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	 43131e141a
			
		
	
	
		43131e141a
		
	
	
	
	
		
			
			This patch enables hwpoison injection through debug/hwpoison interfaces, with which we can test memory error handling for free or reserved hugepages (which cannot be tested by madvise() injector). [AK: Export PageHuge too for the injection module] Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andrew Morton <akpm@linux-foundation.org> Acked-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
		
			
				
	
	
		
			142 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			142 lines
		
	
	
		
			3.3 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 <linux/hugetlb.h>
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| #include "internal.h"
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| 
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| static struct dentry *hwpoison_dir;
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| 
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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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| 	struct page *hpage;
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| 	int err;
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| 
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| 	if (!capable(CAP_SYS_ADMIN))
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| 		return -EPERM;
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| 
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| 	if (!hwpoison_filter_enable)
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| 		goto inject;
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| 	if (!pfn_valid(pfn))
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| 		return -ENXIO;
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| 
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| 	p = pfn_to_page(pfn);
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| 	hpage = compound_head(p);
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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(hpage))
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| 		return 0;
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| 
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| 	if (!PageLRU(p) && !PageHuge(p))
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| 		shake_page(p, 0);
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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) && !PageHuge(p))
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| 		return 0;
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| 
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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(hpage);
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| 	err = hwpoison_filter(hpage);
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| 	unlock_page(hpage);
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| 	if (err)
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| 		return 0;
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| 
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| inject:
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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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| 
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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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| 
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| 	return unpoison_memory(val);
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| }
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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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| 
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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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| 
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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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| 
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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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| 	/*
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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