There tracing fixes:

- Use "nosteal" for ring buffer splice pages
  - Memory leak fix in error path of trace_pid_write()
  - Fix preempt_enable_no_resched() (use preempt_enable()) in ring buffer code
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Merge tag 'trace-v5.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Three tracing fixes:

   - Use "nosteal" for ring buffer splice pages

   - Memory leak fix in error path of trace_pid_write()

   - Fix preempt_enable_no_resched() (use preempt_enable()) in ring
     buffer code"

* tag 'trace-v5.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  trace: Fix preempt_enable_no_resched() abuse
  tracing: Fix a memory leak by early error exit in trace_pid_write()
  tracing: Fix buffer_ref pipe ops
This commit is contained in:
Linus Torvalds 2019-04-26 11:09:55 -07:00
commit e9e1a2e7b4
4 changed files with 23 additions and 19 deletions

View File

@ -330,7 +330,7 @@ const struct pipe_buf_operations default_pipe_buf_ops = {
.get = generic_pipe_buf_get,
};
static int generic_pipe_buf_nosteal(struct pipe_inode_info *pipe,
int generic_pipe_buf_nosteal(struct pipe_inode_info *pipe,
struct pipe_buffer *buf)
{
return 1;

View File

@ -176,6 +176,7 @@ void free_pipe_info(struct pipe_inode_info *);
bool generic_pipe_buf_get(struct pipe_inode_info *, struct pipe_buffer *);
int generic_pipe_buf_confirm(struct pipe_inode_info *, struct pipe_buffer *);
int generic_pipe_buf_steal(struct pipe_inode_info *, struct pipe_buffer *);
int generic_pipe_buf_nosteal(struct pipe_inode_info *, struct pipe_buffer *);
void generic_pipe_buf_release(struct pipe_inode_info *, struct pipe_buffer *);
void pipe_buf_mark_unmergeable(struct pipe_buffer *buf);

View File

@ -762,7 +762,7 @@ u64 ring_buffer_time_stamp(struct ring_buffer *buffer, int cpu)
preempt_disable_notrace();
time = rb_time_stamp(buffer);
preempt_enable_no_resched_notrace();
preempt_enable_notrace();
return time;
}

View File

@ -496,8 +496,10 @@ int trace_pid_write(struct trace_pid_list *filtered_pids,
* not modified.
*/
pid_list = kmalloc(sizeof(*pid_list), GFP_KERNEL);
if (!pid_list)
if (!pid_list) {
trace_parser_put(&parser);
return -ENOMEM;
}
pid_list->pid_max = READ_ONCE(pid_max);
@ -507,6 +509,7 @@ int trace_pid_write(struct trace_pid_list *filtered_pids,
pid_list->pids = vzalloc((pid_list->pid_max + 7) >> 3);
if (!pid_list->pids) {
trace_parser_put(&parser);
kfree(pid_list);
return -ENOMEM;
}
@ -7025,19 +7028,23 @@ struct buffer_ref {
struct ring_buffer *buffer;
void *page;
int cpu;
int ref;
refcount_t refcount;
};
static void buffer_ref_release(struct buffer_ref *ref)
{
if (!refcount_dec_and_test(&ref->refcount))
return;
ring_buffer_free_read_page(ref->buffer, ref->cpu, ref->page);
kfree(ref);
}
static void buffer_pipe_buf_release(struct pipe_inode_info *pipe,
struct pipe_buffer *buf)
{
struct buffer_ref *ref = (struct buffer_ref *)buf->private;
if (--ref->ref)
return;
ring_buffer_free_read_page(ref->buffer, ref->cpu, ref->page);
kfree(ref);
buffer_ref_release(ref);
buf->private = 0;
}
@ -7046,10 +7053,10 @@ static bool buffer_pipe_buf_get(struct pipe_inode_info *pipe,
{
struct buffer_ref *ref = (struct buffer_ref *)buf->private;
if (ref->ref > INT_MAX/2)
if (refcount_read(&ref->refcount) > INT_MAX/2)
return false;
ref->ref++;
refcount_inc(&ref->refcount);
return true;
}
@ -7057,7 +7064,7 @@ static bool buffer_pipe_buf_get(struct pipe_inode_info *pipe,
static const struct pipe_buf_operations buffer_pipe_buf_ops = {
.confirm = generic_pipe_buf_confirm,
.release = buffer_pipe_buf_release,
.steal = generic_pipe_buf_steal,
.steal = generic_pipe_buf_nosteal,
.get = buffer_pipe_buf_get,
};
@ -7070,11 +7077,7 @@ static void buffer_spd_release(struct splice_pipe_desc *spd, unsigned int i)
struct buffer_ref *ref =
(struct buffer_ref *)spd->partial[i].private;
if (--ref->ref)
return;
ring_buffer_free_read_page(ref->buffer, ref->cpu, ref->page);
kfree(ref);
buffer_ref_release(ref);
spd->partial[i].private = 0;
}
@ -7129,7 +7132,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
break;
}
ref->ref = 1;
refcount_set(&ref->refcount, 1);
ref->buffer = iter->trace_buffer->buffer;
ref->page = ring_buffer_alloc_read_page(ref->buffer, iter->cpu_file);
if (IS_ERR(ref->page)) {