projects/linux·commit b7bc9e7d

Merge tag 'trace-fixes-3.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

b7bc9e7d · Linus Torvalds <[email protected]> · 2013-08-07 13:01:30 -07:00

Pull tracing fixes from Steven Rostedt:
 "Oleg Nesterov has been working hard in closing all the holes that can
  lead to race conditions between deleting an event and accessing an
  event debugfs file.  This included a fix to the debugfs system (acked
  by Greg Kroah-Hartman).  We think that all the holes have been patched
  and hopefully we don't find more.  I haven't marked all of them for
  stable because I need to examine them more to figure out how far back
  some of the changes need to go.

  Along the way, some other fixes have been made.  Alexander Z Lam fixed
  some logic where the wrong buffer was being modifed.

  Andrew Vagin found a possible corruption for machines that actually
  allocate cpumask, as a reference to one was being zeroed out by
  mistake.

  Dhaval Giani found a bad prototype when tracing is not configured.

  And I not only had some changes to help Oleg, but also finally fixed a
  long standing bug that Dave Jones and others have been hitting, where
  a module unload and reload can cause the function tracing accounting
  to get screwed up"

* tag 'trace-fixes-3.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix reset of time stamps during trace_clock changes
  tracing: Make TRACE_ITER_STOP_ON_FREE stop the correct buffer
  tracing: Fix trace_dump_stack() proto when CONFIG_TRACING is not set
  tracing: Fix fields of struct trace_iterator that are zeroed by mistake
  tracing/uprobes: Fail to unregister if probe event files are in use
  tracing/kprobes: Fail to unregister if probe event files are in use
  tracing: Add comment to describe special break case in probe_remove_event_call()
  tracing: trace_remove_event_call() should fail if call/file is in use
  debugfs: debugfs_remove_recursive() must not rely on list_empty(d_subdirs)
  ftrace: Check module functions being traced on reload
  ftrace: Consolidate some duplicate code for updating ftrace ops
  tracing: Change remove_event_file_dir() to clear "d_subdirs"->i_private
  tracing: Introduce remove_event_file_dir()
  tracing: Change f_start() to take event_mutex and verify i_private != NULL
  tracing: Change event_filter_read/write to verify i_private != NULL
  tracing: Change event_enable/disable_read() to verify i_private != NULL
  tracing: Turn event/id->i_private into call->event.type
Commit
b7bc9e7d808ba55729bd263b0210cda36965be32
Parents
8ef9c292 · 9457158b

Merge commit. Changes below are compared with the first parent: 8ef9c292.

Changes

9 files changed · +302 −184

Only the first 600 diff lines are shown. Download the complete patch.

fs/debugfs/inode.c

View file
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index 4888cb3..c7c83ff 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -533,8 +533,7 @@ EXPORT_SYMBOL_GPL(debugfs_remove);
*/
void debugfs_remove_recursive(struct dentry *dentry)
{
- struct dentry *child;
- struct dentry *parent;
+ struct dentry *child, *next, *parent;
if (IS_ERR_OR_NULL(dentry))
return;
@@ -544,61 +543,37 @@ void debugfs_remove_recursive(struct dentry *dentry)
return;
parent = dentry;
+ down:
mutex_lock(&parent->d_inode->i_mutex);
+ list_for_each_entry_safe(child, next, &parent->d_subdirs, d_u.d_child) {
+ if (!debugfs_positive(child))
+ continue;
- while (1) {
- /*
- * When all dentries under "parent" has been removed,
- * walk up the tree until we reach our starting point.
- */
- if (list_empty(&parent->d_subdirs)) {
- mutex_unlock(&parent->d_inode->i_mutex);
- if (parent == dentry)
- break;
- parent = parent->d_parent;
- mutex_lock(&parent->d_inode->i_mutex);
- }
- child = list_entry(parent->d_subdirs.next, struct dentry,
- d_u.d_child);
- next_sibling:
-
- /*
- * If "child" isn't empty, walk down the tree and
- * remove all its descendants first.
- */
+ /* perhaps simple_empty(child) makes more sense */
if (!list_empty(&child->d_subdirs)) {
mutex_unlock(&parent->d_inode->i_mutex);
parent = child;
- mutex_lock(&parent->d_inode->i_mutex);
- continue;
+ goto down;
}
- __debugfs_remove(child, parent);
- if (parent->d_subdirs.next == &child->d_u.d_child) {
- /*
- * Try the next sibling.
- */
- if (child->d_u.d_child.next != &parent->d_subdirs) {
- child = list_entry(child->d_u.d_child.next,
- struct dentry,
- d_u.d_child);
- goto next_sibling;
- }
-
- /*
- * Avoid infinite loop if we fail to remove
- * one dentry.
- */
- mutex_unlock(&parent->d_inode->i_mutex);
- break;
- }
- simple_release_fs(&debugfs_mount, &debugfs_mount_count);
+ up:
+ if (!__debugfs_remove(child, parent))
+ simple_release_fs(&debugfs_mount, &debugfs_mount_count);
}
- parent = dentry->d_parent;
+ mutex_unlock(&parent->d_inode->i_mutex);
+ child = parent;
+ parent = parent->d_parent;
mutex_lock(&parent->d_inode->i_mutex);
- __debugfs_remove(dentry, parent);
+
+ if (child != dentry) {
+ next = list_entry(child->d_u.d_child.next, struct dentry,
+ d_u.d_child);
+ goto up;
+ }
+
+ if (!__debugfs_remove(child, parent))
+ simple_release_fs(&debugfs_mount, &debugfs_mount_count);
mutex_unlock(&parent->d_inode->i_mutex);
- simple_release_fs(&debugfs_mount, &debugfs_mount_count);
}
EXPORT_SYMBOL_GPL(debugfs_remove_recursive);

