Due to use of CPUHP_AP_ONLINE_DYN, upon CPU unplug, the CPU is still in the for_each_present_cpu() list when within the handle_hotplug_event(). Thus the CPU must be explicitly excluded when building the new list of CPUs.
This change identifies in handle_hotplug_event() the CPU to be excluded, and the check for excluding the CPU in crash_prepare_elf64_headers(). Signed-off-by: Eric DeVolder <[email protected]> Acked-by: Baoquan He <[email protected]> --- kernel/crash_core.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/kernel/crash_core.c b/kernel/crash_core.c index 154ef532d45a..77f5f3591760 100644 --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -355,6 +355,11 @@ int crash_prepare_elf64_headers(struct kimage *image, struct crash_mem *mem, /* Prepare one phdr of type PT_NOTE for each present CPU */ for_each_present_cpu(cpu) { +#if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_MEMORY_HOTPLUG) + /* Skip the soon-to-be offlined cpu */ + if (image->hotplug_event && (cpu == image->offlinecpu)) + continue; +#endif phdr->p_type = PT_NOTE; notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu)); phdr->p_offset = phdr->p_paddr = notes_addr; @@ -641,6 +646,16 @@ static void handle_hotplug_event(unsigned int hp_action, unsigned int cpu) /* Flag to differentiate between normal load and hotplug */ image->hotplug_event = true; + /* + * Due to use of CPUHP_AP_ONLINE_DYN, upon unplug and during + * this callback, the CPU is still in the for_each_present_cpu() + * list. Must explicitly look to exclude this CPU when building + * new list. + */ + image->offlinecpu = + (hp_action == KEXEC_CRASH_HP_REMOVE_CPU) ? + cpu : KEXEC_CRASH_HP_INVALID_CPU; + /* Now invoke arch-specific update handler */ arch_crash_handle_hotplug_event(image, hp_action, cpu); -- 2.31.1 _______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
