From Michal Ludvig <mludvig@suse.cz>:

* i386-tdep.h (struct gdbarch_tdep): Add members `sc_reg_offset'
and `sc_num_regs'.
(I386_EAX_REGNUM, I386_EDX_REGNUM, I386_ESP_REGNUM,
I386_EBP_REGNUM, I386_EIP_REGNUM, I386_EFLAGS_REGNUM,
I386_ST0_REGNUM): Move here from...
* i386-tdep.c: ... here.
(I386_NUM_SAVED_REGS): Define to I386_NUM_REGS.
(i386_sigtramp_frame_cache): Use `sc_reg_offset' to find saved
registers if possible.
(i386_gdbarch_init): Initialize TDEP->sc_reg_offset.
* i386bsd-tdep.c (i386bsd_sc_pc_offset, i386bsd_sc_sp_offset):
Remove variables.
(i386bsd_sc_reg_offset): New variable.
(i386bsd_init_abi): Initialize TDEP->sc_reg_offset and
TDEP->sc_num_regs instead of TDEP->sc_pc_offset and
TDEP->sc_sp_offset.
(i386fbsd_sc_reg_offset): New variable.
(i386fbsdaout_init_abi): Initialize TDEP->sc_reg_offset and
TDEP->sc_num_regs.
(i386fbsd4_sc_pc_offset, i386fbsd4_sc_sp_offset): Remove
variables.
(i386fbsd4_sc_reg_offset): New variable.
(i3864bsd4_init_abi): Initialize TDEP->sc_reg_offset and
TDEP->sc_num_regs instead of TDEP->sc_pc_offset and
TDEP->sc_sp_offset.
* i386-linux-tdep.c (i386_linux_sc_reg_offset): New variable.
(i386_linux_init_abi): Set TDEP->sc_reg_offset and TDEP->sc_num_regs.
* i386nbsd-tdep.c (i386nbsd_sc_pc_offset, i386nbsd_sc_sp_offset):
Remove variables.
(i386nbsd_sc_reg_offset): New variable.
(i386nbsd_init_abi): Initialize TDEP->sc_reg_offset and
TDEP->sc_num_regs instead of TDEP->sc_pc_offset and
TDEP->sc_sp_offset.
* i386obsd-tdep.c (i386obsd_sc_pc_offset, i386obsd_sc_sp_offset):
Remove variables.
(i386obsd_sc_reg_offset): New variable.
(i386obsd_init_abi): Initialize TDEP->sc_reg_offset and
TDEP->sc_num_regs instead of TDEP->sc_pc_offset and
TDEP->sc_sp_offset.
* i386bsd-nat.c (_initialize_i386bsd_nat): Adjust for changes in
i386bsd-tdep.c, i386nbsd-tdep.c and i386obsd-tdep.c.  Add check
for frame pointer offset in `struct sigcontext'.

8 files changed, 255 insertions, 59 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index cd15457..11eaae9 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,49 @@
+2003-05-31  Mark Kettenis  <kettenis@gnu.org>
+
+	From Michal Ludvig  <mludvig@suse.cz>:
+	* i386-tdep.h (struct gdbarch_tdep): Add members `sc_reg_offset'
+	and `sc_num_regs'.
+	(I386_EAX_REGNUM, I386_EDX_REGNUM, I386_ESP_REGNUM,
+	I386_EBP_REGNUM, I386_EIP_REGNUM, I386_EFLAGS_REGNUM,
+	I386_ST0_REGNUM): Move here from...
+	* i386-tdep.c: ... here.
+	(I386_NUM_SAVED_REGS): Define to I386_NUM_REGS.
+	(i386_sigtramp_frame_cache): Use `sc_reg_offset' to find saved
+	registers if possible.
+	(i386_gdbarch_init): Initialize TDEP->sc_reg_offset.
+	* i386bsd-tdep.c (i386bsd_sc_pc_offset, i386bsd_sc_sp_offset):
+	Remove variables.
+	(i386bsd_sc_reg_offset): New variable.
+	(i386bsd_init_abi): Initialize TDEP->sc_reg_offset and
+	TDEP->sc_num_regs instead of TDEP->sc_pc_offset and
+	TDEP->sc_sp_offset.
+	(i386fbsd_sc_reg_offset): New variable.
+	(i386fbsdaout_init_abi): Initialize TDEP->sc_reg_offset and
+	TDEP->sc_num_regs.
+	(i386fbsd4_sc_pc_offset, i386fbsd4_sc_sp_offset): Remove
+	variables.
+	(i386fbsd4_sc_reg_offset): New variable.
+	(i3864bsd4_init_abi): Initialize TDEP->sc_reg_offset and
+	TDEP->sc_num_regs instead of TDEP->sc_pc_offset and
+	TDEP->sc_sp_offset.
+	* i386-linux-tdep.c (i386_linux_sc_reg_offset): New variable.
+	(i386_linux_init_abi): Set TDEP->sc_reg_offset and TDEP->sc_num_regs.
+	* i386nbsd-tdep.c (i386nbsd_sc_pc_offset, i386nbsd_sc_sp_offset):
+	Remove variables.
+	(i386nbsd_sc_reg_offset): New variable.
+	(i386nbsd_init_abi): Initialize TDEP->sc_reg_offset and
+	TDEP->sc_num_regs instead of TDEP->sc_pc_offset and
+	TDEP->sc_sp_offset.
+	* i386obsd-tdep.c (i386obsd_sc_pc_offset, i386obsd_sc_sp_offset):
+	Remove variables.
+	(i386obsd_sc_reg_offset): New variable.
+	(i386obsd_init_abi): Initialize TDEP->sc_reg_offset and
+	TDEP->sc_num_regs instead of TDEP->sc_pc_offset and
+	TDEP->sc_sp_offset.
+	* i386bsd-nat.c (_initialize_i386bsd_nat): Adjust for changes in
+	i386bsd-tdep.c, i386nbsd-tdep.c and i386obsd-tdep.c.  Add check
+	for frame pointer offset in `struct sigcontext'.
+
 2003-05-31  Andrew Cagney  <cagney@redhat.com>
 
