Hi André, kernel test robot noticed the following build warnings: [auto build test WARNING on tip/locking/core] [also build test WARNING on tip/sched/core linus/master tip/x86/asm v6.12-rc5 next-20241101] [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#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Andr-Almeida/futex-Use-explicit-sizes-for-compat_exit_robust_list/20241102-002419 base: tip/locking/core patch link: https://lore.kernel.org/r/20241101162147.284993-2-andrealmeid%40igalia.com patch subject: [PATCH v2 1/3] futex: Use explicit sizes for compat_exit_robust_list config: x86_64-randconfig-123-20241102 (https://download.01.org/0day-ci/archive/20241102/202411022242.XCJECOCz-lkp@xxxxxxxxx/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/20241102/202411022242.XCJECOCz-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/202411022242.XCJECOCz-lkp@xxxxxxxxx/ sparse warnings: (new ones prefixed by >>) >> kernel/futex/core.c:914:59: sparse: sparse: cast removes address space '__user' of expression >> kernel/futex/core.c:914:59: sparse: sparse: incorrect type in argument 3 (different address spaces) @@ expected unsigned int [noderef] [usertype] __user *head @@ got unsigned int [usertype] * @@ kernel/futex/core.c:914:59: sparse: expected unsigned int [noderef] [usertype] __user *head kernel/futex/core.c:914:59: sparse: got unsigned int [usertype] * vim +/__user +914 kernel/futex/core.c 893 894 /* 895 * Walk curr->robust_list (very carefully, it's a userspace list!) 896 * and mark any locks found there dead, and notify any waiters. 897 * 898 * We silently return on any sign of list-walking problem. 899 */ 900 static void exit_robust_list32(struct task_struct *curr) 901 { 902 struct robust_list_head32 __user *head = curr->compat_robust_list; 903 struct robust_list __user *entry, *next_entry, *pending; 904 unsigned int limit = ROBUST_LIST_LIMIT, pi, pip; 905 unsigned int next_pi; 906 u32 uentry, next_uentry, upending; 907 s32 futex_offset; 908 int rc; 909 910 /* 911 * Fetch the list head (which was registered earlier, via 912 * sys_set_robust_list()): 913 */ > 914 if (fetch_robust_entry32((u32 *)&uentry, &entry, (u32 *)&head->list.next, &pi)) 915 return; 916 /* 917 * Fetch the relative futex offset: 918 */ 919 if (get_user(futex_offset, &head->futex_offset)) 920 return; 921 /* 922 * Fetch any possibly pending lock-add first, and handle it 923 * if it exists: 924 */ 925 if (fetch_robust_entry32(&upending, &pending, 926 &head->list_op_pending, &pip)) 927 return; 928 929 next_entry = NULL; /* avoid warning with gcc */ 930 while (entry != (struct robust_list __user *) &head->list) { 931 /* 932 * Fetch the next entry in the list before calling 933 * handle_futex_death: 934 */ 935 rc = fetch_robust_entry32(&next_uentry, &next_entry, 936 (u32 __user *)&entry->next, &next_pi); 937 /* 938 * A pending lock might already be on the list, so 939 * dont process it twice: 940 */ 941 if (entry != pending) { 942 void __user *uaddr = futex_uaddr(entry, futex_offset); 943 944 if (handle_futex_death(uaddr, curr, pi, 945 HANDLE_DEATH_LIST)) 946 return; 947 } 948 if (rc) 949 return; 950 uentry = next_uentry; 951 entry = next_entry; 952 pi = next_pi; 953 /* 954 * Avoid excessively long or circular lists: 955 */ 956 if (!--limit) 957 break; 958 959 cond_resched(); 960 } 961 if (pending) { 962 void __user *uaddr = futex_uaddr(pending, futex_offset); 963 964 handle_futex_death(uaddr, curr, pip, HANDLE_DEATH_PENDING); 965 } 966 } 967 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
