From 0c54bda932220e07952b39f6673ad54ca97ee8d2 Mon Sep 17 00:00:00 2001 From: Rikard Falkeborn Date: Tue, 9 Apr 2019 11:15:29 +0200 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 6f635c20c7f6 ("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. Signed-off-by: Rikard Falkeborn Reviewed-by: Steven Rostedt (VMware) Cc: Tzvetomir Stoyanov Fixes: 6f635c20c7f6 ("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 --- tools/lib/traceevent/event-parse.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c index 87494c7c619d8..981c6ce2da2c7 100644 --- a/tools/lib/traceevent/event-parse.c +++ b/tools/lib/traceevent/event-parse.c @@ -2233,7 +2233,7 @@ 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) -- 2.39.5