| Message ID | ZMpsQrZadBaJGkt4@work (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [next] RDMA/irdma: Replace one-element array with flexible-array member | expand |
On Wed, 02 Aug 2023 08:46:26 -0600, Gustavo A. R. Silva wrote: > 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. > > [...] Applied, thanks! [1/1] RDMA/irdma: Replace one-element array with flexible-array member https://git.kernel.org/rdma/rdma/c/38313c6d2a02c2 Best regards,
On 8/3/23 12:11, Leon Romanovsky wrote: > > On Wed, 02 Aug 2023 08:46:26 -0600, Gustavo A. R. Silva wrote: >> 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. >> >> [...] > > Applied, thanks! Awesome. :) Thank you! -- Gustavo > > [1/1] RDMA/irdma: Replace one-element array with flexible-array member > https://git.kernel.org/rdma/rdma/c/38313c6d2a02c2 > > Best regards,
diff --git a/drivers/infiniband/hw/irdma/main.h b/drivers/infiniband/hw/irdma/main.h index 5483684a534c..82fc5f5b002c 100644 --- a/drivers/infiniband/hw/irdma/main.h +++ b/drivers/infiniband/hw/irdma/main.h @@ -239,7 +239,7 @@ 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 {
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@intel.com/ [2] Link: https://lore.kernel.org/linux-rdma/20210520143809.819-1-shiraz.saleem@intel.com/T/#u [3] Fixes: 44d9e52977a1 ("RDMA/irdma: Implement device initialization definitions") Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> --- drivers/infiniband/hw/irdma/main.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)