switch debugfs to umode_t
[linux-2.6.git] / lib / fault-inject.c
index 2447829..b4801f5 100644 (file)
@@ -1,21 +1,20 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/random.h>
+#include <linux/sched.h>
 #include <linux/stat.h>
 #include <linux/types.h>
 #include <linux/fs.h>
 #include <linux/module.h>
 #include <linux/interrupt.h>
-#include <linux/unwind.h>
 #include <linux/stacktrace.h>
-#include <linux/kallsyms.h>
 #include <linux/fault-inject.h>
 
 /*
  * setup_fault_attr() is a helper function for various __setup handlers, so it
  * returns 0 on error, because that is what __setup handlers do.
  */
-int __init setup_fault_attr(struct fault_attr *attr, char *str)
+int setup_fault_attr(struct fault_attr *attr, char *str)
 {
        unsigned long probability;
        unsigned long interval;
@@ -37,6 +36,7 @@ int __init setup_fault_attr(struct fault_attr *attr, char *str)
 
        return 1;
 }
+EXPORT_SYMBOL_GPL(setup_fault_attr);
 
 static void fail_dump(struct fault_attr *attr)
 {
@@ -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)
+#ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER
 
 static bool fail_stacktrace(struct fault_attr *attr)
 {
@@ -98,12 +70,10 @@ 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;
 
-       save_stack_trace(&trace, NULL);
+       save_stack_trace(&trace);
        for (n = 0; n < trace.nr_entries; n++) {
                if (attr->reject_start <= entries[n] &&
                               entries[n] < attr->reject_end)
@@ -119,17 +89,10 @@ 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
@@ -141,9 +104,6 @@ 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 +118,12 @@ 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)
@@ -171,150 +131,120 @@ fail:
 
        return true;
 }
+EXPORT_SYMBOL_GPL(should_fail);
 
 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
 
-static void debugfs_ul_set(void *data, u64 val)
+static int debugfs_ul_set(void *data, u64 val)
 {
        *(unsigned long *)data = val;
+       return 0;
 }
 
-static u64 debugfs_ul_get(void *data)
+static int debugfs_ul_get(void *data, u64 *val)
 {
-       return *(unsigned long *)data;
+       *val = *(unsigned long *)data;
+       return 0;
 }
 
 DEFINE_SIMPLE_ATTRIBUTE(fops_ul, debugfs_ul_get, debugfs_ul_set, "%llu\n");
 
-static struct dentry *debugfs_create_ul(const char *name, mode_t mode,
+static struct dentry *debugfs_create_ul(const char *name, umode_t mode,
                                struct dentry *parent, unsigned long *value)
 {
        return debugfs_create_file(name, mode, parent, value, &fops_ul);
 }
 
-static void debugfs_atomic_t_set(void *data, u64 val)
+#ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER
+
+static int debugfs_stacktrace_depth_set(void *data, u64 val)
 {
-       atomic_set((atomic_t *)data, val);
+       *(unsigned long *)data =
+               min_t(unsigned long, val, MAX_STACK_TRACE_DEPTH);
+
+       return 0;
 }
 
-static u64 debugfs_atomic_t_get(void *data)
+DEFINE_SIMPLE_ATTRIBUTE(fops_stacktrace_depth, debugfs_ul_get,
+                       debugfs_stacktrace_depth_set, "%llu\n");
+
+static struct dentry *debugfs_create_stacktrace_depth(
+       const char *name, umode_t mode,
+       struct dentry *parent, unsigned long *value)
 {
-       return atomic_read((atomic_t *)data);
+       return debugfs_create_file(name, mode, parent, value,
+                                  &fops_stacktrace_depth);
 }
 
-DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t, debugfs_atomic_t_get,
-                       debugfs_atomic_t_set, "%lld\n");
+#endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
 
-static struct dentry *debugfs_create_atomic_t(const char *name, mode_t mode,
-                               struct dentry *parent, atomic_t *value)
+static int debugfs_atomic_t_set(void *data, u64 val)
 {
-       return debugfs_create_file(name, mode, parent, value, &fops_atomic_t);
+       atomic_set((atomic_t *)data, val);
+       return 0;
 }
 
