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authorDon Mullis <dwm@meer.net>2006-12-08 02:39:52 -0800
committerLinus Torvalds <torvalds@woody.osdl.org>2006-12-08 08:29:03 -0800
commita124c28ef85d9b780c418b2c5d8f01cd6a06ff3e (patch)
tree8312c4991138c7696eab4a85a245d0e677a79f04 /lib/fault-inject.c
parent08b3df2d16cbebf7d72c09dcbc071696c14d07e3 (diff)
downloadlinux-linaro-stable-a124c28ef85d9b780c418b2c5d8f01cd6a06ff3e.tar.gz
[PATCH] fault-injection: Clamp debugfs stacktrace-depth to MAX_STACK_TRACE_DEPTH
Clamp /debug/fail*/stacktrace-depth to MAX_STACK_TRACE_DEPTH. Ensures that a read of /debug/fail*/stacktrace-depth always returns a truthful answer. Signed-off-by: Don Mullis <dwm@meer.net> Cc: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'lib/fault-inject.c')
-rw-r--r--lib/fault-inject.c27
1 files changed, 23 insertions, 4 deletions
diff --git a/lib/fault-inject.c b/lib/fault-inject.c
index 244782940349..5da665ac2d89 100644
--- a/lib/fault-inject.c
+++ b/lib/fault-inject.c
@@ -53,6 +53,8 @@ static bool fail_task(struct fault_attr *attr, struct task_struct *task)
return !in_interrupt() && task->make_it_fail;
}
+#define MAX_STACK_TRACE_DEPTH 32
+
#ifdef CONFIG_STACK_UNWIND
static asmlinkage int fail_stacktrace_callback(struct unwind_frame_info *info,
@@ -98,8 +100,7 @@ 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;
@@ -179,6 +180,13 @@ 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 +200,17 @@ 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 +303,8 @@ 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);