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mm/memory-failure.c
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/* * Copyright (C) 2008, 2009 Intel Corporation * Authors: Andi Kleen, Fengguang Wu * * This software may be redistributed and/or modified under the terms of * the GNU General Public License ("GPL") version 2 only as published by the * Free Software Foundation. * * High level machine check handler. Handles pages reported by the |
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* hardware as being corrupted usually due to a multi-bit ECC memory or cache |
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* failure. |
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* * In addition there is a "soft offline" entry point that allows stop using * not-yet-corrupted-by-suspicious pages without killing anything. |
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* * Handles page cache pages in various states. The tricky part |
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* 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. * * 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. |
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*/ /* * Notebook: * - hugetlb needs more code * - kcore/oldmem/vmcore/mem/kmem check for hwpoison pages * - pass bad pages to kdump next kernel */ |
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#include <linux/kernel.h> #include <linux/mm.h> #include <linux/page-flags.h> |
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#include <linux/kernel-page-flags.h> |
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#include <linux/sched.h> |
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#include <linux/ksm.h> |
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#include <linux/rmap.h> #include <linux/pagemap.h> #include <linux/swap.h> #include <linux/backing-dev.h> |
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#include <linux/migrate.h> #include <linux/page-isolation.h> #include <linux/suspend.h> |
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#include <linux/slab.h> |
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#include <linux/swapops.h> |
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#include <linux/hugetlb.h> |
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#include <linux/memory_hotplug.h> |
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#include <linux/mm_inline.h> |
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#include <linux/kfifo.h> |
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#include "internal.h" int sysctl_memory_failure_early_kill __read_mostly = 0; int sysctl_memory_failure_recovery __read_mostly = 1; atomic_long_t mce_bad_pages __read_mostly = ATOMIC_LONG_INIT(0); |
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#if defined(CONFIG_HWPOISON_INJECT) || defined(CONFIG_HWPOISON_INJECT_MODULE) |
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u32 hwpoison_filter_enable = 0; |
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u32 hwpoison_filter_dev_major = ~0U; u32 hwpoison_filter_dev_minor = ~0U; |
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u64 hwpoison_filter_flags_mask; u64 hwpoison_filter_flags_value; |
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EXPORT_SYMBOL_GPL(hwpoison_filter_enable); |
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EXPORT_SYMBOL_GPL(hwpoison_filter_dev_major); EXPORT_SYMBOL_GPL(hwpoison_filter_dev_minor); |
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EXPORT_SYMBOL_GPL(hwpoison_filter_flags_mask); EXPORT_SYMBOL_GPL(hwpoison_filter_flags_value); |
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static int hwpoison_filter_dev(struct page *p) { struct address_space *mapping; dev_t dev; if (hwpoison_filter_dev_major == ~0U && hwpoison_filter_dev_minor == ~0U) return 0; /* |
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* page_mapping() does not accept slab pages. |
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*/ if (PageSlab(p)) return -EINVAL; mapping = page_mapping(p); if (mapping == NULL || mapping->host == NULL) return -EINVAL; dev = mapping->host->i_sb->s_dev; if (hwpoison_filter_dev_major != ~0U && hwpoison_filter_dev_major != MAJOR(dev)) return -EINVAL; if (hwpoison_filter_dev_minor != ~0U && hwpoison_filter_dev_minor != MINOR(dev)) return -EINVAL; return 0; } |
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static int hwpoison_filter_flags(struct page *p) { if (!hwpoison_filter_flags_mask) return 0; if ((stable_page_flags(p) & hwpoison_filter_flags_mask) == hwpoison_filter_flags_value) return 0; else return -EINVAL; } |
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/* * This allows stress tests to limit test scope to a collection of tasks * by putting them under some memcg. This prevents killing unrelated/important * processes such as /sbin/init. Note that the target task may share clean * pages with init (eg. libc text), which is harmless. If the target task * share _dirty_ pages with another task B, the test scheme must make sure B * is also included in the memcg. At last, due to race conditions this filter * can only guarantee that the page either belongs to the memcg tasks, or is * a freed page. */ #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP u64 hwpoison_filter_memcg; EXPORT_SYMBOL_GPL(hwpoison_filter_memcg); static int hwpoison_filter_task(struct page *p) { struct mem_cgroup *mem; struct cgroup_subsys_state *css; unsigned long ino; if (!hwpoison_filter_memcg) return 0; mem = try_get_mem_cgroup_from_page(p); if (!mem) return -EINVAL; css = mem_cgroup_css(mem); /* root_mem_cgroup has NULL dentries */ if (!css->cgroup->dentry) return -EINVAL; ino = css->cgroup->dentry->d_inode->i_ino; css_put(css); if (ino != hwpoison_filter_memcg) return -EINVAL; return 0; } #else static int hwpoison_filter_task(struct page *p) { return 0; } #endif |
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int hwpoison_filter(struct page *p) { |
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if (!hwpoison_filter_enable) return 0; |
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if (hwpoison_filter_dev(p)) return -EINVAL; |
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if (hwpoison_filter_flags(p)) return -EINVAL; |
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if (hwpoison_filter_task(p)) return -EINVAL; |
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return 0; } |
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#else int hwpoison_filter(struct page *p) { return 0; } #endif |
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EXPORT_SYMBOL_GPL(hwpoison_filter); |
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/* * Send all the processes who have the page mapped an ``action optional'' * signal. */ static int kill_proc_ao(struct task_struct *t, unsigned long addr, int trapno, |
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unsigned long pfn, struct page *page) |
