tree: https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git pending-4.19 head: 1fb43d741d36cf1330749f79899cce2a47fda8bf commit: 6d5b906ef8333f63970cb9d5218986b5efa28b9a [47/279] powerpc/stacktrace: Fix spurious "stale" traces in raise_backtrace_ipi() config: powerpc-allyesconfig (attached as .config) compiler: powerpc64-linux-gcc (GCC) 10.3.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git/c... git remote add sashal-linux-stable https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git git fetch --no-tags sashal-linux-stable pending-4.19 git checkout 6d5b906ef8333f63970cb9d5218986b5efa28b9a # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-10.3.0 make.cross ARCH=powerpc If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): In file included from arch/powerpc/include/asm/book3s/64/mmu-hash.h:24, from arch/powerpc/include/asm/book3s/64/mmu.h:30, from arch/powerpc/include/asm/mmu.h:313, from arch/powerpc/include/asm/lppaca.h:36, from arch/powerpc/include/asm/paca.h:21, from arch/powerpc/include/asm/hw_irq.h:64, from arch/powerpc/include/asm/irqflags.h:12, from include/linux/irqflags.h:16, from include/linux/spinlock.h:54, from include/linux/mmzone.h:8, from include/linux/gfp.h:6, from include/linux/mm.h:10, from include/linux/kallsyms.h:12, from arch/powerpc/kernel/stacktrace.c:12: arch/powerpc/include/asm/book3s/64/pgtable.h:1292:15: warning: type qualifiers ignored on function return type [-Wignored-qualifiers] 1292 | static inline const int pud_pfn(pud_t pud) | ^~~~~ arch/powerpc/kernel/stacktrace.c: In function 'raise_backtrace_ipi': 222 | udelay(1); | ^~~~~~ cc1: some warnings being treated as errors vim +/udelay +222 arch/powerpc/kernel/stacktrace.c 204 205 static void raise_backtrace_ipi(cpumask_t *mask) 206 { 207 struct paca_struct *p; 208 unsigned int cpu; 209 u64 delay_us; 210 211 for_each_cpu(cpu, mask) { 212 if (cpu == smp_processor_id()) { 213 handle_backtrace_ipi(NULL); 214 continue; 215 } 216 217 delay_us = 5 * USEC_PER_SEC; 218 219 if (smp_send_safe_nmi_ipi(cpu, handle_backtrace_ipi, delay_us)) { 220 // Now wait up to 5s for the other CPU to do its backtrace 221 while (cpumask_test_cpu(cpu, mask) && delay_us) { 223 delay_us--; 224 } 225 226 // Other CPU cleared itself from the mask 227 if (delay_us) 228 continue; 229 } 230 231 p = paca_ptrs[cpu]; 232 233 cpumask_clear_cpu(cpu, mask); 234 235 pr_warn("CPU %d didn't respond to backtrace IPI, inspecting paca.\n", cpu); 236 if (!virt_addr_valid(p)) { 237 pr_warn("paca pointer appears corrupt? (%px)\n", p); 238 continue; 239 } 240 241 pr_warn("irq_soft_mask: 0x%02x in_mce: %d in_nmi: %d", 242 p->irq_soft_mask, p->in_mce, p->in_nmi); 243 244 if (virt_addr_valid(p->__current)) 245 pr_cont(" current: %d (%s)\n", p->__current->pid, 246 p->__current->comm); 247 else 248 pr_cont(" current pointer corrupt? (%px)\n", p->__current); 249 250 pr_warn("Back trace of paca->saved_r1 (0x%016llx) (possibly stale):\n", p->saved_r1); 251 show_stack(p->__current, (unsigned long *)p->saved_r1); 252 } 253 } 254 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org