include/linux/ftrace_event.h

View file
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 4372658..120d57a 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -78,6 +78,11 @@ struct trace_iterator {
/* trace_seq for __print_flags() and __print_symbolic() etc. */
struct trace_seq tmp_seq;
+ cpumask_var_t started;
+
+ /* it's true when current open file is snapshot */
+ bool snapshot;
+
/* The below is zeroed out in pipe_read */
struct trace_seq seq;
struct trace_entry *ent;
@@ -90,10 +95,7 @@ struct trace_iterator {
loff_t pos;
long idx;
- cpumask_var_t started;
-
- /* it's true when current open file is snapshot */
- bool snapshot;
+ /* All new field here will be zeroed out in pipe_read */
};
enum trace_iter_flags {
@@ -332,7 +334,7 @@ extern int trace_define_field(struct ftrace_event_call *call, const char *type,
const char *name, int offset, int size,
int is_signed, int filter_type);
extern int trace_add_event_call(struct ftrace_event_call *call);
-extern void trace_remove_event_call(struct ftrace_event_call *call);
+extern int trace_remove_event_call(struct ftrace_event_call *call);
#define is_signed_type(type) (((type)(-1)) < (type)1)

include/linux/kernel.h

View file
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 3bef14c..482ad2d 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -629,7 +629,7 @@ extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
static inline void tracing_start(void) { }
static inline void tracing_stop(void) { }
static inline void ftrace_off_permanent(void) { }
-static inline void trace_dump_stack(void) { }
+static inline void trace_dump_stack(int skip) { }
static inline void tracing_on(void) { }
static inline void tracing_off(void) { }

