*len = sizeof (break_insn);
return break_insn;
}
+\f
+/* Displaced instruction handling. */
+
+
+static int
+i386_absolute_jmp_p (gdb_byte *insn)
+{
+ /* jmp far (absolute address in operand) */
+ if (insn[0] == 0xea)
+ return 1;
+
+ if (insn[0] == 0xff)
+ {
+ /* jump near, absolute indirect (/4) */
+ if ((insn[1] & 0x38) == 0x20)
+ return 1;
+
+ /* jump far, absolute indirect (/5) */
+ if ((insn[1] & 0x38) == 0x28)
+ return 1;
+ }
+
+ return 0;
+}
+
+static int
+i386_absolute_call_p (gdb_byte *insn)
+{
+ /* call far, absolute */
+ if (insn[0] == 0x9a)
+ return 1;
+
+ if (insn[0] == 0xff)
+ {
+ /* Call near, absolute indirect (/2) */
+ if ((insn[1] & 0x38) == 0x10)
+ return 1;
+
+ /* Call far, absolute indirect (/3) */
+ if ((insn[1] & 0x38) == 0x18)
+ return 1;
+ }
+
+ return 0;
+}
+
+static int
+i386_ret_p (gdb_byte *insn)
+{
+ switch (insn[0])
+ {
+ case 0xc2: /* ret near, pop N bytes */
+ case 0xc3: /* ret near */
+ case 0xca: /* ret far, pop N bytes */
+ case 0xcb: /* ret far */
+ case 0xcf: /* iret */
+ return 1;
+
+ default:
+ return 0;
+ }
+}
+
+static int
+i386_call_p (gdb_byte *insn)
+{
+ if (i386_absolute_call_p (insn))
+ return 1;
+
+ /* call near, relative */
+ if (insn[0] == 0xe8)
+ 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)
+{
+ if (insn[0] == 0xcd)
+ {
+ *lengthp = 2;
+ return 1;
+ }
+
+ return 0;
+}
+
+/* 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,
+ CORE_ADDR from, CORE_ADDR to,
+ struct regcache *regs)
+{
+ /* The offset we applied to the instruction's address.
+ This could well be negative (when viewed as a signed 32-bit
+ value), but ULONGEST won't reflect that, so take care when
+ applying it. */
+ ULONGEST insn_offset = to - from;
+
+ /* Since we use simple_displaced_step_copy_insn, our closure is a
+ copy of the instruction. */
+ gdb_byte *insn = (gdb_byte *) closure;
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog,
+ "displaced: fixup (0x%s, 0x%s), "
+ "insn = 0x%02x 0x%02x ...\n",
+ paddr_nz (from), paddr_nz (to), insn[0], insn[1]);
+
+ /* The list of issues to contend with here is taken from
+ resume_execution in arch/i386/kernel/kprobes.c, Linux 2.6.20.
+ Yay for Free Software! */
+
+ /* Relocate the %eip, if necessary. */
+
+ /* 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
+ handler returns don't need relocation either, but we use the
+ value of %eip to recognize those; see below. */
+ if (! i386_absolute_jmp_p (insn)
+ && ! i386_absolute_call_p (insn)
+ && ! i386_ret_p (insn))
+ {
+ ULONGEST orig_eip;
+ ULONGEST insn_len;
+
+ regcache_cooked_read_unsigned (regs, I386_EIP_REGNUM, &orig_eip);
+
+ /* A signal trampoline system call changes the %eip, resuming
+ execution of the main program after the signal handler has
+ returned. That makes them like 'return' instructions; we
+ shouldn't relocate %eip.
+
+ But most system calls don't, and we do need to relocate %eip.
