Commit b66a1def authored Jul 11, 2023 by Masami Hiramatsu (Google) Committed by Greg Kroah-Hartman Aug 30, 2023

tracing/probes: Fix to update dynamic data counter if fetcharg uses it

[ Upstream commit e38e2c6a9efc435f9de344b7c91f7697e01b47d5 ]

Fix to update dynamic data counter ('dyndata') and max length ('maxlen')
only if the fetcharg uses the dynamic data. Also get out arg->dynamic
from unlikely(). This makes dynamic data address wrong if
process_fetch_insn() returns error on !arg->dynamic case.

Link: https://lore.kernel.org/all/168908494781.123124.8160245359962103684.stgit@devnote2/



Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Link: https://lore.kernel.org/all/20230710233400.5aaf024e@gandalf.local.home/


Fixes: 9178412d ("tracing: probeevent: Return consumed bytes of dynamic area")
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent bdc309d8

kernel/trace/trace_probe_tmpl.h

+7 −5

Original line number	Diff line number	Diff line
		@@ -206,7 +206,8 @@ store_trace_args(void data, struct trace_probe tp, void *rec,
		if (unlikely(arg->dynamic))
		*dl = make_data_loc(maxlen, dyndata - base);
		ret = process_fetch_insn(arg->code, rec, dl, base);
		if (unlikely(ret < 0 && arg->dynamic)) {
		if (arg->dynamic) {
		if (unlikely(ret < 0)) {
		*dl = make_data_loc(0, dyndata - base);
		} else {
		dyndata += ret;
		@@ -214,6 +215,7 @@ store_trace_args(void data, struct trace_probe tp, void *rec,
		}
		}
		}
		}

		static inline int
		print_probe_args(struct trace_seq s, struct probe_arg args, int nr_args,