mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 02:39:48 +00:00
![Laura Abbott](/assets/img/avatar_default.png)
kmem_cache_alloc_bulk/kmem_cache_free_bulk are used to make multiple allocations of the same size to avoid the overhead of multiple kmalloc/kfree calls. Extend the kmem_cache tests to make some calls to these APIs. Link: http://lkml.kernel.org/r/20191107191447.23058-1-labbott@redhat.com Signed-off-by: Laura Abbott <labbott@redhat.com> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Alexander Potapenko <glider@google.com> Cc: Laura Abbott <labbott@redhat.com> Cc: Christoph Lameter <cl@linux.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Sandeep Patil <sspatil@android.com> Cc: Jann Horn <jannh@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
409 lines
9.7 KiB
C
409 lines
9.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Test cases for SL[AOU]B/page initialization at alloc/free time.
|
|
*/
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/module.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/string.h>
|
|
#include <linux/vmalloc.h>
|
|
|
|
#define GARBAGE_INT (0x09A7BA9E)
|
|
#define GARBAGE_BYTE (0x9E)
|
|
|
|
#define REPORT_FAILURES_IN_FN() \
|
|
do { \
|
|
if (failures) \
|
|
pr_info("%s failed %d out of %d times\n", \
|
|
__func__, failures, num_tests); \
|
|
else \
|
|
pr_info("all %d tests in %s passed\n", \
|
|
num_tests, __func__); \
|
|
} while (0)
|
|
|
|
/* Calculate the number of uninitialized bytes in the buffer. */
|
|
static int __init count_nonzero_bytes(void *ptr, size_t size)
|
|
{
|
|
int i, ret = 0;
|
|
unsigned char *p = (unsigned char *)ptr;
|
|
|
|
for (i = 0; i < size; i++)
|
|
if (p[i])
|
|
ret++;
|
|
return ret;
|
|
}
|
|
|
|
/* Fill a buffer with garbage, skipping |skip| first bytes. */
|
|
static void __init fill_with_garbage_skip(void *ptr, int size, size_t skip)
|
|
{
|
|
unsigned int *p = (unsigned int *)((char *)ptr + skip);
|
|
int i = 0;
|
|
|
|
WARN_ON(skip > size);
|
|
size -= skip;
|
|
|
|
while (size >= sizeof(*p)) {
|
|
p[i] = GARBAGE_INT;
|
|
i++;
|
|
size -= sizeof(*p);
|
|
}
|
|
if (size)
|
|
memset(&p[i], GARBAGE_BYTE, size);
|
|
}
|
|
|
|
static void __init fill_with_garbage(void *ptr, size_t size)
|
|
{
|
|
fill_with_garbage_skip(ptr, size, 0);
|
|
}
|
|
|
|
static int __init do_alloc_pages_order(int order, int *total_failures)
|
|
{
|
|
struct page *page;
|
|
void *buf;
|
|
size_t size = PAGE_SIZE << order;
|
|
|
|
page = alloc_pages(GFP_KERNEL, order);
|
|
buf = page_address(page);
|
|
fill_with_garbage(buf, size);
|
|
__free_pages(page, order);
|
|
|
|
page = alloc_pages(GFP_KERNEL, order);
|
|
buf = page_address(page);
|
|
if (count_nonzero_bytes(buf, size))
|
|
(*total_failures)++;
|
|
fill_with_garbage(buf, size);
|
|
__free_pages(page, order);
|
|
return 1;
|
|
}
|
|
|
|
/* Test the page allocator by calling alloc_pages with different orders. */
|
|
static int __init test_pages(int *total_failures)
