[PATCH v17 1/6] crash: forward memory_notify arg to arch crash hotplug handler
Hari Bathini
hbathini at linux.ibm.com
Sun Mar 3 00:17:33 AEDT 2024
On 26/02/24 2:11 pm, 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.
>
Acked-by: Hari Bathini <hbathini at linux.ibm.com>
> Signed-off-by: Sourabh Jain <sourabhjain at linux.ibm.com>
> Acked-by: Baoquan He <bhe at redhat.com>
> Cc: Akhil Raj <lf32.dev at gmail.com>
> Cc: Andrew Morton <akpm at linux-foundation.org>
> Cc: Aneesh Kumar K.V <aneesh.kumar at kernel.org>
> Cc: Borislav Petkov (AMD) <bp at alien8.de>
> Cc: Boris Ostrovsky <boris.ostrovsky at oracle.com>
> Cc: Christophe Leroy <christophe.leroy at csgroup.eu>
> Cc: Dave Hansen <dave.hansen at linux.intel.com>
> Cc: Dave Young <dyoung at redhat.com>
> Cc: David Hildenbrand <david at redhat.com>
> Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
> Cc: Hari Bathini <hbathini at linux.ibm.com>
> Cc: Laurent Dufour <laurent.dufour at fr.ibm.com>
> Cc: Mahesh Salgaonkar <mahesh at linux.ibm.com>
> Cc: Michael Ellerman <mpe at ellerman.id.au>
> Cc: Mimi Zohar <zohar at linux.ibm.com>
> Cc: Naveen N Rao <naveen at kernel.org>
> Cc: Oscar Salvador <osalvador at suse.de>
> Cc: Thomas Gleixner <tglx at linutronix.de>
> Cc: Valentin Schneider <vschneid at redhat.com>
> Cc: Vivek Goyal <vgoyal at redhat.com>
> Cc: kexec at lists.infradead.org
> Cc: x86 at kernel.org
> ---
> arch/x86/include/asm/kexec.h | 2 +-
> arch/x86/kernel/crash.c | 4 +++-
> include/linux/crash_core.h | 2 +-
> kernel/crash_core.c | 14 +++++++-------
> 4 files changed, 12 insertions(+), 10 deletions(-)
>
> diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h
> index 91ca9a9ee3a2..cb1320ebbc23 100644
> --- a/arch/x86/include/asm/kexec.h
> +++ b/arch/x86/include/asm/kexec.h
> @@ -207,7 +207,7 @@ 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 e74d0c4286c1..2a682fe86352 100644
> --- a/arch/x86/kernel/crash.c
> +++ b/arch/x86/kernel/crash.c
> @@ -432,10 +432,12 @@ 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/crash_core.h b/include/linux/crash_core.h
> index d33352c2e386..647e928efee8 100644
> --- a/include/linux/crash_core.h
> +++ b/include/linux/crash_core.h
> @@ -37,7 +37,7 @@ static inline void arch_kexec_unprotect_crashkres(void) { }
>
>
> #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 78b5dc7cee3a..70fa8111a9d6 100644
> --- a/kernel/crash_core.c
> +++ b/kernel/crash_core.c
> @@ -534,7 +534,7 @@ 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;
>
> @@ -596,7 +596,7 @@ 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;
> @@ -612,17 +612,17 @@ 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;
> @@ -635,13 +635,13 @@ 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;
> }
>
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