From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx> 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@xxxxxxxxxxxxxxxx Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx> Cc: Namhyung Kim <namhyung@xxxxxxxxxx> Cc: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Fixes: 100719dcef447 ("tracing: Add simple expression support to hist triggers") Reviewed-by: Tom Zanussi <zanussi@xxxxxxxxxx> Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> --- kernel/trace/trace_events_hist.c | 7 +++++++ 1 file changed, 7 insertions(+) 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 -- 2.30.2
