Hi Kees, I love your patch! Yet something to improve: [auto build test ERROR on linux/master] [also build test ERROR on kees/for-next/pstore linus/master v5.12-rc6 next-20210409] [cannot apply to kees/for-next/loadpin] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Kees-Cook/LoadPin-Allow-filesyst... base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 5e46d1b78a03d52306f21f77a4e4a144b6d31486 config: x86_64-allyesconfig (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://github.com/0day-ci/linux/commit/3dc7289d9d15396745929884191874dc2... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Kees-Cook/LoadPin-Allow-filesystem-switch-when-not-enforcing/20210409-073059 git checkout 3dc7289d9d15396745929884191874dc2cce1afc # save the attached .config to linux build tree make W=1 ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): In file included from include/linux/kernel.h:16, from include/linux/list.h:9, from include/linux/module.h:12, from security/loadpin/loadpin.c:12: security/loadpin/loadpin.c: In function 'report_writable': 106 | load_root_writable ? "writable" : "read-only"); | ^~~~~~~~~~~~~~~~~~ include/linux/printk.h:373:34: note: in definition of macro 'pr_info' 373 | printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__) | ^~~~~~~~~~~ security/loadpin/loadpin.c:106:4: note: each undeclared identifier is reported only once for each function it appears in 106 | load_root_writable ? "writable" : "read-only"); | ^~~~~~~~~~~~~~~~~~ include/linux/printk.h:373:34: note: in definition of macro 'pr_info' 373 | printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__) | ^~~~~~~~~~~ security/loadpin/loadpin.c: In function 'loadpin_sb_free_security': 121 | if (enforced) { | ^~~~~~~~ | enforce security/loadpin/loadpin.c: In function 'loadpin_read_file': security/loadpin/loadpin.c:135:43: warning: variable 'sysctl_needed' set but not used [-Wunused-but-set-variable] 135 | bool load_root_writable, first_root_pin, sysctl_needed; | ^~~~~~~~~~~~~ vim +/load_root_writable +106 security/loadpin/loadpin.c 96 97 static void report_writable(struct block_device *bdev) 98 { 99 if (bdev) { 100 char name[BDEVNAME_SIZE]; 101 102 bdevname(bdev, name); 103 pr_info("%s (%u:%u): %s\n", name, 104 MAJOR(bdev->bd_dev), 105 MINOR(bdev->bd_dev), 107 } else { 108 pr_info("pinned filesystem lacks block device, treating as: writable\n"); 109 } 110 } 111 112 static void loadpin_sb_free_security(struct super_block *mnt_sb) 113 { 114 /* 115 * When unmounting the filesystem we were using for load 116 * pinning, we acknowledge the superblock release, but make sure 117 * no other modules or firmware can be loaded when we are in 118 * enforcing mode. Otherwise, allow the root to be reestablished. 119 */ 120 if (!IS_ERR_OR_NULL(pinned_root) && mnt_sb == pinned_root) { 122 pinned_root = ERR_PTR(-EIO); 123 pr_info("umount pinned fs: refusing further loads\n"); 124 } else { 125 pinned_root = NULL; 126 } 127 } 128 } 129 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org