xen/xenbus: fix W=1 build warning in xenbus_va_dev_error function

This patch fixes a W=1 format-string warning reported by GCC 12.3.0
by annotating xenbus_switch_fatal() and xenbus_va_dev_error()
with the __printf attribute. The attribute enables compile-time
validation of printf-style format strings in these functions.

The original warning trace:
drivers/xen/xenbus/xenbus_client.c:304:9: warning: function 'xenbus_va_dev_error' might be
a candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format]

Signed-off-by: Peng Jiang <jiang.peng9@zte.com.cn>
Reviewed-by: Juergen Gross <jgross@suse.com>
Message-ID: <20250620084104786r5xoR16_AmYZMJLnno3_Q@zte.com.cn>
Signed-off-by: Juergen Gross <jgross@suse.com>

diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c
index 51b3124b0d56c98c316c58fa73d92c07e59b726a..e73ec225d4a61d0da65baf4aef190da376eefb6a 100644 (file)
--- a/drivers/xen/xenbus/xenbus_client.c
+++ b/drivers/xen/xenbus/xenbus_client.c
@@ -202,6 +202,7 @@ int xenbus_watch_pathfmt(struct xenbus_device *dev,
 }
 EXPORT_SYMBOL_GPL(xenbus_watch_pathfmt);
 
+__printf(4, 5)
 static void xenbus_switch_fatal(struct xenbus_device *, int, int,
                                const char *, ...);
 
@@ -287,6 +288,7 @@ int xenbus_frontend_closed(struct xenbus_device *dev)
 }
 EXPORT_SYMBOL_GPL(xenbus_frontend_closed);
 
+__printf(3, 0)
 static void xenbus_va_dev_error(struct xenbus_device *dev, int err,
                                const char *fmt, va_list ap)
 {