Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.12 102/700] tracing/histograms: Fix parsing of "sym-offset" modifier | Date | Mon, 12 Jul 2021 08:03:05 +0200 |
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From: Steven Rostedt (VMware) <rostedt@goodmis.org>
commit 26c563731056c3ee66f91106c3078a8c36bb7a9e upstream.
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 <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: stable@vger.kernel.org Fixes: 100719dcef447 ("tracing: Add simple expression support to hist triggers") Reviewed-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- kernel/trace/trace_events_hist.c | 7 +++++++ 1 file changed, 7 insertions(+)
--- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -1539,6 +1539,13 @@ 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
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