diff mbox series

libtracecmd: Return NULL if page is NULL in peek_last_event()

Message ID 20240111171352.5bd23613@gandalf.local.home (mailing list archive)
State Accepted
Commit 5659b730535a19fc823dea2dd7f64d34fa7a08b8
Headers show
Series libtracecmd: Return NULL if page is NULL in peek_last_event() | expand

Commit Message

Steven Rostedt Jan. 11, 2024, 10:13 p.m. UTC 
From: "Steven Rostedt (Google)" <rostedt@goodmis.org>

If the handle->cpu_data[cpu].page has been freed and cleared, consider the
last event to be empty. This can happen if the buffer size is zero.

 (Should we add a warning if page is NULL and size is not zero?)

Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 lib/trace-cmd/trace-input.c | 4 ++++
 1 file changed, 4 insertions(+)
diff mbox series

Patch

diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
index f458dcec68a8..a10d74cf6cf4 100644
--- a/lib/trace-cmd/trace-input.c
+++ b/lib/trace-cmd/trace-input.c
@@ -2973,6 +2973,10 @@  static struct tep_record *peek_last_event(struct tracecmd_input *handle,
 	if (record)
 		return record;
 
+	/* page can be NULL if the size is zero */
+	if (!page)
+		return NULL;
+
 	page_offset = page->offset - handle->page_size;
 	if (page_offset < handle->cpu_data[cpu].file_offset)
 		return NULL;