Hi Deepak, kernel test robot noticed the following build warnings: [auto build test WARNING on 64f7b77f0bd9271861ed9e410e9856b6b0b21c48] url: https://github.com/intel-lab-lkp/linux/commits/Deepak-Gupta/mm-Introduce-ARCH_HAS_USER_SHADOW_STACK/20241112-050530 base: 64f7b77f0bd9271861ed9e410e9856b6b0b21c48 patch link: https://lore.kernel.org/r/20241111-v5_user_cfi_series-v8-12-dce14aa30207%40rivosinc.com patch subject: [PATCH v8 12/29] riscv/shstk: If needed allocate a new shadow stack on clone config: riscv-defconfig (https://download.01.org/0day-ci/archive/20241112/202411121717.INT1geTN-lkp@xxxxxxxxx/config) compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project 592c0fe55f6d9a811028b5f3507be91458ab2713) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241112/202411121717.INT1geTN-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/202411121717.INT1geTN-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): In file included from arch/riscv/kernel/process.c:17: In file included from include/linux/ptrace.h:10: In file included from include/linux/pid_namespace.h:7: In file included from include/linux/mm.h:2213: include/linux/vmstat.h:518:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion] 518 | return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_" | ~~~~~~~~~~~ ^ ~~~ >> arch/riscv/kernel/process.c:245:36: warning: expression result unused [-Wunused-value] 245 | ssp ? set_active_shstk(p, ssp) : 0; | ^ 2 warnings generated. vim +245 arch/riscv/kernel/process.c 209 210 int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) 211 { 212 unsigned long clone_flags = args->flags; 213 unsigned long usp = args->stack; 214 unsigned long tls = args->tls; 215 unsigned long ssp = 0; 216 struct pt_regs *childregs = task_pt_regs(p); 217 218 /* Ensure all threads in this mm have the same pointer masking mode. */ 219 if (IS_ENABLED(CONFIG_RISCV_ISA_SUPM) && p->mm && (clone_flags & CLONE_VM)) 220 set_bit(MM_CONTEXT_LOCK_PMLEN, &p->mm->context.flags); 221 222 memset(&p->thread.s, 0, sizeof(p->thread.s)); 223 224 /* p->thread holds context to be restored by __switch_to() */ 225 if (unlikely(args->fn)) { 226 /* Kernel thread */ 227 memset(childregs, 0, sizeof(struct pt_regs)); 228 /* Supervisor/Machine, irqs on: */ 229 childregs->status = SR_PP | SR_PIE; 230 231 p->thread.s[0] = (unsigned long)args->fn; 232 p->thread.s[1] = (unsigned long)args->fn_arg; 233 } else { 234 /* allocate new shadow stack if needed. In case of CLONE_VM we have to */ 235 ssp = shstk_alloc_thread_stack(p, args); 236 if (IS_ERR_VALUE(ssp)) 237 return PTR_ERR((void *)ssp); 238 239 *childregs = *(current_pt_regs()); 240 /* Turn off status.VS */ 241 riscv_v_vstate_off(childregs); 242 if (usp) /* User fork */ 243 childregs->sp = usp; 244 /* if needed, set new ssp */ > 245 ssp ? set_active_shstk(p, ssp) : 0; 246 if (clone_flags & CLONE_SETTLS) 247 childregs->tp = tls; 248 childregs->a0 = 0; /* Return value of fork() */ 249 p->thread.s[0] = 0; 250 } 251 p->thread.riscv_v_flags = 0; 252 if (has_vector()) 253 riscv_v_thread_alloc(p); 254 p->thread.ra = (unsigned long)ret_from_fork; 255 p->thread.sp = (unsigned long)childregs; /* kernel sp */ 256 return 0; 257 } 258 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
