On 01/11/24 at 04:21pm, Sourabh Jain wrote:
> In the event of memory hotplug or online/offline events, the crash
> memory hotplug notifier `crash_memhp_notifier()` receives a
> `memory_notify` object but doesn't forward that object to the
> generic and architecture-specific crash hotplug handler.
>
> The `memory_notify` object contains the starting PFN (Page Frame Number)
> and the number of pages in the hot-removed memory. This information is
> necessary for architectures like PowerPC to update/recreate the kdump
> image, specifically `elfcorehdr`.
>
> So update the function signature of `crash_handle_hotplug_event()` and
> `arch_crash_handle_hotplug_event()` to accept the `memory_notify` object
> as an argument from crash memory hotplug notifier.
>
> Since no such object is available in the case of CPU hotplug event, the
> crash CPU hotplug notifier `crash_cpuhp_online()` passes NULL to the
> crash hotplug handler.
>
......
> ---
> arch/x86/include/asm/kexec.h | 2 +-
> arch/x86/kernel/crash.c | 3 ++-
> include/linux/kexec.h | 2 +-
> kernel/crash_core.c | 14 +++++++-------
> 4 files changed, 11 insertions(+), 10 deletions(-)
LGTM,
Acked-by: Baoquan He <b...@redhat.com>
>
> diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h
> index c9f6a6c5de3c..9bb6607e864e 100644
> --- a/arch/x86/include/asm/kexec.h
> +++ b/arch/x86/include/asm/kexec.h
> @@ -208,7 +208,7 @@ int arch_kimage_file_post_load_cleanup(struct kimage
> *image);
> extern void kdump_nmi_shootdown_cpus(void);
>
> #ifdef CONFIG_CRASH_HOTPLUG
> -void arch_crash_handle_hotplug_event(struct kimage *image);
> +void arch_crash_handle_hotplug_event(struct kimage *image, void *arg);
> #define arch_crash_handle_hotplug_event arch_crash_handle_hotplug_event
>
> #ifdef CONFIG_HOTPLUG_CPU
> diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
> index b6b044356f1b..44744e9c68ec 100644
> --- a/arch/x86/kernel/crash.c
> +++ b/arch/x86/kernel/crash.c
> @@ -428,10 +428,11 @@ unsigned int arch_crash_get_elfcorehdr_size(void)
> /**
> * arch_crash_handle_hotplug_event() - Handle hotplug elfcorehdr changes
> * @image: a pointer to kexec_crash_image
> + * @arg: struct memory_notify handler for memory hotplug case and NULL for
> CPU hotplug case.
> *
> * Prepare the new elfcorehdr and replace the existing elfcorehdr.
> */
> -void arch_crash_handle_hotplug_event(struct kimage *image)
> +void arch_crash_handle_hotplug_event(struct kimage *image, void *arg)
> {
> void *elfbuf = NULL, *old_elfcorehdr;
> unsigned long nr_mem_ranges;
> diff --git a/include/linux/kexec.h b/include/linux/kexec.h
> index 400cb6c02176..802052d9c64b 100644
> --- a/include/linux/kexec.h
> +++ b/include/linux/kexec.h
> @@ -483,7 +483,7 @@ static inline void arch_kexec_pre_free_pages(void *vaddr,
> unsigned int pages) {
> #endif
>
> #ifndef arch_crash_handle_hotplug_event
> -static inline void arch_crash_handle_hotplug_event(struct kimage *image) { }
> +static inline void arch_crash_handle_hotplug_event(struct kimage *image,
> void *arg) { }
> #endif
>
> int crash_check_update_elfcorehdr(void);
> diff --git a/kernel/crash_core.c b/kernel/crash_core.c
> index d48315667752..ab1c8e79759d 100644
> --- a/kernel/crash_core.c
> +++ b/kernel/crash_core.c
> @@ -914,7 +914,7 @@ int crash_check_update_elfcorehdr(void)
> * list of segments it checks (since the elfcorehdr changes and thus
> * would require an update to purgatory itself to update the digest).
> */
> -static void crash_handle_hotplug_event(unsigned int hp_action, unsigned int
> cpu)
> +static void crash_handle_hotplug_event(unsigned int hp_action, unsigned int
> cpu, void *arg)
> {
> struct kimage *image;
>
> @@ -976,7 +976,7 @@ static void crash_handle_hotplug_event(unsigned int
> hp_action, unsigned int cpu)
> image->hp_action = hp_action;
>
> /* Now invoke arch-specific update handler */
> - arch_crash_handle_hotplug_event(image);
> + arch_crash_handle_hotplug_event(image, arg);
>
> /* No longer handling a hotplug event */
> image->hp_action = KEXEC_CRASH_HP_NONE;
> @@ -992,17 +992,17 @@ static void crash_handle_hotplug_event(unsigned int
> hp_action, unsigned int cpu)
> crash_hotplug_unlock();
> }
>
> -static int crash_memhp_notifier(struct notifier_block *nb, unsigned long
> val, void *v)
> +static int crash_memhp_notifier(struct notifier_block *nb, unsigned long
> val, void *arg)
> {
> switch (val) {
> case MEM_ONLINE:
> crash_handle_hotplug_event(KEXEC_CRASH_HP_ADD_MEMORY,
> - KEXEC_CRASH_HP_INVALID_CPU);
> + KEXEC_CRASH_HP_INVALID_CPU, arg);
> break;
>
> case MEM_OFFLINE:
> crash_handle_hotplug_event(KEXEC_CRASH_HP_REMOVE_MEMORY,
> - KEXEC_CRASH_HP_INVALID_CPU);
> + KEXEC_CRASH_HP_INVALID_CPU, arg);
> break;
> }
> return NOTIFY_OK;
> @@ -1015,13 +1015,13 @@ static struct notifier_block crash_memhp_nb = {
>
> static int crash_cpuhp_online(unsigned int cpu)
> {
> - crash_handle_hotplug_event(KEXEC_CRASH_HP_ADD_CPU, cpu);
> + crash_handle_hotplug_event(KEXEC_CRASH_HP_ADD_CPU, cpu, NULL);
> return 0;
> }
>
> static int crash_cpuhp_offline(unsigned int cpu)
> {
> - crash_handle_hotplug_event(KEXEC_CRASH_HP_REMOVE_CPU, cpu);
> + crash_handle_hotplug_event(KEXEC_CRASH_HP_REMOVE_CPU, cpu, NULL);
> return 0;
> }
>
> --
> 2.41.0
>
