All callers updated.
(amd64_get_insn_details): Handle more 3-byte opcode insns.
(amd64_breakpoint_p): Delete.
(amd64_displaced_step_fixup): When fixing up after stepping an int3,
don't back up pc to the start of the int3.
* i386-tdep.c: #include opcode/i386.h.
(i386_skip_prefixes): New function.
(i386_absolute_jmp_p): Constify argument.
(i386_absolute_call_p,i386_ret_p,i386_call_p,i386_syscall_p): Ditto.
(i386_breakpoint_p): Delete.
(i386_displaced_step_fixup): Handle unnecessary or redundant prefixes.
When fixing up after stepping an int3, don't back up pc to the start
of the int3.
* gdb.arch/amd64-disp-step.S (test_int3): New test.
* gdb.arch/amd64-disp-step.exp (test_int3): New test.
* gdb.arch/i386-disp-step.S (test_prefixed_abs_jump): New test.
(test_prefixed_syscall,test_int3): New tests.
* gdb.arch/i386-disp-step.exp (test_prefixed_abs_jump): New test.
(test_prefixed_syscall,test_int3): New tests.
+2009-02-16 Doug Evans <dje@google.com>
+
+ * amd64-tdep.c (amd64_skip_prefixes): Renamed from skip_prefixes.
+ All callers updated.
+ (amd64_get_insn_details): Handle more 3-byte opcode insns.
+ (amd64_breakpoint_p): Delete.
+ (amd64_displaced_step_fixup): When fixing up after stepping an int3,
+ don't back up pc to the start of the int3.
+ * i386-tdep.c: #include opcode/i386.h.
+ (i386_skip_prefixes): New function.
+ (i386_absolute_jmp_p): Constify argument.
+ (i386_absolute_call_p,i386_ret_p,i386_call_p,i386_syscall_p): Ditto.
+ (i386_breakpoint_p): Delete.
+ (i386_displaced_step_fixup): Handle unnecessary or redundant prefixes.
+ When fixing up after stepping an int3, don't back up pc to the start
+ of the int3.
+
2009-02-16 Pedro Alves <pedro@codesourcery.com>
* corelow.c (core_close): Don't hardcode the core's pid.
about falling off the end of the buffer. */
static gdb_byte *
-skip_prefixes (gdb_byte *insn)
+amd64_skip_prefixes (gdb_byte *insn)
{
while (1)
{
details->modrm_offset = -1;
/* Skip legacy instruction prefixes. */
- insn = skip_prefixes (insn);
+ insn = amd64_skip_prefixes (insn);
/* Skip REX instruction prefix. */
if (rex_prefix_p (*insn))
need_modrm = twobyte_has_modrm[*insn];
/* Check for three-byte opcode. */
- if (*insn == 0x38 || *insn == 0x3a)
+ switch (*insn)
{
+ case 0x24:
+ case 0x25:
+ case 0x38:
+ case 0x3a:
+ case 0x7a:
+ case 0x7b:
++insn;
details->opcode_len = 3;
+ break;
+ default:
+ details->opcode_len = 2;
+ break;
}
- else
- details->opcode_len = 2;
}
else
{
return 0;
}
-static int
-amd64_breakpoint_p (const struct amd64_insn *details)
-{
- const gdb_byte *insn = &details->raw_insn[details->opcode_offset];
-
- return insn[0] == 0xcc; /* int 3 */
-}
-
/* Return non-zero if INSN is a system call, and set *LENGTHP to its
length in bytes. Otherwise, return zero. */
{
ULONGEST rip = orig_rip - insn_offset;
- /* If we have stepped over a breakpoint, set %rip to
- point at the breakpoint instruction itself.
