[PATCH] RDMA/umem: Constify struct dma_buf_attach_ops

Christophe JAILLET <[email protected]> Tue, 14 Jul 2026 10:47:32 +0200
Newsgroups org.kernel.vger.kernel-janitors,org.kernel.vger.linux-kernel,org.kernel.vger.linux-rdma
Message-ID <3ca4ace543a02ccfdcce1ba568895c994aad7abb.1784018825.git.christophe.jaillet@wanadoo.fr>
'struct dma_buf_attach_ops' are not modified in this driver.

Constifying these structures moves some data to a read-only section, so
increases overall security, especially when the structure holds some
function pointers.

On a x86_64, with allmodconfig, as an example:
Before:
======
   text	   data	    bss	    dec	    hex	filename
  10300	   1216	      0	  11516	   2cfc	drivers/infiniband/core/umem_dmabuf.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
  10428	   1088	      0	  11516	   2cfc	drivers/infiniband/core/umem_dmabuf.o

Signed-off-by: Christophe JAILLET <[email protected]>
---
Compile tested only.
---
 drivers/infiniband/core/umem_dmabuf.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/core/umem_dmabuf.c b/drivers/infiniband/core/umem_dmabuf.c
index ad023c2d84d8..39b5564a4c35 100644
--- a/drivers/infiniband/core/umem_dmabuf.c
+++ b/drivers/infiniband/core/umem_dmabuf.c
@@ -181,7 +181,7 @@ struct ib_umem_dmabuf *ib_umem_dmabuf_get(struct ib_device *device,
 }
 EXPORT_SYMBOL(ib_umem_dmabuf_get);
 
-static struct dma_buf_attach_ops ib_umem_dmabuf_attach_pinned_ops = {
+static const struct dma_buf_attach_ops ib_umem_dmabuf_attach_pinned_ops = {
 	.allow_peer2peer = true,
 };
 
@@ -205,7 +205,7 @@ static void ib_umem_dmabuf_revoke_locked(struct dma_buf_attachment *attach)
 	umem_dmabuf->revoked = 1;
 }
 
-static struct dma_buf_attach_ops ib_umem_dmabuf_attach_pinned_revocable_ops = {
+static const struct dma_buf_attach_ops ib_umem_dmabuf_attach_pinned_revocable_ops = {
 	.allow_peer2peer = true,
 	.invalidate_mappings = ib_umem_dmabuf_revoke_locked,
 };
-- 
2.55.0