Hi Guillaume, FYI, the error/warning still remains. tree: https://gitee.com/openeuler/kernel.git openEuler-1.0-LTS head: 7951fd324625a8af5097e1476cdc8c33c6009b48 commit: 528534f0deda05c668756313a22974429a9df05a [1546/1546] l2tp: remove pppol2tp_tunnel_ioctl() config: arm64-randconfig-002-20250401 (https://download.01.org/0day-ci/archive/20250402/202504021807.twewxnJE-lkp@i...) compiler: aarch64-linux-gcc (GCC) 12.3.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250402/202504021807.twewxnJE-lkp@i...) 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/202504021807.twewxnJE-lkp@intel.com/ Note: it may well be a FALSE warning. FWIW you are at least aware of it now. http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings All warnings (new ones prefixed by >>): net/l2tp/l2tp_ppp.c: In function 'pppol2tp_ioctl': net/l2tp/l2tp_ppp.c:1122:13: warning: variable 'val' set but not used [-Wunused-but-set-variable] 1122 | int val; | ^~~ In file included from net/l2tp/l2tp_ppp.c:62: net/l2tp/l2tp_ppp.c: At top level: include/linux/module.h:132:13: warning: 'init_module' specifies less restrictive attribute than its target 'pppol2tp_init': 'cold' [-Wmissing-attributes] 132 | int init_module(void) __attribute__((alias(#initfn))); | ^~~~~~~~~~~ net/l2tp/l2tp_ppp.c:1802:1: note: in expansion of macro 'module_init' 1802 | module_init(pppol2tp_init); | ^~~~~~~~~~~ net/l2tp/l2tp_ppp.c:1754:19: note: 'init_module' target declared here 1754 | static int __init pppol2tp_init(void) | ^~~~~~~~~~~~~ include/linux/module.h:138:14: warning: 'cleanup_module' specifies less restrictive attribute than its target 'pppol2tp_exit': 'cold' [-Wmissing-attributes] 138 | void cleanup_module(void) __attribute__((alias(#exitfn))); | ^~~~~~~~~~~~~~ net/l2tp/l2tp_ppp.c:1803:1: note: in expansion of macro 'module_exit' 1803 | module_exit(pppol2tp_exit); | ^~~~~~~~~~~ net/l2tp/l2tp_ppp.c:1792:20: note: 'cleanup_module' target declared here 1792 | static void __exit pppol2tp_exit(void) | ^~~~~~~~~~~~~ In file included from net/l2tp/l2tp_ppp.c:65: In function '_copy_from_user', inlined from 'copy_from_user' at include/linux/uaccess.h:147:7, inlined from 'pppol2tp_ioctl' at net/l2tp/l2tp_ppp.c:1163:8:
include/linux/uaccess.h:115:17: warning: 'stats' may be used uninitialized [-Wmaybe-uninitialized] 115 | kasan_check_write(to, n); | ^~~~~~~~~~~~~~~~~~~~~~~~ In file included from include/linux/compiler.h:246, from include/linux/kernel.h:10, from include/linux/list.h:9, from include/linux/module.h:9: include/linux/kasan-checks.h: In function 'pppol2tp_ioctl': include/linux/kasan-checks.h:7:6: note: by argument 1 of type 'const volatile void *' to 'kasan_check_write' declared here 7 | void kasan_check_write(const volatile void *p, unsigned int size); | ^~~~~~~~~~~~~~~~~ net/l2tp/l2tp_ppp.c:1120:35: note: 'stats' declared here 1120 | struct pppol2tp_ioc_stats stats; | ^~~~~
vim +/stats +115 include/linux/uaccess.h d597580d373774 Al Viro 2017-03-20 107 d597580d373774 Al Viro 2017-03-20 108 #ifdef INLINE_COPY_FROM_USER d597580d373774 Al Viro 2017-03-20 109 static inline unsigned long d597580d373774 Al Viro 2017-03-20 110 _copy_from_user(void *to, const void __user *from, unsigned long n) d597580d373774 Al Viro 2017-03-20 111 { d597580d373774 Al Viro 2017-03-20 112 unsigned long res = n; 9c5f6908de03a4 Al Viro 2017-06-29 113 might_fault(); 9c5f6908de03a4 Al Viro 2017-06-29 114 if (likely(access_ok(VERIFY_READ, from, n))) { 9c5f6908de03a4 Al Viro 2017-06-29 @115 kasan_check_write(to, n); d597580d373774 Al Viro 2017-03-20 116 res = raw_copy_from_user(to, from, n); 9c5f6908de03a4 Al Viro 2017-06-29 117 } d597580d373774 Al Viro 2017-03-20 118 if (unlikely(res)) d597580d373774 Al Viro 2017-03-20 119 memset(to + (n - res), 0, res); d597580d373774 Al Viro 2017-03-20 120 return res; d597580d373774 Al Viro 2017-03-20 121 } d597580d373774 Al Viro 2017-03-20 122 #else d597580d373774 Al Viro 2017-03-20 123 extern unsigned long d597580d373774 Al Viro 2017-03-20 124 _copy_from_user(void *, const void __user *, unsigned long); d597580d373774 Al Viro 2017-03-20 125 #endif d597580d373774 Al Viro 2017-03-20 126 :::::: The code at line 115 was first introduced by commit :::::: 9c5f6908de03a4f52ba7364b11fcd6116225480c copy_{from,to}_user(): move kasan checks and might_fault() out-of-line :::::: TO: Al Viro <viro@zeniv.linux.org.uk> :::::: CC: Al Viro <viro@zeniv.linux.org.uk> -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki