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crash: forward memory_notify arg to arch crash hotplug handler

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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.

Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240326055413.186534-2-sourabhjain@linux.ibm.com
This commit is contained in:
Sourabh Jain 2024-03-26 11:24:08 +05:30 committed by Michael Ellerman
parent 39cd87c4eb
commit 118005713e
4 changed files with 12 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/x86/include/asm/kexec.h
View File

@ -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

4
arch/x86/kernel/crash.c
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@ -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;

2
include/linux/crash_core.h
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@ -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);

14
kernel/crash_core.c
View File

@ -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;
}