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authorDon Mullis <dwm@meer.net>2006-12-08 05:39:52 -0500
committerLinus Torvalds <torvalds@woody.osdl.org>2006-12-08 11:29:03 -0500
commita124c28ef85d9b780c418b2c5d8f01cd6a06ff3e (patch)
tree8312c4991138c7696eab4a85a245d0e677a79f04 /lib/fault-inject.c
parent08b3df2d16cbebf7d72c09dcbc071696c14d07e3 (diff)
[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)
53 return !in_interrupt() && task->make_it_fail; 53 return !in_interrupt() && task->make_it_fail;
54} 54}
55 55
56#define MAX_STACK_TRACE_DEPTH 32
57
56#ifdef CONFIG_STACK_UNWIND 58#ifdef CONFIG_STACK_UNWIND
57 59
58static asmlinkage int fail_stacktrace_callback(struct unwind_frame_info *info, 60static asmlinkage int fail_stacktrace_callback(struct unwind_frame_info *info,
@@ -98,8 +100,7 @@ static bool fail_stacktrace(struct fault_attr *attr)
98 100
99 trace.nr_entries = 0; 101 trace.nr_entries = 0;
100 trace.entries = entries; 102 trace.entries = entries;
101 trace.max_entries = (depth < MAX_STACK_TRACE_DEPTH) ? 103 trace.max_entries = depth;
102 depth : MAX_STACK_TRACE_DEPTH;
103 trace.skip = 1; 104 trace.skip = 1;
104 trace.all_contexts = 0; 105 trace.all_contexts = 0;
105 106
@@ -179,6 +180,13 @@ static void debugfs_ul_set(void *data, u64 val)
179 *(unsigned long *)data = val; 180 *(unsigned long *)data = val;
180} 181}
181 182
183static void debugfs_ul_set_MAX_STACK_TRACE_DEPTH(void *data, u64 val)
184{
185 *(unsigned long *)data =
186 val < MAX_STACK_TRACE_DEPTH ?
187 val : MAX_STACK_TRACE_DEPTH;
188}
189
182static u64 debugfs_ul_get(void *data) 190static u64 debugfs_ul_get(void *data)
183{ 191{
184 return *(unsigned long *)data; 192 return *(unsigned long *)data;
@@ -192,6 +200,17 @@ static struct dentry *debugfs_create_ul(const char *name, mode_t mode,
192 return debugfs_create_file(name, mode, parent, value, &fops_ul); 200 return debugfs_create_file(name, mode, parent, value, &fops_ul);
193} 201}
194 202
203DEFINE_SIMPLE_ATTRIBUTE(fops_ul_MAX_STACK_TRACE_DEPTH, debugfs_ul_get,
204 debugfs_ul_set_MAX_STACK_TRACE_DEPTH, "%llu\n");
205
206static struct dentry *debugfs_create_ul_MAX_STACK_TRACE_DEPTH(
207 const char *name, mode_t mode,
208 struct dentry *parent, unsigned long *value)
209{
210 return debugfs_create_file(name, mode, parent, value,
211 &fops_ul_MAX_STACK_TRACE_DEPTH);
212}
213
195static void debugfs_atomic_t_set(void *data, u64 val) 214static void debugfs_atomic_t_set(void *data, u64 val)
196{ 215{
197 atomic_set((atomic_t *)data, val); 216 atomic_set((atomic_t *)data, val);
@@ -284,8 +303,8 @@ int init_fault_attr_dentries(struct fault_attr *attr, const char *name)
284 mode, dir, &attr->task_filter); 303 mode, dir, &attr->task_filter);
285 304
286 attr->dentries.stacktrace_depth_file = 305 attr->dentries.stacktrace_depth_file =
287 debugfs_create_ul("stacktrace-depth", mode, dir, 306 debugfs_create_ul_MAX_STACK_TRACE_DEPTH(
288 &attr->stacktrace_depth); 307 "stacktrace-depth", mode, dir, &attr->stacktrace_depth);
289 308
290 attr->dentries.require_start_file = 309 attr->dentries.require_start_file =
291 debugfs_create_ul("require-start", mode, dir, &attr->require_start); 310 debugfs_create_ul("require-start", mode, dir, &attr->require_start);