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* i386nbsd-tdep.c (i386nbsd_sigtramp_offset): New function.

Browse source 
(i386nbsd_pc_in_sigtramp): Rewrite to use i386nbsd_sigtramp_offset.
(i386nbsd_init_abi): Don't initialize tdep->sigtramp_start or
tdep->sigtramp_end.
(i386nbsd_sigtramp_start, i386nbsd_sigtramp_end): Remove.
* config/i386/tm-nbsd.h (SIGTRAMP_START, SIGTRAMP_END)
(i386bsd_sigtramp_start, i386bsd_sigtramp_end): Remove.
This commit is contained in:
Jason Thorpe 2002-09-02 16:35:14 +00:00
parent 3e369e968e
commit d66198e1a7
3 changed files with 100 additions and 28 deletions
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10
gdb/ChangeLog
View file

@ -1,3 +1,13 @@
2002-09-02 Jason Thorpe <thorpej@wasabisystems.com>
* i386nbsd-tdep.c (i386nbsd_sigtramp_offset): New function.
(i386nbsd_pc_in_sigtramp): Rewrite to use i386nbsd_sigtramp_offset.
(i386nbsd_init_abi): Don't initialize tdep->sigtramp_start or
tdep->sigtramp_end.
(i386nbsd_sigtramp_start, i386nbsd_sigtramp_end): Remove.
* config/i386/tm-nbsd.h (SIGTRAMP_START, SIGTRAMP_END)
(i386bsd_sigtramp_start, i386bsd_sigtramp_end): Remove.
2002-09-02 Jason Thorpe <thorpej@wasabisystems.com>
* Makefile.in (i386nbsd-tdep.o): Add $(arch_utils_h),

12
gdb/config/i386/tm-nbsd.h
View file

@ -23,16 +23,4 @@
#include "i386/tm-i386.h"
/* These defines allow the recognition of sigtramps as a function name
<sigtramp>.
FIXME: kettenis/2002-05-12: Of course these defines will have to go
if we go truly "multi-arch", but I don't know yet how to get rid of
them. */
#define SIGTRAMP_START(pc) i386bsd_sigtramp_start (pc)
#define SIGTRAMP_END(pc) i386bsd_sigtramp_end (pc)
extern CORE_ADDR i386bsd_sigtramp_start (CORE_ADDR pc);
extern CORE_ADDR i386bsd_sigtramp_end (CORE_ADDR pc);
#endif /* TM_NBSD_H */

106
gdb/i386nbsd-tdep.c
View file

@ -140,24 +140,102 @@ static struct core_fns i386nbsd_elfcore_fns =
NULL /* next */
};
/* Under NetBSD/i386, signal handler invocations can be identified by the
designated code sequence that is used to return from a signal handler.
In particular, the return address of a signal handler points to the
following code sequence:
leal 0x10(%esp), %eax
pushl %eax
pushl %eax
movl $0x127, %eax # __sigreturn14
int $0x80
Each instruction has a unique encoding, so we simply attempt to match
the instruction the PC is pointing to with any of the above instructions.
If there is a hit, we know the offset to the start of the designated
sequence and can then check whether we really are executing in the
signal trampoline. If not, -1 is returned, otherwise the offset from the
start of the return sequence is returned. */
#define RETCODE_INSN1 0x8d
#define RETCODE_INSN2 0x50
#define RETCODE_INSN3 0x50
#define RETCODE_INSN4 0xb8
#define RETCODE_INSN5 0xcd
#define RETCODE_INSN2_OFF 4
#define RETCODE_INSN3_OFF 5
#define RETCODE_INSN4_OFF 6
#define RETCODE_INSN5_OFF 11
static const unsigned char sigtramp_retcode[] =
{
RETCODE_INSN1, 0x44, 0x24, 0x10,
RETCODE_INSN2,
RETCODE_INSN3,
RETCODE_INSN4, 0x27, 0x01, 0x00, 0x00,
RETCODE_INSN5, 0x80,
};
static LONGEST
i386nbsd_sigtramp_offset (CORE_ADDR pc)
{
unsigned char ret[sizeof(sigtramp_retcode)], insn;
LONGEST off;
int i;
if (read_memory_nobpt (pc, &insn, 1) != 0)
return -1;
switch (insn)
{
case RETCODE_INSN1:
off = 0;
break;
case RETCODE_INSN2:
/* INSN2 and INSN3 are the same. Read at the location of PC+1
to determine if we're actually looking at INSN2 or INSN3. */
if (read_memory_nobpt (pc + 1, &insn, 1) != 0)
return -1;
if (insn == RETCODE_INSN3)
off = RETCODE_INSN2_OFF;
else
off = RETCODE_INSN3_OFF;
break;
case RETCODE_INSN4:
off = RETCODE_INSN4_OFF;
break;
case RETCODE_INSN5:
off = RETCODE_INSN5_OFF;
break;
default:
return -1;
}
pc -= off;
if (read_memory_nobpt (pc, (char *) ret, sizeof (ret)) != 0)
return -1;
if (memcmp (ret, sigtramp_retcode, sizeof (ret)) == 0)
return off;
return -1;
}
static int
i386nbsd_pc_in_sigtramp (CORE_ADDR pc, char *name)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
/* Check for libc-provided signal trampoline. */
if (nbsd_pc_in_sigtramp (pc, name))
return 1;
/* FIXME: sigtramp_start/sigtramp_end need to go away; we should
not be assuming the location of the kernel-provided trampoline! */
return (pc >= tdep->sigtramp_start && pc < tdep->sigtramp_end);
return (nbsd_pc_in_sigtramp (pc, name)
|| i386nbsd_sigtramp_offset (pc) >= 0);
}
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;
@ -176,10 +254,6 @@ i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
/* NetBSD uses -freg-struct-return by default. */
tdep->struct_return = reg_struct_return;
/* NetBSD uses a different memory layout. */
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. */
tdep->sc_pc_offset = i386nbsd_sc_pc_offset;