On 13/04/13 16:38, Namjae Jeon wrote: > From: Namjae Jeon <namjae.jeon@xxxxxxxxxxx> > > https://lkml.org/lkml/2013/4/1/292 > As per above discussion, there is possibility that request's __data_len > field may overflow when max_discard_sectors greater than UINT_MAX >> 9 > > If multiple discard requests get merged, merged discard request's > size exceeds 4GB, there is possibility that merged discard request's > __data_len field may overflow. > > This patch fixes this issue. > > Reported-by: Max Filippov <jcmvbkbc@xxxxxxxxx> > Signed-off-by: Namjae Jeon <namjae.jeon@xxxxxxxxxxx> > Signed-off-by: Vivek Trivedi <t.vivek@xxxxxxxxxxx> > Tested-by: Max Filippov <jcmvbkbc@xxxxxxxxx> > --- > drivers/mmc/card/queue.c | 2 +- > drivers/mmc/core/core.c | 4 ++-- > 2 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c > index 9447a0e..54726b7 100644 > --- a/drivers/mmc/card/queue.c > +++ b/drivers/mmc/card/queue.c > @@ -166,7 +166,7 @@ static void mmc_queue_setup_discard(struct request_queue *q, > return; > > queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q); > - q->limits.max_discard_sectors = max_discard; > + blk_queue_max_discard_sectors(q, max_discard); > if (card->erased_byte == 0 && !mmc_can_discard(card)) > q->limits.discard_zeroes_data = 1; > q->limits.discard_granularity = card->pref_erase << 9; > diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c > index 7b435a3..6ee530c 100644 > --- a/drivers/mmc/core/core.c > +++ b/drivers/mmc/core/core.c > @@ -2058,7 +2058,7 @@ static unsigned int mmc_do_calc_max_discard(struct mmc_card *card, > if (card->erase_shift) > max_qty = UINT_MAX >> card->erase_shift; > else if (mmc_card_sd(card)) > - max_qty = UINT_MAX; > + max_qty = UINT_MAX >> 9; No. This function calculates max discard for the card not the block layer. Apply the block layer limitation at the block layer interface e.g. in mmc_queue_setup_discard() > else > max_qty = UINT_MAX / card->erase_size; > > @@ -2100,7 +2100,7 @@ unsigned int mmc_calc_max_discard(struct mmc_card *card) > unsigned int max_discard, max_trim; > > if (!host->max_discard_to) > - return UINT_MAX; > + return UINT_MAX >> 9; Ditto. > > /* > * Without erase_group_def set, MMC erase timeout depends on clock > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
