From 26c563731056c3ee66f91106c3078a8c36bb7a9e Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Wed, 7 Jul 2021 11:08:21 -0400 Subject: tracing/histograms: Fix parsing of "sym-offset" modifier With the addition of simple mathematical operations (plus and minus), the parsing of the "sym-offset" modifier broke, as it took the '-' part of the "sym-offset" as a minus, and tried to break it up into a mathematical operation of "field.sym - offset", in which case it failed to parse (unless the event had a field called "offset"). Both .sym and .sym-offset modifiers should not be entered into mathematical calculations anyway. If ".sym-offset" is found in the modifier, then simply make it not an operation that can be calculated on. Link: https://lkml.kernel.org/r/20210707110821.188ae255@oasis.local.home Cc: Ingo Molnar Cc: Andrew Morton Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Daniel Bristot de Oliveira Cc: stable@vger.kernel.org Fixes: 100719dcef447 ("tracing: Add simple expression support to hist triggers") Reviewed-by: Tom Zanussi Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_events_hist.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'kernel') diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index ba03b7d84fc2..0207aeed31e6 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -1555,6 +1555,13 @@ static int contains_operator(char *str) switch (*op) { case '-': + /* + * Unfortunately, the modifier ".sym-offset" + * can confuse things. + */ + if (op - str >= 4 && !strncmp(op - 4, ".sym-offset", 11)) + return FIELD_OP_NONE; + if (*str == '-') field_op = FIELD_OP_UNARY_MINUS; else -- cgit v1.2.3-59-g8ed1b