diff options
| -rw-r--r-- | lib/test_user_copy.c | 37 |
1 files changed, 28 insertions, 9 deletions
diff --git a/lib/test_user_copy.c b/lib/test_user_copy.c index e365ace06538..5ff04d8fe971 100644 --- a/lib/test_user_copy.c +++ b/lib/test_user_copy.c @@ -47,18 +47,35 @@ static bool is_zeroed(void *from, size_t size) static int test_check_nonzero_user(char *kmem, char __user *umem, size_t size) { int ret = 0; - size_t start, end, i; - size_t zero_start = size / 4; - size_t zero_end = size - zero_start; + size_t start, end, i, zero_start, zero_end; + + if (test(size < 2 * PAGE_SIZE, "buffer too small")) + return -EINVAL; + + /* + * We want to cross a page boundary to exercise the code more + * effectively. We also don't want to make the size we scan too large, + * otherwise the test can take a long time and cause soft lockups. So + * scan a 1024 byte region across the page boundary. + */ + size = 1024; + start = PAGE_SIZE - (size / 2); + + kmem += start; + umem += start; + + zero_start = size / 4; + zero_end = size - zero_start; /* - * We conduct a series of check_nonzero_user() tests on a block of memory - * with the following byte-pattern (trying every possible [start,end] - * pair): + * We conduct a series of check_nonzero_user() tests on a block of + * memory with the following byte-pattern (trying every possible + * [start,end] pair): * * [ 00 ff 00 ff ... 00 00 00 00 ... ff 00 ff 00 ] * - * And we verify that check_nonzero_user() acts identically to memchr_inv(). + * And we verify that check_nonzero_user() acts identically to + * memchr_inv(). */ memset(kmem, 0x0, size); @@ -93,11 +110,13 @@ static int test_copy_struct_from_user(char *kmem, char __user *umem, size_t ksize, usize; umem_src = kmalloc(size, GFP_KERNEL); - if ((ret |= test(umem_src == NULL, "kmalloc failed"))) + ret = test(umem_src == NULL, "kmalloc failed"); + if (ret) goto out_free; expected = kmalloc(size, GFP_KERNEL); - if ((ret |= test(expected == NULL, "kmalloc failed"))) + ret = test(expected == NULL, "kmalloc failed"); + if (ret) goto out_free; /* Fill umem with a fixed byte pattern. */ |