[PATCH] libtrace: Fix memory leak in tracefs_cpu

From: Philipp Kutzer <[email protected]>

Hi,

with the introduction of the interface to allow the tracefs_cpu to handle buffer allocation on their
 own a memory leak was built in. 
(Commit 1e1cc549d7e7fa408081e03e4effd3591a131ae5 - libtracefs: Add API to read tracefs_cpu 
and return a kbuffer)

We cyclically call the tracefs_iterate_raw_events function from one of our applications and 
noticed that our application was increasingly allocating memory. 

With the help of Address Sanitizer the root cause, allocating but not freeing memory 
for "tcpu->buffer" was found. The fix will free memory during close and cleanup function 
and has been successfully tested in our environment. The original problem (memory leak) 
has been resolved.

Signed-off-by: Philipp Kutzer mailto:[email protected]
---

diff --git a/src/tracefs-record.c b/src/tracefs-record.c
index a2dcfc2..4cd0917 100644
--- a/src/tracefs-record.c
+++ b/src/tracefs-record.c
@@ -293,6 +293,8 @@ void tracefs_cpu_close(struct tracefs_cpu *tcpu)
        if (!tcpu)
                return;

+       free(tcpu->buffer);
+       tcpu->buffer = NULL;
        close(tcpu->fd);
        tracefs_cpu_free_fd(tcpu);
}