[PATCH] RDMA/hfi1: Constify struct mmu_rb_ops

From: Christophe JAILLET
Date: Mon Jun 24 2024 - 16:15:05 EST


'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@xxxxxxxxxx>
---
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