When using prandom_bytes_state() it is critical to use the same block size in all invocations that are to produce the same random sequence. Otherwise the state of the PRNG will be out of sync if the blocksize is not divisible by 4. This leads to bogus verification errors in several tests which use different block sizes to initialize the buffer for writing and comparison.
Signed-off-by: Lothar Waßmann <[email protected]> --- drivers/mtd/tests/oobtest.c | 14 ++++++++++++-- 1 files changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/mtd/tests/oobtest.c b/drivers/mtd/tests/oobtest.c index 2e9e2d1..72c7359 100644 --- a/drivers/mtd/tests/oobtest.c +++ b/drivers/mtd/tests/oobtest.c @@ -213,8 +213,15 @@ static int verify_eraseblock_in_one_go(int ebnum) int err = 0; loff_t addr = ebnum * mtd->erasesize; size_t len = mtd->ecclayout->oobavail * pgcnt; + int i; + + for (i = 0; i < pgcnt; i++) + prandom_bytes_state(&rnd_state, &writebuf[i * use_len], + use_len); + if (len % use_len) + prandom_bytes_state(&rnd_state, &writebuf[i * use_len], + len % use_len); - prandom_bytes_state(&rnd_state, writebuf, len); ops.mode = MTD_OPS_AUTO_OOB; ops.len = 0; ops.retlen = 0; @@ -594,7 +601,10 @@ static int __init mtd_oobtest_init(void) if (bbt[i] || bbt[i + 1]) continue; prandom_bytes_state(&rnd_state, writebuf, - mtd->ecclayout->oobavail * 2); + mtd->ecclayout->oobavail); + prandom_bytes_state(&rnd_state, + writebuf + mtd->ecclayout->oobavail, + mtd->ecclayout->oobavail); addr = (i + 1) * mtd->erasesize - mtd->writesize; ops.mode = MTD_OPS_AUTO_OOB; ops.len = 0; -- 1.7.2.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
