diff options
Diffstat (limited to 'gdb/i386obsd-nat.c')
-rw-r--r-- | gdb/i386obsd-nat.c | 67 |
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 |