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{ struct siginfo si; int ret; printk(KERN_ERR "MCE %#lx: Killing %s:%d early due to hardware memory corruption ", pfn, t->comm, t->pid); si.si_signo = SIGBUS; si.si_errno = 0; si.si_code = BUS_MCEERR_AO; si.si_addr = (void *)addr; #ifdef __ARCH_SI_TRAPNO si.si_trapno = trapno; #endif |
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si.si_addr_lsb = compound_trans_order(compound_head(page)) + PAGE_SHIFT; |
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/* * Don't use force here, it's convenient if the signal * can be temporarily blocked. * This could cause a loop when the user sets SIGBUS |
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* to SIG_IGN, but hopefully no one will do that? |
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*/ ret = send_sig_info(SIGBUS, &si, t); /* synchronous? */ if (ret < 0) printk(KERN_INFO "MCE: Error sending signal to %s:%d: %d ", t->comm, t->pid, ret); return ret; } /* |
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* When a unknown page type is encountered drain as many buffers as possible * in the hope to turn the page into a LRU or free page, which we can handle. */ |
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void shake_page(struct page *p, int access) |
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{ if (!PageSlab(p)) { lru_add_drain_all(); if (PageLRU(p)) return; drain_all_pages(); if (PageLRU(p) || is_free_buddy_page(p)) return; } |
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|
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/* |
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* Only call shrink_slab here (which would also shrink other caches) if * access is not potentially fatal. |
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*/ |
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if (access) { int nr; do { |
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struct shrink_control shrink = { .gfp_mask = GFP_KERNEL, |
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}; |
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nr = shrink_slab(&shrink, 1000, 1000); |
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if (page_count(p) == 1) |
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break; } while (nr > 10); } |
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} EXPORT_SYMBOL_GPL(shake_page); /* |
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* Kill all processes that have a poisoned page mapped and then isolate * the page. * * General strategy: * Find all processes having the page mapped and kill them. * But we keep a page reference around so that the page is not * actually freed yet. * Then stash the page away * * There's no convenient way to get back to mapped processes * from the VMAs. So do a brute-force search over all * running processes. * * Remember that machine checks are not common (or rather * if they are common you have other problems), so this shouldn't * be a performance issue. * * Also there are some races possible while we get from the * error detection to actually handle it. */ struct to_kill { struct list_head nd; struct task_struct *tsk; unsigned long addr; |
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char addr_valid; |
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}; /* * Failure handling: if we can't find or can't kill a process there's * not much we can do. We just print a message and ignore otherwise. */ /* * Schedule a process for later kill. * Uses GFP_ATOMIC allocations to avoid potential recursions in the VM. * TBD would GFP_NOIO be enough? */ static void add_to_kill(struct task_struct *tsk, struct page *p, struct vm_area_struct *vma, struct list_head *to_kill, struct to_kill **tkc) { struct to_kill *tk; if (*tkc) { tk = *tkc; *tkc = NULL; } else { tk = kmalloc(sizeof(struct to_kill), GFP_ATOMIC); if (!tk) { printk(KERN_ERR "MCE: Out of memory while machine check handling "); return; } } tk->addr = page_address_in_vma(p, vma); tk->addr_valid = 1; /* * In theory we don't have to kill when the page was * munmaped. But it could be also a mremap. Since that's * likely very rare kill anyways just out of paranoia, but use * a SIGKILL because the error is not contained anymore. */ if (tk->addr == -EFAULT) { |
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pr_info("MCE: Unable to find user space address %lx in %s ", |
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page_to_pfn(p), tsk->comm); tk->addr_valid = 0; } get_task_struct(tsk); tk->tsk = tsk; list_add_tail(&tk->nd, to_kill); } /* * Kill the processes that have been collected earlier. * * Only do anything when DOIT is set, otherwise just free the list * (this is used for clean pages which do not need killing) * Also when FAIL is set do a force kill because something went * wrong earlier. */ static void kill_procs_ao(struct list_head *to_kill, int doit, int trapno, |
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int fail, struct page *page, unsigned long pfn) |
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{ struct to_kill *tk, *next; list_for_each_entry_safe (tk, next, to_kill, nd) { if (doit) { /* |
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* In case something went wrong with munmapping |
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* make sure the process doesn't catch the * signal and then access the memory. Just kill it. |
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*/ if (fail || tk->addr_valid == 0) { printk(KERN_ERR "MCE %#lx: forcibly killing %s:%d because of failure to unmap corrupted page ", pfn, tk->tsk->comm, tk->tsk->pid); force_sig(SIGKILL, tk->tsk); } /* * In theory the process could have mapped * something else on the address in-between. We could * check for that, but we need to tell the * process anyways. */ else if (kill_proc_ao(tk->tsk, tk->addr, trapno, |
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pfn, page) < 0) |
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printk(KERN_ERR "MCE %#lx: Cannot send advisory machine check signal to %s:%d ", pfn, tk->tsk->comm, tk->tsk->pid); } put_task_struct(tk->tsk); kfree(tk); } } static int task_early_kill(struct task_struct *tsk) { if (!tsk->mm) return 0; if (tsk->flags & PF_MCE_PROCESS) return !!(tsk->flags & PF_MCE_EARLY); return sysctl_memory_failure_early_kill; } /* * Collect processes when the error hit an anonymous page. */ static void collect_procs_anon(struct page *page, struct list_head *to_kill, struct to_kill **tkc) { struct vm_area_struct *vma; struct task_struct *tsk; struct anon_vma *av; |
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av = page_lock_anon_vma(page); if (av == NULL) /* Not actually mapped anymore */ |
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return; read_lock(&tasklist_lock); |
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for_each_process (tsk) { |
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struct anon_vma_chain *vmac; |
