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authorDominique Martinet <asmadeus@codewreck.org>2022-06-13 01:32:06 +0200
committerDominique Martinet <dominique.martinet@atmark-techno.com>2022-07-02 11:52:21 +0200
commit286c171b86ebc693e18b485dde3a3fc470af37bd (patch)
treea88cd5244bb6b8221928a2781e25fa7cd59ec2bb /include/net/9p
parent9p fid refcount: add p9_fid_get/put wrappers (diff)
downloadlinux-286c171b86ebc693e18b485dde3a3fc470af37bd.tar.xz
linux-286c171b86ebc693e18b485dde3a3fc470af37bd.zip
9p fid refcount: add a 9p_fid_ref tracepoint
This adds a tracepoint event for 9p fid lifecycle tracing: when a fid is created, its reference count increased/decreased, and freed. The new 9p_fid_ref tracepoint should help anyone wishing to debug any fid problem such as missing clunk (destroy) or use-after-free. Link: https://lkml.kernel.org/r/20220612085330.1451496-6-asmadeus@codewreck.org Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Diffstat (limited to 'include/net/9p')
-rw-r--r--include/net/9p/client.h13
1 files changed, 13 insertions, 0 deletions
diff --git a/include/net/9p/client.h b/include/net/9p/client.h
index eabb53992350..8f629f1df865 100644
--- a/include/net/9p/client.h
+++ b/include/net/9p/client.h
@@ -11,6 +11,7 @@
#include <linux/utsname.h>
#include <linux/idr.h>
+#include <linux/tracepoint-defs.h>
/* Number of requests per row */
#define P9_ROW_MAXTAG 255
@@ -237,6 +238,12 @@ static inline int p9_req_try_get(struct p9_req_t *r)
int p9_req_put(struct p9_req_t *r);
+/* We cannot have the real tracepoints in header files,
+ * use a wrapper function */
+DECLARE_TRACEPOINT(9p_fid_ref);
+void do_trace_9p_fid_get(struct p9_fid *fid);
+void do_trace_9p_fid_put(struct p9_fid *fid);
+
/* fid reference counting helpers:
* - fids used for any length of time should always be referenced through
* p9_fid_get(), and released with p9_fid_put()
@@ -249,6 +256,9 @@ int p9_req_put(struct p9_req_t *r);
*/
static inline struct p9_fid *p9_fid_get(struct p9_fid *fid)
{
+ if (tracepoint_enabled(9p_fid_ref))
+ do_trace_9p_fid_get(fid);
+
refcount_inc(&fid->count);
return fid;
@@ -259,6 +269,9 @@ static inline int p9_fid_put(struct p9_fid *fid)
if (!fid || IS_ERR(fid))
return 0;
+ if (tracepoint_enabled(9p_fid_ref))
+ do_trace_9p_fid_put(fid);
+
if (!refcount_dec_and_test(&fid->count))
return 0;