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-rw-r--r--gdb/i386obsd-nat.c67
1 files changed, 66 insertions, 1 deletions
diff --git a/gdb/i386obsd-nat.c b/gdb/i386obsd-nat.c
index 6c7bd50..8be811e 100644
--- a/gdb/i386obsd-nat.c
+++ b/gdb/i386obsd-nat.c
@@ -1,6 +1,6 @@
/* Native-dependent code for OpenBSD/i386.
- Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
+ Copyright (C) 2002, 2003, 2004, 2006 Free Software Foundation, Inc.
This file is part of GDB.
@@ -20,11 +20,70 @@
Boston, MA 02110-1301, USA. */
#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 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.. */
+ read_memory (pcb->pcb_esp, (char *) &sf, sizeof sf);
+ if ((unsigned int) sf.sf_ppl < 0x100 && (sf.sf_ppl & 0xf) == 0)
+ {
+ /* Yes, we have a frame that matches cpu_switch(). */
+ 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
+ {
+ /* No, the pcb must have been last updated by savectx(). */
+ pcb->pcb_esp += 4;
+ regcache_raw_supply (regcache, I386_EIP_REGNUM, &sf);
+ }
+
+ regcache_raw_supply (regcache, I386_EBP_REGNUM, &pcb->pcb_ebp);
+ regcache_raw_supply (regcache, I386_ESP_REGNUM, &pcb->pcb_esp);
+
+ return 1;
+}
+
/* Prevent warning from -Wmissing-prototypes. */
void _initialize_i386obsd_nat (void);
@@ -32,6 +91,12 @@ 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