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if (!task_early_kill(tsk)) continue; |
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list_for_each_entry(vmac, &av->head, same_anon_vma) { vma = vmac->vma; |
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if (!page_mapped_in_vma(page, vma)) continue; if (vma->vm_mm == tsk->mm) add_to_kill(tsk, page, vma, to_kill, tkc); } } |
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read_unlock(&tasklist_lock); |
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page_unlock_anon_vma(av); |
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} /* * Collect processes when the error hit a file mapped page. */ static void collect_procs_file(struct page *page, struct list_head *to_kill, struct to_kill **tkc) { struct vm_area_struct *vma; struct task_struct *tsk; struct prio_tree_iter iter; struct address_space *mapping = page->mapping; |
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mutex_lock(&mapping->i_mmap_mutex); |
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read_lock(&tasklist_lock); |
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for_each_process(tsk) { pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); if (!task_early_kill(tsk)) continue; vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) { /* * Send early kill signal to tasks where a vma covers * the page but the corrupted page is not necessarily * mapped it in its pte. * Assume applications who requested early kill want * to be informed of all such data corruptions. */ if (vma->vm_mm == tsk->mm) add_to_kill(tsk, page, vma, to_kill, tkc); } } |
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read_unlock(&tasklist_lock); |
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mutex_unlock(&mapping->i_mmap_mutex); |
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} /* * Collect the processes who have the corrupted page mapped to kill. * This is done in two steps for locking reasons. * First preallocate one tokill structure outside the spin locks, * so that we can kill at least one process reasonably reliable. */ static void collect_procs(struct page *page, struct list_head *tokill) { struct to_kill *tk; if (!page->mapping) return; tk = kmalloc(sizeof(struct to_kill), GFP_NOIO); if (!tk) return; if (PageAnon(page)) collect_procs_anon(page, tokill, &tk); else collect_procs_file(page, tokill, &tk); kfree(tk); } /* * Error handlers for various types of pages. */ enum outcome { |
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IGNORED, /* Error: cannot be handled */ FAILED, /* Error: handling failed */ |
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DELAYED, /* Will be handled later */ |
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RECOVERED, /* Successfully recovered */ }; static const char *action_name[] = { |
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[IGNORED] = "Ignored", |
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[FAILED] = "Failed", [DELAYED] = "Delayed", |
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[RECOVERED] = "Recovered", }; /* |
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* XXX: It is possible that a page is isolated from LRU cache, * and then kept in swap cache or failed to remove from page cache. * The page count will stop it from being freed by unpoison. * Stress tests should be aware of this memory leak problem. */ static int delete_from_lru_cache(struct page *p) { if (!isolate_lru_page(p)) { /* * Clear sensible page flags, so that the buddy system won't * complain when the page is unpoison-and-freed. */ ClearPageActive(p); ClearPageUnevictable(p); /* * drop the page count elevated by isolate_lru_page() */ page_cache_release(p); return 0; } return -EIO; } /* |
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* Error hit kernel page. * Do nothing, try to be lucky and not touch this instead. For a few cases we * could be more sophisticated. */ static int me_kernel(struct page *p, unsigned long pfn) { |
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return IGNORED; } /* * Page in unknown state. Do nothing. */ static int me_unknown(struct page *p, unsigned long pfn) { printk(KERN_ERR "MCE %#lx: Unknown page state ", pfn); return FAILED; } /* |
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* Clean (or cleaned) page cache page. */ static int me_pagecache_clean(struct page *p, unsigned long pfn) { int err; int ret = FAILED; struct address_space *mapping; |
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delete_from_lru_cache(p); |
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/* * For anonymous pages we're done the only reference left * should be the one m_f() holds. */ if (PageAnon(p)) return RECOVERED; /* * Now truncate the page in the page cache. This is really * more like a "temporary hole punch" * Don't do this for block devices when someone else * has a reference, because it could be file system metadata * and that's not safe to truncate. */ mapping = page_mapping(p); if (!mapping) { /* * Page has been teared down in the meanwhile */ return FAILED; } /* * Truncation is a bit tricky. Enable it per file system for now. * * Open: to take i_mutex or not for this? Right now we don't. */ if (mapping->a_ops->error_remove_page) { err = mapping->a_ops->error_remove_page(mapping, p); if (err != 0) { printk(KERN_INFO "MCE %#lx: Failed to punch page: %d ", pfn, err); } else if (page_has_private(p) && !try_to_release_page(p, GFP_NOIO)) { |
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pr_info("MCE %#lx: failed to release buffers ", pfn); |
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} else { ret = RECOVERED; } } else { /* * If the file system doesn't support it just invalidate * This fails on dirty or anything with private pages */ if (invalidate_inode_page(p)) ret = RECOVERED; else printk(KERN_INFO "MCE %#lx: Failed to invalidate ", pfn); } return ret; } /* * Dirty cache page page * Issues: when the error hit a hole page the error is not properly * propagated. */ static int me_pagecache_dirty(struct page *p, unsigned long pfn) { struct address_space *mapping = page_mapping(p); SetPageError(p); /* TBD: print more information about the file. */ if (mapping) { /* * IO error will be reported by write(), fsync(), etc. * who check the mapping. * This way the application knows that something went * wrong with its dirty file data. * * There's one open issue: * * The EIO will be only reported on the next IO * operation and then cleared through the IO map. * Normally Linux has two mechanisms to pass IO error * first through the AS_EIO flag in the address space * and then through the PageError flag in the page. * Since we drop pages on memory failure handling the * only mechanism open to use is through AS_AIO. * * This has the disadvantage that it gets cleared on * the first operation that returns an error, while * the PageError bit is more sticky and only cleared * when the page is reread or dropped. If an * application assumes it will always get error on * fsync, but does other operations on the fd before |
