Hi Ilya, First bad commit (maybe != root cause): tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 88264981f2082248e892a706b2c5004650faac54 commit: 3a8f6f3b469b4075919a3613e182f9a70df92d46 kmsan: enable on s390 date: 3 months ago config: s390-randconfig-r121-20240922 (https://download.01.org/0day-ci/archive/20240922/202409221923.Z2I9fBpk-lkp@xxxxxxxxx/config) compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project 8663a75fa2f31299ab8d1d90288d9df92aadee88) reproduce: (https://download.01.org/0day-ci/archive/20240922/202409221923.Z2I9fBpk-lkp@xxxxxxxxx/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@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202409221923.Z2I9fBpk-lkp@xxxxxxxxx/ sparse warnings: (new ones prefixed by >>) >> mm/kmsan/hooks.c:269:14: sparse: sparse: cast removes address space '__user' of expression mm/kmsan/hooks.c:271:75: sparse: sparse: incorrect type in argument 3 (different address spaces) @@ expected void const *user_addr @@ got void [noderef] __user *to @@ mm/kmsan/hooks.c:271:75: sparse: expected void const *user_addr mm/kmsan/hooks.c:271:75: sparse: got void [noderef] __user *to mm/kmsan/hooks.c:280:50: sparse: sparse: cast removes address space '__user' of expression mm/kmsan/hooks.c:306:59: sparse: sparse: Using plain integer as NULL pointer mm/kmsan/hooks.c:319:79: sparse: sparse: Using plain integer as NULL pointer mm/kmsan/hooks.c:325:79: sparse: sparse: Using plain integer as NULL pointer mm/kmsan/hooks.c:421:78: sparse: sparse: Using plain integer as NULL pointer vim +/__user +269 mm/kmsan/hooks.c b073d7f8aee4eb Alexander Potapenko 2022-09-15 247 75cf0290271bf6 Alexander Potapenko 2022-09-15 248 void kmsan_copy_to_user(void __user *to, const void *from, size_t to_copy, 75cf0290271bf6 Alexander Potapenko 2022-09-15 249 size_t left) 75cf0290271bf6 Alexander Potapenko 2022-09-15 250 { 75cf0290271bf6 Alexander Potapenko 2022-09-15 251 unsigned long ua_flags; 75cf0290271bf6 Alexander Potapenko 2022-09-15 252 75cf0290271bf6 Alexander Potapenko 2022-09-15 253 if (!kmsan_enabled || kmsan_in_runtime()) 75cf0290271bf6 Alexander Potapenko 2022-09-15 254 return; 75cf0290271bf6 Alexander Potapenko 2022-09-15 255 /* 75cf0290271bf6 Alexander Potapenko 2022-09-15 256 * At this point we've copied the memory already. It's hard to check it 75cf0290271bf6 Alexander Potapenko 2022-09-15 257 * before copying, as the size of actually copied buffer is unknown. 75cf0290271bf6 Alexander Potapenko 2022-09-15 258 */ 75cf0290271bf6 Alexander Potapenko 2022-09-15 259 75cf0290271bf6 Alexander Potapenko 2022-09-15 260 /* copy_to_user() may copy zero bytes. No need to check. */ 75cf0290271bf6 Alexander Potapenko 2022-09-15 261 if (!to_copy) 75cf0290271bf6 Alexander Potapenko 2022-09-15 262 return; 75cf0290271bf6 Alexander Potapenko 2022-09-15 263 /* Or maybe copy_to_user() failed to copy anything. */ 75cf0290271bf6 Alexander Potapenko 2022-09-15 264 if (to_copy <= left) 75cf0290271bf6 Alexander Potapenko 2022-09-15 265 return; 75cf0290271bf6 Alexander Potapenko 2022-09-15 266 75cf0290271bf6 Alexander Potapenko 2022-09-15 267 ua_flags = user_access_save(); f926e9326f3a79 Ilya Leoshkevich 2024-06-21 268 if (!IS_ENABLED(CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE) || f926e9326f3a79 Ilya Leoshkevich 2024-06-21 @269 (u64)to < TASK_SIZE) { 75cf0290271bf6 Alexander Potapenko 2022-09-15 270 /* This is a user memory access, check it. */ 75cf0290271bf6 Alexander Potapenko 2022-09-15 271 kmsan_internal_check_memory((void *)from, to_copy - left, to, 75cf0290271bf6 Alexander Potapenko 2022-09-15 272 REASON_COPY_TO_USER); 75cf0290271bf6 Alexander Potapenko 2022-09-15 273 } else { 75cf0290271bf6 Alexander Potapenko 2022-09-15 274 /* Otherwise this is a kernel memory access. This happens when a 75cf0290271bf6 Alexander Potapenko 2022-09-15 275 * compat syscall passes an argument allocated on the kernel 75cf0290271bf6 Alexander Potapenko 2022-09-15 276 * stack to a real syscall. 75cf0290271bf6 Alexander Potapenko 2022-09-15 277 * Don't check anything, just copy the shadow of the copied 75cf0290271bf6 Alexander Potapenko 2022-09-15 278 * bytes. 75cf0290271bf6 Alexander Potapenko 2022-09-15 279 */ 75cf0290271bf6 Alexander Potapenko 2022-09-15 280 kmsan_internal_memmove_metadata((void *)to, (void *)from, 75cf0290271bf6 Alexander Potapenko 2022-09-15 281 to_copy - left); 75cf0290271bf6 Alexander Potapenko 2022-09-15 282 } 75cf0290271bf6 Alexander Potapenko 2022-09-15 283 user_access_restore(ua_flags); 75cf0290271bf6 Alexander Potapenko 2022-09-15 284 } 75cf0290271bf6 Alexander Potapenko 2022-09-15 285 EXPORT_SYMBOL(kmsan_copy_to_user); 75cf0290271bf6 Alexander Potapenko 2022-09-15 286 :::::: The code at line 269 was first introduced by commit :::::: f926e9326f3a79f7e01ac790e2361f44d8ca8320 kmsan: fix kmsan_copy_to_user() on arches with overlapping address spaces :::::: TO: Ilya Leoshkevich <iii@xxxxxxxxxxxxx> :::::: CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
