From eb0645a8b1f14da300f40bb9f424640cd1181fbf Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Fri, 20 Jul 2007 00:31:46 -0700 Subject: [PATCH] async_tx: fix kmap_atomic usage in async_memcpy Andrew Morton: [async_memcpy] is very wrong if both ASYNC_TX_KMAP_DST and ASYNC_TX_KMAP_SRC can ever be set. We'll end up using the same kmap slot for both src add dest and we get either corrupted data or a BUG. Evgeniy Polyakov: Btw, shouldn't it always be kmap_atomic() even if flag is not set. That pages are usual one returned by alloc_page(). So fix the usage of kmap_atomic and kill the ASYNC_TX_KMAP_DST and ASYNC_TX_KMAP_SRC flags. Cc: Andrew Morton Cc: Evgeniy Polyakov Signed-off-by: Dan Williams Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- crypto/async_tx/async_memcpy.c | 19 ++++--------------- drivers/md/raid5.c | 4 ++-- include/linux/async_tx.h | 6 ------ 3 files changed, 6 insertions(+), 23 deletions(-) diff --git a/crypto/async_tx/async_memcpy.c b/crypto/async_tx/async_memcpy.c index a973f4ef897..047e533fcc5 100644 --- a/crypto/async_tx/async_memcpy.c +++ b/crypto/async_tx/async_memcpy.c @@ -36,7 +36,6 @@ * @offset: offset in pages to start transaction * @len: length in bytes * @flags: ASYNC_TX_ASSUME_COHERENT, ASYNC_TX_ACK, ASYNC_TX_DEP_ACK, - * ASYNC_TX_KMAP_SRC, ASYNC_TX_KMAP_DST * @depend_tx: memcpy depends on the result of this transaction * @cb_fn: function to call when the memcpy completes * @cb_param: parameter to pass to the callback routine @@ -88,23 +87,13 @@ async_memcpy(struct page *dest, struct page *src, unsigned int dest_offset, __FUNCTION__); } - if (flags & ASYNC_TX_KMAP_DST) - dest_buf = kmap_atomic(dest, KM_USER0) + dest_offset; - else - dest_buf = page_address(dest) + dest_offset; - - if (flags & ASYNC_TX_KMAP_SRC) - src_buf = kmap_atomic(src, KM_USER0) + src_offset; - else - src_buf = page_address(src) + src_offset; + dest_buf = kmap_atomic(dest, KM_USER0) + dest_offset; + src_buf = kmap_atomic(src, KM_USER1) + src_offset; memcpy(dest_buf, src_buf, len); - if (flags & ASYNC_TX_KMAP_DST) - kunmap_atomic(dest_buf, KM_USER0); - - if (flags & ASYNC_TX_KMAP_SRC) - kunmap_atomic(src_buf, KM_USER0); + kunmap_atomic(dest_buf, KM_USER0); + kunmap_atomic(src_buf, KM_USER1); async_tx_sync_epilog(flags, depend_tx, cb_fn, cb_param); } diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index c8dfdb30291..d90ee145eff 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -493,12 +493,12 @@ async_copy_data(int frombio, struct bio *bio, struct page *page, if (frombio) tx = async_memcpy(page, bio_page, page_offset, b_offset, clen, - ASYNC_TX_DEP_ACK | ASYNC_TX_KMAP_SRC, + ASYNC_TX_DEP_ACK, tx, NULL, NULL); else tx = async_memcpy(bio_page, page, b_offset, page_offset, clen, - ASYNC_TX_DEP_ACK | ASYNC_TX_KMAP_DST, + ASYNC_TX_DEP_ACK, tx, NULL, NULL); } if (clen < len) /* hit end of page */ diff --git a/include/linux/async_tx.h b/include/linux/async_tx.h index ff1255079fa..bdca3f1b321 100644 --- a/include/linux/async_tx.h +++ b/include/linux/async_tx.h @@ -51,10 +51,6 @@ struct dma_chan_ref { * @ASYNC_TX_ACK: immediately ack the descriptor, precludes setting up a * dependency chain * @ASYNC_TX_DEP_ACK: ack the dependency descriptor. Useful for chaining. - * @ASYNC_TX_KMAP_SRC: if the transaction is to be performed synchronously - * take an atomic mapping (KM_USER0) on the source page(s) - * @ASYNC_TX_KMAP_DST: if the transaction is to be performed synchronously - * take an atomic mapping (KM_USER0) on the dest page(s) */ enum async_tx_flags { ASYNC_TX_XOR_ZERO_DST = (1 << 0), @@ -62,8 +58,6 @@ enum async_tx_flags { ASYNC_TX_ASSUME_COHERENT = (1 << 2), ASYNC_TX_ACK = (1 << 3), ASYNC_TX_DEP_ACK = (1 << 4), - ASYNC_TX_KMAP_SRC = (1 << 5), - ASYNC_TX_KMAP_DST = (1 << 6), }; #ifdef CONFIG_DMA_ENGINE -- 2.20.1