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* and the page is dropped between then the error |
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* will not be properly reported. * * This can already happen even without hwpoisoned * pages: first on metadata IO errors (which only * report through AS_EIO) or when the page is dropped * at the wrong time. * * So right now we assume that the application DTRT on * the first EIO, but we're not worse than other parts * of the kernel. */ mapping_set_error(mapping, EIO); } return me_pagecache_clean(p, pfn); } /* * Clean and dirty swap cache. * * Dirty swap cache page is tricky to handle. The page could live both in page * cache and swap cache(ie. page is freshly swapped in). So it could be * referenced concurrently by 2 types of PTEs: * normal PTEs and swap PTEs. We try to handle them consistently by calling * try_to_unmap(TTU_IGNORE_HWPOISON) to convert the normal PTEs to swap PTEs, * and then * - clear dirty bit to prevent IO * - remove from LRU * - but keep in the swap cache, so that when we return to it on * a later page fault, we know the application is accessing * corrupted data and shall be killed (we installed simple * interception code in do_swap_page to catch it). * * Clean swap cache pages can be directly isolated. A later page fault will * bring in the known good data from disk. */ static int me_swapcache_dirty(struct page *p, unsigned long pfn) { |
6a46079cf HWPOISON: The hig... |
666 667 668 |
ClearPageDirty(p); /* Trigger EIO in shmem: */ ClearPageUptodate(p); |
dc2a1cbf7 HWPOISON: introdu... |
669 670 671 672 |
if (!delete_from_lru_cache(p)) return DELAYED; else return FAILED; |
6a46079cf HWPOISON: The hig... |
673 674 675 676 |
} static int me_swapcache_clean(struct page *p, unsigned long pfn) { |
6a46079cf HWPOISON: The hig... |
677 |
delete_from_swap_cache(p); |
e43c3afb3 HWPOISON: return ... |
678 |
|
dc2a1cbf7 HWPOISON: introdu... |
679 680 681 682 |
if (!delete_from_lru_cache(p)) return RECOVERED; else return FAILED; |
6a46079cf HWPOISON: The hig... |
683 684 685 686 687 |
} /* * Huge pages. Needs work. * Issues: |
93f70f900 HWPOISON, hugetlb... |
688 689 |
* - Error on hugepage is contained in hugepage unit (not in raw page unit.) * To narrow down kill region to one page, we need to break up pmd. |
6a46079cf HWPOISON: The hig... |
690 691 692 |
*/ static int me_huge_page(struct page *p, unsigned long pfn) { |
6de2b1aab HWPOISON, hugetlb... |
693 |
int res = 0; |
93f70f900 HWPOISON, hugetlb... |
694 695 696 697 698 699 700 701 702 703 704 705 |
struct page *hpage = compound_head(p); /* * We can safely recover from error on free or reserved (i.e. * not in-use) hugepage by dequeuing it from freelist. * To check whether a hugepage is in-use or not, we can't use * page->lru because it can be used in other hugepage operations, * such as __unmap_hugepage_range() and gather_surplus_pages(). * So instead we use page_mapping() and PageAnon(). * We assume that this function is called with page lock held, * so there is no race between isolation and mapping/unmapping. */ if (!(page_mapping(hpage) || PageAnon(hpage))) { |
6de2b1aab HWPOISON, hugetlb... |
706 707 708 |
res = dequeue_hwpoisoned_huge_page(hpage); if (!res) return RECOVERED; |
93f70f900 HWPOISON, hugetlb... |
709 710 |
} return DELAYED; |
6a46079cf HWPOISON: The hig... |
711 712 713 714 715 716 717 718 719 |
} /* * Various page states we can handle. * * A page state is defined by its current page->flags bits. * The table matches them in order and calls the right handler. * * This is quite tricky because we can access page at any time |
25985edce Fix common misspe... |
720 |
* in its live cycle, so all accesses have to be extremely careful. |
6a46079cf HWPOISON: The hig... |
721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 |
* * This is not complete. More states could be added. * For any missing state don't attempt recovery. */ #define dirty (1UL << PG_dirty) #define sc (1UL << PG_swapcache) #define unevict (1UL << PG_unevictable) #define mlock (1UL << PG_mlocked) #define writeback (1UL << PG_writeback) #define lru (1UL << PG_lru) #define swapbacked (1UL << PG_swapbacked) #define head (1UL << PG_head) #define tail (1UL << PG_tail) #define compound (1UL << PG_compound) #define slab (1UL << PG_slab) |
6a46079cf HWPOISON: The hig... |
737 738 739 740 741 742 743 744 |
#define reserved (1UL << PG_reserved) static struct page_state { unsigned long mask; unsigned long res; char *msg; int (*action)(struct page *p, unsigned long pfn); } error_states[] = { |
d95ea51e3 HWPOISON: make se... |
745 |
{ reserved, reserved, "reserved kernel", me_kernel }, |
95d01fc66 HWPOISON: remove ... |
746 747 748 749 |
/* * free pages are specially detected outside this table: * PG_buddy pages only make a small fraction of all free pages. */ |
6a46079cf HWPOISON: The hig... |
750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 |
/* * Could in theory check if slab page is free or if we can drop * currently unused objects without touching them. But just * treat it as standard kernel for now. */ { slab, slab, "kernel slab", me_kernel }, #ifdef CONFIG_PAGEFLAGS_EXTENDED { head, head, "huge", me_huge_page }, { tail, tail, "huge", me_huge_page }, #else { compound, compound, "huge", me_huge_page }, #endif { sc|dirty, sc|dirty, "swapcache", me_swapcache_dirty }, { sc|dirty, sc, "swapcache", me_swapcache_clean }, { unevict|dirty, unevict|dirty, "unevictable LRU", me_pagecache_dirty}, { unevict, unevict, "unevictable LRU", me_pagecache_clean}, |
6a46079cf HWPOISON: The hig... |
770 771 |
{ mlock|dirty, mlock|dirty, "mlocked LRU", me_pagecache_dirty }, { mlock, mlock, "mlocked LRU", me_pagecache_clean }, |
6a46079cf HWPOISON: The hig... |
772 773 774 |
{ lru|dirty, lru|dirty, "LRU", me_pagecache_dirty }, { lru|dirty, lru, "clean LRU", me_pagecache_clean }, |
6a46079cf HWPOISON: The hig... |
775 776 777 778 779 780 |
/* * Catchall entry: must be at end. */ { 0, 0, "unknown page state", me_unknown }, }; |
2326c467d HWPOISON: Undefin... |
781 782 783 784 785 786 787 788 789 790 791 792 |
#undef dirty #undef sc #undef unevict #undef mlock #undef writeback #undef lru #undef swapbacked #undef head #undef tail #undef compound #undef slab #undef reserved |
6a46079cf HWPOISON: The hig... |
793 794 |
static void action_result(unsigned long pfn, char *msg, int result) { |
a7560fc80 HWPOISON: return ... |
795 |
struct page *page = pfn_to_page(pfn); |
6a46079cf HWPOISON: The hig... |
796 797 798 799 |
printk(KERN_ERR "MCE %#lx: %s%s page recovery: %s ", pfn, |
a7560fc80 HWPOISON: return ... |
800 |
PageDirty(page) ? "dirty " : "", |
6a46079cf HWPOISON: The hig... |
801 802 803 804 |
msg, action_name[result]); } static int page_action(struct page_state *ps, struct page *p, |
bd1ce5f91 HWPOISON: avoid g... |
805 |
unsigned long pfn) |
6a46079cf HWPOISON: The hig... |
806 807 |
{ int result; |
7456b0405 HWPOISON: fix inv... |
808 |
int count; |
6a46079cf HWPOISON: The hig... |
809 810 811 |
