Merge branch 'hwpoison-cleanups' into hwpoison (e9d08567) · Commits · e / devices / android_kernel_xiaomi_markw

mm/memory-failure.c

+32 −41

Original line number	Diff line number	Diff line
		@@ -7,21 +7,26 @@
		* Free Software Foundation.
		*
		* High level machine check handler. Handles pages reported by the
		* hardware as being corrupted usually due to a 2bit ECC memory or cache
		* hardware as being corrupted usually due to a multi-bit ECC memory or cache
		* failure.
		*
		* In addition there is a "soft offline" entry point that allows stop using
		* not-yet-corrupted-by-suspicious pages without killing anything.
		*
		* Handles page cache pages in various states. The tricky part
		* here is that we can access any page asynchronous to other VM
		* users, because memory failures could happen anytime and anywhere,
		* possibly violating some of their assumptions. This is why this code
		* has to be extremely careful. Generally it tries to use normal locking
		* rules, as in get the standard locks, even if that means the
		* error handling takes potentially a long time.
		* here is that we can access any page asynchronously in respect to
		* other VM users, because memory failures could happen anytime and
		* anywhere. This could violate some of their assumptions. This is why
		* this code has to be extremely careful. Generally it tries to use
		* normal locking rules, as in get the standard locks, even if that means
		* the error handling takes potentially a long time.
		*
		* The operation to map back from RMAP chains to processes has to walk
		* the complete process list and has non linear complexity with the number
		* mappings. In short it can be quite slow. But since memory corruptions
		* are rare we hope to get away with this.
		* There are several operations here with exponential complexity because
		* of unsuitable VM data structures. For example the operation to map back
		* from RMAP chains to processes has to walk the complete process list and
		* has non linear complexity with the number. But since memory corruptions
		* are rare we hope to get away with this. This avoids impacting the core
		* VM.
		*/

		/*
		@@ -30,7 +35,6 @@
		* - kcore/oldmem/vmcore/mem/kmem check for hwpoison pages
		* - pass bad pages to kdump next kernel
		*/
		#define DEBUG 1 /* remove me in 2.6.34 */
		#include <linux/kernel.h>
		#include <linux/mm.h>
		#include <linux/page-flags.h>
		@@ -78,7 +82,7 @@ static int hwpoison_filter_dev(struct page *p)
		return 0;

		/*
		* page_mapping() does not accept slab page
		* page_mapping() does not accept slab pages.
		*/
		if (PageSlab(p))
		return -EINVAL;
		@@ -268,7 +272,7 @@ struct to_kill {
		struct list_head nd;
		struct task_struct *tsk;
		unsigned long addr;
		unsigned addr_valid:1;
		char addr_valid;
		};

		/*
		@@ -309,7 +313,7 @@ static void add_to_kill(struct task_struct tsk, struct page p,
		* a SIGKILL because the error is not contained anymore.
		*/
		if (tk->addr == -EFAULT) {
		pr_debug("MCE: Unable to find user space address %lx in %s\n",
		pr_info("MCE: Unable to find user space address %lx in %s\n",
		page_to_pfn(p), tsk->comm);
		tk->addr_valid = 0;
		}
		@@ -577,7 +581,7 @@ static int me_pagecache_clean(struct page *p, unsigned long pfn)
		pfn, err);
		} else if (page_has_private(p) &&
		!try_to_release_page(p, GFP_NOIO)) {
		pr_debug("MCE %#lx: failed to release buffers\n", pfn);
		pr_info("MCE %#lx: failed to release buffers\n", pfn);
		} else {
		ret = RECOVERED;
		}
		@@ -836,8 +840,6 @@ static int page_action(struct page_state ps, struct page p,
		return (result == RECOVERED \|\| result == DELAYED) ? 0 : -EBUSY;
		}

		#define N_UNMAP_TRIES 5

		/*
		* Do all that is necessary to remove user space mappings. Unmap
		* the pages and send SIGBUS to the processes if the data was dirty.
		@@ -849,7 +851,6 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
		struct address_space *mapping;
		LIST_HEAD(tokill);
		int ret;
		int i;
		int kill = 1;
		struct page *hpage = compound_head(p);

		@@ -903,17 +904,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
		if (kill)
		collect_procs(hpage, &tokill);

