2 files changed, 29 insertions, 22 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 4448f91b865c..3f3e7403dcac 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -411,8 +411,6 @@ config LKDTM
 config FAULT_INJECTION
         bool "Fault-injection framework"
         depends on DEBUG_KERNEL
-        depends on STACKTRACE
-        select FRAME_POINTER
         help
           Provide fault-injection framework.
           For more details, see Documentation/fault-injection/.
@@ -440,3 +438,11 @@ config FAULT_INJECTION_DEBUG_FS
         depends on FAULT_INJECTION && SYSFS && DEBUG_FS
         help
           Enable configuration of fault-injection capabilities via debugfs.
+
+config FAULT_INJECTION_STACKTRACE_FILTER
+        bool "stacktrace filter for fault-injection capabilities"
+        depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
+        select STACKTRACE
+        select FRAME_POINTER
+        help
+          Provide stacktrace filter for fault-injection capabilities
diff --git a/lib/fault-inject.c b/lib/fault-inject.c
index b5a90fc056d3..0fabd12c39d7 100644
--- a/lib/fault-inject.c
+++ b/lib/fault-inject.c
@@ -55,7 +55,7 @@ static bool fail_task(struct fault_attr *attr, struct task_struct *task)
 
 #define MAX_STACK_TRACE_DEPTH 32
 
-#if defined(CONFIG_STACKTRACE)
+#ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER
 
 static bool fail_stacktrace(struct fault_attr *attr)
 {
@@ -90,17 +90,10 @@ static bool fail_stacktrace(struct fault_attr *attr)
 
 static inline bool fail_stacktrace(struct fault_attr *attr)
 {
-        static bool firsttime = true;
-
-        if (firsttime) {
-                printk(KERN_WARNING
-                "This architecture does not implement save_stack_trace()\n");
-                firsttime = false;
-        }
-        return false;
+        return true;
 }
 
-#endif
+#endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
 
 /*
  * This code is stolen from failmalloc-1.0
@@ -217,6 +210,8 @@ void cleanup_fault_attr_dentries(struct fault_attr *attr)
         debugfs_remove(attr->dentries.task_filter_file);
         attr->dentries.task_filter_file = NULL;
 
+#ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER
+
         debugfs_remove(attr->dentries.stacktrace_depth_file);
         attr->dentries.stacktrace_depth_file = NULL;
 
@@ -232,6 +227,8 @@ void cleanup_fault_attr_dentries(struct fault_attr *attr)
         debugfs_remove(attr->dentries.reject_end_file);
         attr->dentries.reject_end_file = NULL;
 
+#endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
+
         if (attr->dentries.dir)
                 WARN_ON(!simple_empty(attr->dentries.dir));
 
@@ -269,6 +266,13 @@ int init_fault_attr_dentries(struct fault_attr *attr, const char *name)
         attr->dentries.task_filter_file = debugfs_create_bool("task-filter",
                                                 mode, dir, &attr->task_filter);
 
+        if (!attr->dentries.probability_file || !attr->dentries.interval_file ||
+            !attr->dentries.times_file || !attr->dentries.space_file ||
+            !attr->dentries.verbose_file || !attr->dentries.task_filter_file)
+                goto fail;
+
+#ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER
+
         attr->dentries.stacktrace_depth_file =
                 debugfs_create_ul_MAX_STACK_TRACE_DEPTH(
                         "stacktrace-depth", mode, dir, &attr->stacktrace_depth);
@@ -285,18 +289,15 @@ int init_fault_attr_dentries(struct fault_attr *attr, const char *name)
         attr->dentries.reject_end_file =
                 debugfs_create_ul("reject-end", mode, dir, &attr->reject_end);
 
-
-        if (!attr->dentries.probability_file || !attr->dentries.interval_file
-            || !attr->dentries.times_file || !attr->dentries.space_file
-            || !attr->dentries.verbose_file || !attr->dentries.task_filter_file
-            || !attr->dentries.stacktrace_depth_file
-            || !attr->dentries.require_start_file
-            || !attr->dentries.require_end_file
-            || !attr->dentries.reject_start_file
-            || !attr->dentries.reject_end_file
-            )
+        if (!attr->dentries.stacktrace_depth_file ||
+            !attr->dentries.require_start_file ||
+            !attr->dentries.require_end_file ||
+            !attr->dentries.reject_start_file ||
+            !attr->dentries.reject_end_file)
                 goto fail;
 
+#endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
+
         return 0;
 fail:
         cleanup_fault_attr_dentries(attr);