result = ps->action(p, pfn); action_result(pfn, ps->msg, result); |
7456b0405 HWPOISON: fix inv... |
812 |
|
bd1ce5f91 HWPOISON: avoid g... |
813 |
count = page_count(p) - 1; |
138ce286e HWPOISON: return ... |
814 815 816 |
if (ps->action == me_swapcache_dirty && result == DELAYED) count--; if (count != 0) { |
6a46079cf HWPOISON: The hig... |
817 818 819 |
printk(KERN_ERR "MCE %#lx: %s page still referenced by %d users ", |
7456b0405 HWPOISON: fix inv... |
820 |
pfn, ps->msg, count); |
138ce286e HWPOISON: return ... |
821 822 |
result = FAILED; } |
6a46079cf HWPOISON: The hig... |
823 824 825 826 827 |
/* Could do more checks here if page looks ok */ /* * Could adjust zone counters here to correct for the missing page. */ |
138ce286e HWPOISON: return ... |
828 |
return (result == RECOVERED || result == DELAYED) ? 0 : -EBUSY; |
6a46079cf HWPOISON: The hig... |
829 |
} |
6a46079cf HWPOISON: The hig... |
830 831 832 833 |
/* * Do all that is necessary to remove user space mappings. Unmap * the pages and send SIGBUS to the processes if the data was dirty. */ |
1668bfd5b HWPOISON: abort o... |
834 |
static int hwpoison_user_mappings(struct page *p, unsigned long pfn, |
6a46079cf HWPOISON: The hig... |
835 836 837 838 839 840 |
int trapno) { enum ttu_flags ttu = TTU_UNMAP | TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS; struct address_space *mapping; LIST_HEAD(tokill); int ret; |
6a46079cf HWPOISON: The hig... |
841 |
int kill = 1; |
7af446a84 HWPOISON, hugetlb... |
842 |
struct page *hpage = compound_head(p); |
a6d30ddda thp: fix the wron... |
843 |
struct page *ppage; |
6a46079cf HWPOISON: The hig... |
844 |
|
1668bfd5b HWPOISON: abort o... |
845 846 |
if (PageReserved(p) || PageSlab(p)) return SWAP_SUCCESS; |
6a46079cf HWPOISON: The hig... |
847 |
|
6a46079cf HWPOISON: The hig... |
848 849 850 851 |
/* * This check implies we don't kill processes if their pages * are in the swap cache early. Those are always late kills. */ |
7af446a84 HWPOISON, hugetlb... |
852 |
if (!page_mapped(hpage)) |
1668bfd5b HWPOISON: abort o... |
853 |
return SWAP_SUCCESS; |
7af446a84 HWPOISON, hugetlb... |
854 |
if (PageKsm(p)) |
1668bfd5b HWPOISON: abort o... |
855 |
return SWAP_FAIL; |
6a46079cf HWPOISON: The hig... |
856 857 858 859 860 861 862 863 864 865 866 |
if (PageSwapCache(p)) { printk(KERN_ERR "MCE %#lx: keeping poisoned page in swap cache ", pfn); ttu |= TTU_IGNORE_HWPOISON; } /* * Propagate the dirty bit from PTEs to struct page first, because we * need this to decide if we should kill or just drop the page. |
db0480b3a HWPOISON: comment... |
867 868 |
* XXX: the dirty test could be racy: set_page_dirty() may not always * be called inside page lock (it's recommended but not enforced). |
6a46079cf HWPOISON: The hig... |
869 |
*/ |
7af446a84 HWPOISON, hugetlb... |
870 871 872 873 874 |
mapping = page_mapping(hpage); if (!PageDirty(hpage) && mapping && mapping_cap_writeback_dirty(mapping)) { if (page_mkclean(hpage)) { SetPageDirty(hpage); |
6a46079cf HWPOISON: The hig... |
875 876 877 878 879 880 881 882 883 |
} else { kill = 0; ttu |= TTU_IGNORE_HWPOISON; printk(KERN_INFO "MCE %#lx: corrupted page was clean: dropped without side effects ", pfn); } } |
a6d30ddda thp: fix the wron... |
884 885 886 887 888 889 890 |
/* * ppage: poisoned page * if p is regular page(4k page) * ppage == real poisoned page; * else p is hugetlb or THP, ppage == head page. */ ppage = hpage; |
efeda7a41 thp: fix splittin... |
891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 |
if (PageTransHuge(hpage)) { /* * Verify that this isn't a hugetlbfs head page, the check for * PageAnon is just for avoid tripping a split_huge_page * internal debug check, as split_huge_page refuses to deal with * anything that isn't an anon page. PageAnon can't go away fro * under us because we hold a refcount on the hpage, without a * refcount on the hpage. split_huge_page can't be safely called * in the first place, having a refcount on the tail isn't * enough * to be safe. */ if (!PageHuge(hpage) && PageAnon(hpage)) { if (unlikely(split_huge_page(hpage))) { /* * FIXME: if splitting THP is failed, it is * better to stop the following operation rather * than causing panic by unmapping. System might * survive if the page is freed later. */ printk(KERN_INFO "MCE %#lx: failed to split THP ", pfn); BUG_ON(!PageHWPoison(p)); return SWAP_FAIL; } |
a6d30ddda thp: fix the wron... |
917 918 |
/* THP is split, so ppage should be the real poisoned page. */ ppage = p; |
efeda7a41 thp: fix splittin... |
919 920 |
} } |
6a46079cf HWPOISON: The hig... |
921 922 923 924 925 926 927 928 929 |
/* * First collect all the processes that have the page * mapped in dirty form. This has to be done before try_to_unmap, * because ttu takes the rmap data structures down. * * Error handling: We ignore errors here because * there's nothing that can be done. */ if (kill) |
a6d30ddda thp: fix the wron... |
930 |
collect_procs(ppage, &tokill); |
6a46079cf HWPOISON: The hig... |
931 |
|
a6d30ddda thp: fix the wron... |
932 |
if (hpage != ppage) |
7eaceacca block: remove per... |
933 |
lock_page(ppage); |
a6d30ddda thp: fix the wron... |
934 935 |
ret = try_to_unmap(ppage, ttu); |
6a46079cf HWPOISON: The hig... |
936 937 938 |
if (ret != SWAP_SUCCESS) printk(KERN_ERR "MCE %#lx: failed to unmap page (mapcount=%d) ", |
a6d30ddda thp: fix the wron... |
939 940 941 942 |
pfn, page_mapcount(ppage)); if (hpage != ppage) unlock_page(ppage); |
6a46079cf HWPOISON: The hig... |
943 944 945 946 947 948 949 950 951 952 |
/* * Now that the dirty bit has been propagated to the * struct page and all unmaps done we can decide if * killing is needed or not. Only kill when the page * was dirty, otherwise the tokill list is merely * freed. When there was a problem unmapping earlier * use a more force-full uncatchable kill to prevent * any accesses to the poisoned memory. */ |
a6d30ddda thp: fix the wron... |
953 |
kill_procs_ao(&tokill, !!PageDirty(ppage), trapno, |
0d9ee6a2d HWPOISON: Report ... |
954 |
ret != SWAP_SUCCESS, p, pfn); |
1668bfd5b HWPOISON: abort o... |
955 956 |
return ret; |
6a46079cf HWPOISON: The hig... |
957 |
} |
7013febc8 HWPOISON, hugetlb... |
958 959 960 |
static void set_page_hwpoison_huge_page(struct page *hpage) { int i; |
37c2ac787 thp: compound_tra... |
961 |
int nr_pages = 1 << compound_trans_order(hpage); |
7013febc8 HWPOISON, hugetlb... |
962 963 964 965 966 967 968 |
for (i = 0; i < nr_pages; i++) SetPageHWPoison(hpage + i); } static void clear_page_hwpoison_huge_page(struct page *hpage) { int i; |
37c2ac787 thp: compound_tra... |
969 |
int nr_pages = 1 << compound_trans_order(hpage); |
7013febc8 HWPOISON, hugetlb... |
970 971 972 |
for (i = 0; i < nr_pages; i++) ClearPageHWPoison(hpage + i); } |
82ba011b9 HWPOISON: Turn re... |
973 |
int __memory_failure(unsigned long pfn, int trapno, int flags) |
6a46079cf HWPOISON: The hig... |
974 975 976 |
{ struct page_state *ps; struct page *p; |
7af446a84 HWPOISON, hugetlb... |
977 |
struct page *hpage; |
6a46079cf HWPOISON: The hig... |
