Commit 6eedb5f3 authored by Ma Wupeng's avatar Ma Wupeng Committed by Wupeng Ma
Browse files

mm/memory-failure: introduce soft_online_page 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I90COS



--------------------------------

Commit 67f22ba7 ("mm/memory-failure: disable unpoison once hw error
happens") disable unpoison_memory once real memory-failure happens since
kpte will be clear in x86 and this will lead to kernel panic after
unpoison.

This problem do not exist on arm64, disable this check by introduce
soft_online_page. This is only used for bypass this check, real failure
pages in x86 should not call this to online.

Signed-off-by: default avatarMa Wupeng <mawupeng1@huawei.com>
parent be331c88

include/linux/mm.h

+1 −0
Original line number Diff line number Diff line
@@ -3883,6 +3883,7 @@ extern int unpoison_memory(unsigned long pfn); 
extern void shake_page(struct page *p);

extern atomic_long_t num_poisoned_pages __read_mostly;

extern int soft_offline_page(unsigned long pfn, int flags);

extern int soft_online_page(unsigned long pfn);

#ifdef CONFIG_MEMORY_FAILURE

/*

 * Sysfs entries for memory failure handling statistics.

mm/memory-failure.c

+40 −14
Original line number Diff line number Diff line
@@ -2496,19 +2496,7 @@ core_initcall(memory_failure_init); 
		pr_info(fmt, pfn);			\

})



/**

 * unpoison_memory - Unpoison a previously poisoned page

 * @pfn: Page number of the to be unpoisoned page

 *

 * Software-unpoison a page that has been poisoned by

 * memory_failure() earlier.

 *

 * This is only done on the software-level, so it only works

 * for linux injected failures, not real hardware failures

 *

 * Returns 0 for success, otherwise -errno.

 */

int unpoison_memory(unsigned long pfn)

static int __unpoison_memory(unsigned long pfn, bool hw_mf_check)

{

	struct folio *folio;

	struct page *p;
@@ -2526,7 +2514,7 @@ int unpoison_memory(unsigned long pfn) 


	mutex_lock(&mf_mutex);



	if (hw_memory_failure) {

	if (hw_mf_check && hw_memory_failure) {

		unpoison_pr_info("Unpoison: Disabled after HW memory failure %#lx\n",

				 pfn, &unpoison_rs);

		ret = -EOPNOTSUPP;
@@ -2609,8 +2597,46 @@ int unpoison_memory(unsigned long pfn) 
	}

	return ret;

}



/**

 * unpoison_memory - Unpoison a previously poisoned page

 * @pfn: Page number of the to be unpoisoned page

 *

 * Software-unpoison a page that has been poisoned by

 * memory_failure() earlier.

 *

 * This is only done on the software-level, so it only works

 * for linux injected failures, not real hardware failures

 *

 * Returns 0 for success, otherwise -errno.

 */

int unpoison_memory(unsigned long pfn)

{

	return __unpoison_memory(pfn, true);

}

EXPORT_SYMBOL(unpoison_memory);



/**

 * soft_online_page - Unpoison a previously poisoned page

 * @pfn: Page number of the to be unpoisoned page

 *

 * Software-unpoison a page that has been poisoned by

 * memory_failure() earlier.

 *

 * This is only done on the software-level, so it only works

 * for linux injected failures, not real hardware failures

 *

 * Since KPTE will be clear once hardware memory corrupts

 * happens in x86, hw_mf_check can not be ignored for x86.

 *

 * Returns 0 for success, otherwise -errno.

 */

int soft_online_page(unsigned long pfn)

{

	return __unpoison_memory(pfn, IS_ENABLED(CONFIG_X86));

}

EXPORT_SYMBOL_GPL(soft_online_page);



static bool isolate_page(struct page *page, struct list_head *pagelist)

{

	bool isolated = false;