NothingOSS/android_kernel_msm-6.1_nothing_sm7635
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Revert "tracing: Have trace_event_file have ref counters"

Browse source 
This reverts commit 2fa74d29fc which is
commit bb32500fb9b78215e4ef6ee8b4345c5f5d7eafb4 upstream.

It breaks the current Android ABI, and if needed, can be brought back in
an abi-safe way in the future.

Bug: 161946584
Change-Id: If981a67442122352b1836c6e75ba2a462cbc731d
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This commit is contained in:
Greg Kroah-Hartman 2023-12-11 12:26:13 +00:00
parent fd71493204
commit 88487f809a
5 changed files with 15 additions and 53 deletions
Download patch file Download diff file Expand all files Collapse all files

4
include/linux/trace_events.h
View file

@ -478,7 +478,6 @@ enum {
EVENT_FILE_FL_TRIGGER_COND_BIT,
EVENT_FILE_FL_PID_FILTER_BIT,
EVENT_FILE_FL_WAS_ENABLED_BIT,
EVENT_FILE_FL_FREED_BIT,
};
extern struct trace_event_file *trace_get_event_file(const char *instance,
@ -617,7 +616,6 @@ extern int __kprobe_event_add_fields(struct dynevent_cmd *cmd, ...);
* TRIGGER_COND - When set, one or more triggers has an associated filter
* PID_FILTER - When set, the event is filtered based on pid
* WAS_ENABLED - Set when enabled to know to clear trace on module removal
* FREED - File descriptor is freed, all fields should be considered invalid
*/
enum {
EVENT_FILE_FL_ENABLED = (1 << EVENT_FILE_FL_ENABLED_BIT),
@ -631,7 +629,6 @@ enum {
EVENT_FILE_FL_TRIGGER_COND = (1 << EVENT_FILE_FL_TRIGGER_COND_BIT),
EVENT_FILE_FL_PID_FILTER = (1 << EVENT_FILE_FL_PID_FILTER_BIT),
EVENT_FILE_FL_WAS_ENABLED = (1 << EVENT_FILE_FL_WAS_ENABLED_BIT),
EVENT_FILE_FL_FREED = (1 << EVENT_FILE_FL_FREED_BIT),
};
struct trace_event_file {
@ -660,7 +657,6 @@ struct trace_event_file {
* caching and such. Which is mostly OK ;-)
*/
unsigned long flags;
atomic_t ref; /* ref count for opened files */
atomic_t sm_ref; /* soft-mode reference counter */
atomic_t tm_ref; /* trigger-mode reference counter */
};

15
kernel/trace/trace.c
View file

@ -4913,20 +4913,6 @@ int tracing_open_file_tr(struct inode *inode, struct file *filp)
if (ret)
return ret;
mutex_lock(&event_mutex);
/* Fail if the file is marked for removal */
if (file->flags & EVENT_FILE_FL_FREED) {
trace_array_put(file->tr);
ret = -ENODEV;
} else {
event_file_get(file);
}
mutex_unlock(&event_mutex);
if (ret)
return ret;
filp->private_data = inode->i_private;
return 0;
@ -4937,7 +4923,6 @@ int tracing_release_file_tr(struct inode *inode, struct file *filp)
struct trace_event_file *file = inode->i_private;
trace_array_put(file->tr);
event_file_put(file);
return 0;
}

3
kernel/trace/trace.h
View file

@ -1629,9 +1629,6 @@ extern void event_trigger_unregister(struct event_command *cmd_ops,
char *glob,
struct event_trigger_data *trigger_data);
extern void event_file_get(struct trace_event_file *file);
extern void event_file_put(struct trace_event_file *file);
/**
* struct event_trigger_ops - callbacks for trace event triggers
*

43
kernel/trace/trace_events.c
View file

@ -988,38 +988,26 @@ static void remove_subsystem(struct trace_subsystem_dir *dir)
}
}
void event_file_get(struct trace_event_file *file)
{
atomic_inc(&file->ref);
}
void event_file_put(struct trace_event_file *file)
{
if (WARN_ON_ONCE(!atomic_read(&file->ref))) {
if (file->flags & EVENT_FILE_FL_FREED)
kmem_cache_free(file_cachep, file);
return;
}
if (atomic_dec_and_test(&file->ref)) {
/* Count should only go to zero when it is freed */
if (WARN_ON_ONCE(!(file->flags & EVENT_FILE_FL_FREED)))
return;
kmem_cache_free(file_cachep, file);
}
}
static void remove_event_file_dir(struct trace_event_file *file)
{
struct dentry *dir = file->dir;
struct dentry *child;
tracefs_remove(dir);
if (dir) {
spin_lock(&dir->d_lock); /* probably unneeded */
list_for_each_entry(child, &dir->d_subdirs, d_child) {
if (d_really_is_positive(child)) /* probably unneeded */
d_inode(child)->i_private = NULL;
}
spin_unlock(&dir->d_lock);
tracefs_remove(dir);
}
list_del(&file->list);
remove_subsystem(file->system);
free_event_filter(file->filter);
file->flags |= EVENT_FILE_FL_FREED;
event_file_put(file);
kmem_cache_free(file_cachep, file);
}
/*
@ -1392,7 +1380,7 @@ event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
flags = file->flags;
mutex_unlock(&event_mutex);
if (!file || flags & EVENT_FILE_FL_FREED)
if (!file)
return -ENODEV;
if (flags & EVENT_FILE_FL_ENABLED &&
@ -1430,7 +1418,7 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
ret = -ENODEV;
mutex_lock(&event_mutex);
file = event_file_data(filp);
if (likely(file && !(file->flags & EVENT_FILE_FL_FREED)))
if (likely(file))
ret = ftrace_event_enable_disable(file, val);
mutex_unlock(&event_mutex);
break;
@ -1704,7 +1692,7 @@ event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
mutex_lock(&event_mutex);
file = event_file_data(filp);
if (file && !(file->flags & EVENT_FILE_FL_FREED))
if (file)
print_event_filter(file, s);
mutex_unlock(&event_mutex);
@ -2822,7 +2810,6 @@ trace_create_new_event(struct trace_event_call *call,
atomic_set(&file->tm_ref, 0);
INIT_LIST_HEAD(&file->triggers);
list_add(&file->list, &tr->events);
event_file_get(file);
return file;
}

3
kernel/trace/trace_events_filter.c
View file

@ -1997,9 +1997,6 @@ int apply_event_filter(struct trace_event_file *file, char *filter_string)
struct event_filter *filter = NULL;
int err;
if (file->flags & EVENT_FILE_FL_FREED)
return -ENODEV;
if (!strcmp(strstrip(filter_string), "0")) {
filter_disable(file);
filter = event_filter(file);