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authorMark Kettenis <kettenis@gnu.org>2004-05-22 22:42:53 +0000
committerMark Kettenis <kettenis@gnu.org>2004-05-22 22:42:53 +0000
commit492cf391e36017aca823e106e1613e93cb4f0870 (patch)
treea5479d757f7726c4e2d690186a514316a7a189ba /gdb/amd64obsd-nat.c
parenta770d4eca642f4ae0d2e2e8d04a76933afed7b78 (diff)
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* amd64obsd-nat.c: Include "gdbcore.h", "regcache.h",
<sys/types.h>, <machine/frame.h>, <machine/pcb.h> and "bsd-kvm.h". (amd64obsd_supply_pcb): New function. (_initialize_amd64obsd_nat): Enable libkvm interface. * Makefile.in (amd64obsd-nat.o): Update dependencies. * config/i386/obsd64.mh (NATDEPFILES): Add bsd-kvm.o (LOADLIBES): New variable.
Diffstat (limited to 'gdb/amd64obsd-nat.c')
-rw-r--r--gdb/amd64obsd-nat.c75
1 files changed, 75 insertions, 0 deletions
diff --git a/gdb/amd64obsd-nat.c b/gdb/amd64obsd-nat.c
index e8d92fe..0f9b5ef 100644
--- a/gdb/amd64obsd-nat.c
+++ b/gdb/amd64obsd-nat.c
@@ -20,6 +20,8 @@
Boston, MA 02111-1307, USA. */
#include "defs.h"
+#include "gdbcore.h"
+#include "regcache.h"
#include "gdb_assert.h"
@@ -56,6 +58,76 @@ static int amd64obsd32_r_reg_offset[] =
};
+/* Support for debugging kernel virtual memory images. */
+
+#include <sys/types.h>
+#include <machine/frame.h>
+#include <machine/pcb.h>
+
+#include "bsd-kvm.h"
+
+static int
+amd64obsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
+{
+ struct switchframe sf;
+ int regnum;
+
+ /* The following is true for OpenBSD 3.5:
+
+ The pcb contains the stack pointer 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 3.5 has the
+ following layout:
+
+ interrupt level
+ %r15
+ %r14
+ %r13
+ %r12
+ %rbp
+ %rbx
+ return address
+
+ Together with %rsp in the pcb, this accounts for all callee-saved
+ registers specified by the psABI. From this information we
+ reconstruct the register state as it would look when we just
+ returned from cpu_switch().
+
+ For core dumps the pcb is saved by savectx(). In that case the
+ stack frame only contains the return address, and there is no way
+ to recover the other registers. */
+
+ /* The stack pointer shouldn't be zero. */
+ if (pcb->pcb_rsp == 0)
+ return 0;
+
+ /* Read the stack frame, and check its validity. */
+ read_memory (pcb->pcb_rsp, (char *) &sf, sizeof sf);
+ if (sf.sf_rbp == pcb->pcb_rbp)
+ {
+ /* Yes, we have a frame that matches cpu_switch(). */
+ pcb->pcb_rsp += sizeof (struct switchframe);
+ regcache_raw_supply (regcache, 12, &sf.sf_r12);
+ regcache_raw_supply (regcache, 13, &sf.sf_r13);
+ regcache_raw_supply (regcache, 14, &sf.sf_r14);
+ regcache_raw_supply (regcache, 15, &sf.sf_r15);
+ regcache_raw_supply (regcache, AMD64_RBX_REGNUM, &sf.sf_rbx);
+ regcache_raw_supply (regcache, AMD64_RIP_REGNUM, &sf.sf_rip);
+ }
+ else
+ {
+ /* No, the pcb must have been last updated by savectx(). */
+ pcb->pcb_rsp += 8;
+ regcache_raw_supply (regcache, AMD64_RIP_REGNUM, &sf);
+ }
+
+ regcache_raw_supply (regcache, AMD64_RSP_REGNUM, &pcb->pcb_rsp);
+ regcache_raw_supply (regcache, AMD64_RBP_REGNUM, &pcb->pcb_rbp);
+
+ return 1;
+}
+
+
/* Provide a prototype to silence -Wmissing-prototypes. */
void _initialize_amd64obsd_nat (void);
@@ -65,4 +137,7 @@ _initialize_amd64obsd_nat (void)
amd64_native_gregset32_reg_offset = amd64obsd32_r_reg_offset;
amd64_native_gregset32_num_regs = ARRAY_SIZE (amd64obsd32_r_reg_offset);
amd64_native_gregset64_reg_offset = amd64obsd_r_reg_offset;
+
+ /* Support debugging kernel virtual memory images. */
+ bsd_kvm_add_target (amd64obsd_supply_pcb);
}