|
|
{
|
|
int failures = 0, num_tests = 0;
|
|
int i;
|
|
|
|
for (i = 0; i < 10; i++)
|
|
num_tests += do_alloc_pages_order(i, &failures);
|
|
|
|
REPORT_FAILURES_IN_FN();
|
|
*total_failures += failures;
|
|
return num_tests;
|
|
}
|
|
|
|
/* Test kmalloc() with given parameters. */
|
|
static int __init do_kmalloc_size(size_t size, int *total_failures)
|
|
{
|
|
void *buf;
|
|
|
|
buf = kmalloc(size, GFP_KERNEL);
|
|
fill_with_garbage(buf, size);
|
|
kfree(buf);
|
|
|
|
buf = kmalloc(size, GFP_KERNEL);
|
|
if (count_nonzero_bytes(buf, size))
|
|
(*total_failures)++;
|
|
fill_with_garbage(buf, size);
|
|
kfree(buf);
|
|
return 1;
|
|
}
|
|
|
|
/* Test vmalloc() with given parameters. */
|
|
static int __init do_vmalloc_size(size_t size, int *total_failures)
|
|
{
|
|
void *buf;
|
|
|
|
buf = vmalloc(size);
|
|
fill_with_garbage(buf, size);
|
|
vfree(buf);
|
|
|
|
buf = vmalloc(size);
|
|
if (count_nonzero_bytes(buf, size))
|
|
(*total_failures)++;
|
|
fill_with_garbage(buf, size);
|
|
vfree(buf);
|
|
return 1;
|
|
}
|
|
|
|
/* Test kmalloc()/vmalloc() by allocating objects of different sizes. */
|
|
static int __init test_kvmalloc(int *total_failures)
|
|
{
|
|
int failures = 0, num_tests = 0;
|
|
int i, size;
|
|
|
|
for (i = 0; i < 20; i++) {
|
|
size = 1 << i;
|
|
num_tests += do_kmalloc_size(size, &failures);
|
|
num_tests += do_vmalloc_size(size, &failures);
|
|
}
|
|
|
|
REPORT_FAILURES_IN_FN();
|
|
*total_failures += failures;
|
|
return num_tests;
|
|
}
|
|
|
|
#define CTOR_BYTES (sizeof(unsigned int))
|
|
#define CTOR_PATTERN (0x41414141)
|
|
/* Initialize the first 4 bytes of the object. */
|
|
static void test_ctor(void *obj)
|
|
{
|
|
*(unsigned int *)obj = CTOR_PATTERN;
|
|
}
|
|
|
|
/*
|
|
* Check the invariants for the buffer allocated from a slab cache.
|
|
* If the cache has a test constructor, the first 4 bytes of the object must
|
|
* always remain equal to CTOR_PATTERN.
|
|
* If the cache isn't an RCU-typesafe one, or if the allocation is done with
|
|
* __GFP_ZERO, then the object contents must be zeroed after allocation.
|
|
* If the cache is an RCU-typesafe one, the object contents must never be
|
|
* zeroed after the first use. This is checked by memcmp() in
|
|
* do_kmem_cache_size().
|
|
*/
|
|
static bool __init check_buf(void *buf, int size, bool want_ctor,
|
|
bool want_rcu, bool want_zero)
|
|
{
|
|
int bytes;
|
|
bool fail = false;
|
|
|
|
bytes = count_nonzero_bytes(buf, size);
|
|
WARN_ON(want_ctor && want_zero);
|
|
if (want_zero)
|
|
return bytes;
|
|
if (want_ctor) {
|
|
if (*(unsigned int *)buf != CTOR_PATTERN)
|
|
fail = 1;
|
|
} else {
|
|
if (bytes)
|
|
fail = !want_rcu;
|
|
}
|
|
return fail;
|
|
}
|
|
|
|
#define BULK_SIZE 100
|
|
static void *bulk_array[BULK_SIZE];
|
|
|
|
/*
|
|
* Test kmem_cache with given parameters:
|
|
* want_ctor - use a constructor;
|
|
* want_rcu - use SLAB_TYPESAFE_BY_RCU;
|
|
* want_zero - use __GFP_ZERO.
