X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Ffault-inject.c;h=b5a90fc056d3406b838cd71632b91985ce62b09e;hb=ac98695d6c1508b724f246f38ce57fb4e3cec356;hp=244782940349ba8aea5c9d4750bfc028a506b9a0;hpb=08b3df2d16cbebf7d72c09dcbc071696c14d07e3;p=linux-2.6

diff --git a/lib/fault-inject.c b/lib/fault-inject.c
index 2447829403..b5a90fc056 100644
--- a/lib/fault-inject.c
+++ b/lib/fault-inject.c
@@ -53,37 +53,9 @@ static bool fail_task(struct fault_attr *attr, struct task_struct *task)
 	return !in_interrupt() && task->make_it_fail;
 }
 
-#ifdef CONFIG_STACK_UNWIND
+#define MAX_STACK_TRACE_DEPTH 32
 
-static asmlinkage int fail_stacktrace_callback(struct unwind_frame_info *info,
-						void *arg)
-{
-	int depth;
-	struct fault_attr *attr = arg;
-	bool found = (attr->require_start == 0 && attr->require_end == ULONG_MAX);
-
-	for (depth = 0; depth < attr->stacktrace_depth
-			&& unwind(info) == 0 && UNW_PC(info); depth++) {
-		if (arch_unw_user_mode(info))
-			break;
-		if (attr->reject_start <= UNW_PC(info) &&
-			       UNW_PC(info) < attr->reject_end)
-			return false;
-		if (attr->require_start <= UNW_PC(info) &&
-			       UNW_PC(info) < attr->require_end)
-			found = true;
-	}
-	return found;
-}
-
-static bool fail_stacktrace(struct fault_attr *attr)
-{
-	struct unwind_frame_info info;
-
-	return unwind_init_running(&info, fail_stacktrace_callback, attr);
-}
-
-#elif defined(CONFIG_STACKTRACE)
+#if defined(CONFIG_STACKTRACE)
 
 static bool fail_stacktrace(struct fault_attr *attr)
 {
@@ -98,8 +70,7 @@ static bool fail_stacktrace(struct fault_attr *attr)
 
 	trace.nr_entries = 0;
 	trace.entries = entries;
-	trace.max_entries = (depth < MAX_STACK_TRACE_DEPTH) ?
-				depth : MAX_STACK_TRACE_DEPTH;
+	trace.max_entries = depth;
 	trace.skip = 1;
 	trace.all_contexts = 0;
 
@@ -141,9 +112,6 @@ bool should_fail(struct fault_attr *attr, ssize_t size)
 	if (attr->task_filter && !fail_task(attr, current))
 		return false;
 
-	if (!fail_stacktrace(attr))
-		return false;
-
 	if (atomic_read(&attr->times) == 0)
 		return false;
 
@@ -158,12 +126,12 @@ bool should_fail(struct fault_attr *attr, ssize_t size)
 			return false;
 	}
 
-	if (attr->probability > random32() % 100)
-		goto fail;
+	if (attr->probability <= random32() % 100)
+		return false;
 
-	return false;
+	if (!fail_stacktrace(attr))
+		return false;
 
-fail:
 	fail_dump(attr);
 
 	if (atomic_read(&attr->times) != -1)
@@ -179,6 +147,13 @@ static void debugfs_ul_set(void *data, u64 val)
 	*(unsigned long *)data = val;
 }
 
+static void debugfs_ul_set_MAX_STACK_TRACE_DEPTH(void *data, u64 val)
+{
+	*(unsigned long *)data =
+		val < MAX_STACK_TRACE_DEPTH ?
+		val : MAX_STACK_TRACE_DEPTH;
+}
+
 static u64 debugfs_ul_get(void *data)
 {
 	return *(unsigned long *)data;
@@ -192,6 +167,17 @@ static struct dentry *debugfs_create_ul(const char *name, mode_t mode,
 	return debugfs_create_file(name, mode, parent, value, &fops_ul);
 }
 
+DEFINE_SIMPLE_ATTRIBUTE(fops_ul_MAX_STACK_TRACE_DEPTH, debugfs_ul_get,
+			debugfs_ul_set_MAX_STACK_TRACE_DEPTH, "%llu\n");
+
+static struct dentry *debugfs_create_ul_MAX_STACK_TRACE_DEPTH(
+	const char *name, mode_t mode,
+	struct dentry *parent, unsigned long *value)
+{
+	return debugfs_create_file(name, mode, parent, value,
+				   &fops_ul_MAX_STACK_TRACE_DEPTH);
+}
+
 static void debugfs_atomic_t_set(void *data, u64 val)
 {
 	atomic_set((atomic_t *)data, val);
@@ -284,8 +270,8 @@ int init_fault_attr_dentries(struct fault_attr *attr, const char *name)
 						mode, dir, &attr->task_filter);
 
 	attr->dentries.stacktrace_depth_file =
-		debugfs_create_ul("stacktrace-depth", mode, dir,
-				  &attr->stacktrace_depth);
+		debugfs_create_ul_MAX_STACK_TRACE_DEPTH(
+			"stacktrace-depth", mode, dir, &attr->stacktrace_depth);
 
 	attr->dentries.require_start_file =
 		debugfs_create_ul("require-start", mode, dir, &attr->require_start);