 	* mips-tdep.c (mips_gdbarch_init): Do not set the deprecated
diff --git a/gdb/i386-linux-tdep.c b/gdb/i386-linux-tdep.c
index e666610..13ed1ff 100644
--- a/gdb/i386-linux-tdep.c
+++ b/gdb/i386-linux-tdep.c
@@ -439,6 +439,27 @@ i386_linux_svr4_fetch_link_map_offsets (void)
 }
 
 
+/* From <asm/sigcontext.h>.  */
+static int i386_linux_sc_reg_offset[I386_NUM_GREGS] =
+{
+  11 * 4,			/* %eax */
+  10 * 4,			/* %ecx */
+  9 * 4,			/* %edx */
+  8 * 4,			/* %ebx */
+  7 * 4,			/* %esp */
+  6 * 4,			/* %ebp */
+  5 * 4,			/* %esi */
+  4 * 4,			/* %edi */
+  14 * 4,			/* %eip */
+  16 * 4,			/* %eflags */
+  15 * 4,			/* %cs */
+  18 * 4,			/* %ss */
+  3 * 4,			/* %ds */
+  2 * 4,			/* %es */
+  1 * 4,			/* %fs */
+  0 * 4				/* %gs */
+};
+
 static void
 i386_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 {
@@ -462,8 +483,8 @@ i386_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   tdep->jb_pc_offset = 20;	/* From <bits/setjmp.h>.  */
 
   tdep->sigcontext_addr = i386_linux_sigcontext_addr;
-  tdep->sc_pc_offset = 14 * 4;	/* From <asm/sigcontext.h>.  */
-  tdep->sc_sp_offset = 7 * 4;
+  tdep->sc_reg_offset = i386_linux_sc_reg_offset;
+  tdep->sc_num_regs = I386_NUM_GREGS;
 
   /* When the i386 Linux kernel calls a signal handler, the return
      address points to a bit of code on the stack.  This function is
diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c
index 47bf95c..7daea31 100644
--- a/gdb/i386-tdep.c
+++ b/gdb/i386-tdep.c
@@ -47,16 +47,6 @@
 #include "i386-tdep.h"
 #include "i387-tdep.h"
 
-/* Register numbers of various important registers.  */
-
-#define I386_EAX_REGNUM		0 /* %eax */
-#define I386_EDX_REGNUM		2 /* %edx */
-#define I386_ESP_REGNUM		4 /* %esp */
-#define I386_EBP_REGNUM		5 /* %ebp */
-#define I386_EIP_REGNUM		8 /* %eip */
-#define I386_EFLAGS_REGNUM	9 /* %eflags */
-#define I386_ST0_REGNUM		16 /* %st(0) */
-
 /* Names of the registers.  The first 10 registers match the register
    numbering scheme used by GCC for stabs and DWARF.  */
 
