Hi André,
kernel test robot noticed the following build warnings:
[auto build test WARNING on c42ba5a87bdccbca11403b7ca8bad1a57b833732]
url: https://github.com/intel-lab-lkp/linux/commits/Andr-Almeida/futex-Use-explic... base: c42ba5a87bdccbca11403b7ca8bad1a57b833732 patch link: https://lore.kernel.org/r/20251122-tonyk-robust_futex-v6-4-05fea005a0fd%40ig... patch subject: [PATCH v6 4/9] futex: Create get_robust_list2() syscall config: loongarch-randconfig-r122-20251123 (https://download.01.org/0day-ci/archive/20251123/202511231703.YmF7ihi0-lkp@i...) compiler: loongarch64-linux-gcc (GCC) 15.1.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251123/202511231703.YmF7ihi0-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/202511231703.YmF7ihi0-lkp@intel.com/
sparse warnings: (new ones prefixed by >>) kernel/futex/syscalls.c:200:22: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct robust_list_head *head @@ got struct robust_list_head [noderef] __user * @@ kernel/futex/syscalls.c:200:22: sparse: expected struct robust_list_head *head kernel/futex/syscalls.c:200:22: sparse: got struct robust_list_head [noderef] __user *
kernel/futex/syscalls.c:202:24: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected void [noderef] __user *__pu_val @@ got struct robust_list_head *head @@
kernel/futex/syscalls.c:202:24: sparse: expected void [noderef] __user *__pu_val kernel/futex/syscalls.c:202:24: sparse: got struct robust_list_head *head
vim +202 kernel/futex/syscalls.c
160 161 SYSCALL_DEFINE4(get_robust_list2, int, pid, 162 void __user * __user *, head_ptr, 163 unsigned int, index, unsigned int, flags) 164 { 165 void __user *entry_ptr; 166 uintptr_t entry; 167 168 if (index >= FUTEX_ROBUST_LISTS_PER_USER) 169 return -EINVAL; 170 171 if (flags) 172 return -EINVAL; 173 174 /* 175 * The first two indexes are reserved for the kernel to be used with the 176 * legacy syscall, so we hide them from userspace. 177 * 178 * We map [0, FUTEX_ROBUST_LISTS_PER_USER) to 179 * [FUTEX_ROBUST_LIST2_IDX, FUTEX_ROBUST_LIST2_MAX_IDX) 180 */ 181 index += FUTEX_ROBUST_LIST2_IDX; 182 183 entry_ptr = futex_get_robust_list_common(pid, false, index); 184 if (IS_ERR(entry_ptr)) 185 return PTR_ERR(entry_ptr); 186 187 entry = (uintptr_t) entry_ptr; 188 189 if (entry & FUTEX_ROBUST_LIST_ENTRY_32BIT) { 190 entry &= FUTEX_ROBUST_LIST_ENTRY_MASK; 191 192 if (copy_to_user(head_ptr, &entry, sizeof(u32))) 193 return -EFAULT; 194 195 return 0; 196 } else { 197 struct robust_list_head *head; 198 199 entry &= FUTEX_ROBUST_LIST_ENTRY_MASK;
200 head = (__force struct robust_list_head __user *)entry;
201
202 return put_user(head, head_ptr);
203 } 204 } 205