From: Mark Kettenis <kettenis@gnu.org>
Date: Sat, 15 May 2004 21:06:50 +0000 (+0000)
Subject: * amd64obsd-tdep.c (amd64obsd_sigtramp_p): Replace hexadecimal
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=0fe85704c41edcaec1c672f3fe45413e4b15fa04;p=binutils-gdb.git

* amd64obsd-tdep.c (amd64obsd_sigtramp_p): Replace hexadecimal
offset with decimal offset.
(amd64obsd_sigcontext_addr): Return correct address for entire
signal trampoline.
---

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 9f546b46f02..04e8da8a893 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,10 @@
 2004-05-15  Mark Kettenis  <kettenis@gnu.org>
 
+	* amd64obsd-tdep.c (amd64obsd_sigtramp_p): Replace hexadecimal
+	offset with decimal offset.
+	(amd64obsd_sigcontext_addr): Return correct address for entire
+	signal trampoline.
+
 	* vax-tdep.c (vax_frame_num_args): Use get_frame_base_address
 	instead of get_frame_base.
 
diff --git a/gdb/amd64obsd-tdep.c b/gdb/amd64obsd-tdep.c
index af110b3447c..f9e0f69fe6e 100644
--- a/gdb/amd64obsd-tdep.c
+++ b/gdb/amd64obsd-tdep.c
@@ -109,7 +109,7 @@ amd64obsd_sigtramp_p (struct frame_info *next_frame)
 
   /* If we can't read the instructions at START_PC, return zero.  */
   buf = alloca (sizeof sigreturn);
-  if (target_read_memory (start_pc + 0x7, buf, sizeof sigreturn))
+  if (target_read_memory (start_pc + 7, buf, sizeof sigreturn))
     return 0;
 
   /* Check for sigreturn(2).  */
@@ -125,9 +125,25 @@ amd64obsd_sigtramp_p (struct frame_info *next_frame)
 static CORE_ADDR
 amd64obsd_sigcontext_addr (struct frame_info *next_frame)
 {
+  CORE_ADDR pc = frame_pc_unwind (next_frame);
+  ULONGEST offset = (pc & (amd64obsd_page_size - 1));
+
   /* The %rsp register points at `struct sigcontext' upon entry of a
-     signal trampoline.  */
-  return frame_unwind_register_unsigned (next_frame, AMD64_RSP_REGNUM);
+     signal trampoline.  The relevant part of the trampoline is
+
+        call    *%rax
+        movq    %rsp, %rdi
+        pushq   %rdi
+        movq    $SYS_sigreturn,%rax
+        int     $0x80
+
+     (see /usr/src/sys/arch/amd64/amd64/locore.S).  The `pushq'
+     instruction clobbers %rsp, but its value is saved in `%rdi'.  */
+
+  if (offset > 6)
+    return frame_unwind_register_unsigned (next_frame, AMD64_RDI_REGNUM);
+  else
+    return frame_unwind_register_unsigned (next_frame, AMD64_RSP_REGNUM);
 }
 
 /* OpenBSD 3.5 or later.  */