Re: [Crash-utility] poisoned per_cpu data not handled on ppc64

Olaf Hering wrote: Hi Olaf, Thanks for the heads-up: Index: linux-2.6.16-rc1-git3/arch/powerpc/kernel/setup_64.c =================================================================== --- linux-2.6.16-rc1-git3.orig/arch/powerpc/kernel/setup_64.c +++ linux-2.6.16-rc1-git3/arch/powerpc/kernel/setup_64.c @@ -670,6 +670,14 @@ void __init setup_per_cpu_areas(void) size = PERCPU_ENOUGH_ROOM; #endif + /* + * Poison invalid cpus, with lots of high bits set this should + * always fault + */ + for (i = 0; i < NR_CPUS; i++) { + paca[i].data_offset = 0xeeeeeeeeeeeeeeeeULL; + } + for_each_cpu(i) { ptr = alloc_bootmem_node(NODE_DATA(cpu_to_node(i)), size); if (!ptr) I'll defer this to the IBM ppc64 guys, but it would seemingly be simple enough to detect this in ppc64.c:ppc64_paca_init() by checking for both 0 and 0xeeeeeeeeeeeeeeeeULL: for (i = cpus = 0; i < nr_paca; i++) { readmem(symbol_value("paca") + (i * SIZE(ppc64_paca)), KVADDR, cpu_paca_buf, SIZE(ppc64_paca), "paca entry", FAULT_ON_ERROR); per_cpu_offset = ULONG(cpu_paca_buf + data_offset); - if (per_cpu_offset == 0) + if ((per_cpu_offset == 0) || + (per_cpu_offset == 0xeeeeeeeeeeeeeeeeULL)) continue; kt->__per_cpu_offset[i] = per_cpu_offset; kt->flags |= PER_CPU_OFF; cpus++; } Thanks again, Dave