Messages in this thread Patch in this message | | | Subject | [git patch review 4/5] [IB] mthca: Avoid SRQ free WQE list corruption | From | Roland Dreier <> | Date | Mon, 31 Oct 2005 22:34:42 +0000 |
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Fix wqe_to_link() to use a structure field that we know is definitely always unused for receive work requests, so that it really avoids the free list corruption bug that the comment claims it does.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
---
drivers/infiniband/hw/mthca/mthca_srq.c | 13 +++++++------ 1 files changed, 7 insertions(+), 6 deletions(-)
applies-to: ffd7eba03f29dd2932dd32ac4adc2921bde7644b e5b251a24a9cd34a7ef98e361eb94e7ab122a554 diff --git a/drivers/infiniband/hw/mthca/mthca_srq.c b/drivers/infiniband/hw/mthca/mthca_srq.c index 64f70aa..292f55b 100644 --- a/drivers/infiniband/hw/mthca/mthca_srq.c +++ b/drivers/infiniband/hw/mthca/mthca_srq.c @@ -75,15 +75,16 @@ static void *get_wqe(struct mthca_srq *s /* * Return a pointer to the location within a WQE that we're using as a - * link when the WQE is in the free list. We use an offset of 4 - * because in the Tavor case, posting a WQE may overwrite the first - * four bytes of the previous WQE. The offset avoids corrupting our - * free list if the WQE has already completed and been put on the free - * list when we post the next WQE. + * link when the WQE is in the free list. We use the imm field + * because in the Tavor case, posting a WQE may overwrite the next + * segment of the previous WQE, but a receive WQE will never touch the + * imm field. This avoids corrupting our free list if the previous + * WQE has already completed and been put on the free list when we + * post the next WQE. */ static inline int *wqe_to_link(void *wqe) { - return (int *) (wqe + 4); + return (int *) (wqe + offsetof(struct mthca_next_seg, imm)); } static void mthca_tavor_init_srq_context(struct mthca_dev *dev, --- 0.99.9 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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