-
- (gdbarch_decr_pc_after_break was never something the core
- of GDB should have been concerned with; arch-specific
- code should be making PC values consistent before
- presenting them to GDB.) */
- if (amd64_breakpoint_p (insn_details))
- {
- if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog,
- "displaced: stepped breakpoint\n");
- rip--;
- }
+ /* If we just stepped over a breakpoint insn, we don't backup
+ the pc on purpose; this is to match behaviour without
+ stepping. */
regcache_cooked_write_unsigned (regs, AMD64_RIP_REGNUM, rip);
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
+#include "opcode/i386.h"
#include "arch-utils.h"
#include "command.h"
#include "dummy-frame.h"
\f
/* Displaced instruction handling. */
+/* Skip the legacy instruction prefixes in INSN.
+ Not all prefixes are valid for any particular insn
+ but we needn't care, the insn will fault if it's invalid.
+ The result is a pointer to the first opcode byte,
+ or NULL if we run off the end of the buffer. */
+
+static gdb_byte *
+i386_skip_prefixes (gdb_byte *insn, size_t max_len)
+{
+ gdb_byte *end = insn + max_len;
+
+ while (insn < end)
+ {
+ switch (*insn)
+ {
+ case DATA_PREFIX_OPCODE:
+ case ADDR_PREFIX_OPCODE:
+ case CS_PREFIX_OPCODE:
+ case DS_PREFIX_OPCODE:
+ case ES_PREFIX_OPCODE:
+ case FS_PREFIX_OPCODE:
+ case GS_PREFIX_OPCODE:
+ case SS_PREFIX_OPCODE:
+ case LOCK_PREFIX_OPCODE:
+ case REPE_PREFIX_OPCODE:
+ case REPNE_PREFIX_OPCODE:
+ ++insn;
+ continue;
+ default:
+ return insn;
+ }
+ }
+
+ return NULL;
+}
static int
-i386_absolute_jmp_p (gdb_byte *insn)
+i386_absolute_jmp_p (const gdb_byte *insn)
{
/* jmp far (absolute address in operand) */
if (insn[0] == 0xea)
}
static int
-i386_absolute_call_p (gdb_byte *insn)
+i386_absolute_call_p (const gdb_byte *insn)
{
/* call far, absolute */
if (insn[0] == 0x9a)
}
static int
-i386_ret_p (gdb_byte *insn)
+i386_ret_p (const gdb_byte *insn)
{
switch (insn[0])
{
}
static int
-i386_call_p (gdb_byte *insn)
+i386_call_p (const gdb_byte *insn)
{
if (i386_absolute_call_p (insn))
return 1;
return 0;
}
-static int
-i386_breakpoint_p (gdb_byte *insn)
-{
- return insn[0] == 0xcc; /* int 3 */
-}
-
/* Return non-zero if INSN is a system call, and set *LENGTHP to its
length in bytes. Otherwise, return zero. */
+
static int
-i386_syscall_p (gdb_byte *insn, ULONGEST *lengthp)
+i386_syscall_p (const gdb_byte *insn, ULONGEST *lengthp)
{
if (insn[0] == 0xcd)
{
/* Fix up the state of registers and memory after having single-stepped
a displaced instruction. */
+
void
i386_displaced_step_fixup (struct gdbarch *gdbarch,
struct displaced_step_closure *closure,
/* Since we use simple_displaced_step_copy_insn, our closure is a
copy of the instruction. */
gdb_byte *insn = (gdb_byte *) closure;
+ /* The start of the insn, needed in case we see some prefixes. */
+ gdb_byte *insn_start = insn;
if (debug_displaced)
fprintf_unfiltered (gdb_stdlog,
/* Relocate the %eip, if necessary. */
+ /* The instruction recognizers we use assume any leading prefixes
+ have been skipped. */
+ {
+ /* This is the size of the buffer in closure. */
+ size_t max_insn_len = gdbarch_max_insn_length (gdbarch);
+ gdb_byte *opcode = i386_skip_prefixes (insn, max_insn_len);
+ /* If there are too many prefixes, just ignore the insn.
