firmware: qemu_fw_cfg: constify 'struct bin_attribute'

The sysfs core now allows instances of 'struct bin_attribute' to be
moved into read-only memory. Make use of that to protect them against
accidental or malicious modifications.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Gabriel Somlo <somlo@cmu.edu>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20250114-sysfs-const-bin_attr-qemu_fw_cfg-v1-1-76f525a3ee72@weissschuh.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/firmware/qemu_fw_cfg.c b/drivers/firmware/qemu_fw_cfg.c
index d58da3e4500a5e230b7da9a75e4d70df7c38c542..2615fb780e3c4500db36d4746880455f05479f1f 100644 (file)
--- a/drivers/firmware/qemu_fw_cfg.c
+++ b/drivers/firmware/qemu_fw_cfg.c
@@ -460,7 +460,7 @@ static const struct kobj_type fw_cfg_sysfs_entry_ktype = {
 
 /* raw-read method and attribute */
 static ssize_t fw_cfg_sysfs_read_raw(struct file *filp, struct kobject *kobj,
-                                    struct bin_attribute *bin_attr,
+                                    const struct bin_attribute *bin_attr,
                                     char *buf, loff_t pos, size_t count)
 {
        struct fw_cfg_sysfs_entry *entry = to_entry(kobj);
@@ -474,9 +474,9 @@ static ssize_t fw_cfg_sysfs_read_raw(struct file *filp, struct kobject *kobj,
        return fw_cfg_read_blob(entry->select, buf, pos, count);
 }
 
-static struct bin_attribute fw_cfg_sysfs_attr_raw = {
+static const struct bin_attribute fw_cfg_sysfs_attr_raw = {
        .attr = { .name = "raw", .mode = S_IRUSR },
-       .read = fw_cfg_sysfs_read_raw,
+       .read_new = fw_cfg_sysfs_read_raw,
 };
 
 /*