1bfe5febe3
In some use cases, user doesn't need extra filtering. E.g. user program can inject errors through madvise syscall to its own pages, however it might not know what the page state exactly is or which inode the page belongs to. So introduce an one-off interface "corrupt-filter-enable". Echo 0 to switch off page filters, and echo 1 to switch on the filters. [AK: changed default to 0] Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
136 lines
3.2 KiB
C
136 lines
3.2 KiB
C
/* Inject a hwpoison memory failure on a arbitary pfn */
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#include <linux/module.h>
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#include <linux/debugfs.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/swap.h>
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#include <linux/pagemap.h>
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#include "internal.h"
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static struct dentry *hwpoison_dir;
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static int hwpoison_inject(void *data, u64 val)
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{
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unsigned long pfn = val;
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struct page *p;
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int err;
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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if (!pfn_valid(pfn))
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return -ENXIO;
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p = pfn_to_page(pfn);
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/*
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* This implies unable to support free buddy pages.
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*/
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if (!get_page_unless_zero(p))
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return 0;
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if (!PageLRU(p))
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shake_page(p);
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/*
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* This implies unable to support non-LRU pages.
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*/
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if (!PageLRU(p))
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return 0;
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/*
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* do a racy check with elevated page count, to make sure PG_hwpoison
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* will only be set for the targeted owner (or on a free page).
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* We temporarily take page lock for try_get_mem_cgroup_from_page().
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* __memory_failure() will redo the check reliably inside page lock.
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*/
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lock_page(p);
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err = hwpoison_filter(p);
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unlock_page(p);
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if (err)
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return 0;
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printk(KERN_INFO "Injecting memory failure at pfn %lx\n", pfn);
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return __memory_failure(pfn, 18, MF_COUNT_INCREASED);
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}
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static int hwpoison_unpoison(void *data, u64 val)
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{
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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return unpoison_memory(val);
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}
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DEFINE_SIMPLE_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");
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DEFINE_SIMPLE_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n");
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static void pfn_inject_exit(void)
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{
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if (hwpoison_dir)
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debugfs_remove_recursive(hwpoison_dir);
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}
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static int pfn_inject_init(void)
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{
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struct dentry *dentry;
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hwpoison_dir = debugfs_create_dir("hwpoison", NULL);
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if (hwpoison_dir == NULL)
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return -ENOMEM;
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/*
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* Note that the below poison/unpoison interfaces do not involve
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* hardware status change, hence do not require hardware support.
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* They are mainly for testing hwpoison in software level.
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*/
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dentry = debugfs_create_file("corrupt-pfn", 0600, hwpoison_dir,
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NULL, &hwpoison_fops);
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if (!dentry)
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goto fail;
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dentry = debugfs_create_file("unpoison-pfn", 0600, hwpoison_dir,
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NULL, &unpoison_fops);
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if (!dentry)
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goto fail;
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dentry = debugfs_create_u32("corrupt-filter-enable", 0600,
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hwpoison_dir, &hwpoison_filter_enable);
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if (!dentry)
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goto fail;
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dentry = debugfs_create_u32("corrupt-filter-dev-major", 0600,
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hwpoison_dir, &hwpoison_filter_dev_major);
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if (!dentry)
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goto fail;
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dentry = debugfs_create_u32("corrupt-filter-dev-minor", 0600,
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hwpoison_dir, &hwpoison_filter_dev_minor);
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if (!dentry)
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goto fail;
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dentry = debugfs_create_u64("corrupt-filter-flags-mask", 0600,
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hwpoison_dir, &hwpoison_filter_flags_mask);
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if (!dentry)
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goto fail;
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dentry = debugfs_create_u64("corrupt-filter-flags-value", 0600,
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hwpoison_dir, &hwpoison_filter_flags_value);
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if (!dentry)
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goto fail;
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#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
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dentry = debugfs_create_u64("corrupt-filter-memcg", 0600,
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hwpoison_dir, &hwpoison_filter_memcg);
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if (!dentry)
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goto fail;
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#endif
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return 0;
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fail:
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pfn_inject_exit();
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return -ENOMEM;
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}
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module_init(pfn_inject_init);
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module_exit(pfn_inject_exit);
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MODULE_LICENSE("GPL");
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