-void cleanup_fault_attr_dentries(struct fault_attr *attr)
+static int debugfs_atomic_t_get(void *data, u64 *val)
 {
-       debugfs_remove(attr->dentries.probability_file);
-       attr->dentries.probability_file = NULL;
-
-       debugfs_remove(attr->dentries.interval_file);
-       attr->dentries.interval_file = NULL;
-
-       debugfs_remove(attr->dentries.times_file);
-       attr->dentries.times_file = NULL;
-
-       debugfs_remove(attr->dentries.space_file);
-       attr->dentries.space_file = NULL;
-
-       debugfs_remove(attr->dentries.verbose_file);
-       attr->dentries.verbose_file = NULL;
-
-       debugfs_remove(attr->dentries.task_filter_file);
-       attr->dentries.task_filter_file = NULL;
-
-       debugfs_remove(attr->dentries.stacktrace_depth_file);
-       attr->dentries.stacktrace_depth_file = NULL;
-
-       debugfs_remove(attr->dentries.require_start_file);
-       attr->dentries.require_start_file = NULL;
-
-       debugfs_remove(attr->dentries.require_end_file);
-       attr->dentries.require_end_file = NULL;
-
-       debugfs_remove(attr->dentries.reject_start_file);
-       attr->dentries.reject_start_file = NULL;
-
-       debugfs_remove(attr->dentries.reject_end_file);
-       attr->dentries.reject_end_file = NULL;
+       *val = atomic_read((atomic_t *)data);
+       return 0;
+}
 
-       if (attr->dentries.dir)
-               WARN_ON(!simple_empty(attr->dentries.dir));
+DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t, debugfs_atomic_t_get,
+                       debugfs_atomic_t_set, "%lld\n");
 
-       debugfs_remove(attr->dentries.dir);
-       attr->dentries.dir = NULL;
+static struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode,
+                               struct dentry *parent, atomic_t *value)
+{
+       return debugfs_create_file(name, mode, parent, value, &fops_atomic_t);
 }
 
-int init_fault_attr_dentries(struct fault_attr *attr, const char *name)
+struct dentry *fault_create_debugfs_attr(const char *name,
+                       struct dentry *parent, struct fault_attr *attr)
 {
-       mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
+       umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
        struct dentry *dir;
 
-       memset(&attr->dentries, 0, sizeof(attr->dentries));
-
-       dir = debugfs_create_dir(name, NULL);
+       dir = debugfs_create_dir(name, parent);
        if (!dir)
-               goto fail;
-       attr->dentries.dir = dir;
-
-       attr->dentries.probability_file =
-               debugfs_create_ul("probability", mode, dir, &attr->probability);
-
-       attr->dentries.interval_file =
-               debugfs_create_ul("interval", mode, dir, &attr->interval);
-
-       attr->dentries.times_file =
-               debugfs_create_atomic_t("times", mode, dir, &attr->times);
+               return ERR_PTR(-ENOMEM);
 
-       attr->dentries.space_file =
-               debugfs_create_atomic_t("space", mode, dir, &attr->space);
-
-       attr->dentries.verbose_file =
-               debugfs_create_ul("verbose", mode, dir, &attr->verbose);
-
-       attr->dentries.task_filter_file = debugfs_create_bool("task-filter",
-                                               mode, dir, &attr->task_filter);
-
-       attr->dentries.stacktrace_depth_file =
-               debugfs_create_ul("stacktrace-depth", mode, dir,
-                                 &attr->stacktrace_depth);
-
-       attr->dentries.require_start_file =
-               debugfs_create_ul("require-start", mode, dir, &attr->require_start);
-
-       attr->dentries.require_end_file =
-               debugfs_create_ul("require-end", mode, dir, &attr->require_end);
-
-       attr->dentries.reject_start_file =
-               debugfs_create_ul("reject-start", mode, dir, &attr->reject_start);
-
-       attr->dentries.reject_end_file =
-               debugfs_create_ul("reject-end", mode, dir, &attr->reject_end);
+       if (!debugfs_create_ul("probability", mode, dir, &attr->probability))
+               goto fail;
+       if (!debugfs_create_ul("interval", mode, dir, &attr->interval))
+               goto fail;
+       if (!debugfs_create_atomic_t("times", mode, dir, &attr->times))
+               goto fail;
+       if (!debugfs_create_atomic_t("space", mode, dir, &attr->space))
+               goto fail;
+       if (!debugfs_create_ul("verbose", mode, dir, &attr->verbose))
+               goto fail;
+       if (!debugfs_create_bool("task-filter", mode, dir, &attr->task_filter))
+               goto fail;
 
+#ifdef CONFIG_FAULT_INJECTION_STACKTRACE_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
-           || !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 (!debugfs_create_stacktrace_depth("stacktrace-depth", mode, dir,
+                               &attr->stacktrace_depth))
+               goto fail;
+       if (!debugfs_create_ul("require-start", mode, dir,
+                               &attr->require_start))
+               goto fail;
+       if (!debugfs_create_ul("require-end", mode, dir, &attr->require_end))
+               goto fail;
+       if (!debugfs_create_ul("reject-start", mode, dir, &attr->reject_start))
+               goto fail;
+       if (!debugfs_create_ul("reject-end", mode, dir, &attr->reject_end))
                goto fail;
 
-       return 0;
+#endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
+
+       return dir;
 fail:
-       cleanup_fault_attr_dentries(attr);
-       return -ENOMEM;
+       debugfs_remove_recursive(dir);
+
+       return ERR_PTR(-ENOMEM);
 }
+EXPORT_SYMBOL_GPL(fault_create_debugfs_attr);
 
 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */