x86: change fetch error handling in get_valid_dis386()
Introduce a special error indicator node, for the sole (real) caller
to recognize and act upon.
diff --git a/opcodes/i386-dis.c b/opcodes/i386-dis.c
index 60bfa41..3db4b18 100644
--- a/opcodes/i386-dis.c
+++ b/opcodes/i386-dis.c
@@ -9196,6 +9196,9 @@
/* Bad opcode. */
static const struct dis386 bad_opcode = { "(bad)", { XX }, 0 };
+/* Fetch error indicator. */
+static const struct dis386 err_opcode = { NULL, { XX }, 0 };
+
/* Get a pointer to struct dis386 with a valid name. */
static const struct dis386 *
@@ -9297,13 +9300,13 @@
break;
case USE_3BYTE_TABLE:
- FETCH_DATA (ins->info, ins->codep + 2);
+ if (!fetch_code (ins->info, ins->codep + 2))
+ return &err_opcode;
vindex = *ins->codep++;
dp = &three_byte_table[dp->op[1].bytemode][vindex];
ins->end_codep = ins->codep;
- ins->modrm.mod = (*ins->codep >> 6) & 3;
- ins->modrm.reg = (*ins->codep >> 3) & 7;
- ins->modrm.rm = *ins->codep & 7;
+ if (!fetch_modrm (ins))
+ return &err_opcode;
break;
case USE_VEX_LEN_TABLE:
@@ -9357,7 +9360,8 @@
break;
case USE_XOP_8F_TABLE:
- FETCH_DATA (ins->info, ins->codep + 3);
+ if (!fetch_code (ins->info, ins->codep + 3))
+ return &err_opcode;
ins->rex = ~(*ins->codep >> 5) & 0x7;
/* VEX_TABLE_INDEX is the mmmmm part of the XOP byte 1 "RCB.mmmmm". */
@@ -9409,10 +9413,8 @@
dp = &xop_table[vex_table_index][vindex];
ins->end_codep = ins->codep;
- FETCH_DATA (ins->info, ins->codep + 1);
- ins->modrm.mod = (*ins->codep >> 6) & 3;
- ins->modrm.reg = (*ins->codep >> 3) & 7;
- ins->modrm.rm = *ins->codep & 7;
+ if (!fetch_modrm (ins))
+ return &err_opcode;
/* No XOP encoding so far allows for a non-zero embedded prefix. Avoid
having to decode the bits for every otherwise valid encoding. */
@@ -9422,7 +9424,8 @@
case USE_VEX_C4_TABLE:
/* VEX prefix. */
- FETCH_DATA (ins->info, ins->codep + 3);
+ if (!fetch_code (ins->info, ins->codep + 3))
+ return &err_opcode;
ins->rex = ~(*ins->codep >> 5) & 0x7;
switch ((*ins->codep & 0x1f))
{
@@ -9475,18 +9478,15 @@
dp = &vex_table[vex_table_index][vindex];
ins->end_codep = ins->codep;
/* There is no MODRM byte for VEX0F 77. */
- if (vex_table_index != VEX_0F || vindex != 0x77)
- {
- FETCH_DATA (ins->info, ins->codep + 1);
- ins->modrm.mod = (*ins->codep >> 6) & 3;
- ins->modrm.reg = (*ins->codep >> 3) & 7;
- ins->modrm.rm = *ins->codep & 7;
- }
+ if ((vex_table_index != VEX_0F || vindex != 0x77)
+ && !fetch_modrm (ins))
+ return &err_opcode;
break;
case USE_VEX_C5_TABLE:
/* VEX prefix. */
- FETCH_DATA (ins->info, ins->codep + 2);
+ if (!fetch_code (ins->info, ins->codep + 2))
+ return &err_opcode;
ins->rex = (*ins->codep & 0x80) ? 0 : REX_R;
/* For the 2-byte VEX prefix in 32-bit mode, the highest bit in
@@ -9513,13 +9513,8 @@
dp = &vex_table[dp->op[1].bytemode][vindex];
ins->end_codep = ins->codep;
/* There is no MODRM byte for VEX 77. */
- if (vindex != 0x77)
- {
- FETCH_DATA (ins->info, ins->codep + 1);
- ins->modrm.mod = (*ins->codep >> 6) & 3;
- ins->modrm.reg = (*ins->codep >> 3) & 7;
- ins->modrm.rm = *ins->codep & 7;
- }
+ if (vindex != 0x77 && !fetch_modrm (ins))
+ return &err_opcode;
break;
case USE_VEX_W_TABLE:
@@ -9533,7 +9528,8 @@
ins->two_source_ops = false;
/* EVEX prefix. */
ins->vex.evex = true;
- FETCH_DATA (ins->info, ins->codep + 4);
+ if (!fetch_code (ins->info, ins->codep + 4))
+ return &err_opcode;
/* The first byte after 0x62. */
ins->rex = ~(*ins->codep >> 5) & 0x7;
ins->vex.r = *ins->codep & 0x10;
@@ -9608,10 +9604,8 @@
vindex = *ins->codep++;
dp = &evex_table[vex_table_index][vindex];
ins->end_codep = ins->codep;
- FETCH_DATA (ins->info, ins->codep + 1);
- ins->modrm.mod = (*ins->codep >> 6) & 3;
- ins->modrm.reg = (*ins->codep >> 3) & 7;
- ins->modrm.rm = *ins->codep & 7;
+ if (!fetch_modrm (ins))
+ return &err_opcode;
/* Set vector length. */
if (ins->modrm.mod == 3 && ins->vex.b)
@@ -9998,6 +9992,8 @@
else
{
dp = get_valid_dis386 (dp, &ins);
+ if (dp == &err_opcode)
+ return fetch_error (&ins);
if (dp != NULL && putop (&ins, dp->name, sizeflag) == 0)
{
if (!get_sib (&ins, sizeflag))
