forked from Minki/linux
b473a3891c
Some architectures do not define clear_bit_unlock_is_negative_byte(). Only test it when it is actually defined (similar to other usage, such as in lib/test_kasan.c). Link: https://lkml.kernel.org/r/202112050757.x67rHnFU-lkp@intel.com Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
273 lines
9.7 KiB
C
273 lines
9.7 KiB
C
// 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 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 __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;
|
|
|
|
prandom_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);
|