+
+ Our heuristic for distinguishing these cases: if stepping
+ over the system call instruction left control directly after
+ the instruction, the we relocate --- control almost certainly
+ doesn't belong in the displaced copy. Otherwise, we assume
+ the instruction has put control where it belongs, and leave
+ it unrelocated. Goodness help us if there are PC-relative
+ system calls. */
+ if (i386_syscall_p (insn, &insn_len)
+ && orig_eip != to + insn_len)
+ {
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog,
+ "displaced: syscall changed %%eip; "
+ "not relocating\n");
+ }
+ else
+ {
+ 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))
+ {
+ fprintf_unfiltered (gdb_stdlog,
+ "displaced: stepped breakpoint\n");
+ eip--;
+ }
+
+ regcache_cooked_write_unsigned (regs, I386_EIP_REGNUM, eip);
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog,
+ "displaced: "
+ "relocated %%eip from 0x%s to 0x%s\n",
+ paddr_nz (orig_eip), paddr_nz (eip));
+ }
+ }
+
+ /* If the instruction was PUSHFL, then the TF bit will be set in the
+ pushed value, and should be cleared. We'll leave this for later,
+ since GDB already messes up the TF flag when stepping over a
+ pushfl. */
+
+ /* If the instruction was a call, the return address now atop the
+ stack is the address following the copied instruction. We need
+ to make it the address following the original instruction. */
+ if (i386_call_p (insn))
+ {
+ ULONGEST esp;
+ ULONGEST retaddr;
+ const ULONGEST retaddr_len = 4;
+
+ regcache_cooked_read_unsigned (regs, I386_ESP_REGNUM, &esp);
+ retaddr = read_memory_unsigned_integer (esp, retaddr_len);
+ retaddr = (retaddr - insn_offset) & 0xffffffffUL;
+ write_memory_unsigned_integer (esp, retaddr_len, retaddr);
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog,
+ "displaced: relocated return addr at 0x%s "
+ "to 0x%s\n",
+ paddr_nz (esp),
+ paddr_nz (retaddr));
+ }
+}
+
+
\f
#ifdef I386_REGNO_TO_SYMMETRY
#error "The Sequent Symmetry is no longer supported."
}
/* Maximum instruction length we need to handle. */
-#define I386_MAX_INSN_LEN 6
+#define I386_MAX_MATCHED_INSN_LEN 6
/* Instruction description. */
struct i386_insn
{
size_t len;
- gdb_byte insn[I386_MAX_INSN_LEN];
- gdb_byte mask[I386_MAX_INSN_LEN];
+ gdb_byte insn[I386_MAX_MATCHED_INSN_LEN];
+ gdb_byte mask[I386_MAX_MATCHED_INSN_LEN];
};
/* Search for the instruction at PC in the list SKIP_INSNS. Return
{
if ((op & insn->mask[0]) == insn->insn[0])
{
- gdb_byte buf[I386_MAX_INSN_LEN - 1];
+ gdb_byte buf[I386_MAX_MATCHED_INSN_LEN - 1];
int insn_matched = 1;
size_t i;
gdb_assert (insn->len > 1);
- gdb_assert (insn->len <= I386_MAX_INSN_LEN);
+ gdb_assert (insn->len <= I386_MAX_MATCHED_INSN_LEN);
target_read_memory (pc + 1, buf, insn->len - 1);
for (i = 1; i < insn->len; i++)
/* Normal frames. */
static struct i386_frame_cache *
-i386_frame_cache (struct frame_info *next_frame, void **this_cache)
+i386_frame_cache (struct frame_info *this_frame, void **this_cache)
{
struct i386_frame_cache *cache;
gdb_byte buf[4];
They (usually) share their frame pointer with the frame that was
in progress when the signal occurred. */
- frame_unwind_register (next_frame, I386_EBP_REGNUM, buf);
+ get_frame_register (this_frame, I386_EBP_REGNUM, buf);
cache->base = extract_unsigned_integer (buf, 4);
if (cache->base == 0)
return cache;
/* For normal frames, %eip is stored at 4(%ebp). */
cache->saved_regs[I386_EIP_REGNUM] = 4;
- cache->pc = frame_func_unwind (next_frame, NORMAL_FRAME);
+ cache->pc = get_frame_func (this_frame);
if (cache->pc != 0)
- i386_analyze_prologue (cache->pc, frame_pc_unwind (next_frame), cache);
+ i386_analyze_prologue (cache->pc, get_frame_pc (this_frame), cache);
if (cache->stack_align)
{
/* Saved stack pointer has been saved in %ecx. */
