drivers/xen/manage.c:337:60: warning: '%s' directive output may be truncated writing up to 95 bytes into a region of size 12

From: kernel test robot <lkp@intel.com>
To: Juergen Gross <jgross@suse.com>
Cc: oe-kbuild-all@lists.linux.dev, linux-kernel@vger.kernel.org,
	David Vrabel <david.vrabel@citrix.com>,
	Paul Durrant <paul.durrant@citrix.com>
Subject: drivers/xen/manage.c:337:60: warning: '%s' directive output may be truncated writing up to 95 bytes into a region of size 12
Date: Mon, 4 Dec 2023 03:55:46 +0800	[thread overview]
Message-ID: <202312040309.sACmAKoo-lkp@intel.com> (raw)

Hi Juergen,

FYI, the error/warning still remains.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   33cc938e65a98f1d29d0a18403dbbee050dcad9a
commit: 44b3c7af02ca2701b6b90ee30c9d1d9c3ae07653 xenbus: advertise control feature flags
date:   7 years ago
config: x86_64-randconfig-015-20231009 (https://download.01.org/0day-ci/archive/20231204/202312040309.sACmAKoo-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231204/202312040309.sACmAKoo-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202312040309.sACmAKoo-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from include/linux/kobject.h:21,
                    from include/linux/device.h:17,
                    from include/linux/node.h:17,
                    from include/linux/cpu.h:16,
                    from include/linux/stop_machine.h:4,
                    from drivers/xen/manage.c:12:
   include/linux/sysfs.h: In function 'sysfs_get_dirent':
   include/linux/sysfs.h:517:44: warning: pointer targets in passing argument 2 of 'kernfs_find_and_get' differ in signedness [-Wpointer-sign]
     517 |         return kernfs_find_and_get(parent, name);
         |                                            ^~~~
         |                                            |
         |                                            const unsigned char *
   In file included from include/linux/sysfs.h:15:
   include/linux/kernfs.h:440:57: note: expected 'const char *' but argument is of type 'const unsigned char *'
     440 | kernfs_find_and_get(struct kernfs_node *kn, const char *name)
         |                                             ~~~~~~~~~~~~^~~~
   drivers/xen/manage.c: In function 'shutdown_event':
>> drivers/xen/manage.c:337:60: warning: '%s' directive output may be truncated writing up to 95 bytes into a region of size 12 [-Wformat-truncation=]
     337 |                 snprintf(node, FEATURE_PATH_SIZE, "feature-%s",
         |                                                            ^~
   In function 'setup_shutdown_watcher',
       inlined from 'shutdown_event' at drivers/xen/manage.c:349:2:
   drivers/xen/manage.c:337:17: note: 'snprintf' output between 9 and 104 bytes into a destination of size 20
     337 |                 snprintf(node, FEATURE_PATH_SIZE, "feature-%s",
         |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     338 |                          shutdown_handlers[idx].command);
         |                          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

vim +337 drivers/xen/manage.c

   333	
   334		for (idx = 0; idx < ARRAY_SIZE(shutdown_handlers); idx++) {
   335			if (!shutdown_handlers[idx].flag)
   336				continue;
 > 337			snprintf(node, FEATURE_PATH_SIZE, "feature-%s",
   338				 shutdown_handlers[idx].command);
   339			xenbus_printf(XBT_NIL, "control", node, "%u", 1);
   340		}
   341	
   342		return 0;
   343	}
   344	

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