[PATCH v2] tracing: fprobe: do not zero out unused fgraph_data

[Martin Kaiser <martin@kaiser.cx>]

If fprobe_entry does not fill the allocated fgraph_data completely, the
unused part does not have to be zeroed.

fgraph_data is a short-lived part of the shadow stack. The preceding
length field allows locating the end regardless of the content.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
---
v2:
 - remove the memset instead of fixing the length

 kernel/trace/fprobe.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
index dcadf1d23b8a..56d145017902 100644
--- a/kernel/trace/fprobe.c
+++ b/kernel/trace/fprobe.c
@@ -450,8 +450,6 @@ static int fprobe_fgraph_entry(struct ftrace_graph_ent *trace, struct fgraph_ops
 				used += FPROBE_HEADER_SIZE_IN_LONG + size_words;
 		}
 	}
-	if (used < reserved_words)
-		memset(fgraph_data + used, 0, reserved_words - used);
 
 	/* If any exit_handler is set, data must be used. */
 	return used != 0;
-- 
2.43.7