[PATCH] RDMA/hfi1: Constify struct mmu_rb_ops

[PATCH] RDMA/hfi1: Constify struct mmu_rb_ops

[Christophe JAILLET]

'struct mmu_rb_ops' is not modified in this driver.

Constifying this structure moves some data to a read-only section, so
increase overall security.

On a x86_64, with allmodconfig, as an example:
Before:
======
   text	   data	    bss	    dec	    hex	filename
  10879	    164	      0	  11043	   2b23	drivers/infiniband/hw/hfi1/pin_system.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
  10907	    140	      0	  11047	   2b27	drivers/infiniband/hw/hfi1/pin_system.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
Compile tested-only
---
 drivers/infiniband/hw/hfi1/mmu_rb.c     | 2 +-
 drivers/infiniband/hw/hfi1/mmu_rb.h     | 4 ++--
 drivers/infiniband/hw/hfi1/pin_system.c | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/mmu_rb.c b/drivers/infiniband/hw/hfi1/mmu_rb.c
index d4a6acad0e65..67a5c410fb5e 100644
--- a/drivers/infiniband/hw/hfi1/mmu_rb.c
+++ b/drivers/infiniband/hw/hfi1/mmu_rb.c
@@ -40,7 +40,7 @@ static unsigned long mmu_node_last(struct mmu_rb_node *node)
 }
 
 int hfi1_mmu_rb_register(void *ops_arg,
-			 struct mmu_rb_ops *ops,
+			 const struct mmu_rb_ops *ops,
 			 struct workqueue_struct *wq,
 			 struct mmu_rb_handler **handler)
 {
diff --git a/drivers/infiniband/hw/hfi1/mmu_rb.h b/drivers/infiniband/hw/hfi1/mmu_rb.h
index 8e5d05454d70..3fa50dd64db6 100644
--- a/drivers/infiniband/hw/hfi1/mmu_rb.h
+++ b/drivers/infiniband/hw/hfi1/mmu_rb.h
@@ -42,7 +42,7 @@ struct mmu_rb_handler {
 	/* Begin on a new cachline boundary here */
 	struct rb_root_cached root ____cacheline_aligned_in_smp;
 	void *ops_arg;
-	struct mmu_rb_ops *ops;
+	const struct mmu_rb_ops *ops;
 	struct list_head lru_list;
 	struct work_struct del_work;
 	struct list_head del_list;
@@ -51,7 +51,7 @@ struct mmu_rb_handler {
 };
 
 int hfi1_mmu_rb_register(void *ops_arg,
-			 struct mmu_rb_ops *ops,
+			 const struct mmu_rb_ops *ops,
 			 struct workqueue_struct *wq,
 			 struct mmu_rb_handler **handler);
 void hfi1_mmu_rb_unregister(struct mmu_rb_handler *handler);
diff --git a/drivers/infiniband/hw/hfi1/pin_system.c b/drivers/infiniband/hw/hfi1/pin_system.c
index 384f722093e0..cce56134519b 100644
--- a/drivers/infiniband/hw/hfi1/pin_system.c
+++ b/drivers/infiniband/hw/hfi1/pin_system.c
@@ -26,7 +26,7 @@ static int sdma_rb_evict(void *arg, struct mmu_rb_node *mnode, void *arg2,
 			 bool *stop);
 static void sdma_rb_remove(void *arg, struct mmu_rb_node *mnode);
 
-static struct mmu_rb_ops sdma_rb_ops = {
+static const struct mmu_rb_ops sdma_rb_ops = {
 	.filter = sdma_rb_filter,
 	.evict = sdma_rb_evict,
 	.remove = sdma_rb_remove,
-- 
2.45.2

Re: [PATCH] RDMA/hfi1: Constify struct mmu_rb_ops

[Leon Romanovsky]

On Mon, 24 Jun 2024 22:13:27 +0200, Christophe JAILLET wrote:
> 'struct mmu_rb_ops' is not modified in this driver.
> 
> Constifying this structure moves some data to a read-only section, so
> increase overall security.
> 
> On a x86_64, with allmodconfig, as an example:
> Before:
> ======
>    text	   data	    bss	    dec	    hex	filename
>   10879	    164	      0	  11043	   2b23	drivers/infiniband/hw/hfi1/pin_system.o
> 
> [...]

Applied, thanks!

[1/1] RDMA/hfi1: Constify struct mmu_rb_ops
      https://git.kernel.org/rdma/rdma/c/ccf238c8da1511

Best regards,
-- 
Leon Romanovsky <leon@kernel.org>