- frame_unwind_register (next_frame, I386_ECX_REGNUM, buf);
+ get_frame_register (this_frame, I386_ECX_REGNUM, buf);
cache->saved_sp = extract_unsigned_integer(buf, 4);
}
}
else
{
- frame_unwind_register (next_frame, I386_ESP_REGNUM, buf);
+ get_frame_register (this_frame, I386_ESP_REGNUM, buf);
cache->base = extract_unsigned_integer (buf, 4) + cache->sp_offset;
}
}
}
static void
-i386_frame_this_id (struct frame_info *next_frame, void **this_cache,
+i386_frame_this_id (struct frame_info *this_frame, void **this_cache,
struct frame_id *this_id)
{
- struct i386_frame_cache *cache = i386_frame_cache (next_frame, this_cache);
+ struct i386_frame_cache *cache = i386_frame_cache (this_frame, this_cache);
/* This marks the outermost frame. */
if (cache->base == 0)
(*this_id) = frame_id_build (cache->base + 8, cache->pc);
}
-static void
-i386_frame_prev_register (struct frame_info *next_frame, void **this_cache,
- int regnum, int *optimizedp,
- enum lval_type *lvalp, CORE_ADDR *addrp,
- int *realnump, gdb_byte *valuep)
+static struct value *
+i386_frame_prev_register (struct frame_info *this_frame, void **this_cache,
+ int regnum)
{
- struct i386_frame_cache *cache = i386_frame_cache (next_frame, this_cache);
+ struct i386_frame_cache *cache = i386_frame_cache (this_frame, this_cache);
gdb_assert (regnum >= 0);
if (regnum == I386_EFLAGS_REGNUM)
{
- *optimizedp = 0;
- *lvalp = not_lval;
- *addrp = 0;
- *realnump = -1;
- if (valuep)
- {
- ULONGEST val;
+ ULONGEST val;
- /* Clear the direction flag. */
- val = frame_unwind_register_unsigned (next_frame,
- I386_EFLAGS_REGNUM);
- val &= ~(1 << 10);
- store_unsigned_integer (valuep, 4, val);
- }
-
- return;
+ val = get_frame_register_unsigned (this_frame, regnum);
+ val &= ~(1 << 10);
+ return frame_unwind_got_constant (this_frame, regnum, val);
}
if (regnum == I386_EIP_REGNUM && cache->pc_in_eax)
- {
- *optimizedp = 0;
- *lvalp = lval_register;
- *addrp = 0;
- *realnump = I386_EAX_REGNUM;
- if (valuep)
- frame_unwind_register (next_frame, (*realnump), valuep);
- return;
- }
+ return frame_unwind_got_register (this_frame, regnum, I386_EAX_REGNUM);
if (regnum == I386_ESP_REGNUM && cache->saved_sp)
- {
- *optimizedp = 0;
- *lvalp = not_lval;
- *addrp = 0;
- *realnump = -1;
- if (valuep)
- {
- /* Store the value. */
- store_unsigned_integer (valuep, 4, cache->saved_sp);
- }
- return;
- }
+ return frame_unwind_got_constant (this_frame, regnum, cache->saved_sp);
if (regnum < I386_NUM_SAVED_REGS && cache->saved_regs[regnum] != -1)
- {
- *optimizedp = 0;
- *lvalp = lval_memory;
- *addrp = cache->saved_regs[regnum];
- *realnump = -1;
- if (valuep)
- {
- /* Read the value in from memory. */
- read_memory (*addrp, valuep,
- register_size (get_frame_arch (next_frame), regnum));
- }
- return;
- }
+ return frame_unwind_got_memory (this_frame, regnum,
+ cache->saved_regs[regnum]);
- *optimizedp = 0;
- *lvalp = lval_register;
- *addrp = 0;
- *realnump = regnum;
- if (valuep)
- frame_unwind_register (next_frame, (*realnump), valuep);
+ return frame_unwind_got_register (this_frame, regnum, regnum);
}
static const struct frame_unwind i386_frame_unwind =
{
NORMAL_FRAME,
i386_frame_this_id,
- i386_frame_prev_register
+ i386_frame_prev_register,
+ NULL,
+ default_frame_sniffer
};
-
-static const struct frame_unwind *
-i386_frame_sniffer (struct frame_info *next_frame)
-{
- return &i386_frame_unwind;
-}
\f
/* Signal trampolines. */
static struct i386_frame_cache *
-i386_sigtramp_frame_cache (struct frame_info *next_frame, void **this_cache)
+i386_sigtramp_frame_cache (struct frame_info *this_frame, void **this_cache)
{
struct i386_frame_cache *cache;
- struct gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (next_frame));
+ struct gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (this_frame));