|
|
*/
|
|
static int __init do_kmem_cache_size(size_t size, bool want_ctor,
|
|
bool want_rcu, bool want_zero,
|
|
int *total_failures)
|
|
{
|
|
struct kmem_cache *c;
|
|
int iter;
|
|
bool fail = false;
|
|
gfp_t alloc_mask = GFP_KERNEL | (want_zero ? __GFP_ZERO : 0);
|
|
void *buf, *buf_copy;
|
|
|
|
c = kmem_cache_create("test_cache", size, 1,
|
|
want_rcu ? SLAB_TYPESAFE_BY_RCU : 0,
|
|
want_ctor ? test_ctor : NULL);
|
|
for (iter = 0; iter < 10; iter++) {
|
|
/* Do a test of bulk allocations */
|
|
if (!want_rcu && !want_ctor) {
|
|
int ret;
|
|
|
|
ret = kmem_cache_alloc_bulk(c, alloc_mask, BULK_SIZE, bulk_array);
|
|
if (!ret) {
|
|
fail = true;
|
|
} else {
|
|
int i;
|
|
for (i = 0; i < ret; i++)
|
|
fail |= check_buf(bulk_array[i], size, want_ctor, want_rcu, want_zero);
|
|
kmem_cache_free_bulk(c, ret, bulk_array);
|
|
}
|
|
}
|
|
|
|
buf = kmem_cache_alloc(c, alloc_mask);
|
|
/* Check that buf is zeroed, if it must be. */
|
|
fail |= check_buf(buf, size, want_ctor, want_rcu, want_zero);
|
|
fill_with_garbage_skip(buf, size, want_ctor ? CTOR_BYTES : 0);
|
|
|
|
if (!want_rcu) {
|
|
kmem_cache_free(c, buf);
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* If this is an RCU cache, use a critical section to ensure we
|
|
* can touch objects after they're freed.
|
|
*/
|
|
rcu_read_lock();
|
|
/*
|
|
* Copy the buffer to check that it's not wiped on
|
|
* free().
|
|
*/
|
|
buf_copy = kmalloc(size, GFP_ATOMIC);
|
|
if (buf_copy)
|
|
memcpy(buf_copy, buf, size);
|
|
|
|
kmem_cache_free(c, buf);
|
|
/*
|
|
* Check that |buf| is intact after kmem_cache_free().
|
|
* |want_zero| is false, because we wrote garbage to
|
|
* the buffer already.
|
|
*/
|
|
fail |= check_buf(buf, size, want_ctor, want_rcu,
|
|
false);
|
|
if (buf_copy) {
|
|
fail |= (bool)memcmp(buf, buf_copy, size);
|
|
kfree(buf_copy);
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
kmem_cache_destroy(c);
|
|
|
|
*total_failures += fail;
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Check that the data written to an RCU-allocated object survives
|
|
* reallocation.
|
|
*/
|
|
static int __init do_kmem_cache_rcu_persistent(int size, int *total_failures)
|
|
{
|
|
struct kmem_cache *c;
|
|
void *buf, *buf_contents, *saved_ptr;
|
|
void **used_objects;
|
|
int i, iter, maxiter = 1024;
|
|
bool fail = false;
|
|
|
|
c = kmem_cache_create("test_cache", size, size, SLAB_TYPESAFE_BY_RCU,
|
|
NULL);
|
|
buf = kmem_cache_alloc(c, GFP_KERNEL);
|
|
saved_ptr = buf;
|
|
fill_with_garbage(buf, size);
|
|
buf_contents = kmalloc(size, GFP_KERNEL);
|
|
if (!buf_contents)
|
|
goto out;
|
|
used_objects = kmalloc_array(maxiter, sizeof(void *), GFP_KERNEL);
|
|
if (!used_objects) {
|
|
kfree(buf_contents);
|
|
goto out;
|
|
}
|
|
memcpy(buf_contents, buf, size);
|
|
kmem_cache_free(c, buf);
|
|
/*
|
|
* Run for a fixed number of iterations. If we never hit saved_ptr,
|
|
* assume the test passes.