@@ -248,7 +238,7 @@ i386_breakpoint_from_pc (CORE_ADDR *pc, int *len)
 
 /* The maximum number of saved registers.  This should include all
    registers mentioned above, and %eip.  */
-#define I386_NUM_SAVED_REGS	9
+#define I386_NUM_SAVED_REGS	I386_NUM_GREGS
 
 struct i386_frame_cache
 {
@@ -884,8 +874,21 @@ i386_sigtramp_frame_cache (struct frame_info *next_frame, void **this_cache)
   cache->base = extract_unsigned_integer (buf, 4) - 4;
 
   addr = tdep->sigcontext_addr (next_frame);
-  cache->saved_regs[I386_EIP_REGNUM] = addr + tdep->sc_pc_offset;
-  cache->saved_regs[I386_ESP_REGNUM] = addr + tdep->sc_sp_offset;
+  if (tdep->sc_reg_offset)
+    {
+      int i;
+
+      gdb_assert (tdep->sc_num_regs <= I386_NUM_SAVED_REGS);
+
+      for (i = 0; i < tdep->sc_num_regs; i++)
+	if (tdep->sc_reg_offset[i] != -1)
+	  cache->saved_regs[i] = addr + tdep->sc_reg_offset[i];
+    }
+  else
+    {
+      cache->saved_regs[I386_EIP_REGNUM] = addr + tdep->sc_pc_offset;
+      cache->saved_regs[I386_ESP_REGNUM] = addr + tdep->sc_sp_offset;
+    }
 
   *this_cache = cache;
   return cache;
@@ -1621,6 +1624,7 @@ i386_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   tdep->sigtramp_start = 0;
   tdep->sigtramp_end = 0;
   tdep->sigcontext_addr = NULL;
+  tdep->sc_reg_offset = NULL;
   tdep->sc_pc_offset = -1;
   tdep->sc_sp_offset = -1;
 
diff --git a/gdb/i386-tdep.h b/gdb/i386-tdep.h
index b2c2dff..38eac20 100644
--- a/gdb/i386-tdep.h
+++ b/gdb/i386-tdep.h
@@ -71,7 +71,12 @@ struct gdbarch_tdep
   /* Get address of sigcontext for sigtramp.  */
   CORE_ADDR (*sigcontext_addr) (struct frame_info *);
 
-  /* Offset of saved PC and SP in `struct sigcontext'.  */
+  /* Offset of registers in `struct sigcontext'.  */
+  int *sc_reg_offset;
+  int sc_num_regs;
+
+  /* Offset of saved PC and SP in `struct sigcontext'.  Usage of these
+     is deprecated, please use `sc_reg_offset' instead.  */
   int sc_pc_offset;
   int sc_sp_offset;
 };
@@ -137,6 +142,16 @@ extern int i386_mxcsr_regnum_p (int regnum);
 #define FDS_REGNUM FOSEG_REGNUM
 #define FDOFF_REGNUM FOOFF_REGNUM
 
+/* Register numbers of various important registers.  */
+
+#define I386_EAX_REGNUM		0 /* %eax */
+#define I386_EDX_REGNUM		2 /* %edx */
+#define I386_ESP_REGNUM		4 /* %esp */
+#define I386_EBP_REGNUM		5 /* %ebp */
+#define I386_EIP_REGNUM		8 /* %eip */
+#define I386_EFLAGS_REGNUM	9 /* %eflags */
+#define I386_ST0_REGNUM		16 /* %st(0) */
+
 #define I386_NUM_GREGS	16
 #define I386_NUM_FREGS	16
 #define I386_NUM_XREGS  9
diff --git a/gdb/i386bsd-nat.c b/gdb/i386bsd-nat.c
index ec38e13..60524de 100644
--- a/gdb/i386bsd-nat.c
+++ b/gdb/i386bsd-nat.c
@@ -386,8 +386,7 @@ kernel_u_size (void)
 void
 _initialize_i386bsd_nat (void)
 {
-  int sc_pc_offset;
-  int sc_sp_offset;
+  int offset;
 
   /* To support the recognition of signal handlers, i386bsd-tdep.c
      hardcodes some constants.  Inclusion of this file means that we
@@ -396,51 +395,69 @@ _initialize_i386bsd_nat (void)
      information.  */
 
