Hi Ding, FYI, the error/warning still remains. tree: https://gitee.com/openeuler/kernel.git openEuler-1.0-LTS head: 02951ceaa6d546dfa0f741f52f6d47e0fb0ac7b4 commit: 9469d1759c2905dcef49df7e6240ad5c32b66296 [1341/1341] ascend: share_pool: enable svm to use share pool memory config: arm64-randconfig-002-20241220 (https://download.01.org/0day-ci/archive/20241221/202412210226.N1hHrIDJ-lkp@i...) compiler: aarch64-linux-gcc (GCC) 14.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241221/202412210226.N1hHrIDJ-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/202412210226.N1hHrIDJ-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 >>): drivers/char/svm.c:249:21: warning: no previous prototype for 'svm_find_mem_reg_node' [-Wmissing-prototypes] 249 | struct device_node *svm_find_mem_reg_node(struct device *dev, const char *compat) | ^~~~~~~~~~~~~~~~~~~~~ drivers/char/svm.c:419:6: warning: no previous prototype for 'sysrq_sched_debug_show_export' [-Wmissing-prototypes] 419 | void sysrq_sched_debug_show_export(void) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/char/svm.c:1429:5: warning: no previous prototype for 'svm_get_pasid' [-Wmissing-prototypes] 1429 | int svm_get_pasid(pid_t vpid, int dev_id __maybe_unused) | ^~~~~~~~~~~~~ drivers/char/svm.c:1502:5: warning: no previous prototype for '__svm_get_mpam' [-Wmissing-prototypes] 1502 | int __svm_get_mpam(struct svm_mpam *mpam) | ^~~~~~~~~~~~~~ In file included from arch/arm64/include/asm/atomic.h:34, from include/linux/atomic.h:7, from include/asm-generic/bitops/atomic.h:5, from arch/arm64/include/asm/bitops.h:37, from include/linux/bitops.h:19, from include/linux/kernel.h:11, from include/asm-generic/bug.h:18, from arch/arm64/include/asm/bug.h:37, from arch/arm64/include/asm/memory.h:27, from arch/arm64/include/asm/esr.h:21, from drivers/char/svm.c:10: In function '__cmpxchg_case_mb_4', inlined from '__cmpxchg_mb' at arch/arm64/include/asm/cmpxchg.h:143:1, inlined from 'svm_proc_load_flag' at drivers/char/svm.c:1967:12: arch/arm64/include/asm/atomic_lse.h:492:9: warning: array subscript 'long unsigned int[0]' is partly outside array bounds of 'atomic_t[1]' [-Warray-bounds=] 492 | asm volatile( \ | ^~~ arch/arm64/include/asm/atomic_lse.h:523:1: note: in expansion of macro '__CMPXCHG_CASE' 523 | __CMPXCHG_CASE(w, , mb_4, al, "memory") | ^~~~~~~~~~~~~~ drivers/char/svm.c: In function 'svm_proc_load_flag': drivers/char/svm.c:1958:25: note: object 'l2buf_load_flag' of size 4 1958 | static atomic_t l2buf_load_flag = ATOMIC_INIT(0); | ^~~~~~~~~~~~~~~ In function '__cmpxchg_case_mb_4', inlined from '__cmpxchg_mb' at arch/arm64/include/asm/cmpxchg.h:143:1, inlined from 'svm_proc_load_flag' at drivers/char/svm.c:1967:12: arch/arm64/include/asm/atomic_lse.h:492:9: warning: array subscript 'long unsigned int[0]' is partly outside array bounds of 'atomic_t[1]' [-Warray-bounds=] 492 | asm volatile( \ | ^~~ arch/arm64/include/asm/atomic_lse.h:523:1: note: in expansion of macro '__CMPXCHG_CASE' 523 | __CMPXCHG_CASE(w, , mb_4, al, "memory") | ^~~~~~~~~~~~~~ drivers/char/svm.c: In function 'svm_proc_load_flag': drivers/char/svm.c:1958:25: note: object 'l2buf_load_flag' of size 4 1958 | static atomic_t l2buf_load_flag = ATOMIC_INIT(0); | ^~~~~~~~~~~~~~~ In file included from drivers/char/svm.c:29: In function '_copy_from_user', inlined from 'copy_from_user' at include/linux/uaccess.h:144:7, inlined from 'svm_sp_alloc_mem' at drivers/char/svm.c:2144:8:

...

