Hi Adrian,
On Fri, Mar 23 2012, Linus Walleij wrote:
> I was pretty tired of seeing these in my kernel compiles:
>
> drivers/mmc/card/block.c: In function ‘mmc_blk_issue_secdiscard_rq’:
> drivers/mmc/card/block.c:911:18: warning: ‘arg’ may be used uninitialized in this function [-Wuninitialized]
> drivers/mmc/card/block.c:910:6: warning: ‘nr’ may be used uninitialized in this function [-Wuninitialized]
> drivers/mmc/card/block.c:910:6: warning: ‘from’ may be used uninitialized in this function [-Wuninitialized]
>
> The problem stems from the code path in
> mmc_blk_issue_secdiscard_rq() where mmc_switch()
> with EXT_CSD_SANITIZE_START may return -EIO and fall back
> to using the default trim operations instead. At this point
> the variables needed for the fallback will be uninitialized.
>
> Cc: Ulf Hansson <ulf.hansson@xxxxxxxxxxxxxx>
> Cc: Rabin Vincent <rabin@xxxxxx>
> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> ---
> I don't know if this is the actual intention - maybe we
> should just fail the call entirely if the sanitize command
> fails?
I think you (Adrian) introduced this "goto out->goto retry" logic in
upstream commit 67716327eec7e9 -- please could you take a look here?
> ---
> drivers/mmc/card/block.c | 15 ++++++++-------
> 1 files changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
> index c6a383d..2741d93 100644
> --- a/drivers/mmc/card/block.c
> +++ b/drivers/mmc/card/block.c
> @@ -877,6 +877,14 @@ static int mmc_blk_issue_secdiscard_rq(struct mmc_queue *mq,
> unsigned int from, nr, arg;
> int err = 0, type = MMC_BLK_SECDISCARD;
>
> + from = blk_rq_pos(req);
> + nr = blk_rq_sectors(req);
> +
> + if (mmc_can_trim(card) && !mmc_erase_group_aligned(card, from, nr))
> + arg = MMC_SECURE_TRIM1_ARG;
> + else
> + arg = MMC_SECURE_ERASE_ARG;
> +
> if (!(mmc_can_secure_erase_trim(card) || mmc_can_sanitize(card))) {
> err = -EOPNOTSUPP;
> goto out;
> @@ -889,13 +897,6 @@ static int mmc_blk_issue_secdiscard_rq(struct mmc_queue *mq,
> goto out;
> }
>
> - from = blk_rq_pos(req);
> - nr = blk_rq_sectors(req);
> -
> - if (mmc_can_trim(card) && !mmc_erase_group_aligned(card, from, nr))
> - arg = MMC_SECURE_TRIM1_ARG;
> - else
> - arg = MMC_SECURE_ERASE_ARG;
> retry:
> if (card->quirks & MMC_QUIRK_INAND_CMD38) {
> err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
Thanks,
- Chris.
--
Chris Ball <cjb@xxxxxxxxxx> <http://printf.net/>
One Laptop Per Child
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