kernel/trace/ftrace.c

View file
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 8ce9eef..a6d098c 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2169,12 +2169,57 @@ static cycle_t ftrace_update_time;
static unsigned long ftrace_update_cnt;
unsigned long ftrace_update_tot_cnt;
-static int ops_traces_mod(struct ftrace_ops *ops)
+static inline int ops_traces_mod(struct ftrace_ops *ops)
{
- struct ftrace_hash *hash;
+ /*
+ * Filter_hash being empty will default to trace module.
+ * But notrace hash requires a test of individual module functions.
+ */
+ return ftrace_hash_empty(ops->filter_hash) &&
+ ftrace_hash_empty(ops->notrace_hash);
+}
+
+/*
+ * Check if the current ops references the record.
+ *
+ * If the ops traces all functions, then it was already accounted for.
+ * If the ops does not trace the current record function, skip it.
+ * If the ops ignores the function via notrace filter, skip it.
+ */
+static inline bool
+ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
+{
+ /* If ops isn't enabled, ignore it */
+ if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
+ return 0;
+
+ /* If ops traces all mods, we already accounted for it */
+ if (ops_traces_mod(ops))
+ return 0;
+
+ /* The function must be in the filter */
+ if (!ftrace_hash_empty(ops->filter_hash) &&
+ !ftrace_lookup_ip(ops->filter_hash, rec->ip))
+ return 0;
+
+ /* If in notrace hash, we ignore it too */
+ if (ftrace_lookup_ip(ops->notrace_hash, rec->ip))
+ return 0;
+
+ return 1;
+}
+
+static int referenced_filters(struct dyn_ftrace *rec)
+{
+ struct ftrace_ops *ops;
+ int cnt = 0;
- hash = ops->filter_hash;
- return ftrace_hash_empty(hash);
+ for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
+ if (ops_references_rec(ops, rec))
+ cnt++;
+ }
+
+ return cnt;
}
static int ftrace_update_code(struct module *mod)
@@ -2183,6 +2228,7 @@ static int ftrace_update_code(struct module *mod)
struct dyn_ftrace *p;
cycle_t start, stop;
unsigned long ref = 0;
+ bool test = false;
int i;
/*
@@ -2196,9 +2242,12 @@ static int ftrace_update_code(struct module *mod)
for (ops = ftrace_ops_list;
ops != &ftrace_list_end; ops = ops->next) {
- if (ops->flags & FTRACE_OPS_FL_ENABLED &&
- ops_traces_mod(ops))
- ref++;
+ if (ops->flags & FTRACE_OPS_FL_ENABLED) {
+ if (ops_traces_mod(ops))
+ ref++;
+ else
+ test = true;
+ }
}
}
@@ -2208,12 +2257,16 @@ static int ftrace_update_code(struct module *mod)
for (pg = ftrace_new_pgs; pg; pg = pg->next) {
for (i = 0; i < pg->index; i++) {
+ int cnt = ref;
+
/* If something went wrong, bail without enabling anything */
if (unlikely(ftrace_disabled))
return -1;
p = &pg->records[i];
- p->flags = ref;
+ if (test)
+ cnt += referenced_filters(p);
+ p->flags = cnt;
/*
* Do the initial record conversion from mcount jump
@@ -2233,7 +2286,7 @@ static int ftrace_update_code(struct module *mod)
* conversion puts the module to the correct state, thus
* passing the ftrace_make_call check.
*/
- if (ftrace_start_up && ref) {
+ if (ftrace_start_up && cnt) {
int failed = __ftrace_replace_code(p, 1);
if (failed)
ftrace_bug(failed, p->ip);
@@ -3384,6 +3437,12 @@ ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
return add_hash_entry(hash, ip);
}
+static void ftrace_ops_update_code(struct ftrace_ops *ops)
+{
+ if (ops->flags & FTRACE_OPS_FL_ENABLED && ftrace_enabled)
+ ftrace_run_update_code(FTRACE_UPDATE_CALLS);
+}
+
static int
ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
unsigned long ip, int remove, int reset, int enable)
@@ -3426,9 +3485,8 @@ ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
mutex_lock(&ftrace_lock);
ret = ftrace_hash_move(ops, enable, orig_hash, hash);
- if (!ret && ops->flags & FTRACE_OPS_FL_ENABLED
- && ftrace_enabled)
- ftrace_run_update_code(FTRACE_UPDATE_CALLS);
+ if (!ret)
+ ftrace_ops_update_code(ops);
mutex_unlock(&ftrace_lock);
@@ -3655,9 +3713,8 @@ int ftrace_regex_release(struct inode *inode, struct file *file)
mutex_lock(&ftrace_lock);
ret = ftrace_hash_move(iter->ops, filter_hash,
orig_hash, iter->hash);
- if (!ret && (iter->ops->flags & FTRACE_OPS_FL_ENABLED)
- && ftrace_enabled)
- ftrace_run_update_code(FTRACE_UPDATE_CALLS);
+ if (!ret)
+ ftrace_ops_update_code(iter->ops);
mutex_unlock(&ftrace_lock);
}

