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	Today 4 architectures set ARCH_SUPPORTS_MEMORY_FAILURE (arm64, parisc, powerpc, and x86), while 4 other architectures set __ARCH_SI_TRAPNO (alpha, metag, sparc, and tile). These two sets of architectures do not interesect so remove the trapno paramater to remove confusion. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
		
			
				
	
	
		
			140 lines
		
	
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			140 lines
		
	
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* Inject a hwpoison memory failure on a arbitrary 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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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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	struct page *hpage;
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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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	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_hwpoison_page(p))
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		return 0;
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	if (!hwpoison_filter_enable)
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		goto inject;
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	shake_page(hpage, 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(hpage) && !PageHuge(p))
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		goto put_out;
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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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	 * memory_failure() will redo the check reliably inside page lock.
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	 */
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	err = hwpoison_filter(hpage);
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	if (err)
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		goto put_out;
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inject:
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	pr_info("Injecting memory failure at pfn %#lx\n", pfn);
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	return memory_failure(pfn, MF_COUNT_INCREASED);
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put_out:
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	put_hwpoison_page(p);
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	return 0;
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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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	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", 0200, 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", 0200, 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_MEMCG
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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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