 #if defined (__FreeBSD_version) && __FreeBSD_version >= 400011
-  extern int i386fbsd4_sc_pc_offset;
-  extern int i386fbsd4_sc_sp_offset;
-#define SC_PC_OFFSET i386fbsd4_sc_pc_offset
-#define SC_SP_OFFSET i386fbsd4_sc_sp_offset
+  extern int i386fbsd4_sc_reg_offset[];
+#define SC_REG_OFFSET i386fbsd4_sc_reg_offset
+#elif defined (__FreeBSD_version) && __FreeBSD_version >= 300005
+  extern int i386fbsd_sc_reg_offset[];
+#define SC_REG_OFFSET i386fbsd_sc_reg_offset
 #elif defined (NetBSD) || defined (__NetBSD_Version__)
-  extern int i386nbsd_sc_pc_offset;
-  extern int i386nbsd_sc_sp_offset;
-#define SC_PC_OFFSET i386nbsd_sc_pc_offset
-#define SC_SP_OFFSET i386nbsd_sc_sp_offset
+  extern int i386nbsd_sc_reg_offset[];
+#define SC_REG_OFFSET i386nbsd_sc_reg_offset
 #elif defined (OpenBSD)
-  extern int i386obsd_sc_pc_offset;
-  extern int i386obsd_sc_sp_offset;
-#define SC_PC_OFFSET i386obsd_sc_pc_offset
-#define SC_SP_OFFSET i386obsd_sc_sp_offset
+  extern int i386obsd_sc_reg_offset[];
+#define SC_REG_OFFSET i386obsd_sc_reg_offset
 #else
-  extern int i386bsd_sc_pc_offset;
-  extern int i386bsd_sc_sp_offset;
-#define SC_PC_OFFSET i386bsd_sc_pc_offset
-#define SC_SP_OFFSET i386bsd_sc_sp_offset
+  extern int i386bsd_sc_reg_offset[];
+#define SC_PC_OFFSET i386bsd_sc_reg_offset
 #endif
 
+  /* We only check the program counter, stack pointer and frame
+     pointer since these members of `struct sigcontext' are essential
+     for providing backtraces.  More checks could be added, but would
+     involve adding configure checks for the appropriate structure
+     members, since older BSD's don't provide all of them.  */
+
+#define SC_PC_OFFSET SC_REG_OFFSET[I386_EIP_REGNUM]
+#define SC_SP_OFFSET SC_REG_OFFSET[I386_ESP_REGNUM]
+#define SC_FP_OFFSET SC_REG_OFFSET[I386_EBP_REGNUM]
+
   /* Override the default value for the offset of the program counter
      in the sigcontext structure.  */
-  sc_pc_offset = offsetof (struct sigcontext, sc_pc);
+  offset = offsetof (struct sigcontext, sc_pc);
 
-  if (SC_PC_OFFSET != sc_pc_offset)
+  if (SC_PC_OFFSET != offset)
     {
       warning ("\
 offsetof (struct sigcontext, sc_pc) yields %d instead of %d.\n\
-Please report this to <bug-gdb@gnu.org>.",
-	       sc_pc_offset, SC_PC_OFFSET);
+Please report this to <bug-gdb@gnu.org>.", 
+	       offset, SC_PC_OFFSET);
     }
 
-  SC_PC_OFFSET = sc_pc_offset;
+  SC_PC_OFFSET = offset;
 
   /* Likewise for the stack pointer.  */
-  sc_sp_offset = offsetof (struct sigcontext, sc_sp);
+  offset = offsetof (struct sigcontext, sc_sp);
 
-  if (SC_SP_OFFSET != sc_sp_offset)
+  if (SC_SP_OFFSET != offset)
     {
       warning ("\
 offsetof (struct sigcontext, sc_sp) yields %d instead of %d.\n\
 Please report this to <bug-gdb@gnu.org>.",
-	       sc_sp_offset, SC_SP_OFFSET);
+	       offset, SC_SP_OFFSET);
+    }
+
+  SC_SP_OFFSET = offset;
+
+  /* And the frame pointer.  */
+  offset = offsetof (struct sigcontext, sc_fp);
+
+  if (SC_FP_OFFSET != offset)
+    {
+      warning ("\
+offsetof (struct sigcontext, sc_fp) yields %d instead of %d.\n\
+Please report this to <bug-gdb@gnu.org>.",
+	       offset, SC_FP_OFFSET);
     }
 
-  SC_SP_OFFSET = sc_sp_offset;
+  SC_FP_OFFSET = offset;
 }
diff --git a/gdb/i386bsd-tdep.c b/gdb/i386bsd-tdep.c
index d91be26..80e057b 100644
--- a/gdb/i386bsd-tdep.c
+++ b/gdb/i386bsd-tdep.c
@@ -86,8 +86,25 @@ i386bsd_aout_in_solib_call_trampoline (CORE_ADDR pc, char *name)
 /* Traditional BSD (4.3 BSD, still used for BSDI and 386BSD).  */
 
