https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69863
Bug ID: 69863
Summary: no_sanitize_address doesn't disable stack
instrumentation
Product: gcc
Version: 5.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: sanitizer
Assignee: unassigned at gcc dot gnu.org
Reporter: ryabinin.a.a at gmail dot com
CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
jakub at gcc dot gnu.org, kcc at gcc dot gnu.org
Target Milestone: ---
Attribute no_sanitize_address doesn't disable instrumentation completely.
Apparently no_sanitize_address only disables memory access checks, but it
doesn't have influence on stack redzones.
Regardless of this attribute gcc creates and poisons/unpoisons stack redzones.
$ cat no_sanitize_stack_test.c
void g(int *a);
__attribute__((no_sanitize_address))
void func(void)
{
int a;
g(&a);
}
$ gcc -fsanitize=address -c no_sanitize_stack_test.c && objdump -d
no_sanitize_stack_test.o
0000000000000000 <func>:
....
4d: 49 c1 ec 03 shr $0x3,%r12
51: 41 c7 84 24 00 80 ff movl $0xf1f1f1f1,0x7fff8000(%r12)
58: 7f f1 f1 f1 f1
5d: 41 c7 84 24 04 80 ff movl $0xf4f4f404,0x7fff8004(%r12)
64: 7f 04 f4 f4 f4
69: 41 c7 84 24 08 80 ff movl $0xf3f3f3f3,0x7fff8008(%r12)
70: 7f f3 f3 f3 f3
75: 64 48 8b 14 25 28 00 mov %fs:0x28,%rdx
