Fix a typo in bunzip2..

[deliverable/binutils-gdb.git] / gdb / amd64obsd-tdep.c

diff --git a/gdb/amd64obsd-tdep.c b/gdb/amd64obsd-tdep.c
index af110b3447c0ed09f85ac03b198bfeeceaf9f2d4..acef49e9d555524da28f0a0da6f575418927866b 100644 (file)
--- a/gdb/amd64obsd-tdep.c
+++ b/gdb/amd64obsd-tdep.c
@@ -1,6 +1,6 @@
 /* Target-dependent code for OpenBSD/amd64.
 
-   Copyright 2003, 2004 Free Software Foundation, Inc.
+   Copyright 2003, 2004, 2005 Free Software Foundation, Inc.
 
    This file is part of GDB.
 
@@ -42,12 +42,13 @@ amd64obsd_supply_regset (const struct regset *regset,
                         struct regcache *regcache, int regnum,
                         const void *regs, size_t len)
 {
-  const struct gdbarch_tdep *tdep = regset->descr;
+  const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch);
 
   gdb_assert (len >= tdep->sizeof_gregset + I387_SIZEOF_FXSAVE);
 
   i386_supply_gregset (regset, regcache, regnum, regs, tdep->sizeof_gregset);
-  amd64_supply_fxsave (regcache, regnum, (char *)regs + tdep->sizeof_gregset);
+  amd64_supply_fxsave (regcache, regnum,
+                      ((const gdb_byte *)regs) + tdep->sizeof_gregset);
 }
 
 static const struct regset *
@@ -63,11 +64,7 @@ amd64obsd_regset_from_core_section (struct gdbarch *gdbarch,
       && sect_size >= tdep->sizeof_gregset + I387_SIZEOF_FXSAVE)
     {
       if (tdep->gregset == NULL)
-       {
-         tdep->gregset = XMALLOC (struct regset);
-         tdep->gregset->descr = tdep;
-         tdep->gregset->supply_regset = amd64obsd_supply_regset;
-       }
+        tdep->gregset = regset_alloc (gdbarch, amd64obsd_supply_regset, NULL);
       return tdep->gregset;
     }
 
@@ -88,13 +85,15 @@ amd64obsd_sigtramp_p (struct frame_info *next_frame)
 {
   CORE_ADDR pc = frame_pc_unwind (next_frame);
   CORE_ADDR start_pc = (pc & ~(amd64obsd_page_size - 1));
-  const char sigreturn[] =
+  const gdb_byte sigreturn[] =
   {
     0x48, 0xc7, 0xc0,
     0x67, 0x00, 0x00, 0x00,    /* movq $SYS_sigreturn, %rax */
     0xcd, 0x80                 /* int $0x80 */
   };
-  char *name, *buf;
+  size_t buflen = (sizeof sigreturn) + 1;
+  gdb_byte *buf;
+  char *name;
 
   /* If the function has a valid symbol name, it isn't a
      trampoline.  */
@@ -108,12 +107,15 @@ amd64obsd_sigtramp_p (struct frame_info *next_frame)
     return 0;
 
   /* 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))
+  buf = alloca ((sizeof sigreturn) + 1);
+  if (!safe_frame_unwind_memory (next_frame, start_pc + 6, buf, buflen))
     return 0;
 
-  /* Check for sigreturn(2).  */
-  if (memcmp (buf, sigreturn, sizeof sigreturn))
+  /* Check for sigreturn(2).  Depending on how the assembler encoded
+     the `movq %rsp, %rdi' instruction, the code starts at offset 6 or
+     7.  */
+  if (memcmp (buf, sigreturn, sizeof sigreturn)
+      && memcpy (buf + 1, sigreturn, sizeof sigreturn))
     return 0;
 
   return 1;
@@ -125,9 +127,25 @@ 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 > 5)
+    return frame_unwind_register_unsigned (next_frame, AMD64_RDI_REGNUM);
+  else
+    return frame_unwind_register_unsigned (next_frame, AMD64_RSP_REGNUM);
 }
 \f
 /* OpenBSD 3.5 or later.  */