s390/kdump: Add PM notifier for kdump (b66ac63e) · Commits · 戴 / test

For s390 the page table mapping for the crashkernel memory is removed to protect the pre-loaded kdump kernel and ramdisk. Because the crashkernel memory is not included in the page tables for suspend/resume it is not included in the suspend image. Therefore after resume the resumed system does no longer contain the pre-loaded kdump kernel and when kdump is triggered it fails. This patch adds a PM notifier that creates the page tables before suspend is done and removes them for resume. This ensures that the kdump kernel is included in the suspend image. Signed-off-by:

Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by:

Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/machine_kexec.c

+30 −0

Original line number	Diff line number	Diff line
		@@ -13,6 +13,7 @@
		#include <linux/reboot.h>
		#include <linux/ftrace.h>
		#include <linux/debug_locks.h>
		#include <linux/suspend.h>
		#include <asm/cio.h>
		#include <asm/setup.h>
		#include <asm/pgtable.h>
		@@ -67,6 +68,35 @@ void setup_regs(void)
		memcpy((void ) SAVE_AREA_BASE, (void ) sa, sizeof(struct save_area));
		}

		/*
		* PM notifier callback for kdump
		*/
		static int machine_kdump_pm_cb(struct notifier_block *nb, unsigned long action,
		void *ptr)
		{
		switch (action) {
		case PM_SUSPEND_PREPARE:
		case PM_HIBERNATION_PREPARE:
		if (crashk_res.start)
		crash_map_reserved_pages();
		break;
		case PM_POST_SUSPEND:
		case PM_POST_HIBERNATION:
		if (crashk_res.start)
		crash_unmap_reserved_pages();
		break;
		default:
		return NOTIFY_DONE;
		}
		return NOTIFY_OK;
		}

		static int __init machine_kdump_pm_init(void)
		{
		pm_notifier(machine_kdump_pm_cb, 0);
		return 0;
		}
		arch_initcall(machine_kdump_pm_init);
		#endif

		/*

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