gdb/

[deliverable/binutils-gdb.git] / gdb / i386obsd-nat.c

diff --git a/gdb/i386obsd-nat.c b/gdb/i386obsd-nat.c
index 6c7bd50a153008ac7a93f6962d433c541d7c1b6c..e64c587d8f66767f35c0b301ea15312d579e7659 100644 (file)
--- a/gdb/i386obsd-nat.c
+++ b/gdb/i386obsd-nat.c
@@ -1,12 +1,12 @@
 /* Native-dependent code for OpenBSD/i386.
 
-   Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
+   Copyright (C) 2002-2004, 2006-2012 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
+   the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
@@ -15,16 +15,79 @@
    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., 51 Franklin Street, Fifth Floor,
-   Boston, MA 02110-1301, USA.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "defs.h"
+#include "gdbcore.h"
+#include "regcache.h"
+#include "target.h"
 
 #include <sys/param.h>
 #include <sys/sysctl.h>
+#include <machine/frame.h>
+#include <machine/pcb.h>
 
 #include "i386-tdep.h"
+#include "i386bsd-nat.h"
+#include "bsd-kvm.h"
+
+static int
+i386obsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
+{
+  struct gdbarch *gdbarch = get_regcache_arch (regcache);
+  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+  struct switchframe sf;
+
+  /* The following is true for OpenBSD 3.6:
+
+     The pcb contains %esp and %ebp at the point of the context switch
+     in cpu_switch().  At that point we have a stack frame as
+     described by `struct switchframe', which for OpenBSD 3.6 has the
+     following layout:
+
+     interrupt level
+     %edi
+     %esi
+     %ebx
+     %eip
+
+     we reconstruct the register state as it would look when we just
+     returned from cpu_switch().  */
+
+  /* The stack pointer shouldn't be zero.  */
+  if (pcb->pcb_esp == 0)
+    return 0;
+
+  /* Read the stack frame, and check its validity.  We do this by
+     checking if the saved interrupt priority level in the stack frame
+     looks reasonable..  */
+#ifdef PCB_SAVECTX
+  if ((pcb->pcb_flags & PCB_SAVECTX) == 0)
+    {
+      /* Yes, we have a frame that matches cpu_switch().  */
+      read_memory (pcb->pcb_esp, (char *) &sf, sizeof sf);
+      pcb->pcb_esp += sizeof (struct switchframe);
+      regcache_raw_supply (regcache, I386_EDI_REGNUM, &sf.sf_edi);
+      regcache_raw_supply (regcache, I386_ESI_REGNUM, &sf.sf_esi);
+      regcache_raw_supply (regcache, I386_EBX_REGNUM, &sf.sf_ebx);
+      regcache_raw_supply (regcache, I386_EIP_REGNUM, &sf.sf_eip);
+    }
+  else
+#endif
+    {
+      /* No, the pcb must have been last updated by savectx().  */
+      pcb->pcb_esp = pcb->pcb_ebp;
+      pcb->pcb_ebp = read_memory_integer(pcb->pcb_esp, 4, byte_order);
+      sf.sf_eip = read_memory_integer(pcb->pcb_esp + 4, 4, byte_order);
+      regcache_raw_supply (regcache, I386_EIP_REGNUM, &sf.sf_eip);
+    }
+
+  regcache_raw_supply (regcache, I386_EBP_REGNUM, &pcb->pcb_ebp);
+  regcache_raw_supply (regcache, I386_ESP_REGNUM, &pcb->pcb_esp);
+
+  return 1;
+}
+\f
 
 /* Prevent warning from -Wmissing-prototypes.  */
 void _initialize_i386obsd_nat (void);
@@ -32,6 +95,12 @@ void _initialize_i386obsd_nat (void);
 void
 _initialize_i386obsd_nat (void)
 {
+  /* We've got nothing to add to the common *BSD/i386 target.  */
+  add_target (i386bsd_target ());
+
+  /* Support debugging kernel virtual memory images.  */
+  bsd_kvm_add_target (i386obsd_supply_pcb);
+
   /* 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