On the quest to remove all VLAs from the kernel[1], this avoids VLAs in dm-raid1.c by just using the maximum size for the stack arrays. The nr_mirrors value was already capped at 9, so this makes it a trivial adjustment to the array sizes.
[1] https://lkml.org/lkml/2018/3/7/621 Signed-off-by: Kees Cook <keesc...@chromium.org> --- drivers/md/dm-raid1.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c index 580c49cc8079..5903e492bb34 100644 --- a/drivers/md/dm-raid1.c +++ b/drivers/md/dm-raid1.c @@ -23,6 +23,8 @@ #define MAX_RECOVERY 1 /* Maximum number of regions recovered in parallel. */ +#define MAX_NR_MIRRORS (DM_KCOPYD_MAX_REGIONS + 1) + #define DM_RAID1_HANDLE_ERRORS 0x01 #define DM_RAID1_KEEP_LOG 0x02 #define errors_handled(p) ((p)->features & DM_RAID1_HANDLE_ERRORS) @@ -255,7 +257,7 @@ static int mirror_flush(struct dm_target *ti) unsigned long error_bits; unsigned int i; - struct dm_io_region io[ms->nr_mirrors]; + struct dm_io_region io[MAX_NR_MIRRORS]; struct mirror *m; struct dm_io_request io_req = { .bi_op = REQ_OP_WRITE, @@ -651,7 +653,7 @@ static void write_callback(unsigned long error, void *context) static void do_write(struct mirror_set *ms, struct bio *bio) { unsigned int i; - struct dm_io_region io[ms->nr_mirrors], *dest = io; + struct dm_io_region io[MAX_NR_MIRRORS], *dest = io; struct mirror *m; struct dm_io_request io_req = { .bi_op = REQ_OP_WRITE, @@ -1083,7 +1085,7 @@ static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv) argc -= args_used; if (!argc || sscanf(argv[0], "%u%c", &nr_mirrors, &dummy) != 1 || - nr_mirrors < 2 || nr_mirrors > DM_KCOPYD_MAX_REGIONS + 1) { + nr_mirrors < 2 || nr_mirrors > MAX_NR_MIRRORS) { ti->error = "Invalid number of mirrors"; dm_dirty_log_destroy(dl); return -EINVAL; @@ -1404,7 +1406,7 @@ static void mirror_status(struct dm_target *ti, status_type_t type, int num_feature_args = 0; struct mirror_set *ms = (struct mirror_set *) ti->private; struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh); - char buffer[ms->nr_mirrors + 1]; + char buffer[MAX_NR_MIRRORS + 1]; switch (type) { case STATUSTYPE_INFO: -- 2.7.4 -- Kees Cook Pixel Security -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel
