137 lines
3.6 KiB
C
137 lines
3.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
|
|
#define pr_fmt(fmt) "kcsan: " fmt
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/printk.h>
|
|
#include <linux/random.h>
|
|
#include <linux/types.h>
|
|
|
|
#include "encoding.h"
|
|
|
|
#define ITERS_PER_TEST 2000
|
|
|
|
/* Test requirements. */
|
|
static bool test_requires(void)
|
|
{
|
|
/* random should be initialized for the below tests */
|
|
return prandom_u32() + prandom_u32() != 0;
|
|
}
|
|
|
|
/*
|
|
* Test watchpoint encode and decode: check that encoding some access's info,
|
|
* and then subsequent decode preserves the access's info.
|
|
*/
|
|
static bool test_encode_decode(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < ITERS_PER_TEST; ++i) {
|
|
size_t size = prandom_u32_max(MAX_ENCODABLE_SIZE) + 1;
|
|
bool is_write = !!prandom_u32_max(2);
|
|
unsigned long addr;
|
|
|
|
prandom_bytes(&addr, sizeof(addr));
|
|
if (addr < PAGE_SIZE)
|
|
addr = PAGE_SIZE;
|
|
|
|
if (WARN_ON(!check_encodable(addr, size)))
|
|
return false;
|
|
|
|
/* Encode and decode */
|
|
{
|
|
const long encoded_watchpoint =
|
|
encode_watchpoint(addr, size, is_write);
|
|
unsigned long verif_masked_addr;
|
|
size_t verif_size;
|
|
bool verif_is_write;
|
|
|
|
/* Check special watchpoints */
|
|
if (WARN_ON(decode_watchpoint(
|
|
INVALID_WATCHPOINT, &verif_masked_addr,
|
|
&verif_size, &verif_is_write)))
|
|
return false;
|
|
if (WARN_ON(decode_watchpoint(
|
|
CONSUMED_WATCHPOINT, &verif_masked_addr,
|
|
&verif_size, &verif_is_write)))
|
|
return false;
|
|
|
|
/* Check decoding watchpoint returns same data */
|
|
if (WARN_ON(!decode_watchpoint(
|
|
encoded_watchpoint, &verif_masked_addr,
|
|
&verif_size, &verif_is_write)))
|
|
return false;
|
|
if (WARN_ON(verif_masked_addr !=
|
|
(addr & WATCHPOINT_ADDR_MASK)))
|
|
goto fail;
|
|
if (WARN_ON(verif_size != size))
|
|
goto fail;
|
|
if (WARN_ON(is_write != verif_is_write))
|
|
goto fail;
|
|
|
|
continue;
|
|
fail:
|
|
pr_err("%s fail: %s %zu bytes @ %lx -> encoded: %lx -> %s %zu bytes @ %lx\n",
|
|
__func__, is_write ? "write" : "read", size,
|
|
addr, encoded_watchpoint,
|
|
verif_is_write ? "write" : "read", verif_size,
|
|
verif_masked_addr);
|
|
return false;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/* Test access matching function. */
|
|
static bool test_matching_access(void)
|
|
{
|
|
if (WARN_ON(!matching_access(10, 1, 10, 1)))
|
|
return false;
|
|
if (WARN_ON(!matching_access(10, 2, 11, 1)))
|
|
return false;
|
|
if (WARN_ON(!matching_access(10, 1, 9, 2)))
|
|
return false;
|
|
if (WARN_ON(matching_access(10, 1, 11, 1)))
|
|
return false;
|
|
if (WARN_ON(matching_access(9, 1, 10, 1)))
|
|
return false;
|
|
|
|
/*
|
|
* An access of size 0 could match another access, as demonstrated here.
|
|
* Rather than add more comparisons to 'matching_access()', which would
|
|
* end up in the fast-path for *all* checks, check_access() simply
|
|
* returns for all accesses of size 0.
|
|
*/
|
|
if (WARN_ON(!matching_access(8, 8, 12, 0)))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
static int __init kcsan_selftest(void)
|
|
{
|
|
int passed = 0;
|
|
int total = 0;
|
|
|
|
#define RUN_TEST(do_test) \
|
|
do { \
|
|
++total; \
|
|
if (do_test()) \
|
|
++passed; \
|
|
else \
|
|
pr_err("selftest: " #do_test " failed"); \
|
|
} while (0)
|
|
|
|
RUN_TEST(test_requires);
|
|
RUN_TEST(test_encode_decode);
|
|
RUN_TEST(test_matching_access);
|
|
|
|
pr_info("selftest: %d/%d tests passed\n", passed, total);
|
|
if (passed != total)
|
|
panic("selftests failed");
|
|
return 0;
|
|
}
|
|
postcore_initcall(kcsan_selftest);
|