diff --git a/arch/powerpc/platforms/powernv/opal-fadump.c b/arch/powerpc/platforms/powernv/opal-fadump.c index 5ace7c4d6bc1..533adae545d8 100644 --- a/arch/powerpc/platforms/powernv/opal-fadump.c +++ b/arch/powerpc/platforms/powernv/opal-fadump.c @@ -69,6 +69,30 @@ static void opal_fadump_get_config(struct fw_dump *fadump_conf, */ fadump_conf->reserve_dump_area_start = fdm->rgn[0].dest; + /* + * Rarely, but it can so happen that system crashes before all + * boot memory regions are registered for MPIPL. In such + * cases, warn that the vmcore may not be accurate and proceed + * anyway as that is the best bet considering free pages, cache + * pages, user pages, etc are usually filtered out. + * + * Hope the memory that could not be preserved only has pages + * that are usually filtered out while saving the vmcore. + */ + if (fdm->region_cnt > fdm->registered_regions) { + pr_warn("Not all memory regions were saved!!!\n"); + pr_warn(" Unsaved memory regions:\n"); + i = fdm->registered_regions; + while (i < fdm->region_cnt) { + pr_warn("\t[%03d] base: 0x%llx, size: 0x%llx\n", + i, fdm->rgn[i].src, fdm->rgn[i].size); + i++; + } + + pr_warn("If the unsaved regions only contain pages that are filtered out (eg. free/user pages), the vmcore should still be usable.\n"); + pr_warn("WARNING: If the unsaved regions contain kernel pages, the vmcore will be corrupted.\n"); + } + opal_fadump_update_config(fadump_conf, fdm); }