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Fix bug in arm_push_dummy_call by -fsanitize=address

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When I build GDB with -fsanitize=address, and run testsuite,
some gdb.base/*.exp test triggers the ERROR below,

=================================================================
==7646==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x603000242810 at pc 0x487844 bp 0x7fffe32e84e0 sp 0x7fffe32e84d8
READ of size 4 at 0x603000242810 thread T0
    #0 0x487843 in push_stack_item /home/yao/SourceCode/gnu/gdb/git/gdb/arm-tdep.c:3405
    #1 0x48998a in arm_push_dummy_call /home/yao/SourceCode/gnu/gdb/git/gdb/arm-tdep.c:3960

In that path, GDB passes value on stack, in an INT_REGISTER_SIZE slot,
but the value contents' length can be less than INT_REGISTER_SIZE, so
the contents will be accessed out of the bound.  This patch adds an
array buf[INT_REGISTER_SIZE], and copy val to buf before writing them
to stack.

gdb:

2015-11-16  Yao Qi  <yao.qi@linaro.org>

	* arm-tdep.c (arm_push_dummy_call): New array buf.  Store regval
	to buf.  Pass buf instead of val to push_stack_item.
This commit is contained in:
Yao Qi 2015-11-16 14:44:19 +00:00
parent 3940d2c36a
commit ef9bd0b8d7
2 changed files with 13 additions and 3 deletions
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5
gdb/ChangeLog
View File

@ -1,3 +1,8 @@
2015-11-16 Yao Qi <yao.qi@linaro.org>
* arm-tdep.c (arm_push_dummy_call): New array buf. Store regval
to buf. Pass buf instead of val to push_stack_item.
2015-11-13 Yao Qi <yao.qi@linaro.org>
PR tdep/19051

11
gdb/arm-tdep.c
View File

@ -3925,13 +3925,13 @@ arm_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
while (len > 0)
{
int partial_len = len < INT_REGISTER_SIZE ? len : INT_REGISTER_SIZE;
CORE_ADDR regval
= extract_unsigned_integer (val, partial_len, byte_order);
if (may_use_core_reg && argreg <= ARM_LAST_ARG_REGNUM)
{
/* The argument is being passed in a general purpose
register. */
CORE_ADDR regval
= extract_unsigned_integer (val, partial_len, byte_order);
if (byte_order == BFD_ENDIAN_BIG)
regval <<= (INT_REGISTER_SIZE - partial_len) * 8;
if (arm_debug)
@ -3945,11 +3945,16 @@ arm_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
}
else
{
gdb_byte buf[INT_REGISTER_SIZE];
memset (buf, 0, sizeof (buf));
store_unsigned_integer (buf, partial_len, byte_order, regval);
/* Push the arguments onto the stack. */
if (arm_debug)
fprintf_unfiltered (gdb_stdlog, "arg %d @ sp + %d\n",
argnum, nstack);
si = push_stack_item (si, val, INT_REGISTER_SIZE);
si = push_stack_item (si, buf, INT_REGISTER_SIZE);
nstack += INT_REGISTER_SIZE;
}