Re: [PATCH v4 01/10] KVM: selftests: Remove dynamic memory allocation for stats header
From: David Matlack
Date: Mon Apr 11 2022 - 17:52:58 EST
On Mon, Apr 11, 2022 at 2:10 PM Ben Gardon <bgardon@xxxxxxxxxx> wrote:
>
> There's no need to allocate dynamic memory for the stats header since
> its size is known at compile time.
>
> Signed-off-by: Ben Gardon <bgardon@xxxxxxxxxx>
Reviewed-by: David Matlack <dmatlack@xxxxxxxxxx>
> ---
> .../selftests/kvm/kvm_binary_stats_test.c | 58 +++++++++----------
> 1 file changed, 27 insertions(+), 31 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/kvm_binary_stats_test.c b/tools/testing/selftests/kvm/kvm_binary_stats_test.c
> index 17f65d514915..dad34d8a41fe 100644
> --- a/tools/testing/selftests/kvm/kvm_binary_stats_test.c
> +++ b/tools/testing/selftests/kvm/kvm_binary_stats_test.c
> @@ -26,56 +26,53 @@ static void stats_test(int stats_fd)
> int i;
> size_t size_desc;
> size_t size_data = 0;
> - struct kvm_stats_header *header;
> + struct kvm_stats_header header;
> char *id;
> struct kvm_stats_desc *stats_desc;
> u64 *stats_data;
> struct kvm_stats_desc *pdesc;
>
> /* Read kvm stats header */
> - header = malloc(sizeof(*header));
> - TEST_ASSERT(header, "Allocate memory for stats header");
> -
> - ret = read(stats_fd, header, sizeof(*header));
> - TEST_ASSERT(ret == sizeof(*header), "Read stats header");
> - size_desc = sizeof(*stats_desc) + header->name_size;
> + ret = read(stats_fd, &header, sizeof(header));
> + TEST_ASSERT(ret == sizeof(header), "Read stats header");
> + size_desc = sizeof(*stats_desc) + header.name_size;
>
> /* Read kvm stats id string */
> - id = malloc(header->name_size);
> + id = malloc(header.name_size);
> TEST_ASSERT(id, "Allocate memory for id string");
> - ret = read(stats_fd, id, header->name_size);
> - TEST_ASSERT(ret == header->name_size, "Read id string");
> + ret = read(stats_fd, id, header.name_size);
> + TEST_ASSERT(ret == header.name_size, "Read id string");
>
> /* Check id string, that should start with "kvm" */
> - TEST_ASSERT(!strncmp(id, "kvm", 3) && strlen(id) < header->name_size,
> + TEST_ASSERT(!strncmp(id, "kvm", 3) && strlen(id) < header.name_size,
> "Invalid KVM stats type, id: %s", id);
>
> /* Sanity check for other fields in header */
> - if (header->num_desc == 0) {
> + if (header.num_desc == 0) {
> printf("No KVM stats defined!");
> return;
> }
> /* Check overlap */
> - TEST_ASSERT(header->desc_offset > 0 && header->data_offset > 0
> - && header->desc_offset >= sizeof(*header)
> - && header->data_offset >= sizeof(*header),
> + TEST_ASSERT(header.desc_offset > 0 && header.data_offset > 0
> + && header.desc_offset >= sizeof(header)
> + && header.data_offset >= sizeof(header),
> "Invalid offset fields in header");
> - TEST_ASSERT(header->desc_offset > header->data_offset ||
> - (header->desc_offset + size_desc * header->num_desc <=
> - header->data_offset),
> + TEST_ASSERT(header.desc_offset > header.data_offset ||
> + (header.desc_offset + size_desc * header.num_desc <=
> + header.data_offset),
> "Descriptor block is overlapped with data block");
>
> /* Allocate memory for stats descriptors */
> - stats_desc = calloc(header->num_desc, size_desc);
> + stats_desc = calloc(header.num_desc, size_desc);
> TEST_ASSERT(stats_desc, "Allocate memory for stats descriptors");
> /* Read kvm stats descriptors */
> ret = pread(stats_fd, stats_desc,
> - size_desc * header->num_desc, header->desc_offset);
> - TEST_ASSERT(ret == size_desc * header->num_desc,
> + size_desc * header.num_desc, header.desc_offset);
> + TEST_ASSERT(ret == size_desc * header.num_desc,
> "Read KVM stats descriptors");
>
> /* Sanity check for fields in descriptors */
> - for (i = 0; i < header->num_desc; ++i) {
> + for (i = 0; i < header.num_desc; ++i) {
> pdesc = (void *)stats_desc + i * size_desc;
> /* Check type,unit,base boundaries */
> TEST_ASSERT((pdesc->flags & KVM_STATS_TYPE_MASK)
> @@ -104,7 +101,7 @@ static void stats_test(int stats_fd)
> break;
> }
> /* Check name string */
> - TEST_ASSERT(strlen(pdesc->name) < header->name_size,
> + TEST_ASSERT(strlen(pdesc->name) < header.name_size,
> "KVM stats name(%s) too long", pdesc->name);
> /* Check size field, which should not be zero */
> TEST_ASSERT(pdesc->size, "KVM descriptor(%s) with size of 0",
> @@ -124,14 +121,14 @@ static void stats_test(int stats_fd)
> size_data += pdesc->size * sizeof(*stats_data);
> }
> /* Check overlap */
> - TEST_ASSERT(header->data_offset >= header->desc_offset
> - || header->data_offset + size_data <= header->desc_offset,
> + TEST_ASSERT(header.data_offset >= header.desc_offset
> + || header.data_offset + size_data <= header.desc_offset,
> "Data block is overlapped with Descriptor block");
> /* Check validity of all stats data size */
> - TEST_ASSERT(size_data >= header->num_desc * sizeof(*stats_data),
> + TEST_ASSERT(size_data >= header.num_desc * sizeof(*stats_data),
> "Data size is not correct");
> /* Check stats offset */
> - for (i = 0; i < header->num_desc; ++i) {
> + for (i = 0; i < header.num_desc; ++i) {
> pdesc = (void *)stats_desc + i * size_desc;
> TEST_ASSERT(pdesc->offset < size_data,
> "Invalid offset (%u) for stats: %s",
> @@ -142,15 +139,15 @@ static void stats_test(int stats_fd)
> stats_data = malloc(size_data);
> TEST_ASSERT(stats_data, "Allocate memory for stats data");
> /* Read kvm stats data as a bulk */
> - ret = pread(stats_fd, stats_data, size_data, header->data_offset);
> + ret = pread(stats_fd, stats_data, size_data, header.data_offset);
> TEST_ASSERT(ret == size_data, "Read KVM stats data");
> /* Read kvm stats data one by one */
> size_data = 0;
> - for (i = 0; i < header->num_desc; ++i) {
> + for (i = 0; i < header.num_desc; ++i) {
> pdesc = (void *)stats_desc + i * size_desc;
> ret = pread(stats_fd, stats_data,
> pdesc->size * sizeof(*stats_data),
> - header->data_offset + size_data);
> + header.data_offset + size_data);
> TEST_ASSERT(ret == pdesc->size * sizeof(*stats_data),
> "Read data of KVM stats: %s", pdesc->name);
> size_data += pdesc->size * sizeof(*stats_data);
> @@ -159,7 +156,6 @@ static void stats_test(int stats_fd)
> free(stats_data);
> free(stats_desc);
> free(id);
> - free(header);
> }
>
>
> --
> 2.35.1.1178.g4f1659d476-goog
>