+ It will fault when run. */
+ if (opcode != NULL)
+ insn = opcode;
+ }
+
/* Except in the case of absolute or indirect jump or call
instructions, or a return instruction, the new eip is relative to
the displaced instruction; make it relative. Well, signal
it unrelocated. Goodness help us if there are PC-relative
system calls. */
if (i386_syscall_p (insn, &insn_len)
- && orig_eip != to + insn_len)
+ && orig_eip != to + (insn - insn_start) + insn_len)
{
if (debug_displaced)
fprintf_unfiltered (gdb_stdlog,
{
ULONGEST eip = (orig_eip - insn_offset) & 0xffffffffUL;
- /* If we have stepped over a breakpoint, set the %eip to
- point at the breakpoint instruction itself.
-
- (gdbarch_decr_pc_after_break was never something the core
- of GDB should have been concerned with; arch-specific
- code should be making PC values consistent before
- presenting them to GDB.) */
- if (i386_breakpoint_p (insn))
- {
- if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog,
- "displaced: stepped breakpoint\n");
- eip--;
- }
+ /* If we just stepped over a breakpoint insn, we don't backup
+ the pc on purpose; this is to match behaviour without
+ stepping. */
regcache_cooked_write_unsigned (regs, I386_EIP_REGNUM, eip);
paddr_nz (retaddr));
}
}
-
-
\f
#ifdef I386_REGNO_TO_SYMMETRY
#error "The Sequent Symmetry is no longer supported."
+2009-02-16 Doug Evans <dje@google.com>
+
+ * gdb.arch/amd64-disp-step.S (test_int3): New test.
+ * gdb.arch/amd64-disp-step.exp (test_int3): New test.
+ * gdb.arch/i386-disp-step.S (test_prefixed_abs_jump): New test.
+ (test_prefixed_syscall,test_int3): New tests.
+ * gdb.arch/i386-disp-step.exp (test_prefixed_abs_jump): New test.
+ (test_prefixed_syscall,test_int3): New tests.
+
2009-02-14 Vladimir Prus <vladimir@codesourcery.com>
* lib/mi-support.exp (mi_expect_stop): Adjust the order of fields.
main:
nop
+/***********************************************/
+
/* test call/ret */
.global test_call
test_ret_end:
nop
+/***********************************************/
+
/* test abs-jmp/rep-ret */
test_abs_jmp_setup:
test_rep_ret_end:
nop
+/***********************************************/
+
/* test syscall */
.global test_syscall
test_syscall_end:
nop
+/***********************************************/
+
+/* Test stepping over int3.
+ The prefixes are pointless, but it's possible, so we exercise it. */
+
+ nop
+ .global test_int3
+test_int3:
+ repz
+ repz
+ int3
+ nop
+ .global test_int3_end
+test_int3_end:
+ nop
+
+/***********************************************/
+
/* test rip-relative
GDB picks a spare register to hold the rip-relative address.
Exercise all the possibilities (rax-rdi, sans rsp). */
answer: .8byte 42
+/***********************************************/
+
/* all done */
done:
test_ret:
ret
+/***********************************************/
+
/* subroutine to help test abs-jmp/rep-ret */
test_abs_jmp_subr:
##########################################
+# int3 (with prefixes)
+# These don't occur in normal code, but gdb should still DTRT.
+
+gdb_test "break test_int3" \
+ "Breakpoint.*at.* file .*$srcfile, line.*" \
+ "break test_int3"
+gdb_test "break test_int3_end" \
+ "Breakpoint.*at.* file .*$srcfile, line.*" \
+ "break test_int3_end"
+
+gdb_test "continue" \
+ "Continuing.*Breakpoint.*, test_int3 ().*" \
+ "continue to test_int3"
+
+gdb_test "continue" \
+ "Continuing.*Breakpoint.*, test_int3_end ().*" \
+ "continue to test_int3_end"
+
+##########################################
+
# Test rip-relative.
# GDB picks a spare register to hold the rip-relative address.
# Exercise all the possibilities (rax-rdi, sans rsp).
main:
nop
-/* test call/ret */
+/***********************************************/
+
+/* Test call/ret. */
+ nop
.global test_call
test_call:
call test_call_subr
test_ret_end:
nop
-/* test syscall */
+/***********************************************/
+
+/* Absolute jump with leading prefixes.