CORE_ADDR addr;
gdb_byte buf[4];
cache = i386_alloc_frame_cache ();
- frame_unwind_register (next_frame, I386_ESP_REGNUM, buf);
+ get_frame_register (this_frame, I386_ESP_REGNUM, buf);
cache->base = extract_unsigned_integer (buf, 4) - 4;
- addr = tdep->sigcontext_addr (next_frame);
+ addr = tdep->sigcontext_addr (this_frame);
if (tdep->sc_reg_offset)
{
int i;
}
static void
-i386_sigtramp_frame_this_id (struct frame_info *next_frame, void **this_cache,
+i386_sigtramp_frame_this_id (struct frame_info *this_frame, void **this_cache,
struct frame_id *this_id)
{
struct i386_frame_cache *cache =
- i386_sigtramp_frame_cache (next_frame, this_cache);
+ i386_sigtramp_frame_cache (this_frame, this_cache);
/* See the end of i386_push_dummy_call. */
- (*this_id) = frame_id_build (cache->base + 8, frame_pc_unwind (next_frame));
+ (*this_id) = frame_id_build (cache->base + 8, get_frame_pc (this_frame));
}
-static void
-i386_sigtramp_frame_prev_register (struct frame_info *next_frame,
- void **this_cache,
- int regnum, int *optimizedp,
- enum lval_type *lvalp, CORE_ADDR *addrp,
- int *realnump, gdb_byte *valuep)
+static struct value *
+i386_sigtramp_frame_prev_register (struct frame_info *this_frame,
+ void **this_cache, int regnum)
{
/* Make sure we've initialized the cache. */
- i386_sigtramp_frame_cache (next_frame, this_cache);
+ i386_sigtramp_frame_cache (this_frame, this_cache);
- i386_frame_prev_register (next_frame, this_cache, regnum,
- optimizedp, lvalp, addrp, realnump, valuep);
+ return i386_frame_prev_register (this_frame, this_cache, regnum);
}
-static const struct frame_unwind i386_sigtramp_frame_unwind =
-{
- SIGTRAMP_FRAME,
- i386_sigtramp_frame_this_id,
- i386_sigtramp_frame_prev_register
-};
-
-static const struct frame_unwind *
-i386_sigtramp_frame_sniffer (struct frame_info *next_frame)
+static int
+i386_sigtramp_frame_sniffer (const struct frame_unwind *self,
+ struct frame_info *this_frame,
+ void **this_prologue_cache)
{
- struct gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (next_frame));
+ struct gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (this_frame));
/* We shouldn't even bother if we don't have a sigcontext_addr
handler. */
if (tdep->sigcontext_addr == NULL)
- return NULL;
+ return 0;
if (tdep->sigtramp_p != NULL)
{
- if (tdep->sigtramp_p (next_frame))
- return &i386_sigtramp_frame_unwind;
+ if (tdep->sigtramp_p (this_frame))
+ return 1;
}
if (tdep->sigtramp_start != 0)
{
- CORE_ADDR pc = frame_pc_unwind (next_frame);
+ CORE_ADDR pc = get_frame_pc (this_frame);
gdb_assert (tdep->sigtramp_end != 0);
if (pc >= tdep->sigtramp_start && pc < tdep->sigtramp_end)
- return &i386_sigtramp_frame_unwind;
+ return 1;
}
- return NULL;
+ return 0;
}
+
+static const struct frame_unwind i386_sigtramp_frame_unwind =
+{
+ SIGTRAMP_FRAME,
+ i386_sigtramp_frame_this_id,
+ i386_sigtramp_frame_prev_register,
+ NULL,
+ i386_sigtramp_frame_sniffer
+};
\f
static CORE_ADDR
-i386_frame_base_address (struct frame_info *next_frame, void **this_cache)
+i386_frame_base_address (struct frame_info *this_frame, void **this_cache)
{
- struct i386_frame_cache *cache = i386_frame_cache (next_frame, this_cache);
+ struct i386_frame_cache *cache = i386_frame_cache (this_frame, this_cache);
return cache->base;
}
};
static struct frame_id
-i386_unwind_dummy_id (struct gdbarch *gdbarch, struct frame_info *next_frame)
+i386_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame)
{
- gdb_byte buf[4];
CORE_ADDR fp;
- frame_unwind_register (next_frame, I386_EBP_REGNUM, buf);
- fp = extract_unsigned_integer (buf, 4);
+ fp = get_frame_register_unsigned (this_frame, I386_EBP_REGNUM);
/* See the end of i386_push_dummy_call. */
- return frame_id_build (fp + 8, frame_pc_unwind (next_frame));
