forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
272 lines
9.7 KiB
272 lines
9.7 KiB
// SPDX-License-Identifier: GPL-2.0 |
|
/* |
|
* KCSAN short boot-time selftests. |
|
* |
|
* Copyright (C) 2019, Google LLC. |
|
*/ |
|
|
|
#define pr_fmt(fmt) "kcsan: " fmt |
|
|
|
#include <linux/atomic.h> |
|
#include <linux/bitops.h> |
|
#include <linux/init.h> |
|
#include <linux/kcsan-checks.h> |
|
#include <linux/kernel.h> |
|
#include <linux/printk.h> |
|
#include <linux/random.h> |
|
#include <linux/sched.h> |
|
#include <linux/spinlock.h> |
|
#include <linux/types.h> |
|
|
|
#include "encoding.h" |
|
|
|
#define ITERS_PER_TEST 2000 |
|
|
|
/* Test requirements. */ |
|
static bool __init test_requires(void) |
|
{ |
|
/* random should be initialized for the below tests */ |
|
return get_random_u32() + get_random_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 __init 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 verif_masked_addr; |
|
long encoded_watchpoint; |
|
bool verif_is_write; |
|
unsigned long addr; |
|
size_t verif_size; |
|
|
|
get_random_bytes(&addr, sizeof(addr)); |
|
if (addr < PAGE_SIZE) |
|
addr = PAGE_SIZE; |
|
|
|
if (WARN_ON(!check_encodable(addr, size))) |
|
return false; |
|
|
|
encoded_watchpoint = encode_watchpoint(addr, size, 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 __init 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; |
|
} |
|
|
|
/* |
|
* Correct memory barrier instrumentation is critical to avoiding false |
|
* positives: simple test to check at boot certain barriers are always properly |
|
* instrumented. See kcsan_test for a more complete test. |
|
*/ |
|
static DEFINE_SPINLOCK(test_spinlock); |
|
static bool __init test_barrier(void) |
|
{ |
|
#ifdef CONFIG_KCSAN_WEAK_MEMORY |
|
struct kcsan_scoped_access *reorder_access = ¤t->kcsan_ctx.reorder_access; |
|
#else |
|
struct kcsan_scoped_access *reorder_access = NULL; |
|
#endif |
|
bool ret = true; |
|
arch_spinlock_t arch_spinlock = __ARCH_SPIN_LOCK_UNLOCKED; |
|
atomic_t dummy; |
|
long test_var; |
|
|
|
if (!reorder_access || !IS_ENABLED(CONFIG_SMP)) |
|
return true; |
|
|
|
#define __KCSAN_CHECK_BARRIER(access_type, barrier, name) \ |
|
do { \ |
|
reorder_access->type = (access_type) | KCSAN_ACCESS_SCOPED; \ |
|
reorder_access->size = 1; \ |
|
barrier; \ |
|
if (reorder_access->size != 0) { \ |
|
pr_err("improperly instrumented type=(" #access_type "): " name "\n"); \ |
|
ret = false; \ |
|
} \ |
|
} while (0) |
|
#define KCSAN_CHECK_READ_BARRIER(b) __KCSAN_CHECK_BARRIER(0, b, #b) |
|
#define KCSAN_CHECK_WRITE_BARRIER(b) __KCSAN_CHECK_BARRIER(KCSAN_ACCESS_WRITE, b, #b) |
|
#define KCSAN_CHECK_RW_BARRIER(b) __KCSAN_CHECK_BARRIER(KCSAN_ACCESS_WRITE | KCSAN_ACCESS_COMPOUND, b, #b) |