+ These don't occur in normal code, but gdb should still DTRT. */
+
+ nop
+ .global test_prefixed_abs_jump
+test_prefixed_abs_jump:
+ ds
+ jmp *test_prefixed_abs_jump_addr
+ .data
+test_prefixed_abs_jump_addr:
+ .4byte test_prefixed_abs_jump_target
+ .text
+test_prefixed_abs_jump_target:
+ nop
+ .global test_prefixed_abs_jump_end
+test_prefixed_abs_jump_end:
+ nop
+
+/***********************************************/
+
+/* Test syscall. */
- .global test_syscall
mov $0x14,%eax /* getpid */
+ .global test_syscall
test_syscall:
int $0x80
nop
+ .global test_syscall_end
test_syscall_end:
nop
+/***********************************************/
+
+/* Test syscall again, this time with a prefix.
+ These don't occur in normal code, but gdb should still DTRT. */
+
+ mov $0x14,%eax /* getpid */
+ .global test_prefixed_syscall
+test_prefixed_syscall:
+ repnz
+ int $0x80
+ nop
+ .global test_prefixed_syscall_end
+test_prefixed_syscall_end:
+ nop
+
+/***********************************************/
+
+/* Test stepping over int3.
+ The prefixes are pointless, but it's possible, so we exercise it. */
+
+ nop
+ .global test_int3
+test_int3:
+ repz
+ repz
+ int3
+ nop
+ .global test_int3_end
+test_int3_end:
+ nop
+
+/***********************************************/
+
/* all done */
pushl $0
##########################################
+# Absolute jump with leading prefixes.
+# These don't occur in normal code, but gdb should still DTRT.
+
+gdb_test "break test_prefixed_abs_jump" \
+ "Breakpoint.*at.* file .*$srcfile, line.*" \
+ "break test_prefixed_abs_jump"
+gdb_test "break test_prefixed_abs_jump_end" \
+ "Breakpoint.*at.* file .*$srcfile, line.*" \
+ "break test_prefixed_abs_jump_end"
+
+gdb_test "continue" \
+ "Continuing.*Breakpoint.*, test_prefixed_abs_jump ().*" \
+ "continue to test_prefixed_abs_jump"
+gdb_test "continue" \
+ "Continuing.*Breakpoint.*, test_prefixed_abs_jump_end ().*" \
+ "continue to test_prefixed_abs_jump_end"
+
+##########################################
+
# Test syscall.
gdb_test "break test_syscall" \
##########################################
+# Test prefixed syscall.
+# These don't occur in normal code, but gdb should still DTRT.
+
+gdb_test "break test_prefixed_syscall" \
+ "Breakpoint.*at.* file .*$srcfile, line.*" \
+ "break test_prefixed_syscall"
+gdb_test "break test_prefixed_syscall_end" \
+ "Breakpoint.*at.* file .*$srcfile, line.*" \
+ "break test_prefixed_syscall_end"
+
+gdb_test "continue" \
+ "Continuing.*Breakpoint.*, test_prefixed_syscall ().*" \
+ "continue to test_prefixed_syscall"
+gdb_test "continue" \
+ "Continuing.*Breakpoint.*, test_prefixed_syscall_end ().*" \
+ "continue to test_prefixed_syscall_end"
+
+##########################################
+
+# int3 (with prefixes)
+# These don't occur in normal code, but gdb should still DTRT.
+
+gdb_test "break test_int3" \
+ "Breakpoint.*at.* file .*$srcfile, line.*" \
+ "break test_int3"
+gdb_test "break test_int3_end" \
+ "Breakpoint.*at.* file .*$srcfile, line.*" \
+ "break test_int3_end"
+
+gdb_test "continue" \
+ "Continuing.*Breakpoint.*, test_int3 ().*" \
+ "continue to test_int3"
+
+gdb_test "continue" \
+ "Continuing.*Breakpoint.*, test_int3_end ().*" \
+ "continue to test_int3_end"
+
+##########################################
+
# Done, run program to exit.
gdb_continue_to_end "i386-disp-step"
projects / binutils-gdb.git / commitdiff