From b41326b5e0f82e93592c4366359917b5d67b529f Mon Sep 17 00:00:00 2001
From: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Date: Tue, 11 Jul 2023 23:15:38 +0900
Subject: [PATCH] tracing/probes: Fix not to count error code to total length
Fix not to count the error code (which is minus value) to the total
used length of array, because it can mess up the return code of
process_fetch_insn_bottom(). Also clear the 'ret' value because it
will be used for calculating next data_loc entry.
Link: https://lore.kernel.org/all/168908493827.123124.2175257289106364229.stgit@devnote2/
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/all/8819b154-2ba1-43c3-98a2-cbde20892023@moroto.mountain/
Fixes: 9b960a38835f ("tracing: probeevent: Unify fetch_insn processing common part")
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
kernel/trace/trace_probe_tmpl.h | 2 ++
1 file changed, 2 insertions(+)
diff --git a/kernel/trace/trace_probe_tmpl.h b/kernel/trace/trace_probe_tmpl.h
index 4735c5cb76fac..ed9d57c6b0414 100644
--- a/kernel/trace/trace_probe_tmpl.h
+++ b/kernel/trace/trace_probe_tmpl.h
@@ -204,6 +204,8 @@ process_fetch_insn_bottom(struct fetch_insn *code, unsigned long val,
array:
/* the last stage: Loop on array */
if (code->op == FETCH_OP_LP_ARRAY) {
+ if (ret < 0)
+ ret = 0;
total += ret;
if (++i < code->param) {
code = s3;
--
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