|
|
|
kcsan_nestable_atomic_begin(); /* No watchpoints in called functions. */ |
|
|
|
KCSAN_CHECK_READ_BARRIER(mb()); |
|
KCSAN_CHECK_READ_BARRIER(rmb()); |
|
KCSAN_CHECK_READ_BARRIER(smp_mb()); |
|
KCSAN_CHECK_READ_BARRIER(smp_rmb()); |
|
KCSAN_CHECK_READ_BARRIER(dma_rmb()); |
|
KCSAN_CHECK_READ_BARRIER(smp_mb__before_atomic()); |
|
KCSAN_CHECK_READ_BARRIER(smp_mb__after_atomic()); |
|
KCSAN_CHECK_READ_BARRIER(smp_mb__after_spinlock()); |
|
KCSAN_CHECK_READ_BARRIER(smp_store_mb(test_var, 0)); |
|
KCSAN_CHECK_READ_BARRIER(smp_store_release(&test_var, 0)); |
|
KCSAN_CHECK_READ_BARRIER(xchg(&test_var, 0)); |
|
KCSAN_CHECK_READ_BARRIER(xchg_release(&test_var, 0)); |
|
KCSAN_CHECK_READ_BARRIER(cmpxchg(&test_var, 0, 0)); |
|
KCSAN_CHECK_READ_BARRIER(cmpxchg_release(&test_var, 0, 0)); |
|
KCSAN_CHECK_READ_BARRIER(atomic_set_release(&dummy, 0)); |
|
KCSAN_CHECK_READ_BARRIER(atomic_add_return(1, &dummy)); |
|
KCSAN_CHECK_READ_BARRIER(atomic_add_return_release(1, &dummy)); |
|
KCSAN_CHECK_READ_BARRIER(atomic_fetch_add(1, &dummy)); |
|
KCSAN_CHECK_READ_BARRIER(atomic_fetch_add_release(1, &dummy)); |
|
KCSAN_CHECK_READ_BARRIER(test_and_set_bit(0, &test_var)); |
|
KCSAN_CHECK_READ_BARRIER(test_and_clear_bit(0, &test_var)); |
|
KCSAN_CHECK_READ_BARRIER(test_and_change_bit(0, &test_var)); |
|
KCSAN_CHECK_READ_BARRIER(clear_bit_unlock(0, &test_var)); |
|
KCSAN_CHECK_READ_BARRIER(__clear_bit_unlock(0, &test_var)); |
|
arch_spin_lock(&arch_spinlock); |
|
KCSAN_CHECK_READ_BARRIER(arch_spin_unlock(&arch_spinlock)); |
|
spin_lock(&test_spinlock); |
|
KCSAN_CHECK_READ_BARRIER(spin_unlock(&test_spinlock)); |
|
|
|
KCSAN_CHECK_WRITE_BARRIER(mb()); |
|
KCSAN_CHECK_WRITE_BARRIER(wmb()); |
|
KCSAN_CHECK_WRITE_BARRIER(smp_mb()); |
|
KCSAN_CHECK_WRITE_BARRIER(smp_wmb()); |
|
KCSAN_CHECK_WRITE_BARRIER(dma_wmb()); |
|
KCSAN_CHECK_WRITE_BARRIER(smp_mb__before_atomic()); |
|
KCSAN_CHECK_WRITE_BARRIER(smp_mb__after_atomic()); |
|
KCSAN_CHECK_WRITE_BARRIER(smp_mb__after_spinlock()); |
|
KCSAN_CHECK_WRITE_BARRIER(smp_store_mb(test_var, 0)); |
|
KCSAN_CHECK_WRITE_BARRIER(smp_store_release(&test_var, 0)); |
|
KCSAN_CHECK_WRITE_BARRIER(xchg(&test_var, 0)); |
|
KCSAN_CHECK_WRITE_BARRIER(xchg_release(&test_var, 0)); |
|
KCSAN_CHECK_WRITE_BARRIER(cmpxchg(&test_var, 0, 0)); |
|
KCSAN_CHECK_WRITE_BARRIER(cmpxchg_release(&test_var, 0, 0)); |
|
KCSAN_CHECK_WRITE_BARRIER(atomic_set_release(&dummy, 0)); |
|
KCSAN_CHECK_WRITE_BARRIER(atomic_add_return(1, &dummy)); |
|
KCSAN_CHECK_WRITE_BARRIER(atomic_add_return_release(1, &dummy)); |
|
KCSAN_CHECK_WRITE_BARRIER(atomic_fetch_add(1, &dummy)); |
|
KCSAN_CHECK_WRITE_BARRIER(atomic_fetch_add_release(1, &dummy)); |
|
