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authorLinus Torvalds <torvalds@linux-foundation.org>2019-04-26 11:09:55 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-04-26 11:09:55 -0700
commite9e1a2e7b486e3940badb6d743c8841ed94517b6 (patch)
tree7bccb028f07659cbc060e142ecb8f46f4073b206
parent29279d21997ae4e80dc8b094c5b916cca3e366b8 (diff)
parentd6097c9e4454adf1f8f2c9547c2fa6060d55d952 (diff)
download96b-common-e9e1a2e7b486e3940badb6d743c8841ed94517b6.tar.gz
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
-rw-r--r--fs/splice.c4
-rw-r--r--include/linux/pipe_fs_i.h1
-rw-r--r--kernel/trace/ring_buffer.c2
-rw-r--r--kernel/trace/trace.c35
4 files changed, 23 insertions, 19 deletions
diff --git a/fs/splice.c b/fs/splice.c
index 98943d9b219c..25212dcca2df 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -330,8 +330,8 @@ 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,
- struct pipe_buffer *buf)
+int generic_pipe_buf_nosteal(struct pipe_inode_info *pipe,
+ struct pipe_buffer *buf)
{
return 1;
}
diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h
index abb2dac3da9b..5c626fdc10db 100644
--- a/include/linux/pipe_fs_i.h
+++ b/include/linux/pipe_fs_i.h
@@ -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);
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 41b6f96e5366..4ee8d8aa3d0f 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -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;
}
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 6c24755655c7..ca1ee656d6d8 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -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)) {