From 8e8f12df7500f501447a2926a9e1db9ff42d882c Mon Sep 17 00:00:00 2001 From: Rikard Falkeborn Date: Fri, 12 Apr 2019 11:22:49 -0300 Subject: [PATCH] tools lib traceevent: Fix missing equality check for strcmp There was a missing comparison with 0 when checking if type is "s64" or "u64". Therefore, the body of the if-statement was entered if "type" was "u64" or not "s64", which made the first strcmp() redundant since if type is "u64", it's not "s64". If type is "s64", the body of the if-statement is not entered but since the remainder of the function consists of if-statements which will not be entered if type is "s64", we will just return "val", which is correct, albeit at the cost of a few more calls to strcmp(), i.e., it will behave just as if the if-statement was entered. If type is neither "s64" or "u64", the body of the if-statement will be entered incorrectly and "val" returned. This means that any type that is checked after "s64" and "u64" is handled the same way as "s64" and "u64", i.e., the limiting of "val" to fit in for example "s8" is never reached. This was introduced in the kernel tree when the sources were copied from trace-cmd in commit f7d82350e597 ("tools/events: Add files to create libtraceevent.a"), and in the trace-cmd repo in 1cdbae6035cei ("Implement typecasting in parser") when the function was introduced, i.e., it has always behaved the wrong way. Detected by cppcheck. Link: http://lkml.kernel.org/r/20190412142250.20595-7-acme@kernel.org Signed-off-by: Rikard Falkeborn Reviewed-by: Steven Rostedt (VMware) Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Jiri Olsa Cc: Namhyung Kim Cc: Clark Williams Cc: Tzvetomir Stoyanov Fixes: f7d82350e597 ("tools/events: Add files to create libtraceevent.a") Link: http://lkml.kernel.org/r/20190409091529.2686-1-rikard.falkeborn@gmail.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Steven Rostedt (VMware) Signed-off-by: John Kacur --- event-parse.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/event-parse.c b/event-parse.c index e5f2acbb70cc..7dba02bd19fe 100644 --- a/event-parse.c +++ b/event-parse.c @@ -2206,7 +2206,7 @@ eval_type_str(unsigned long long val, const char *type, int pointer) return val & 0xffffffff; if (strcmp(type, "u64") == 0 || - strcmp(type, "s64")) + strcmp(type, "s64") == 0) return val; if (strcmp(type, "s8") == 0) -- 2.20.1