 /* From <machine/signal.h>.  */
-int i386bsd_sc_pc_offset = 20;
-int i386bsd_sc_sp_offset = 8;
+int i386bsd_sc_reg_offset[I386_NUM_GREGS] =
+{
+  -1,				/* %eax */
+  -1,				/* %ecx */
+  -1,				/* %edx */
+  -1,				/* %ebx */
+  8 + 0 * 4,			/* %esp */
+  8 + 1 * 4,			/* %ebp */
+  -1,				/* %esi */
+  -1,				/* %edi */
+  8 + 3 * 4,			/* %eip */
+  8 + 4 * 4,			/* %eflags */
+  -1,				/* %cs */
+  -1,				/* %ss */
+  -1,				/* %ds */
+  -1,				/* %es */
+  -1,				/* %fs */
+  -1				/* %gs */
+};
 
 void
 i386bsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
@@ -109,8 +126,8 @@ i386bsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   tdep->sigtramp_start = 0xfdbfdfc0;
   tdep->sigtramp_end = 0xfdbfe000;
   tdep->sigcontext_addr = i386bsd_sigcontext_addr;
-  tdep->sc_pc_offset = i386bsd_sc_pc_offset;
-  tdep->sc_sp_offset = i386bsd_sc_sp_offset;
+  tdep->sc_reg_offset = i386bsd_sc_reg_offset;
+  tdep->sc_num_regs = I386_NUM_GREGS;
 }
 
 /* FreeBSD 3.0-RELEASE or later.  */
@@ -118,6 +135,27 @@ i386bsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 CORE_ADDR i386fbsd_sigtramp_start = 0xbfbfdf20;
 CORE_ADDR i386fbsd_sigtramp_end = 0xbfbfdff0;
 
+/* From <machine/signal.h>.  */
+int i386fbsd_sc_reg_offset[I386_NUM_GREGS] =
+{
+  8 + 14 * 4,			/* %eax */
+  8 + 13 * 4,			/* %ecx */
+  8 + 12 * 4,			/* %edx */
+  8 + 11 * 4,			/* %ebx */
+  8 + 0 * 4,                    /* %esp */
+  8 + 1 * 4,                    /* %ebp */
+  8 + 10 * 4,                   /* %esi */
+  8 + 9 * 4,                    /* %edi */
+  8 + 3 * 4,                    /* %eip */
+  8 + 4 * 4,                    /* %eflags */
+  8 + 7 * 4,                    /* %cs */
+  8 + 8 * 4,                    /* %ss */
+  8 + 6 * 4,                    /* %ds */
+  8 + 5 * 4,                    /* %es */
+  8 + 15 * 4,			/* %fs */
+  8 + 16 * 4			/* %gs */
+};
+
 static void
 i386fbsdaout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 {
@@ -132,6 +170,10 @@ i386fbsdaout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   /* FreeBSD uses a different memory layout.  */
   tdep->sigtramp_start = i386fbsd_sigtramp_start;
   tdep->sigtramp_end = i386fbsd_sigtramp_end;
+
+  /* FreeBSD has a more complete `struct sigcontext'.  */
+  tdep->sc_reg_offset = i386fbsd_sc_reg_offset;
+  tdep->sc_num_regs = I386_NUM_GREGS;
 }
 
 static void
@@ -151,8 +193,25 @@ i386fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 /* FreeBSD 4.0-RELEASE or later.  */
 
 /* From <machine/signal.h>.  */
-int i386fbsd4_sc_pc_offset = 76;
-int i386fbsd4_sc_sp_offset = 88;
+int i386fbsd4_sc_reg_offset[I386_NUM_GREGS] =
+{
+  20 + 11 * 4,			/* %eax */
+  20 + 10 * 4,			/* %ecx */
+  20 + 9 * 4,			/* %edx */
+  20 + 8 * 4,			/* %ebx */
+  20 + 17 * 4,			/* %esp */
+  20 + 6 * 4,			/* %ebp */
+  20 + 5 * 4,			/* %esi */
+  20 + 4 * 4,			/* %edi */
+  20 + 14 * 4,			/* %eip */
+  20 + 16 * 4,			/* %eflags */
+  20 + 15 * 4,			/* %cs */
+  20 + 18 * 4,			/* %ss */
+  20 + 3 * 4,			/* %ds */
+  20 + 2 * 4,			/* %es */
+  20 + 1 * 4,			/* %fs */
+  20 + 0 * 4			/* %gs */
+};
 
 static void
 i386fbsd4_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
@@ -164,8 +223,8 @@ i386fbsd4_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   i386fbsd_init_abi (info, gdbarch);
 
