* NS32K arg_bufs uninitialised
@ 2020-03-22 12:53 Alan Modra
0 siblings, 0 replies; only message in thread
From: Alan Modra @ 2020-03-22 12:53 UTC (permalink / raw)
To: binutils
git commit d1e304bc27 was aimed at stopping uninitialised memory
access to the index_offset array. Unfortunately that patch resulted
in a different array being uninitialised for all instructions with
more than two arguments.
* ns32k-dis.c (print_insn_arg): Update comment.
(print_insn_ns32k): Reduce size of index_offset array, and
initialize, passing -1 to print_insn_arg for args that are not
an index. Don't exit arg loop early. Abort on bad arg number.
diff --git a/opcodes/ns32k-dis.c b/opcodes/ns32k-dis.c
index d505edd774..12df182d0a 100644
--- a/opcodes/ns32k-dis.c
+++ b/opcodes/ns32k-dis.c
@@ -446,7 +446,7 @@ invalid_float (float_type_u *p, int len)
bit position of the addressing extension. BUFFER contains the
instruction. ADDR is where BUFFER was read from. Put the disassembled
version of the operand in RESULT. INDEX_OFFSET is the bit position
- of the index byte (it contains garbage if this operand is not a
+ of the index byte (it contains -1 if this operand is not a
general operand using scaled indexed addressing mode). */
static int
@@ -790,10 +790,8 @@ print_insn_ns32k (bfd_vma memaddr, disassemble_info *info)
if (*d)
{
/* Offset in bits of the first thing beyond each index byte.
- Element 0 is for operand A and element 1 is for operand B.
- The rest are irrelevant, but we put them here so we don't
- index outside the array. */
- int index_offset[MAX_ARGS];
+ Element 0 is for operand A and element 1 is for operand B. */
+ int index_offset[2];
/* 0 for operand A, 1 for operand B, greater for other args. */
int whicharg = 0;
@@ -806,6 +804,8 @@ print_insn_ns32k (bfd_vma memaddr, disassemble_info *info)
if we are using scaled indexed addressing mode, since the index
bytes occur right after the basic instruction, not as part
of the addressing extension. */
+ index_offset[0] = -1;
+ index_offset[1] = -1;
if (Is_gen (d[1]))
{
int bitoff = d[1] == 'f' ? 10 : 5;
@@ -832,15 +832,16 @@ print_insn_ns32k (bfd_vma memaddr, disassemble_info *info)
while (*d)
{
argnum = *d - '1';
+ if (argnum >= MAX_ARGS)
+ abort ();
d++;
- if (argnum > maxarg && argnum < MAX_ARGS)
+ if (argnum > maxarg)
maxarg = argnum;
ioffset = print_insn_arg (*d, ioffset, &aoffset, buffer,
memaddr, arg_bufs[argnum],
- index_offset[whicharg]);
+ whicharg > 1 ? -1 : index_offset[whicharg]);
d++;
- if (whicharg++ >= 1)
- break;
+ whicharg++;
}
for (argnum = 0; argnum <= maxarg; argnum++)
--
Alan Modra
Australia Development Lab, IBM
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