mm/rodata_test: verify test data is unchanged, rather than non-zero

Verify that the test variable holds the initialization value, rather than
any non-zero value.

Link: https://lkml.kernel.org/r/386ffda192eb4a26f68c526c496afd48a5cd87ce.1732016064.git.ptesarik@suse.com
Signed-off-by: Petr Tesarik <ptesarik@suse.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Cc: Jinbum Park <jinb.park7@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Petr Tesarik 2024-11-19 12:37:39 +01:00 committed by Andrew Morton
parent 3e29764ee2
commit a0a6837326

View File

@ -12,7 +12,8 @@
#include <linux/mm.h>
#include <asm/sections.h>
static const int rodata_test_data = 0xC3;
#define TEST_VALUE 0xC3
static const int rodata_test_data = TEST_VALUE;
void rodata_test(void)
{
@ -20,7 +21,7 @@ void rodata_test(void)
/* test 1: read the value */
/* If this test fails, some previous testrun has clobbered the state */
if (!READ_ONCE(rodata_test_data)) {
if (unlikely(READ_ONCE(rodata_test_data) != TEST_VALUE)) {
pr_err("test 1 fails (start data)\n");
return;
}
@ -33,7 +34,7 @@ void rodata_test(void)
}
/* test 3: check the value hasn't changed */
if (READ_ONCE(rodata_test_data) == zero) {
if (unlikely(READ_ONCE(rodata_test_data) != TEST_VALUE)) {
pr_err("test data was changed\n");
return;
}