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Re: [RFA] i386-tdep.c, check target_read_memory for error.
> Date: Tue, 08 Mar 2011 10:37:55 -0800
> From: Michael Snyder <msnyder@vmware.com>
>
> Thanks for your perseverance. New patch attached.
>
> There's still one more "return pc + skip" in there, which you
> didn't mention. Should I take it out?
No, that one is right as far as I can tell. Diff looks good to me.
> 2011-03-08 Michael Snyder <msnyder@vmware.com>
>
> * i386-tdep.c (i386_follow_jump): Check return value of
> target_read_memory.
> (i386_analyze_struct_return): Ditto.
> (i386_skip_probe): Ditto.
> (i386_match_insn): Ditto.
> (i386_skip_noop): Ditto.
> (i386_analyze_frame_setup): Ditto.
> (i386_analyze_register_saves): Ditto.
> (i386_skip_prologue): Ditto.
> (i386_skip_main_prologue): Ditto.
>
> Index: i386-tdep.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/i386-tdep.c,v
> retrieving revision 1.324
> diff -u -p -r1.324 i386-tdep.c
> --- i386-tdep.c 8 Feb 2011 14:01:47 -0000 1.324
> +++ i386-tdep.c 8 Mar 2011 18:32:01 -0000
> @@ -850,7 +850,9 @@ i386_follow_jump (struct gdbarch *gdbarc
> long delta = 0;
> int data16 = 0;
>
> - target_read_memory (pc, &op, 1);
> + if (target_read_memory (pc, &op, 1))
> + return pc;
> +
> if (op == 0x66)
> {
> data16 = 1;
> @@ -916,12 +918,15 @@ i386_analyze_struct_return (CORE_ADDR pc
> if (current_pc <= pc)
> return pc;
>
> - target_read_memory (pc, &op, 1);
> + if (target_read_memory (pc, &op, 1))
> + return pc;
>
> if (op != 0x58) /* popl %eax */
> return pc;
>
> - target_read_memory (pc + 1, buf, 4);
> + if (target_read_memory (pc + 1, buf, 4))
> + return pc;
> +
> if (memcmp (buf, proto1, 3) != 0 && memcmp (buf, proto2, 4) != 0)
> return pc;
>
> @@ -960,7 +965,8 @@ i386_skip_probe (CORE_ADDR pc)
> gdb_byte buf[8];
> gdb_byte op;
>
> - target_read_memory (pc, &op, 1);
> + if (target_read_memory (pc, &op, 1))
> + return pc;
>
> if (op == 0x68 || op == 0x6a)
> {
> @@ -1121,7 +1127,8 @@ i386_match_insn (CORE_ADDR pc, struct i3
> struct i386_insn *insn;
> gdb_byte op;
>
> - target_read_memory (pc, &op, 1);
> + if (target_read_memory (pc, &op, 1))
> + return NULL;
>
> for (insn = skip_insns; insn->len > 0; insn++)
> {
> @@ -1134,7 +1141,9 @@ i386_match_insn (CORE_ADDR pc, struct i3
> gdb_assert (insn->len > 1);
> gdb_assert (insn->len <= I386_MAX_MATCHED_INSN_LEN);
>
> - target_read_memory (pc + 1, buf, insn->len - 1);
> + if (target_read_memory (pc + 1, buf, insn->len - 1))
> + return NULL;
> +
> for (i = 1; i < insn->len; i++)
> {
> if ((buf[i - 1] & insn->mask[i]) != insn->insn[i])
> @@ -1212,7 +1221,8 @@ i386_skip_noop (CORE_ADDR pc)
> gdb_byte op;
> int check = 1;
>
> - target_read_memory (pc, &op, 1);
> + if (target_read_memory (pc, &op, 1))
> + return pc;
>
> while (check)
> {
> @@ -1221,7 +1231,8 @@ i386_skip_noop (CORE_ADDR pc)
> if (op == 0x90)
> {
> pc += 1;
> - target_read_memory (pc, &op, 1);
> + if (target_read_memory (pc, &op, 1))
> + return pc;
> check = 1;
> }
> /* Ignore no-op instruction `mov %edi, %edi'.
> @@ -1237,11 +1248,15 @@ i386_skip_noop (CORE_ADDR pc)
>
> else if (op == 0x8b)
> {
> - target_read_memory (pc + 1, &op, 1);
> + if (target_read_memory (pc + 1, &op, 1))
> + return pc;
> +
> if (op == 0xff)
> {
> pc += 2;
> - target_read_memory (pc, &op, 1);
> + if (target_read_memory (pc, &op, 1))
> + return pc;
> +
> check = 1;
> }
> }
> @@ -1267,7 +1282,8 @@ i386_analyze_frame_setup (struct gdbarch
> if (limit <= pc)
> return limit;
>
> - target_read_memory (pc, &op, 1);
> + if (target_read_memory (pc, &op, 1))
> + return pc;
>
> if (op == 0x55) /* pushl %ebp */
> {
> @@ -1302,7 +1318,8 @@ i386_analyze_frame_setup (struct gdbarch
> if (limit <= pc + skip)
> return limit;
>
> - target_read_memory (pc + skip, &op, 1);
> + if (target_read_memory (pc + skip, &op, 1))
> + return pc + skip;
>
> /* Check for `movl %esp, %ebp' -- can be written in two ways. */
> switch (op)
> @@ -1338,7 +1355,8 @@ i386_analyze_frame_setup (struct gdbarch
>
> NOTE: You can't subtract a 16-bit immediate from a 32-bit
> reg, so we don't have to worry about a data16 prefix. */
> - target_read_memory (pc, &op, 1);
> + if (target_read_memory (pc, &op, 1))
> + return pc;
> if (op == 0x83)
> {
> /* `subl' with 8-bit immediate. */
> @@ -1394,7 +1412,8 @@ i386_analyze_register_saves (CORE_ADDR p
> offset -= cache->locals;
> for (i = 0; i < 8 && pc < current_pc; i++)
> {
> - target_read_memory (pc, &op, 1);
> + if (target_read_memory (pc, &op, 1))
> + return pc;
> if (op < 0x50 || op > 0x57)
> break;
>
> @@ -1487,7 +1506,9 @@ i386_skip_prologue (struct gdbarch *gdba
>
> for (i = 0; i < 6; i++)
> {
> - target_read_memory (pc + i, &op, 1);
> + if (target_read_memory (pc + i, &op, 1))
> + return pc;
> +
> if (pic_pat[i] != op)
> break;
> }
> @@ -1495,7 +1516,8 @@ i386_skip_prologue (struct gdbarch *gdba
> {
> int delta = 6;
>
> - target_read_memory (pc + delta, &op, 1);
> + if (target_read_memory (pc + delta, &op, 1))
> + return pc;
>
> if (op == 0x89) /* movl %ebx, x(%ebp) */
> {
> @@ -1508,7 +1530,8 @@ i386_skip_prologue (struct gdbarch *gdba
> else /* Unexpected instruction. */
> delta = 0;
>
> - target_read_memory (pc + delta, &op, 1);
> + if (target_read_memory (pc + delta, &op, 1))
> + return pc;
> }
>
> /* addl y,%ebx */
> @@ -1538,7 +1561,8 @@ i386_skip_main_prologue (struct gdbarch
> enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
> gdb_byte op;
>
> - target_read_memory (pc, &op, 1);
> + if (target_read_memory (pc, &op, 1))
> + return pc;
> if (op == 0xe8)
> {
> gdb_byte buf[4];
>
> --------------090807040303000008010100--
>