   /* FreeBSD 4.0 introduced a new `struct sigcontext'.  */
-  tdep->sc_pc_offset = i386fbsd4_sc_pc_offset;
-  tdep->sc_sp_offset = i386fbsd4_sc_sp_offset;
+  tdep->sc_reg_offset = i386fbsd4_sc_reg_offset;
+  tdep->sc_num_regs = I386_NUM_GREGS;
 }
 
 
diff --git a/gdb/i386nbsd-tdep.c b/gdb/i386nbsd-tdep.c
index 64b3dc0..601530b 100644
--- a/gdb/i386nbsd-tdep.c
+++ b/gdb/i386nbsd-tdep.c
@@ -239,8 +239,25 @@ i386nbsd_pc_in_sigtramp (CORE_ADDR pc, char *name)
 }
 
 /* From <machine/signal.h>.  */
-int i386nbsd_sc_pc_offset = 44;
-int i386nbsd_sc_sp_offset = 56;
+int i386nbsd_sc_reg_offset[I386_NUM_GREGS] =
+{
+  10 * 4,			/* %eax */
+  9 * 4,			/* %ecx */
+  8 * 4,			/* %edx */
+  7 * 4,			/* %ebx */
+  14 * 4,			/* %esp */
+  6 * 4,			/* %ebp */
+  5 * 4,			/* %esi */
+  4 * 4,			/* %edi */
+  11 * 4,			/* %eip */
+  13 * 4,			/* %eflags */
+  12 * 4,			/* %cs */
+  15 * 4,			/* %ss */
+  3 * 4,			/* %ds */
+  2 * 4,			/* %es */
+  1 * 4,			/* %fs */
+  0 * 4				/* %gs */
+};
 
 static void 
 i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
@@ -263,8 +280,8 @@ i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 
   /* NetBSD has a `struct sigcontext' that's different from the
      origional 4.3 BSD.  */
-  tdep->sc_pc_offset = i386nbsd_sc_pc_offset;
-  tdep->sc_sp_offset = i386nbsd_sc_sp_offset;
+  tdep->sc_reg_offset = i386nbsd_sc_reg_offset;
+  tdep->sc_num_regs = I386_NUM_GREGS;
 }
 
 /* NetBSD ELF.  */
diff --git a/gdb/i386obsd-tdep.c b/gdb/i386obsd-tdep.c
index be0c674..7db076d 100644
--- a/gdb/i386obsd-tdep.c
+++ b/gdb/i386obsd-tdep.c
@@ -83,8 +83,25 @@ CORE_ADDR i386obsd_sigtramp_start = 0xbfbfdf20;
 CORE_ADDR i386obsd_sigtramp_end = 0xbfbfdff0;
 
 /* From <machine/signal.h>.  */
-int i386obsd_sc_pc_offset = 44;
-int i386obsd_sc_sp_offset = 56;
+int i386obsd_sc_reg_offset[I386_NUM_GREGS] =
+{
+  10 * 4,			/* %eax */
+  9 * 4,			/* %ecx */
+  8 * 4,			/* %edx */
+  7 * 4,			/* %ebx */
+  14 * 4,			/* %esp */
+  6 * 4,			/* %ebp */
+  5 * 4,			/* %esi */
+  4 * 4,			/* %edi */
+  11 * 4,			/* %eip */
+  13 * 4,			/* %eflags */
+  12 * 4,			/* %cs */
+  15 * 4,			/* %ss */
+  3 * 4,			/* %ds */
+  2 * 4,			/* %es */
+  1 * 4,			/* %fs */
+  0 * 4				/* %gs */
+};
 
 static void 
 i386obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
@@ -103,8 +120,8 @@ i386obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 
   /* OpenBSD has a `struct sigcontext' that's different from the
      origional 4.3 BSD.  */
-  tdep->sc_pc_offset = i386obsd_sc_pc_offset;
-  tdep->sc_sp_offset = i386obsd_sc_sp_offset;
+  tdep->sc_reg_offset = i386obsd_sc_reg_offset;
+  tdep->sc_num_regs = I386_NUM_GREGS;
 }
 
 void