From 797311bce5c2ac90b8d65e357603cfd410d36ebb Mon Sep 17 00:00:00 2001 From: "Masami Hiramatsu (Google)" Date: Tue, 11 Jul 2023 23:16:07 +0900 Subject: tracing/probes: Fix to record 0-length data_loc in fetch_store_string*() if fails Fix to record 0-length data to data_loc in fetch_store_string*() if it fails to get the string data. Currently those expect that the data_loc is updated by store_trace_args() if it returns the error code. However, that does not work correctly if the argument is an array of strings. In that case, store_trace_args() only clears the first entry of the array (which may have no error) and leaves other entries. So it should be cleared by fetch_store_string*() itself. Also, 'dyndata' and 'maxlen' in store_trace_args() should be updated only if it is used (ret > 0 and argument is a dynamic data.) Link: https://lore.kernel.org/all/168908496683.123124.4761206188794205601.stgit@devnote2/ Fixes: 40b53b771806 ("tracing: probeevent: Add array type support") Cc: stable@vger.kernel.org Reviewed-by: Steven Rostedt (Google) Signed-off-by: Masami Hiramatsu (Google) --- kernel/trace/trace_probe_tmpl.h | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) (limited to 'kernel/trace/trace_probe_tmpl.h') diff --git a/kernel/trace/trace_probe_tmpl.h b/kernel/trace/trace_probe_tmpl.h index 185da001f4c3..3935b347f874 100644 --- a/kernel/trace/trace_probe_tmpl.h +++ b/kernel/trace/trace_probe_tmpl.h @@ -267,13 +267,9 @@ 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 (arg->dynamic) { - if (unlikely(ret < 0)) { - *dl = make_data_loc(0, dyndata - base); - } else { - dyndata += ret; - maxlen -= ret; - } + if (arg->dynamic && likely(ret > 0)) { + dyndata += ret; + maxlen -= ret; } } } -- cgit v1.2.3