sparc64obsd-tdep.c b/gdb/sparc64obsd-tdep.c
index 8ad88b5..bb6626d 100644
--- a/gdb/sparc64obsd-tdep.c
+++ b/gdb/sparc64obsd-tdep.c
@@ -74,43 +74,40 @@ sparc64obsd_supply_gregset (const struct regset *regset,
 
    The signal trampoline will be mapped at an address that is page
    aligned.  We recognize the signal trampoline by the looking for the
-   sigreturn system call.  */
+   sigreturn system call.  The offset where we can find the code that
+   makes this system call varies from release to release.  For OpenBSD
+   3.6 and later releases we can find the code at offset 0xec.  For
+   OpenBSD 3.5 and earlier releases, we find it at offset 0xe8.  */
 
 static const int sparc64obsd_page_size = 8192;
+static const int sparc64obsd_sigreturn_offset[] = { 0xec, 0xe8, -1 };
 
 static int
 sparc64obsd_pc_in_sigtramp (CORE_ADDR pc, char *name)
 {
   CORE_ADDR start_pc = (pc & ~(sparc64obsd_page_size - 1));
   unsigned long insn;
-  int offset = 0;
+  const int *offset;
 
   if (name)
     return 0;
 
- retry:
-  /* Check for "restore %g0, SYS_sigreturn, %g1".  */
-  insn = sparc_fetch_instruction (start_pc + offset + 0xec);
-  if (insn != 0x83e82067)
+  for (offset = sparc64obsd_sigreturn_offset; *offset != -1; offset++)
     {
-      if (offset == 0)
-	{
-	  /* In OpenBSD 3.5 and earlier releases, the code
-             implementing the sigreturn system call was at a different
-             offset within the signal trampoline.  Try again.  */
-	  offset = -4;
-	  goto retry;
-	}
-
-      return 0;
-    }
+      /* Check for "restore %g0, SYS_sigreturn, %g1".  */
+      insn = sparc_fetch_instruction (start_pc + *offset);
+      if (insn != 0x83e82067)
+	continue;
 
-  /* Check for "t ST_SYSCALL".  */
-  insn = sparc_fetch_instruction (start_pc + offset + 0xf4);
-  if (insn != 0x91d02000)
-    return 0;
+      /* Check for "t ST_SYSCALL".  */
+      insn = sparc_fetch_instruction (start_pc + *offset + 8);
+      if (insn != 0x91d02000)
+	continue;
+
+      return 1;
+  }
 
-  return 1;
+  return 0;
 }
 
 static struct sparc_frame_cache *