		/*
		* try_to_unmap can fail temporarily due to races.
		* Try a few times (RED-PEN better strategy?)
		*/
		for (i = 0; i < N_UNMAP_TRIES; i++) {
		ret = try_to_unmap(hpage, ttu);
		if (ret == SWAP_SUCCESS)
		break;
		pr_debug("MCE %#lx: try_to_unmap retry needed %d\n", pfn, ret);
		}

		if (ret != SWAP_SUCCESS)
		printk(KERN_ERR "MCE %#lx: failed to unmap page (mapcount=%d)\n",
		pfn, page_mapcount(hpage));
		@@ -1147,7 +1138,7 @@ int unpoison_memory(unsigned long pfn)
		page = compound_head(p);

		if (!PageHWPoison(p)) {
		pr_debug("MCE: Page was already unpoisoned %#lx\n", pfn);
		pr_info("MCE: Page was already unpoisoned %#lx\n", pfn);
		return 0;
		}

		@@ -1156,7 +1147,7 @@ int unpoison_memory(unsigned long pfn)
		if (!get_page_unless_zero(page)) {
		if (TestClearPageHWPoison(p))
		atomic_long_sub(nr_pages, &mce_bad_pages);
		pr_debug("MCE: Software-unpoisoned free page %#lx\n", pfn);
		pr_info("MCE: Software-unpoisoned free page %#lx\n", pfn);
		return 0;
		}

		@@ -1168,7 +1159,7 @@ int unpoison_memory(unsigned long pfn)
		* the free buddy page pool.
		*/
		if (TestClearPageHWPoison(page)) {
		pr_debug("MCE: Software-unpoisoned page %#lx\n", pfn);
		pr_info("MCE: Software-unpoisoned page %#lx\n", pfn);
		atomic_long_sub(nr_pages, &mce_bad_pages);
		freeit = 1;
		}
		@@ -1217,12 +1208,12 @@ static int get_any_page(struct page *p, unsigned long pfn, int flags)
		set_migratetype_isolate(p);
		if (!get_page_unless_zero(compound_head(p))) {
		if (is_free_buddy_page(p)) {
		pr_debug("get_any_page: %#lx free buddy page\n", pfn);
		pr_info("get_any_page: %#lx free buddy page\n", pfn);
		/* Set hwpoison bit while page is still isolated */
		SetPageHWPoison(p);
		ret = 0;
		} else {
		pr_debug("get_any_page: %#lx: unknown zero refcount page type %lx\n",
		pr_info("get_any_page: %#lx: unknown zero refcount page type %lx\n",
		pfn, p->flags);
		ret = -EIO;
		}
		@@ -1288,7 +1279,7 @@ int soft_offline_page(struct page *page, int flags)
		goto done;
		}
		if (!PageLRU(page)) {
		pr_debug("soft_offline: %#lx: unknown non LRU page type %lx\n",
		pr_info("soft_offline: %#lx: unknown non LRU page type %lx\n",
		pfn, page->flags);
		return -EIO;
		}
		@@ -1302,7 +1293,7 @@ int soft_offline_page(struct page *page, int flags)
		if (PageHWPoison(page)) {
		unlock_page(page);
		put_page(page);
		pr_debug("soft offline: %#lx page already poisoned\n", pfn);
		pr_info("soft offline: %#lx page already poisoned\n", pfn);
		return -EBUSY;
		}

		@@ -1323,7 +1314,7 @@ int soft_offline_page(struct page *page, int flags)
		put_page(page);
		if (ret == 1) {
		ret = 0;
		pr_debug("soft_offline: %#lx: invalidated\n", pfn);
		pr_info("soft_offline: %#lx: invalidated\n", pfn);
		goto done;
		}

		@@ -1339,13 +1330,13 @@ int soft_offline_page(struct page *page, int flags)
		list_add(&page->lru, &pagelist);
		ret = migrate_pages(&pagelist, new_page, MPOL_MF_MOVE_ALL, 0);
		if (ret) {
		pr_debug("soft offline: %#lx: migration failed %d, type %lx\n",
		pr_info("soft offline: %#lx: migration failed %d, type %lx\n",
		pfn, ret, page->flags);
		if (ret > 0)
		ret = -EIO;
		}
		} else {
		pr_debug("soft offline: %#lx: isolation failed: %d, page count %d, type %lx\n",
		pr_info("soft offline: %#lx: isolation failed: %d, page count %d, type %lx\n",
		pfn, ret, page_count(page), page->flags);
		}
		if (ret)