KCSAN_CHECK_WRITE_BARRIER(test_and_set_bit(0, &test_var)); |
|
KCSAN_CHECK_WRITE_BARRIER(test_and_clear_bit(0, &test_var)); |
|
KCSAN_CHECK_WRITE_BARRIER(test_and_change_bit(0, &test_var)); |
|
KCSAN_CHECK_WRITE_BARRIER(clear_bit_unlock(0, &test_var)); |
|
KCSAN_CHECK_WRITE_BARRIER(__clear_bit_unlock(0, &test_var)); |
|
arch_spin_lock(&arch_spinlock); |
|
KCSAN_CHECK_WRITE_BARRIER(arch_spin_unlock(&arch_spinlock)); |
|
spin_lock(&test_spinlock); |
|
KCSAN_CHECK_WRITE_BARRIER(spin_unlock(&test_spinlock)); |
|
|
|
KCSAN_CHECK_RW_BARRIER(mb()); |
|
KCSAN_CHECK_RW_BARRIER(wmb()); |
|
KCSAN_CHECK_RW_BARRIER(rmb()); |
|
KCSAN_CHECK_RW_BARRIER(smp_mb()); |
|
KCSAN_CHECK_RW_BARRIER(smp_wmb()); |
|
KCSAN_CHECK_RW_BARRIER(smp_rmb()); |
|
KCSAN_CHECK_RW_BARRIER(dma_wmb()); |
|
KCSAN_CHECK_RW_BARRIER(dma_rmb()); |
|
KCSAN_CHECK_RW_BARRIER(smp_mb__before_atomic()); |
|
KCSAN_CHECK_RW_BARRIER(smp_mb__after_atomic()); |
|
KCSAN_CHECK_RW_BARRIER(smp_mb__after_spinlock()); |
|
KCSAN_CHECK_RW_BARRIER(smp_store_mb(test_var, 0)); |
|
KCSAN_CHECK_RW_BARRIER(smp_store_release(&test_var, 0)); |
|
KCSAN_CHECK_RW_BARRIER(xchg(&test_var, 0)); |
|
KCSAN_CHECK_RW_BARRIER(xchg_release(&test_var, 0)); |
|
KCSAN_CHECK_RW_BARRIER(cmpxchg(&test_var, 0, 0)); |
|
KCSAN_CHECK_RW_BARRIER(cmpxchg_release(&test_var, 0, 0)); |
|
KCSAN_CHECK_RW_BARRIER(atomic_set_release(&dummy, 0)); |
|
KCSAN_CHECK_RW_BARRIER(atomic_add_return(1, &dummy)); |
|
KCSAN_CHECK_RW_BARRIER(atomic_add_return_release(1, &dummy)); |
|
KCSAN_CHECK_RW_BARRIER(atomic_fetch_add(1, &dummy)); |
|
KCSAN_CHECK_RW_BARRIER(atomic_fetch_add_release(1, &dummy)); |
|
KCSAN_CHECK_RW_BARRIER(test_and_set_bit(0, &test_var)); |
|
KCSAN_CHECK_RW_BARRIER(test_and_clear_bit(0, &test_var)); |
|
KCSAN_CHECK_RW_BARRIER(test_and_change_bit(0, &test_var)); |
|
KCSAN_CHECK_RW_BARRIER(clear_bit_unlock(0, &test_var)); |
|
KCSAN_CHECK_RW_BARRIER(__clear_bit_unlock(0, &test_var)); |
|
arch_spin_lock(&arch_spinlock); |
|
KCSAN_CHECK_RW_BARRIER(arch_spin_unlock(&arch_spinlock)); |
|
spin_lock(&test_spinlock); |
|
KCSAN_CHECK_RW_BARRIER(spin_unlock(&test_spinlock)); |
|
|
|
#ifdef clear_bit_unlock_is_negative_byte |
|
KCSAN_CHECK_RW_BARRIER(clear_bit_unlock_is_negative_byte(0, &test_var)); |
|
KCSAN_CHECK_READ_BARRIER(clear_bit_unlock_is_negative_byte(0, &test_var)); |
|
KCSAN_CHECK_WRITE_BARRIER(clear_bit_unlock_is_negative_byte(0, &test_var)); |
|
#endif |
|
kcsan_nestable_atomic_end(); |
|
|
|
return ret; |
|
} |
|
|
|
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); |
|
RUN_TEST(test_barrier); |
|
|
|
pr_info("selftest: %d/%d tests passed\n", passed, total); |
|
if (passed != total) |
|
panic("selftests failed"); |
|
return 0; |
|
} |
|
postcore_initcall(kcsan_selftest);
|
|
|