[PATCH] selftests/mm: use calloc instead of malloc in pagemap_ioctl.c

As per Documentation/process/deprecated.rst, dynamic size calculations should not be performed in memory allocator arguments due to possible overflows.

Replaced malloc with calloc to avoid open-ended arithmetic and prevent possible overflows.

Signed-off-by: I Viswanath viswanathiyyappan@gmail.com --- Even though the arguments are small enough an overflow cannot happen, I think it's still better to follow kernel standard practices.

tools/testing/selftests/mm/pagemap_ioctl.c | 24 +++++++++++----------- 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/tools/testing/selftests/mm/pagemap_ioctl.c b/tools/testing/selftests/mm/pagemap_ioctl.c index 0d4209eef0c3..4e6b815e96b2 100644 --- a/tools/testing/selftests/mm/pagemap_ioctl.c +++ b/tools/testing/selftests/mm/pagemap_ioctl.c @@ -209,7 +209,7 @@ int userfaultfd_tests(void) wp_addr_range(mem, mem_size);

vec_size = mem_size/page_size; - vec = malloc(sizeof(struct page_region) * vec_size); + vec = calloc(vec_size, sizeof(struct page_region));

written = pagemap_ioctl(mem, mem_size, vec, 1, PM_SCAN_WP_MATCHING | PM_SCAN_CHECK_WPASYNC, vec_size - 2, PAGE_IS_WRITTEN, 0, 0, PAGE_IS_WRITTEN); @@ -247,11 +247,11 @@ int sanity_tests_sd(void) vec_size = num_pages/2; mem_size = num_pages * page_size;

- vec = malloc(sizeof(struct page_region) * vec_size); + vec = calloc(vec_size, sizeof(struct page_region)); if (!vec) ksft_exit_fail_msg("error nomem\n");

- vec2 = malloc(sizeof(struct page_region) * vec_size); + vec2 = calloc(vec_size, sizeof(struct page_region)); if (!vec2) ksft_exit_fail_msg("error nomem\n");

@@ -436,7 +436,7 @@ int sanity_tests_sd(void) mem_size = 1050 * page_size; vec_size = mem_size/(page_size*2);

- vec = malloc(sizeof(struct page_region) * vec_size); + vec = calloc(vec_size, sizeof(struct page_region)); if (!vec) ksft_exit_fail_msg("error nomem\n");

@@ -491,7 +491,7 @@ int sanity_tests_sd(void) mem_size = 10000 * page_size; vec_size = 50;

- vec = malloc(sizeof(struct page_region) * vec_size); + vec = calloc(vec_size, sizeof(struct page_region)); if (!vec) ksft_exit_fail_msg("error nomem\n");

@@ -541,7 +541,7 @@ int sanity_tests_sd(void) vec_size = 1000; mem_size = vec_size * page_size;

- vec = malloc(sizeof(struct page_region) * vec_size); + vec = calloc(vec_size, sizeof(struct page_region)); if (!vec) ksft_exit_fail_msg("error nomem\n");

@@ -695,8 +695,8 @@ int base_tests(char *prefix, char *mem, unsigned long long mem_size, int skip) }

vec_size = mem_size/page_size; - vec = malloc(sizeof(struct page_region) * vec_size); - vec2 = malloc(sizeof(struct page_region) * vec_size); + vec = calloc(vec_size, sizeof(struct page_region)); + vec2 = calloc(vec_size, sizeof(struct page_region));

/* 1. all new pages must be not be written (dirty) */ written = pagemap_ioctl(mem, mem_size, vec, 1, PM_SCAN_WP_MATCHING | PM_SCAN_CHECK_WPASYNC, @@ -807,8 +807,8 @@ int hpage_unit_tests(void) unsigned long long vec_size = map_size/page_size; struct page_region *vec, *vec2;

- vec = malloc(sizeof(struct page_region) * vec_size); - vec2 = malloc(sizeof(struct page_region) * vec_size); + vec = calloc(vec_size, sizeof(struct page_region)); + vec2 = calloc(vec_size, sizeof(struct page_region)); if (!vec || !vec2) ksft_exit_fail_msg("malloc failed\n");

@@ -997,7 +997,7 @@ int unmapped_region_tests(void) void *start = (void *)0x10000000; int written, len = 0x00040000; long vec_size = len / page_size; - struct page_region *vec = malloc(sizeof(struct page_region) * vec_size); + struct page_region *vec = calloc(vec_size, sizeof(struct page_region));

/* 1. Get written pages */ written = pagemap_ioctl(start, len, vec, vec_size, 0, 0, @@ -1062,7 +1062,7 @@ int sanity_tests(void) mem_size = 10 * page_size; vec_size = mem_size / page_size;

- vec = malloc(sizeof(struct page_region) * vec_size); + vec = calloc(vec_size, sizeof(struct page_region)); mem = mmap(NULL, mem_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); if (mem == MAP_FAILED || vec == MAP_FAILED) ksft_exit_fail_msg("error nomem\n");