1 files changed, 38 insertions, 22 deletions

diff --git a/mm/failslab.c b/mm/failslab.c
index fefaabaab76d..c3901b136498 100644
--- a/mm/failslab.c
+++ b/mm/failslab.c
@@ -1,29 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/fault-inject.h>
+#include <linux/error-injection.h>
+#include <linux/debugfs.h>
 #include <linux/slab.h>
+#include <linux/mm.h>
+#include "slab.h"
 
 static struct {
 	struct fault_attr attr;
-	u32 ignore_gfp_wait;
-	int cache_filter;
+	bool ignore_gfp_reclaim;
+	bool cache_filter;
 } failslab = {
 	.attr = FAULT_ATTR_INITIALIZER,
-	.ignore_gfp_wait = 1,
-	.cache_filter = 0,
+	.ignore_gfp_reclaim = true,
+	.cache_filter = false,
 };
 
-bool should_failslab(size_t size, gfp_t gfpflags, unsigned long cache_flags)
+int should_failslab(struct kmem_cache *s, gfp_t gfpflags)
 {
+	int flags = 0;
+
+	/* No fault-injection for bootstrap cache */
+	if (unlikely(s == kmem_cache))
+		return 0;
+
 	if (gfpflags & __GFP_NOFAIL)
-		return false;
+		return 0;
 
-        if (failslab.ignore_gfp_wait && (gfpflags & __GFP_WAIT))
-		return false;
+	if (failslab.ignore_gfp_reclaim &&
+			(gfpflags & __GFP_DIRECT_RECLAIM))
+		return 0;
 
-	if (failslab.cache_filter && !(cache_flags & SLAB_FAILSLAB))
-		return false;
+	if (failslab.cache_filter && !(s->flags & SLAB_FAILSLAB))
+		return 0;
 
-	return should_fail(&failslab.attr, size);
+	/*
+	 * In some cases, it expects to specify __GFP_NOWARN
+	 * to avoid printing any information(not just a warning),
+	 * thus avoiding deadlocks. See commit 6b9dbedbe349 for
+	 * details.
+	 */
+	if (gfpflags & __GFP_NOWARN)
+		flags |= FAULT_NOWARN;
+
+	return should_fail_ex(&failslab.attr, s->object_size, flags) ? -ENOMEM : 0;
 }
+ALLOW_ERROR_INJECTION(should_failslab, ERRNO);
 
 static int __init setup_failslab(char *str)
 {
@@ -35,24 +57,18 @@ __setup("failslab=", setup_failslab);
 static int __init failslab_debugfs_init(void)
 {
 	struct dentry *dir;
-	umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
+	umode_t mode = S_IFREG | 0600;
 
 	dir = fault_create_debugfs_attr("failslab", NULL, &failslab.attr);
 	if (IS_ERR(dir))
 		return PTR_ERR(dir);
 
-	if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
-				&failslab.ignore_gfp_wait))
-		goto fail;
-	if (!debugfs_create_bool("cache-filter", mode, dir,
-				&failslab.cache_filter))
-		goto fail;
+	debugfs_create_bool("ignore-gfp-wait", mode, dir,
+			    &failslab.ignore_gfp_reclaim);
+	debugfs_create_bool("cache-filter", mode, dir,
+			    &failslab.cache_filter);
 
 	return 0;
-fail:
-	debugfs_remove_recursive(dir);
-
-	return -ENOMEM;
 }
 
 late_initcall(failslab_debugfs_init);