978 |
int res; |
c9fbdd5f1 HWPOISON, hugetlb... |
979 |
unsigned int nr_pages; |
6a46079cf HWPOISON: The hig... |
980 981 982 983 984 |
if (!sysctl_memory_failure_recovery) panic("Memory failure from trap %d on page %lx", trapno, pfn); if (!pfn_valid(pfn)) { |
a7560fc80 HWPOISON: return ... |
985 986 987 988 989 |
printk(KERN_ERR "MCE %#lx: memory outside kernel control ", pfn); return -ENXIO; |
6a46079cf HWPOISON: The hig... |
990 991 992 |
} p = pfn_to_page(pfn); |
7af446a84 HWPOISON, hugetlb... |
993 |
hpage = compound_head(p); |
6a46079cf HWPOISON: The hig... |
994 |
if (TestSetPageHWPoison(p)) { |
d95ea51e3 HWPOISON: make se... |
995 996 |
printk(KERN_ERR "MCE %#lx: already hardware poisoned ", pfn); |
6a46079cf HWPOISON: The hig... |
997 998 |
return 0; } |
37c2ac787 thp: compound_tra... |
999 |
nr_pages = 1 << compound_trans_order(hpage); |
c9fbdd5f1 HWPOISON, hugetlb... |
1000 |
atomic_long_add(nr_pages, &mce_bad_pages); |
6a46079cf HWPOISON: The hig... |
1001 1002 1003 1004 1005 |
/* * We need/can do nothing about count=0 pages. * 1) it's a free page, and therefore in safe hand: * prep_new_page() will be the gate keeper. |
8c6c2ecb4 HWPOSION, hugetlb... |
1006 1007 1008 1009 |
* 2) it's a free hugepage, which is also safe: * an affected hugepage will be dequeued from hugepage freelist, * so there's no concern about reusing it ever after. * 3) it's part of a non-compound high order page. |
6a46079cf HWPOISON: The hig... |
1010 1011 1012 1013 1014 1015 |
* Implies some kernel user: cannot stop them from * R/W the page; let's pray that the page has been * used and will be freed some time later. * In fact it's dangerous to directly bump up page count from 0, * that may make page_freeze_refs()/page_unfreeze_refs() mismatch. */ |
82ba011b9 HWPOISON: Turn re... |
1016 |
if (!(flags & MF_COUNT_INCREASED) && |
7af446a84 HWPOISON, hugetlb... |
1017 |
!get_page_unless_zero(hpage)) { |
8d22ba1b7 HWPOISON: detect ... |
1018 1019 1020 |
if (is_free_buddy_page(p)) { action_result(pfn, "free buddy", DELAYED); return 0; |
8c6c2ecb4 HWPOSION, hugetlb... |
1021 1022 1023 1024 1025 |
} else if (PageHuge(hpage)) { /* * Check "just unpoisoned", "filter hit", and * "race with other subpage." */ |
7eaceacca block: remove per... |
1026 |
lock_page(hpage); |
8c6c2ecb4 HWPOSION, hugetlb... |
1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 |
if (!PageHWPoison(hpage) || (hwpoison_filter(p) && TestClearPageHWPoison(p)) || (p != hpage && TestSetPageHWPoison(hpage))) { atomic_long_sub(nr_pages, &mce_bad_pages); return 0; } set_page_hwpoison_huge_page(hpage); res = dequeue_hwpoisoned_huge_page(hpage); action_result(pfn, "free huge", res ? IGNORED : DELAYED); unlock_page(hpage); return res; |
8d22ba1b7 HWPOISON: detect ... |
1039 1040 1041 1042 |
} else { action_result(pfn, "high order kernel", IGNORED); return -EBUSY; } |
6a46079cf HWPOISON: The hig... |
1043 1044 1045 |
} /* |
e43c3afb3 HWPOISON: return ... |
1046 1047 1048 1049 1050 1051 1052 |
* We ignore non-LRU pages for good reasons. * - PG_locked is only well defined for LRU pages and a few others * - to avoid races with __set_page_locked() * - to avoid races with __SetPageSlab*() (and more non-atomic ops) * The check (unnecessarily) ignores LRU pages being isolated and * walked by the page reclaim code, however that's not a big loss. */ |
af241a083 thp: fix unsuitab... |
1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 |
if (!PageHuge(p) && !PageTransCompound(p)) { if (!PageLRU(p)) shake_page(p, 0); if (!PageLRU(p)) { /* * shake_page could have turned it free. */ if (is_free_buddy_page(p)) { action_result(pfn, "free buddy, 2nd try", DELAYED); return 0; } action_result(pfn, "non LRU", IGNORED); put_page(p); return -EBUSY; |
0474a60ec HWPOISON: Use new... |
1068 |
} |
e43c3afb3 HWPOISON: return ... |
1069 |
} |
e43c3afb3 HWPOISON: return ... |
1070 1071 |
/* |
6a46079cf HWPOISON: The hig... |
1072 1073 1074 1075 |
* Lock the page and wait for writeback to finish. * It's very difficult to mess with pages currently under IO * and in many cases impossible, so we just avoid it here. */ |
7eaceacca block: remove per... |
1076 |
lock_page(hpage); |
847ce401d HWPOISON: Add unp... |
1077 1078 1079 1080 1081 |
/* * unpoison always clear PG_hwpoison inside page lock */ if (!PageHWPoison(p)) { |
d95ea51e3 HWPOISON: make se... |
1082 1083 |
printk(KERN_ERR "MCE %#lx: just unpoisoned ", pfn); |
847ce401d HWPOISON: Add unp... |
1084 1085 1086 |
res = 0; goto out; } |
7c116f2b0 HWPOISON: add fs/... |
1087 1088 |
if (hwpoison_filter(p)) { if (TestClearPageHWPoison(p)) |
c9fbdd5f1 HWPOISON, hugetlb... |
1089 |
atomic_long_sub(nr_pages, &mce_bad_pages); |
7af446a84 HWPOISON, hugetlb... |
1090 1091 |
unlock_page(hpage); put_page(hpage); |
7c116f2b0 HWPOISON: add fs/... |
1092 1093 |
return 0; } |
847ce401d HWPOISON: Add unp... |
1094 |
|
7013febc8 HWPOISON, hugetlb... |
1095 1096 1097 1098 |
/* * For error on the tail page, we should set PG_hwpoison * on the head page to show that the hugepage is hwpoisoned */ |
a6d30ddda thp: fix the wron... |
1099 |
if (PageHuge(p) && PageTail(p) && TestSetPageHWPoison(hpage)) { |
7013febc8 HWPOISON, hugetlb... |
1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 |
action_result(pfn, "hugepage already hardware poisoned", IGNORED); unlock_page(hpage); put_page(hpage); return 0; } /* * Set PG_hwpoison on all pages in an error hugepage, * because containment is done in hugepage unit for now. * Since we have done TestSetPageHWPoison() for the head page with * page lock held, we can safely set PG_hwpoison bits on tail pages. */ if (PageHuge(p)) set_page_hwpoison_huge_page(hpage); |
6a46079cf HWPOISON: The hig... |
1114 1115 1116 1117 |
wait_on_page_writeback(p); /* * Now take care of user space mappings. |
e64a782fe mm: change __remo... |
1118 |
* Abort on fail: __delete_from_page_cache() assumes unmapped page. |
6a46079cf HWPOISON: The hig... |
1119 |
*/ |
1668bfd5b HWPOISON: abort o... |
1120 1121 1122 1123 1124 1125 |
if (hwpoison_user_mappings(p, pfn, trapno) != SWAP_SUCCESS) { printk(KERN_ERR "MCE %#lx: cannot unmap page, give up ", pfn); res = -EBUSY; goto out; } |
6a46079cf HWPOISON: The hig... |
1126 1127 1128 1129 |
/* * Torn down by someone else? */ |
dc2a1cbf7 HWPOISON: introdu... |
1130 |
if (PageLRU(p) && !PageSwapCache(p) && p->mapping == NULL) { |
6a46079cf HWPOISON: The hig... |
1131 |
action_result(pfn, "already truncated LRU", IGNORED); |
d95ea51e3 HWPOISON: make se... |
1132 |
res = -EBUSY; |
6a46079cf HWPOISON: The hig... |
1133 1134 1135 1136 1137 |
goto out; } res = -EBUSY; for (ps = error_states;; ps++) { |
dc2a1cbf7 HWPOISON: introdu... |
1138 |
if ((p->flags & ps->mask) == ps->res) { |
bd1ce5f91 HWPOISON: avoid g... |
1139 |
res = page_action(ps, p, pfn); |
6a46079cf HWPOISON: The hig... |
1140 1141 1142 1143 |
break; } } out: |
7af446a84 HWPOISON, hugetlb... |
1144 |
unlock_page(hpage); |
6a46079cf HWPOISON: The hig... |
1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 |
