This is a note to let you know that I've just added the patch titled
RDMA/irdma: Replace one-element array with flexible-array member
to the 5.15-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:
rdma-irdma-replace-one-element-array-with-flexible-a.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c803961c79342476a921b5cf42a349f6257ac842
Author: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
Date: Wed Aug 2 08:46:26 2023 -0600
RDMA/irdma: Replace one-element array with flexible-array member
[ Upstream commit 38313c6d2a02c28162e06753b01bd885caf9386d ]
One-element and zero-length arrays are deprecated. So, replace
one-element array in struct irdma_qvlist_info with flexible-array
member.
A patch for this was sent a while ago[1]. However, it seems that, at
the time, the changes were partially folded[2][3], and the actual
flexible-array transformation was omitted. This patch fixes that.
The only binary difference seen before/after changes is shown below:
| drivers/infiniband/hw/irdma/hw.o
| @@ -868,7 +868,7 @@
| drivers/infiniband/hw/irdma/hw.c:484 (discriminator 2)
| size += struct_size(iw_qvlist, qv_info, rf->msix_count);
| 55b: imul $0x45c,%rdi,%rdi
|- 562: add $0x10,%rdi
|+ 562: add $0x4,%rdi
which is, of course, expected as it reflects the mistake made
while folding the patch I've mentioned above.
Worth mentioning is the fact that with this change we save 12 bytes
of memory, as can be inferred from the diff snapshot above. Notice
that:
$ pahole -C rdma_qv_info idrivers/infiniband/hw/irdma/hw.o
struct irdma_qv_info {
u32 v_idx; /* 0 4 */
u16 ceq_idx; /* 4 2 */
u16 aeq_idx; /* 6 2 */
u8 itr_idx; /* 8 1 */
/* size: 12, cachelines: 1, members: 4 */
/* padding: 3 */
/* last cacheline: 12 bytes */
};
Link: https://lore.kernel.org/linux-hardening/20210525230038.GA175516@embeddedor/ [1]
Link: https://lore.kernel.org/linux-hardening/bf46b428deef4e9e89b0ea1704b1f0e5@xxxxxxxxx/ [2]
Link: https://lore.kernel.org/linux-rdma/20210520143809.819-1-shiraz.saleem@xxxxxxxxx/T/#u [3]
Fixes: 44d9e52977a1 ("RDMA/irdma: Implement device initialization definitions")
Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
Link: https://lore.kernel.org/r/ZMpsQrZadBaJGkt4@work
Signed-off-by: Leon Romanovsky <leon@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/infiniband/hw/irdma/main.h b/drivers/infiniband/hw/irdma/main.h
index f2e2bc50c6f7b..bd13cc38e5ae1 100644
--- a/drivers/infiniband/hw/irdma/main.h
+++ b/drivers/infiniband/hw/irdma/main.h
@@ -237,7 +237,7 @@ struct irdma_qv_info {
struct irdma_qvlist_info {
u32 num_vectors;
- struct irdma_qv_info qv_info[1];
+ struct irdma_qv_info qv_info[];
};
struct irdma_gen_ops {
