Who know proper fixing way? ================= Subject: [Untested][RFC][PATCH] don't use bio-map in read() path __bio_map_user_iov() has wrong usage of get_user_pages_fast(). it doesn't have prevent fork mechanism. then, it sould be used read-side (memory to device transfer) gup only. This patch is obviously temporally fix. we can implement fork safe bio_map_user() the future... Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> Cc: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> Cc: Jens Axboe <jens.axboe@xxxxxxxxxx> Cc: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> --- block/blk-map.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) Index: b/block/blk-map.c =================================================================== --- a/block/blk-map.c 2009-02-21 16:53:21.000000000 +0900 +++ b/block/blk-map.c 2009-04-12 23:36:32.000000000 +0900 @@ -55,7 +55,7 @@ static int __blk_rq_map_user(struct requ * direct dma. else, set up kernel bounce buffers */ uaddr = (unsigned long) ubuf; - if (blk_rq_aligned(q, ubuf, len) && !map_data) + if (blk_rq_aligned(q, ubuf, len) && !map_data && !reading) bio = bio_map_user(q, NULL, uaddr, len, reading, gfp_mask); else bio = bio_copy_user(q, map_data, uaddr, len, reading, gfp_mask); @@ -208,7 +208,7 @@ int blk_rq_map_user_iov(struct request_q } } - if (unaligned || (q->dma_pad_mask & len) || map_data) + if (unaligned || (q->dma_pad_mask & len) || map_data || read) bio = bio_copy_user_iov(q, map_data, iov, iov_count, read, gfp_mask); else -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
