diff mbox series

[4/8] x86: change fetch error handling in get_valid_dis386()

Message ID b4c84a3d-5266-2395-ba72-97e5ec540b3c@suse.com
State Accepted
Headers
Series x86: do away with (ab)using setjmp/longjmp for error handling |

Checks

Context Check Description
snail/binutils-gdb-check success Github commit url

Commit Message

Jan Beulich April 4, 2023, 6:59 a.m. UTC 
  Introduce a special error indicator node, for the sole (real) caller
to recognize and act upon.
diff mbox series

Patch

--- a/opcodes/i386-dis.c
+++ b/opcodes/i386-dis.c
@@ -9164,6 +9164,9 @@  with the -M switch (multiple options sho
 /* 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 *
@@ -9265,13 +9268,13 @@  get_valid_dis386 (const struct dis386 *d
       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:
@@ -9325,7 +9328,8 @@  get_valid_dis386 (const struct dis386 *d
       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".  */
@@ -9377,10 +9381,8 @@  get_valid_dis386 (const struct dis386 *d
       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.  */
@@ -9390,7 +9392,8 @@  get_valid_dis386 (const struct dis386 *d
 
     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))
 	{
@@ -9443,18 +9446,15 @@  get_valid_dis386 (const struct dis386 *d
       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
@@ -9481,13 +9481,8 @@  get_valid_dis386 (const struct dis386 *d
       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:
@@ -9501,7 +9496,8 @@  get_valid_dis386 (const struct dis386 *d
       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;
@@ -9576,10 +9572,8 @@  get_valid_dis386 (const struct dis386 *d
       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)
@@ -9966,6 +9960,8 @@  print_insn (bfd_vma pc, disassemble_info
   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))