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2024-02-20 102a0743326a03cd1a1202ceda21e175b7d3575c

 kernel/mm/hwpoison-inject.c
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@@ -1,3 +1,4 @@
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+// SPDX-License-Identifier: GPL-2.0-only
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 /* 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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@@ -25,11 +26,6 @@
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26
 
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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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29
 
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 	if (!hwpoison_filter_enable)
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 		goto inject;
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@@ -39,23 +35,20 @@
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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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+		return 0;
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39
 
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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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+	 * do a racy check to make sure PG_hwpoison will only be set for
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+	 * 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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+		return 0;
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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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+	return memory_failure(pfn, 0);
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 }
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53
 
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 static int hwpoison_unpoison(void *data, u64 val)
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@@ -66,8 +59,8 @@
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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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+DEFINE_DEBUGFS_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");
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+DEFINE_DEBUGFS_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n");
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64
 
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 static void pfn_inject_exit(void)
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 {
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@@ -76,63 +69,40 @@
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69
 
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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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 	 * 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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+	debugfs_create_file("corrupt-pfn", 0200, hwpoison_dir, NULL,
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+			    &hwpoison_fops);
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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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+	debugfs_create_file("unpoison-pfn", 0200, hwpoison_dir, NULL,
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+			    &unpoison_fops);
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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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+	debugfs_create_u32("corrupt-filter-enable", 0600, hwpoison_dir,
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+			   &hwpoison_filter_enable);
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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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+	debugfs_create_u32("corrupt-filter-dev-major", 0600, hwpoison_dir,
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+			   &hwpoison_filter_dev_major);
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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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+	debugfs_create_u32("corrupt-filter-dev-minor", 0600, hwpoison_dir,
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+			   &hwpoison_filter_dev_minor);
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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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+	debugfs_create_u64("corrupt-filter-flags-mask", 0600, hwpoison_dir,
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+			   &hwpoison_filter_flags_mask);
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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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+	debugfs_create_u64("corrupt-filter-flags-value", 0600, hwpoison_dir,
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+			   &hwpoison_filter_flags_value);
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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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+	debugfs_create_u64("corrupt-filter-memcg", 0600, hwpoison_dir,
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+			   &hwpoison_filter_memcg);
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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);