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authorAlan Modra <amodra@gmail.com>2019-12-10 23:22:10 +1030
committerAlan Modra <amodra@gmail.com>2019-12-11 11:38:24 +1030
commitc202f69e5130fed314afa079ce30abaad4d34991 (patch)
treec4e19f714b47d869d10de621416ebd7436d24ba6 /opcodes
parent0ef562a4b5da6bc1f16b2ea801b228acafd033d8 (diff)
downloadgdb-c202f69e5130fed314afa079ce30abaad4d34991.zip
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ubsan: cris: signed integer overflow
This was the following in print_with_operands case 4: number = buffer[2] + buffer[3] * 256 + buffer[4] * 65536 + buffer[5] * 0x1000000; and buffer[5] * 0x1000000 can indeed overflow. So to fix this we need to use unsigned arithmetic where overflow semantics are specified. But number is a long, and the expression is int which will be sign extended to long. If we make the expression unsigned it will be zero extended. So make number an int32_t and rearrange a little for some of the places that need fixing. * cris-dis.c (print_with_operands): Avoid signed integer overflow when collecting bytes of a 32-bit integer.
Diffstat (limited to 'opcodes')
-rw-r--r--opcodes/ChangeLog5
-rw-r--r--opcodes/cris-dis.c35
2 files changed, 21 insertions, 19 deletions
diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index 57212f8..6b76f15 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,5 +1,10 @@
2019-12-11 Alan Modra <amodra@gmail.com>
+ * cris-dis.c (print_with_operands): Avoid signed integer
+ overflow when collecting bytes of a 32-bit integer.
+
+2019-12-11 Alan Modra <amodra@gmail.com>
+
* cr16-dis.c (EXTRACT, SBM): Rewrite.
(cr16_match_opcode): Delete duplicate bcond test.
diff --git a/opcodes/cris-dis.c b/opcodes/cris-dis.c
index 793549d..c501ba0 100644
--- a/opcodes/cris-dis.c
+++ b/opcodes/cris-dis.c
@@ -850,9 +850,8 @@ print_with_operands (const struct cris_opcode *opcodep,
case 'n':
{
/* Like N but pc-relative to the start of the insn. */
- unsigned long number
- = (buffer[2] + buffer[3] * 256 + buffer[4] * 65536
- + buffer[5] * 0x1000000 + addr);
+ int32_t number = (buffer[2] + buffer[3] * 256 + buffer[4] * 65536
+ + buffer[5] * 0x1000000u);
/* Finish off and output previous formatted bytes. */
*tp = 0;
@@ -860,14 +859,14 @@ print_with_operands (const struct cris_opcode *opcodep,
(*info->fprintf_func) (info->stream, "%s", temp);
tp = temp;
- (*info->print_address_func) ((bfd_vma) number, info);
+ (*info->print_address_func) (addr + number, info);
}
break;
case 'u':
{
/* Like n but the offset is bits <3:0> in the instruction. */
- unsigned long number = (buffer[0] & 0xf) * 2 + addr;
+ unsigned int number = (buffer[0] & 0xf) * 2;
/* Finish off and output previous formatted bytes. */
*tp = 0;
@@ -875,7 +874,7 @@ print_with_operands (const struct cris_opcode *opcodep,
(*info->fprintf_func) (info->stream, "%s", temp);
tp = temp;
- (*info->print_address_func) ((bfd_vma) number, info);
+ (*info->print_address_func) (addr + number, info);
}
break;
@@ -889,7 +888,7 @@ print_with_operands (const struct cris_opcode *opcodep,
{
/* We're looking at [pc+], i.e. we need to output an immediate
number, where the size can depend on different things. */
- long number;
+ int32_t number;
int signedp
= ((*cs == 'z' && (insn & 0x20))
|| opcodep->match == BDAP_QUICK_OPCODE);
@@ -940,9 +939,8 @@ print_with_operands (const struct cris_opcode *opcodep,
break;
case 4:
- number
- = buffer[2] + buffer[3] * 256 + buffer[4] * 65536
- + buffer[5] * 0x1000000;
+ number = (buffer[2] + buffer[3] * 256 + buffer[4] * 65536
+ + buffer[5] * 0x1000000u);
break;
default:
@@ -1042,10 +1040,10 @@ print_with_operands (const struct cris_opcode *opcodep,
{
/* It's [pc+]. This cannot possibly be anything
but an address. */
- unsigned long number
- = prefix_buffer[2] + prefix_buffer[3] * 256
- + prefix_buffer[4] * 65536
- + prefix_buffer[5] * 0x1000000;
+ int32_t number = (prefix_buffer[2]
+ + prefix_buffer[3] * 256
+ + prefix_buffer[4] * 65536
+ + prefix_buffer[5] * 0x1000000u);
info->target = (bfd_vma) number;
@@ -1131,7 +1129,7 @@ print_with_operands (const struct cris_opcode *opcodep,
if ((prefix_insn & 0x400) && (prefix_insn & 15) == 15)
{
- long number;
+ int32_t number;
unsigned int nbytes;
/* It's a value. Get its size. */
@@ -1157,10 +1155,9 @@ print_with_operands (const struct cris_opcode *opcodep,
break;
case 4:
- number
- = prefix_buffer[2] + prefix_buffer[3] * 256
- + prefix_buffer[4] * 65536
- + prefix_buffer[5] * 0x1000000;
+ number = (prefix_buffer[2] + prefix_buffer[3] * 256
+ + prefix_buffer[4] * 65536
+ + prefix_buffer[5] * 0x1000000u);
break;
default: