[PATCH] ksmbd: Constify struct ksmbd_transport_ops

From: Christophe JAILLET
Date: Sun Jun 23 2024 - 14:09:33 EST


'struct ksmbd_transport_ops' is not modified in these drivers.

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
52184 2085 256 54525 d4fd fs/smb/server/transport_rdma.o

After:
=====
text data bss dec hex filename
52260 2021 256 54537 d509 fs/smb/server/transport_rdma.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
Compile tested-only
---
fs/smb/server/connection.h | 4 ++--
fs/smb/server/transport_rdma.c | 4 ++--
fs/smb/server/transport_tcp.c | 4 ++--
3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/fs/smb/server/connection.h b/fs/smb/server/connection.h
index 0e04cf8b1d89..5c2845e47cf2 100644
--- a/fs/smb/server/connection.h
+++ b/fs/smb/server/connection.h
@@ -133,8 +133,8 @@ struct ksmbd_transport_ops {
};

struct ksmbd_transport {
- struct ksmbd_conn *conn;
- struct ksmbd_transport_ops *ops;
+ struct ksmbd_conn *conn;
+ const struct ksmbd_transport_ops *ops;
};

#define KSMBD_TCP_RECV_TIMEOUT (7 * HZ)
diff --git a/fs/smb/server/transport_rdma.c b/fs/smb/server/transport_rdma.c
index 8faa25c6e129..cf4418f72772 100644
--- a/fs/smb/server/transport_rdma.c
+++ b/fs/smb/server/transport_rdma.c
@@ -164,7 +164,7 @@ enum {
SMB_DIRECT_MSG_DATA_TRANSFER
};

-static struct ksmbd_transport_ops ksmbd_smb_direct_transport_ops;
+static const struct ksmbd_transport_ops ksmbd_smb_direct_transport_ops;

struct smb_direct_send_ctx {
struct list_head msg_list;
@@ -2292,7 +2292,7 @@ bool ksmbd_rdma_capable_netdev(struct net_device *netdev)
return rdma_capable;
}

-static struct ksmbd_transport_ops ksmbd_smb_direct_transport_ops = {
+static const struct ksmbd_transport_ops ksmbd_smb_direct_transport_ops = {
.prepare = smb_direct_prepare,
.disconnect = smb_direct_disconnect,
.shutdown = smb_direct_shutdown,
diff --git a/fs/smb/server/transport_tcp.c b/fs/smb/server/transport_tcp.c
index 6633fa78e9b9..a84788396daa 100644
--- a/fs/smb/server/transport_tcp.c
+++ b/fs/smb/server/transport_tcp.c
@@ -37,7 +37,7 @@ struct tcp_transport {
unsigned int nr_iov;
};

-static struct ksmbd_transport_ops ksmbd_tcp_transport_ops;
+static const struct ksmbd_transport_ops ksmbd_tcp_transport_ops;

static void tcp_stop_kthread(struct task_struct *kthread);
static struct interface *alloc_iface(char *ifname);
@@ -649,7 +649,7 @@ int ksmbd_tcp_set_interfaces(char *ifc_list, int ifc_list_sz)
return 0;
}

-static struct ksmbd_transport_ops ksmbd_tcp_transport_ops = {
+static const struct ksmbd_transport_ops ksmbd_tcp_transport_ops = {
.read = ksmbd_tcp_read,
.writev = ksmbd_tcp_writev,
.disconnect = ksmbd_tcp_disconnect,
--
2.45.2