include/linux/uaccess.h:112:17: warning: 'spallocinfo' may be used uninitialized [-Wmaybe-uninitialized] 112 | kasan_check_write(to, n); | ^~~~~~~~~~~~~~~~~~~~~~~~ In file included from include/linux/compiler.h:251, from arch/arm64/include/asm/memory.h:24: include/linux/kasan-checks.h: In function 'svm_sp_alloc_mem': 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); | ^~~~~~~~~~~~~~~~~ drivers/char/svm.c:2135:24: note: 'spallocinfo' declared here 2135 | struct spalloc spallocinfo; | ^~~~~~~~~~~ In function '_copy_from_user', inlined from 'copy_from_user' at include/linux/uaccess.h:144:7, inlined from 'svm_get_phy_memory_info' at drivers/char/svm.c:1805:6: include/linux/uaccess.h:112:17: warning: 'para' may be used uninitialized [-Wmaybe-uninitialized] 112 | kasan_check_write(to, n); | ^~~~~~~~~~~~~~~~~~~~~~~~ include/linux/kasan-checks.h: In function 'svm_get_phy_memory_info': 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); | ^~~~~~~~~~~~~~~~~ drivers/char/svm.c:1800:33: note: 'para' declared here 1800 | struct phymeminfo_ioctl para; | ^~~~ In function '_copy_from_user', inlined from 'copy_from_user' at include/linux/uaccess.h:144:7, inlined from 'svm_remap_proc' at drivers/char/svm.c:1863:8: include/linux/uaccess.h:112:17: warning: 'pmem' may be used uninitialized [-Wmaybe-uninitialized] 112 | kasan_check_write(to, n); | ^~~~~~~~~~~~~~~~~~~~~~~~ include/linux/kasan-checks.h: In function 'svm_remap_proc': 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); | ^~~~~~~~~~~~~~~~~ drivers/char/svm.c:1849:29: note: 'pmem' declared here 1849 | struct svm_proc_mem pmem; | ^~~~ In function '_copy_from_user', inlined from 'copy_from_user' at include/linux/uaccess.h:144:7, inlined from 'svm_ioctl' at drivers/char/svm.c:2217:9: include/linux/uaccess.h:112:17: warning: 'params' may be used uninitialized [-Wmaybe-uninitialized] 112 | kasan_check_write(to, n); | ^~~~~~~~~~~~~~~~~~~~~~~~ include/linux/kasan-checks.h: In function 'svm_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); | ^~~~~~~~~~~~~~~~~ drivers/char/svm.c:2209:33: note: 'params' declared here 2209 | struct svm_bind_process params; | ^~~~~~ In function '_copy_from_user', inlined from 'copy_from_user' at include/linux/uaccess.h:144:7, inlined from 'svm_sp_free_mem' at drivers/char/svm.c:2179:8, inlined from 'svm_ioctl' at drivers/char/svm.c:2280:9: include/linux/uaccess.h:112:17: warning: 'spallocinfo' may be used uninitialized [-Wmaybe-uninitialized] 112 | kasan_check_write(to, n); | ^~~~~~~~~~~~~~~~~~~~~~~~ include/linux/kasan-checks.h: In function 'svm_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); | ^~~~~~~~~~~~~~~~~ drivers/char/svm.c:2172:24: note: 'spallocinfo' declared here 2172 | struct spalloc spallocinfo; | ^~~~~~~~~~~

vim +/spallocinfo +112 include/linux/uaccess.h d597580d373774 Al Viro 2017-03-20 104 d597580d373774 Al Viro 2017-03-20 105 #ifdef INLINE_COPY_FROM_USER d597580d373774 Al Viro 2017-03-20 106 static inline unsigned long d597580d373774 Al Viro 2017-03-20 107 _copy_from_user(void *to, const void __user *from, unsigned long n) d597580d373774 Al Viro 2017-03-20 108 { d597580d373774 Al Viro 2017-03-20 109 unsigned long res = n; 9c5f6908de03a4 Al Viro 2017-06-29 110 might_fault(); 4983cb67a383a7 Linus Torvalds 2019-02-14 111 if (likely(access_ok(from, n))) { 9c5f6908de03a4 Al Viro 2017-06-29 @112 kasan_check_write(to, n); d597580d373774 Al Viro 2017-03-20 113 res = raw_copy_from_user(to, from, n); 9c5f6908de03a4 Al Viro 2017-06-29 114 } d597580d373774 Al Viro 2017-03-20 115 if (unlikely(res)) d597580d373774 Al Viro 2017-03-20 116 memset(to + (n - res), 0, res); d597580d373774 Al Viro 2017-03-20 117 return res; d597580d373774 Al Viro 2017-03-20 118 } d597580d373774 Al Viro 2017-03-20 119 #else d597580d373774 Al Viro 2017-03-20 120 extern unsigned long d597580d373774 Al Viro 2017-03-20 121 _copy_from_user(void *, const void __user *, unsigned long); d597580d373774 Al Viro 2017-03-20 122 #endif d597580d373774 Al Viro 2017-03-20 123 :::::: The code at line 112 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