|
|
*/
|
|
for (iter = 0; iter < maxiter; iter++) {
|
|
buf = kmem_cache_alloc(c, GFP_KERNEL);
|
|
used_objects[iter] = buf;
|
|
if (buf == saved_ptr) {
|
|
fail = memcmp(buf_contents, buf, size);
|
|
for (i = 0; i <= iter; i++)
|
|
kmem_cache_free(c, used_objects[i]);
|
|
goto free_out;
|
|
}
|
|
}
|
|
|
|
free_out:
|
|
kmem_cache_destroy(c);
|
|
kfree(buf_contents);
|
|
kfree(used_objects);
|
|
out:
|
|
*total_failures += fail;
|
|
return 1;
|
|
}
|
|
|
|
static int __init do_kmem_cache_size_bulk(int size, int *total_failures)
|
|
{
|
|
struct kmem_cache *c;
|
|
int i, iter, maxiter = 1024;
|
|
int num, bytes;
|
|
bool fail = false;
|
|
void *objects[10];
|
|
|
|
c = kmem_cache_create("test_cache", size, size, 0, NULL);
|
|
for (iter = 0; (iter < maxiter) && !fail; iter++) {
|
|
num = kmem_cache_alloc_bulk(c, GFP_KERNEL, ARRAY_SIZE(objects),
|
|
objects);
|
|
for (i = 0; i < num; i++) {
|
|
bytes = count_nonzero_bytes(objects[i], size);
|
|
if (bytes)
|
|
fail = true;
|
|
fill_with_garbage(objects[i], size);
|
|
}
|
|
|
|
if (num)
|
|
kmem_cache_free_bulk(c, num, objects);
|
|
}
|
|
*total_failures += fail;
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Test kmem_cache allocation by creating caches of different sizes, with and
|
|
* without constructors, with and without SLAB_TYPESAFE_BY_RCU.
|
|
*/
|
|
static int __init test_kmemcache(int *total_failures)
|
|
{
|
|
int failures = 0, num_tests = 0;
|
|
int i, flags, size;
|
|
bool ctor, rcu, zero;
|
|
|
|
for (i = 0; i < 10; i++) {
|
|
size = 8 << i;
|
|
for (flags = 0; flags < 8; flags++) {
|
|
ctor = flags & 1;
|
|
rcu = flags & 2;
|
|
zero = flags & 4;
|
|
if (ctor & zero)
|
|
continue;
|
|
num_tests += do_kmem_cache_size(size, ctor, rcu, zero,
|
|
&failures);
|
|
}
|
|
num_tests += do_kmem_cache_size_bulk(size, &failures);
|
|
}
|
|
REPORT_FAILURES_IN_FN();
|
|
*total_failures += failures;
|
|
return num_tests;
|
|
}
|
|
|
|
/* Test the behavior of SLAB_TYPESAFE_BY_RCU caches of different sizes. */
|
|
static int __init test_rcu_persistent(int *total_failures)
|
|
{
|
|
int failures = 0, num_tests = 0;
|
|
int i, size;
|
|
|
|
for (i = 0; i < 10; i++) {
|
|
size = 8 << i;
|
|
num_tests += do_kmem_cache_rcu_persistent(size, &failures);
|
|
}
|
|
REPORT_FAILURES_IN_FN();
|
|
*total_failures += failures;
|
|
return num_tests;
|
|
}
|
|
|
|
/*
|
|
* Run the tests. Each test function returns the number of executed tests and
|
|
* updates |failures| with the number of failed tests.
|
|
*/
|
|
static int __init test_meminit_init(void)
|
|
{
|
|
int failures = 0, num_tests = 0;
|
|
|
|
num_tests += test_pages(&failures);
|
|
num_tests += test_kvmalloc(&failures);
|
|
num_tests += test_kmemcache(&failures);
|
|
num_tests += test_rcu_persistent(&failures);
|
|
|
|
if (failures == 0)
|
|
pr_info("all %d tests passed!\n", num_tests);
|
|
else
|
|
pr_info("failures: %d out of %d\n", failures, num_tests);
|
|
|
|
return failures ? -EINVAL : 0;
|
|
}
|
|
module_init(test_meminit_init);
|
|
|
|
MODULE_LICENSE("GPL");
|