+ return frame_id_build (fp + 8, get_frame_pc (this_frame));
}
\f
/* MarkK wrote: This "+ 8" is all over the place:
(i386_frame_this_id, i386_sigtramp_frame_this_id,
- i386_unwind_dummy_id). It's there, since all frame unwinders for
+ i386_dummy_id). It's there, since all frame unwinders for
a given target have to agree (within a certain margin) on the
definition of the stack address of a frame. Otherwise
frame_id_inner() won't work correctly. Since DWARF2/GCC uses the
}
\f
-/* Return whether the frame preceding NEXT_FRAME corresponds to a
- sigtramp routine. */
+/* Return whether the THIS_FRAME corresponds to a sigtramp
+ routine. */
static int
-i386_sigtramp_p (struct frame_info *next_frame)
+i386_sigtramp_p (struct frame_info *this_frame)
{
- CORE_ADDR pc = frame_pc_unwind (next_frame);
+ CORE_ADDR pc = get_frame_pc (this_frame);
char *name;
find_pc_partial_function (pc, &name, NULL, NULL);
/* System V Release 4 (SVR4). */
-/* Return whether the frame preceding NEXT_FRAME corresponds to a SVR4
- sigtramp routine. */
+/* Return whether THIS_FRAME corresponds to a SVR4 sigtramp
+ routine. */
static int
-i386_svr4_sigtramp_p (struct frame_info *next_frame)
+i386_svr4_sigtramp_p (struct frame_info *this_frame)
{
- CORE_ADDR pc = frame_pc_unwind (next_frame);
+ CORE_ADDR pc = get_frame_pc (this_frame);
char *name;
/* UnixWare uses _sigacthandler. The origin of the other symbols is
|| strcmp ("sigvechandler", name) == 0));
}
-/* Assuming NEXT_FRAME is for a frame following a SVR4 sigtramp
- routine, return the address of the associated sigcontext (ucontext)
- structure. */
+/* Assuming THIS_FRAME is for a SVR4 sigtramp routine, return the
+ address of the associated sigcontext (ucontext) structure. */
static CORE_ADDR
-i386_svr4_sigcontext_addr (struct frame_info *next_frame)
+i386_svr4_sigcontext_addr (struct frame_info *this_frame)
{
gdb_byte buf[4];
CORE_ADDR sp;
- frame_unwind_register (next_frame, I386_ESP_REGNUM, buf);
+ get_frame_register (this_frame, I386_ESP_REGNUM, buf);
sp = extract_unsigned_integer (buf, 4);
return read_memory_unsigned_integer (sp + 8, 4);
set_gdbarch_stab_reg_to_regnum (gdbarch, i386_dbx_reg_to_regnum);
set_gdbarch_sdb_reg_to_regnum (gdbarch, i386_dbx_reg_to_regnum);
- /* Use the SVR4 register numbering scheme for DWARF and DWARF 2. */
- set_gdbarch_dwarf_reg_to_regnum (gdbarch, i386_svr4_reg_to_regnum);
+ /* Use the SVR4 register numbering scheme for DWARF 2. */
set_gdbarch_dwarf2_reg_to_regnum (gdbarch, i386_svr4_reg_to_regnum);
/* We don't set gdbarch_stab_reg_to_regnum, since ECOFF doesn't seem to
set_gdbarch_breakpoint_from_pc (gdbarch, i386_breakpoint_from_pc);
set_gdbarch_decr_pc_after_break (gdbarch, 1);
+ set_gdbarch_max_insn_length (gdbarch, I386_MAX_INSN_LEN);
set_gdbarch_frame_args_skip (gdbarch, 8);
set_gdbarch_print_insn (gdbarch, i386_print_insn);
- set_gdbarch_unwind_dummy_id (gdbarch, i386_unwind_dummy_id);
+ set_gdbarch_dummy_id (gdbarch, i386_dummy_id);
set_gdbarch_unwind_pc (gdbarch, i386_unwind_pc);
set_gdbarch_fetch_pointer_argument (gdbarch, i386_fetch_pointer_argument);
/* Hook in the DWARF CFI frame unwinder. */
- frame_unwind_append_sniffer (gdbarch, dwarf2_frame_sniffer);
+ dwarf2_append_unwinders (gdbarch);
frame_base_set_default (gdbarch, &i386_frame_base);
/* Hook in ABI-specific overrides, if they have been registered. */
gdbarch_init_osabi (info, gdbarch);
- frame_unwind_append_sniffer (gdbarch, i386_sigtramp_frame_sniffer);
- frame_unwind_append_sniffer (gdbarch, i386_frame_sniffer);
+ frame_unwind_append_unwinder (gdbarch, &i386_sigtramp_frame_unwind);
+ frame_unwind_append_unwinder (gdbarch, &i386_frame_unwind);
/* If we have a register mapping, enable the generic core file
support, unless it has already been enabled. */
projects / deliverable / binutils-gdb.git / blobdiff