Commit 65972a6f authored by Kees Cook's avatar Kees Cook Committed by Mike Snitzer
Browse files

dm mirror: remove VLA usage 

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: default avatarKees Cook <keescook@chromium.org>
Acked-by: default avatarHeinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 3d97c829

drivers/md/dm-raid1.c

+6 −4
Original line number Diff line number Diff line
@@ -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:

CRA Git | Maintained and supported by SUSTech CRA and CCSE