From 63cfcf90fe02ebd75bb148d6817ccecaa91c0a1f Mon Sep 17 00:00:00 2001 From: Wang Xiao W Date: Thu, 10 Sep 2015 12:38:16 +0800 Subject: [PATCH] fm10k/base: ignore oversized mailbox messages When we call update_max_size, it does not drop all oversized messages. This is due to the difficulty in performing this operation, since it is a FIFO which makes updating anything other than head or tail very difficult. To fix this, modify validate_msg_size to ensure that we error out later when trying to transmit the message that could be oversized. This will generally be a rare condition, as it requires the FIFO to include a message larger than the max_size negotiated during mailbox connect. Note that max_size is always smaller than rx.size, so it should be safe to use here. Also, update the update_max_size function header comment to clearly indicate that it does not drop all oversized messages, but only those at the head of the FIFO. Signed-off-by: Wang Xiao W --- drivers/net/fm10k/base/fm10k_mbx.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/net/fm10k/base/fm10k_mbx.c b/drivers/net/fm10k/base/fm10k_mbx.c index a0b7930d5a..ad9d81a103 100644 --- a/drivers/net/fm10k/base/fm10k_mbx.c +++ b/drivers/net/fm10k/base/fm10k_mbx.c @@ -344,7 +344,7 @@ STATIC u16 fm10k_mbx_validate_msg_size(struct fm10k_mbx_info *mbx, u16 len) } while (total_len < len); /* message extends out of pushed section, but fits in FIFO */ - if ((len < total_len) && (msg_len <= mbx->rx.size)) + if ((len < total_len) && (msg_len <= mbx->max_size)) return 0; /* return length of invalid section */ @@ -1088,12 +1088,15 @@ STATIC void fm10k_mbx_reset_work(struct fm10k_mbx_info *mbx) } /** - * fm10k_mbx_update_max_size - Update the max_size and drop any large messages + * fm10k_mbx_update_max_size - Update the max_size and drop large messages * @mbx: pointer to mailbox * @size: new value for max_size * - * This function will update the max_size value and drop any outgoing messages - * from the head of the Tx FIFO that are larger than max_size. + * This function updates the max_size value and drops any outgoing messages + * at the head of the Tx FIFO if they are larger than max_size. It does not + * drop all messages, as this is too difficult to parse and remove them from + * the FIFO. Instead, rely on the checking to ensure that messages larger + * than max_size aren't pushed into the memory buffer. **/ STATIC void fm10k_mbx_update_max_size(struct fm10k_mbx_info *mbx, u16 size) { -- 2.20.1