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| author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2013-04-19 17:10:27 -0400 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2013-04-19 17:10:27 -0400 |
| commit | d2802d0739dcc61af5e5ea00773ce7ddead4e9c2 (patch) | |
| tree | 29d27970f8830dabeea7647479cc4bf9adda5929 /include | |
| parent | c192c8356cc878cfa98ebd3056478674786c0a4d (diff) | |
| download | linux-d2802d0739dcc61af5e5ea00773ce7ddead4e9c2.tar.gz linux-d2802d0739dcc61af5e5ea00773ce7ddead4e9c2.tar.bz2 linux-d2802d0739dcc61af5e5ea00773ce7ddead4e9c2.zip | |
tracing: Compare to 1 instead of zero for is_signed_type()
The formats of the trace events show if the type of a event field
is signed or not via a macro called is_signed_type(). This does
a trick with the type and compares a -1 to zero after typecasting
to the tested type. If it returns true, it's signed, otherwise
its not. But this unfortunately triggers a warning by gcc:
warning: comparison of unsigned expression < 0 is always false
As we know it is always false (that's why we do it), this is a
false warning. Luckily for us, the comparison works with a 1 as
well, without giving the warning.
Convert the check to compare (type)-1 < (type)0 to (type)-1 < (type)1
to determine if the type is signed or not.
Link: http://lkml.kernel.org/r/CAErSpo4YXcY9fuOKWYGDkddJwk68kmZTohsmVB6QvrhjboOh1Q@mail.gmail.com
Reported-by: Bjorn Helgaas <bhelgaas@google.com>
Reported-by: Gary Hade <garyhade@us.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/ftrace_event.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h index 4e28b011e63b..34e00fb49bec 100644 --- a/include/linux/ftrace_event.h +++ b/include/linux/ftrace_event.h @@ -333,7 +333,7 @@ extern int trace_define_field(struct ftrace_event_call *call, const char *type, extern int trace_add_event_call(struct ftrace_event_call *call); extern void trace_remove_event_call(struct ftrace_event_call *call); -#define is_signed_type(type) (((type)(-1)) < (type)0) +#define is_signed_type(type) (((type)(-1)) < (type)1) int trace_set_clr_event(const char *system, const char *event, int set); |