kernel/trace/trace.c

View file
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 882ec1d..496f94d 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -243,20 +243,25 @@ int filter_current_check_discard(struct ring_buffer *buffer,
}
EXPORT_SYMBOL_GPL(filter_current_check_discard);
-cycle_t ftrace_now(int cpu)
+cycle_t buffer_ftrace_now(struct trace_buffer *buf, int cpu)
{
u64 ts;
/* Early boot up does not have a buffer yet */
- if (!global_trace.trace_buffer.buffer)
+ if (!buf->buffer)
return trace_clock_local();
- ts = ring_buffer_time_stamp(global_trace.trace_buffer.buffer, cpu);
- ring_buffer_normalize_time_stamp(global_trace.trace_buffer.buffer, cpu, &ts);
+ ts = ring_buffer_time_stamp(buf->buffer, cpu);
+ ring_buffer_normalize_time_stamp(buf->buffer, cpu, &ts);
return ts;
}
+cycle_t ftrace_now(int cpu)
+{
+ return buffer_ftrace_now(&global_trace.trace_buffer, cpu);
+}
+
/**
* tracing_is_enabled - Show if global_trace has been disabled
*
@@ -1211,7 +1216,7 @@ void tracing_reset_online_cpus(struct trace_buffer *buf)
/* Make sure all commits have finished */
synchronize_sched();
- buf->time_start = ftrace_now(buf->cpu);
+ buf->time_start = buffer_ftrace_now(buf, buf->cpu);
for_each_online_cpu(cpu)
ring_buffer_reset_cpu(buffer, cpu);
@@ -1219,11 +1224,6 @@ void tracing_reset_online_cpus(struct trace_buffer *buf)
ring_buffer_record_enable(buffer);
}
-void tracing_reset_current(int cpu)
-{
- tracing_reset(&global_trace.trace_buffer, cpu);
-}
-
/* Must have trace_types_lock held */
void tracing_reset_all_online_cpus(void)
{
@@ -4151,6 +4151,7 @@ waitagain:
memset(&iter->seq, 0,
sizeof(struct trace_iterator) -
offsetof(struct trace_iterator, seq));
+ cpumask_clear(iter->started);
iter->pos = -1;
trace_event_read_lock();
@@ -4468,7 +4469,7 @@ tracing_free_buffer_release(struct inode *inode, struct file *filp)
/* disable tracing ? */
if (trace_flags & TRACE_ITER_STOP_ON_FREE)
- tracing_off();
+ tracer_tracing_off(tr);
/* resize the ring buffer to 0 */
tracing_resize_ring_buffer(tr, 0, RING_BUFFER_ALL_CPUS);
@@ -4633,12 +4634,12 @@ static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
* New clock may not be consistent with the previous clock.
* Reset the buffer so that it doesn't have incomparable timestamps.
*/
- tracing_reset_online_cpus(&global_trace.trace_buffer);
+ tracing_reset_online_cpus(&tr->trace_buffer);
#ifdef CONFIG_TRACER_MAX_TRACE
if (tr->flags & TRACE_ARRAY_FL_GLOBAL && tr->max_buffer.buffer)
ring_buffer_set_clock(tr->max_buffer.buffer, trace_clocks[i].func);
- tracing_reset_online_cpus(&global_trace.max_buffer);
+ tracing_reset_online_cpus(&tr->max_buffer);
#endif
mutex_unlock(&trace_types_lock);