return res; } EXPORT_SYMBOL_GPL(__memory_failure); /** * memory_failure - Handle memory failure of a page. * @pfn: Page Number of the corrupted page * @trapno: Trap number reported in the signal to user space. * * This function is called by the low level machine check code * of an architecture when it detects hardware memory corruption * of a page. It tries its best to recover, which includes * dropping pages, killing processes etc. * * The function is primarily of use for corruptions that * happen outside the current execution context (e.g. when * detected by a background scrubber) * * Must run in process context (e.g. a work queue) with interrupts * enabled and no spinlocks hold. */ void memory_failure(unsigned long pfn, int trapno) { __memory_failure(pfn, trapno, 0); } |
847ce401d HWPOISON: Add unp... |
1170 |
|
ea8f5fb8a HWPoison: add mem... |
1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 |
#define MEMORY_FAILURE_FIFO_ORDER 4 #define MEMORY_FAILURE_FIFO_SIZE (1 << MEMORY_FAILURE_FIFO_ORDER) struct memory_failure_entry { unsigned long pfn; int trapno; int flags; }; struct memory_failure_cpu { DECLARE_KFIFO(fifo, struct memory_failure_entry, MEMORY_FAILURE_FIFO_SIZE); spinlock_t lock; struct work_struct work; }; static DEFINE_PER_CPU(struct memory_failure_cpu, memory_failure_cpu); /** * memory_failure_queue - Schedule handling memory failure of a page. * @pfn: Page Number of the corrupted page * @trapno: Trap number reported in the signal to user space. * @flags: Flags for memory failure handling * * This function is called by the low level hardware error handler * when it detects hardware memory corruption of a page. It schedules * the recovering of error page, including dropping pages, killing * processes etc. * * The function is primarily of use for corruptions that * happen outside the current execution context (e.g. when * detected by a background scrubber) * * Can run in IRQ context. */ void memory_failure_queue(unsigned long pfn, int trapno, int flags) { struct memory_failure_cpu *mf_cpu; unsigned long proc_flags; struct memory_failure_entry entry = { .pfn = pfn, .trapno = trapno, .flags = flags, }; mf_cpu = &get_cpu_var(memory_failure_cpu); spin_lock_irqsave(&mf_cpu->lock, proc_flags); if (kfifo_put(&mf_cpu->fifo, &entry)) schedule_work_on(smp_processor_id(), &mf_cpu->work); else pr_err("Memory failure: buffer overflow when queuing memory failure at 0x%#lx ", pfn); spin_unlock_irqrestore(&mf_cpu->lock, proc_flags); put_cpu_var(memory_failure_cpu); } EXPORT_SYMBOL_GPL(memory_failure_queue); static void memory_failure_work_func(struct work_struct *work) { struct memory_failure_cpu *mf_cpu; struct memory_failure_entry entry = { 0, }; unsigned long proc_flags; int gotten; mf_cpu = &__get_cpu_var(memory_failure_cpu); for (;;) { spin_lock_irqsave(&mf_cpu->lock, proc_flags); gotten = kfifo_get(&mf_cpu->fifo, &entry); spin_unlock_irqrestore(&mf_cpu->lock, proc_flags); if (!gotten) break; __memory_failure(entry.pfn, entry.trapno, entry.flags); } } static int __init memory_failure_init(void) { struct memory_failure_cpu *mf_cpu; int cpu; for_each_possible_cpu(cpu) { mf_cpu = &per_cpu(memory_failure_cpu, cpu); spin_lock_init(&mf_cpu->lock); INIT_KFIFO(mf_cpu->fifo); INIT_WORK(&mf_cpu->work, memory_failure_work_func); } return 0; } core_initcall(memory_failure_init); |
847ce401d HWPOISON: Add unp... |
1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 |
/** * 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) { struct page *page; struct page *p; int freeit = 0; |
c9fbdd5f1 HWPOISON, hugetlb... |
1279 |
unsigned int nr_pages; |
847ce401d HWPOISON: Add unp... |
1280 1281 1282 1283 1284 1285 1286 1287 |
if (!pfn_valid(pfn)) return -ENXIO; p = pfn_to_page(pfn); page = compound_head(p); if (!PageHWPoison(p)) { |
fb46e7352 HWPOISON: Convert... |
1288 1289 |
pr_info("MCE: Page was already unpoisoned %#lx ", pfn); |
847ce401d HWPOISON: Add unp... |
1290 1291 |
return 0; } |
37c2ac787 thp: compound_tra... |
1292 |
nr_pages = 1 << compound_trans_order(page); |
c9fbdd5f1 HWPOISON, hugetlb... |
1293 |
|
847ce401d HWPOISON: Add unp... |
1294 |
if (!get_page_unless_zero(page)) { |
8c6c2ecb4 HWPOSION, hugetlb... |
1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 |
/* * Since HWPoisoned hugepage should have non-zero refcount, * race between memory failure and unpoison seems to happen. * In such case unpoison fails and memory failure runs * to the end. */ if (PageHuge(page)) { pr_debug("MCE: Memory failure is now running on free hugepage %#lx ", pfn); return 0; } |
847ce401d HWPOISON: Add unp... |
1306 |
if (TestClearPageHWPoison(p)) |
c9fbdd5f1 HWPOISON, hugetlb... |
1307 |
atomic_long_sub(nr_pages, &mce_bad_pages); |
fb46e7352 HWPOISON: Convert... |
1308 1309 |
pr_info("MCE: Software-unpoisoned free page %#lx ", pfn); |
847ce401d HWPOISON: Add unp... |
1310 1311 |
return 0; } |
7eaceacca block: remove per... |
1312 |
lock_page(page); |
847ce401d HWPOISON: Add unp... |
1313 1314 1315 1316 1317 1318 |
/* * This test is racy because PG_hwpoison is set outside of page lock. * That's acceptable because that won't trigger kernel panic. Instead, * the PG_hwpoison page will be caught and isolated on the entrance to * the free buddy page pool. */ |
c9fbdd5f1 HWPOISON, hugetlb... |
1319 |
if (TestClearPageHWPoison(page)) { |
fb46e7352 HWPOISON: Convert... |
1320 1321 |
pr_info("MCE: Software-unpoisoned page %#lx ", pfn); |
c9fbdd5f1 HWPOISON, hugetlb... |
1322 |
atomic_long_sub(nr_pages, &mce_bad_pages); |
847ce401d HWPOISON: Add unp... |
1323 |
freeit = 1; |
6a90181c7 HWPOISON, hugetlb... |
1324 1325 |
if (PageHuge(page)) clear_page_hwpoison_huge_page(page); |
847ce401d HWPOISON: Add unp... |
1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 |
} unlock_page(page); put_page(page); if (freeit) put_page(page); return 0; } EXPORT_SYMBOL(unpoison_memory); |
facb6011f HWPOISON: Add sof... |
1336 1337 1338 |
static struct page *new_page(struct page *p, unsigned long private, int **x) { |
12686d153 HWPOISON: Try to ... |
1339 |
int nid = page_to_nid(p); |
d950b9588 HWPOISON, hugetlb... |
1340 1341 1342 1343 1344 |
if (PageHuge(p)) return alloc_huge_page_node(page_hstate(compound_head(p)), nid); else return alloc_pages_exact_node(nid, GFP_HIGHUSER_MOVABLE, 0); |
facb6011f HWPOISON: Add sof... |
1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 |
} /* * Safely get reference count of an arbitrary page. * Returns 0 for a free page, -EIO for a zero refcount page * that is not free, and 1 for any other page type. * For 1 the page is returned with increased page count, otherwise not. */ static int get_any_page(struct page *p, unsigned long pfn, int flags) { int ret; if (flags & MF_COUNT_INCREASED) return 1; /* |
20d6c96b5 mem-hotplug: intr... |
1361 |
* The lock_memory_hotplug prevents a race with memory hotplug. |
facb6011f HWPOISON: Add sof... |
1362 1363 |
* This is a big hammer, a better would be nicer. */ |
20d6c96b5 mem-hotplug: intr... |
1364 |
lock_memory_hotplug(); |
facb6011f HWPOISON: Add sof... |
1365 1366 1367 1368 1369 1370 |
/* * Isolate the page, so that it doesn't get reallocated if it * was free. */ set_migratetype_isolate(p); |
d950b9588 HWPOISON, hugetlb... |
1371 1372 1373 1374 |
/* * When the target page is a free hugepage, just remove it * from free hugepage list. */ |
facb6011f HWPOISON: Add sof... |
1375 |
if (!get_page_unless_zero(compound_head(p))) { |
d950b9588 HWPOISON, hugetlb... |
1376 |
if (PageHuge(p)) { |
46e387bbd Merge branch 'hwp... |
1377 1378 |
pr_info("get_any_page: %#lx free huge page ", pfn); |
d950b9588 HWPOISON, hugetlb... |
1379 1380 |
ret = dequeue_hwpoisoned_huge_page(compound_head(p)); } else if (is_free_buddy_page(p)) { |
fb46e7352 HWPOISON: Convert... |
1381 1382 |
pr_info("get_any_page: %#lx free buddy page ", pfn); |
facb6011f HWPOISON: Add sof... |
1383 1384 1385 1386 |
/* Set hwpoison bit while page is still isolated */ SetPageHWPoison(p); ret = 0; } else { |
fb46e7352 HWPOISON: Convert... |
1387 1388 |
pr_info("get_any_page: %#lx: unknown zero refcount page type %lx ", |
facb6011f HWPOISON: Add sof... |
1389 1390 1391 1392 1393 1394 1395 1396 |
pfn, p->flags); ret = -EIO; } } else { /* Not a free page */ ret = 1; } unset_migratetype_isolate(p); |
20d6c96b5 mem-hotplug: intr... |
1397 |
unlock_memory_hotplug(); |
facb6011f HWPOISON: Add sof... |
1398 1399 |
return ret; } |
d950b9588 HWPOISON, hugetlb... |
1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 |
static int soft_offline_huge_page(struct page *page, int flags) { int ret; unsigned long pfn = page_to_pfn(page); struct page *hpage = compound_head(page); LIST_HEAD(pagelist); ret = get_any_page(page, pfn, flags); if (ret < 0) return ret; if (ret == 0) goto done; if (PageHWPoison(hpage)) { put_page(hpage); pr_debug("soft offline: %#lx hugepage already poisoned ", pfn); return -EBUSY; } /* Keep page count to indicate a given hugepage is isolated. */ list_add(&hpage->lru, &pagelist); |
77f1fe6b0 mm: migration: al... |
1423 1424 |
ret = migrate_huge_pages(&pagelist, new_page, MPOL_MF_MOVE_ALL, 0, true); |
d950b9588 HWPOISON, hugetlb... |
1425 |
if (ret) { |
48db54ee2 mm/migration: fix... |
1426 1427 1428 |
struct page *page1, *page2; list_for_each_entry_safe(page1, page2, &pagelist, lru) put_page(page1); |
d950b9588 HWPOISON, hugetlb... |
1429 1430 1431 1432 1433 1434 1435 1436 1437 |
pr_debug("soft offline: %#lx: migration failed %d, type %lx ", pfn, ret, page->flags); if (ret > 0) ret = -EIO; return ret; } done: if (!PageHWPoison(hpage)) |
37c2ac787 thp: compound_tra... |
1438 |
atomic_long_add(1 << compound_trans_order(hpage), &mce_bad_pages); |
d950b9588 HWPOISON, hugetlb... |
1439 1440 1441 1442 1443 |
set_page_hwpoison_huge_page(hpage); dequeue_hwpoisoned_huge_page(hpage); /* keep elevated page count for bad page */ return ret; } |
facb6011f HWPOISON: Add sof... |
1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 |
/** * soft_offline_page - Soft offline a page. * @page: page to offline * @flags: flags. Same as memory_failure(). * * Returns 0 on success, otherwise negated errno. * * Soft offline a page, by migration or invalidation, * without killing anything. This is for the case when * a page is not corrupted yet (so it's still valid to access), * but has had a number of corrected errors and is better taken * out. * * The actual policy on when to do that is maintained by * user space. * * This should never impact any application or cause data loss, * however it might take some time. * * This is not a 100% solution for all memory, but tries to be * ``good enough'' for the majority of memory. */ int soft_offline_page(struct page *page, int flags) { int ret; unsigned long pfn = page_to_pfn(page); |
d950b9588 HWPOISON, hugetlb... |
1470 1471 |
if (PageHuge(page)) return soft_offline_huge_page(page, flags); |
facb6011f HWPOISON: Add sof... |
1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 |
ret = get_any_page(page, pfn, flags); if (ret < 0) return ret; if (ret == 0) goto done; /* * Page cache page we can handle? */ if (!PageLRU(page)) { /* * Try to free it. */ put_page(page); shake_page(page, 1); /* * Did it turn free? */ ret = get_any_page(page, pfn, 0); if (ret < 0) return ret; if (ret == 0) goto done; } if (!PageLRU(page)) { |
fb46e7352 HWPOISON: Convert... |
1498 1499 |
pr_info("soft_offline: %#lx: unknown non LRU page type %lx ", |
facb6011f HWPOISON: Add sof... |
1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 |
pfn, page->flags); return -EIO; } lock_page(page); wait_on_page_writeback(page); /* * Synchronized using the page lock with memory_failure() */ if (PageHWPoison(page)) { unlock_page(page); put_page(page); |
fb46e7352 HWPOISON: Convert... |
1513 1514 |
pr_info("soft offline: %#lx page already poisoned ", pfn); |
facb6011f HWPOISON: Add sof... |
1515 1516 1517 1518 1519 1520 1521 1522 1523 |
return -EBUSY; } /* * Try to invalidate first. This should work for * non dirty unmapped page cache pages. */ ret = invalidate_inode_page(page); unlock_page(page); |
facb6011f HWPOISON: Add sof... |
1524 |
/* |
facb6011f HWPOISON: Add sof... |
1525 1526 1527 |
* RED-PEN would be better to keep it isolated here, but we * would need to fix isolation locking first. */ |
facb6011f HWPOISON: Add sof... |
1528 |
if (ret == 1) { |
bd486285f mem-hwpoison: fix... |
1529 |
put_page(page); |
facb6011f HWPOISON: Add sof... |
1530 |
ret = 0; |
fb46e7352 HWPOISON: Convert... |
1531 1532 |
pr_info("soft_offline: %#lx: invalidated ", pfn); |
facb6011f HWPOISON: Add sof... |
1533 1534 1535 1536 1537 1538 1539 1540 1541 |
goto done; } /* * Simple invalidation didn't work. * Try to migrate to a new page instead. migrate.c * handles a large number of cases for us. */ ret = isolate_lru_page(page); |
bd486285f mem-hwpoison: fix... |
1542 1543 1544 1545 1546 |
/* * Drop page reference which is came from get_any_page() * successful isolate_lru_page() already took another one. */ put_page(page); |
facb6011f HWPOISON: Add sof... |
1547 1548 |
if (!ret) { LIST_HEAD(pagelist); |
5db8a73a8 mm/memory-failure... |
1549 1550 |
inc_zone_page_state(page, NR_ISOLATED_ANON + page_is_file_cache(page)); |
facb6011f HWPOISON: Add sof... |
1551 |
list_add(&page->lru, &pagelist); |
77f1fe6b0 mm: migration: al... |
1552 1553 |
ret = migrate_pages(&pagelist, new_page, MPOL_MF_MOVE_ALL, 0, true); |
facb6011f HWPOISON: Add sof... |
1554 |
if (ret) { |
57fc4a5ee mm: when migrate_... |
1555 |
putback_lru_pages(&pagelist); |
fb46e7352 HWPOISON: Convert... |
1556 1557 |
pr_info("soft offline: %#lx: migration failed %d, type %lx ", |
facb6011f HWPOISON: Add sof... |
1558 1559 1560 1561 1562 |
pfn, ret, page->flags); if (ret > 0) ret = -EIO; } } else { |
fb46e7352 HWPOISON: Convert... |
1563 1564 |
pr_info("soft offline: %#lx: isolation failed: %d, page count %d, type %lx ", |
facb6011f HWPOISON: Add sof... |
1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 |
pfn, ret, page_count(page), page->flags); } if (ret) return ret; done: atomic_long_add(1, &mce_bad_pages); SetPageHWPoison(page); /* keep elevated page count for bad page */ return ret; } |