Patch "tcmu: Fix flushing cmd entry dcache page" has been added to the 4.12-stable tree

This is a note to let you know that I've just added the patch titled

tcmu: Fix flushing cmd entry dcache page

to the 4.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
tcmu-fix-flushing-cmd-entry-dcache-page.patch
and it can be found in the queue-4.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Xiubo Li <[email protected]>
Date: Fri, 30 Jun 2017 16:14:16 +0800
Subject: tcmu: Fix flushing cmd entry dcache page

From: Xiubo Li <[email protected]>

commit 9d62bc0e6d79b11e3298e831358155930fb8f5e3 upstream.

When feeding the tcmu's cmd ring, we need to flush the dcache page for the cmd entry to make sure these kernel stores are visible to user space mappings of that page.

For the none PAD cmd entry, this will be flushed at the end of the tcmu_queue_cmd_ring().

---
 drivers/target/target_core_user.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

@@ -699,21 +699,21 @@ tcmu_queue_cmd_ring(struct tcmu_cmd *tcm
 		size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);
 
 		entry = (void *) mb + CMDR_OFF + cmd_head;
-		tcmu_flush_dcache_range(entry, sizeof(*entry));
 		tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_PAD);
 		tcmu_hdr_set_len(&entry->hdr.len_op, pad_size);
 		entry->hdr.cmd_id = 0; /* not used for PAD */
 		entry->hdr.kflags = 0;
 		entry->hdr.uflags = 0;
+		tcmu_flush_dcache_range(entry, sizeof(*entry));
 
 		UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
+		tcmu_flush_dcache_range(mb, sizeof(*mb));
 
 		cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
 		WARN_ON(cmd_head != 0);
 	}
 
 	entry = (void *) mb + CMDR_OFF + cmd_head;
-	tcmu_flush_dcache_range(entry, sizeof(*entry));
 	tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD);
 	entry->hdr.cmd_id = tcmu_cmd->cmd_id;
 	entry->hdr.kflags = 0;

Patches currently in stable-queue which might be from [email protected] are

queue-4.12/tcmu-fix-flushing-cmd-entry-dcache-page.patch queue-4.12/tcmu-fix-possbile-memory-leak-oops-when-recalculating-cmd-base-size.patch