kernel/trace/trace_events.c

View file
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 898f868..29a7ebc 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -409,33 +409,42 @@ static void put_system(struct ftrace_subsystem_dir *dir)
mutex_unlock(&event_mutex);
}
-/*
- * Open and update trace_array ref count.
- * Must have the current trace_array passed to it.
- */
-static int tracing_open_generic_file(struct inode *inode, struct file *filp)
+static void remove_subsystem(struct ftrace_subsystem_dir *dir)
{
- struct ftrace_event_file *file = inode->i_private;
- struct trace_array *tr = file->tr;
- int ret;
+ if (!dir)
+ return;
- if (trace_array_get(tr) < 0)
- return -ENODEV;
+ if (!--dir->nr_events) {
+ debugfs_remove_recursive(dir->entry);
+ list_del(&dir->list);
+ __put_system_dir(dir);
+ }
+}
- ret = tracing_open_generic(inode, filp);
- if (ret < 0)
- trace_array_put(tr);
- return ret;
+static void *event_file_data(struct file *filp)
+{
+ return ACCESS_ONCE(file_inode(filp)->i_private);
}
-static int tracing_release_generic_file(struct inode *inode, struct file *filp)
+static void remove_event_file_dir(struct ftrace_event_file *file)
{
- struct ftrace_event_file *file = inode->i_private;
- struct trace_array *tr = file->tr;
+ struct dentry *dir = file->dir;
+ struct dentry *child;
- trace_array_put(tr);
+ if (dir) {
+ spin_lock(&dir->d_lock); /* probably unneeded */
+ list_for_each_entry(child, &dir->d_subdirs, d_u.d_child) {
+ if (child->d_inode) /* probably unneeded */
+ child->d_inode->i_private = NULL;
+ }
+ spin_unlock(&dir->d_lock);
- return 0;
+ debugfs_remove_recursive(dir);
+ }
+
+ list_del(&file->list);
+ remove_subsystem(file->system);
+ kmem_cache_free(file_cachep, file);
}
/*
@@ -679,15 +688,25 @@ static ssize_t
event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
loff_t *ppos)
{
- struct ftrace_event_file *file = filp->private_data;
+ struct ftrace_event_file *file;
+ unsigned long flags;
char buf[4] = "0";
- if (file->flags & FTRACE_EVENT_FL_ENABLED &&
- !(file->flags & FTRACE_EVENT_FL_SOFT_DISABLED))
+ mutex_lock(&event_mutex);
+ file = event_file_data(filp);
+ if (likely(file))
+ flags = file->flags;
+ mutex_unlock(&event_mutex);
+
+ if (!file)
+ return -ENODEV;
+
+ if (flags & FTRACE_EVENT_FL_ENABLED &&
+ !(flags & FTRACE_EVENT_FL_SOFT_DISABLED))
strcpy(buf, "1");
- if (file->flags & FTRACE_EVENT_FL_SOFT_DISABLED ||
- file->flags & FTRACE_EVENT_FL_SOFT_MODE)
+ if (flags & FTRACE_EVENT_FL_SOFT_DISABLED ||
+ flags & FTRACE_EVENT_FL_SOFT_MODE)
strcat(buf, "*");
strcat(buf, "\n");
@@ -699,13 +718,10 @@ static ssize_t
event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
loff_t *ppos)
{
- struct ftrace_event_file *file = filp->private_data;
+ struct ftrace_event_file *file;
unsigned long val;
int ret;
- if (!file)
- return -EINVAL;
-
ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
if (ret)
return ret;
@@ -717,8 +733,11 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
switch (val) {
case 0:
case 1:
+ ret = -ENODEV;
mutex_lock(&event_mutex);
- ret = ftrace_event_enable_disable(file, val);
+ file = event_file_data(filp);
+ if (likely(file))
+ ret = ftrace_event_enable_disable(file, val);
mutex_unlock(&event_mutex);
break;
@@ -825,7 +844,7 @@ enum {
static void *f_next(struct seq_file *m, void *v, loff_t *pos)
{
- struct ftrace_event_call *call = m->private;
+ struct ftrace_event_call *call = event_file_data(m->private);
struct list_head *common_head = &ftrace_common_fields;
struct list_head *head = trace_get_fields(call);
struct list_head *node = v;
@@ -857,7 +876,7 @@ static void *f_next(struct seq_file *m, void *v, loff_t *pos)
static int f_show(struct seq_file *m, void *v)
{
- struct ftrace_event_call *call = m->private;
+ struct ftrace_event_call *call = event_file_data(m->private);
struct ftrace_event_field *field;
const char *array_descriptor;
@@ -910,6 +929,11 @@ static void *f_start(struct seq_file *m, loff_t *pos)
void *p = (void *)FORMAT_HEADER;
loff_t l = 0;
+ /* ->stop() is called even if ->start() fails */
+ mutex_lock(&event_mutex);
+ if (!event_file_data(m->private))
+ return ERR_PTR(-ENODEV);
+
while (l < *pos && p)
p = f_next(m, p, &l);
@@ -918,6 +942,7 @@ static void *f_start(struct seq_file *m, loff_t *pos)
static void f_stop(struct seq_file *m, void *p)
{
+ mutex_unlock(&event_mutex);
}
static const struct seq_operations trace_format_seq_ops = {
@@ -929,7 +954,6 @@ static const struct seq_operations trace_format_seq_ops = {
static int trace_format_open(struct inode *inode, struct file *file)
{
- struct ftrace_event_call *call = inode->i_private;
struct seq_file *m;
int ret;
@@ -938,7 +962,7 @@ static int trace_format_open(struct inode *inode, struct file *file)
return ret;
m = file->private_data;
- m->private = call;
+ m->private = file;
return 0;
}
@@ -946,14 +970,18 @@ static int trace_format_open(struct inode *inode, struct file *file)
static ssize_t
event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
{
- struct ftrace_event_call *call = filp->private_data;
+ int id = (long)event_file_data(filp);
char buf[32];
int len;
if (*ppos)
return 0;
- len = sprintf(buf, "%d\n", call->event.type);
+ if (unlikely(!id))
+ return -ENODEV;
+
+ len = sprintf(buf, "%d\n", id);
+
return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
}
@@ -961,21 +989,28 @@ static ssize_t
event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
loff_t *ppos)
{
- struct ftrace_event_call *call = filp->private_data;
+ struct ftrace_event_call *call;
struct trace_seq *s;
- int r;
+ int r = -ENODEV;
if (*ppos)

This diff is incomplete. Download the complete patch.

kernel/trace/trace_events_filter.c

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kernel/trace/trace_kprobe.c

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kernel/trace/trace_uprobe.c

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