* i386bsd-tdep.c (i386nbsd_sigtramp_start, i386nbsd_sigtramp_end):

New variables.
(i386nbsd_init_abi): Use these to initialize tdep->sigtramp_start
and tdep->sigtramp_end.
* i386obsd-nat.c: New file.
* config/i386/obsd.mh (NATDEPFILES): Add i386obsd-nat.o.

4 files changed, 73 insertions, 3 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index d8fab79..f1b38ee 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,12 @@
 2002-07-04  Mark Kettenis  <kettenis@gnu.org>
 
+	* i386bsd-tdep.c (i386nbsd_sigtramp_start, i386nbsd_sigtramp_end):
+	New variables.
+	(i386nbsd_init_abi): Use these to initialize tdep->sigtramp_start
+	and tdep->sigtramp_end.
+	* i386obsd-nat.c: New file.
+	* config/i386/obsd.mh (NATDEPFILES): Add i386obsd-nat.o.
+
 	* dwarf2cfi.c (cfi_pop_frame): Use alloca() for regbuf.
 	Don't call get_current_frame().
 
diff --git a/gdb/config/i386/obsd.mh b/gdb/config/i386/obsd.mh
index 8a40001..ec22fcb 100644
--- a/gdb/config/i386/obsd.mh
+++ b/gdb/config/i386/obsd.mh
@@ -3,7 +3,7 @@
 XM_FILE= xm-i386.h
 
 NAT_FILE= nm-obsd.h
-NATDEPFILES= fork-child.o infptrace.o inftarg.o i386bsd-nat.o \
+NATDEPFILES= fork-child.o infptrace.o inftarg.o i386bsd-nat.o i386obsd-nat.o \
 	solib.o solib-sunos.o
 
 # The OpenBSD yacc generates yyname and yyrule tables that conflict at
diff --git a/gdb/i386bsd-tdep.c b/gdb/i386bsd-tdep.c
index 61213ff..ea96ee4 100644
--- a/gdb/i386bsd-tdep.c
+++ b/gdb/i386bsd-tdep.c
@@ -113,6 +113,9 @@ i386bsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 
 /* NetBSD 1.0 or later.  */
 
+CORE_ADDR i386nbsd_sigtramp_start = 0xbfbfdf20;
+CORE_ADDR i386nbsd_sigtramp_end = 0xbfbfdff0;
+
 /* From <machine/signal.h>.  */
 int i386nbsd_sc_pc_offset = 44;
 int i386nbsd_sc_sp_offset = 56;
@@ -129,8 +132,8 @@ i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   tdep->struct_return = reg_struct_return;
 
   /* NetBSD uses a different memory layout.  */
-  tdep->sigtramp_start = 0xbfbfdf20;
-  tdep->sigtramp_end = 0xbfbfdff0;
+  tdep->sigtramp_start = i386nbsd_sigtramp_start;
+  tdep->sigtramp_end = i386nbsd_sigtramp_end;
 
   /* NetBSD has a `struct sigcontext' that's different from the
      origional 4.3 BSD.  */
diff --git a/gdb/i386obsd-nat.c b/gdb/i386obsd-nat.c
new file mode 100644
index 0000000..01a2bbe
--- /dev/null
+++ b/gdb/i386obsd-nat.c
@@ -0,0 +1,60 @@
+/* Native-dependent code for OpenBSD/i386.
+   Copyright 2002 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include "defs.h"
+
+#include <sys/param.h>
+#include <sys/sysctl.h>
+
+/* Prevent warning from -Wmissing-prototypes.  */
+void _initialize_i386fbsd_nat (void);
+
+void
+_initialize_i386obsd_nat (void)
+{
+  /* OpenBSD provides a vm.psstrings sysctl that we can use to locate
+     the sigtramp.  That way we can still recognize a sigtramp if its
+     location is changed in a new kernel.  This is especially
+     important for OpenBSD, since it uses a different memory layout
+     than NetBSD, yet we cannot distinguish between the two.
+
+     Of course this is still based on the assumption that the sigtramp
+     is placed directly under the location where the program arguments
+     and environment can be found.  */
+#ifdef VM_PSSTRINGS
+  {
+    struct _ps_strings _ps;
+    int mib[2];
+    size_t len;
+
+    extern CORE_ADDR i386nbsd_sigtramp_start;
+    extern CORE_ADDR i386nbsd_sigtramp_end;
+
+    mib[0] = CTL_VM;
+    mib[1] = VM_PSSTRINGS;
+    len = sizeof (_ps);
+    if (sysctl (mib, 2, &_ps, &len, NULL, 0) == 0)
+      {
+	i386nbsd_sigtramp_start = (CORE_ADDR)_ps.val - 128;
+	i386nbsd_sigtramp_end = (CORE_ADDR)_ps.val;
+      }
+  }
+#endif
+}