Use a temporary variable to store the expansion of the len expression.
If the evaluation is expensive, this commit will ensure it is evaluated
only once inside ftrace_get_offsets_<call>.

Signed-off-by: Filipe Brandenburger <filbran...@google.com>
---
 include/trace/ftrace.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 82e8d89..86a056a 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -373,10 +373,11 @@ ftrace_define_fields_##call(struct ftrace_event_call 
*event_call) \
 
 #undef __dynamic_array
 #define __dynamic_array(type, item, len)                               \
+       __item_length = (len) * sizeof(type);                           \
        __data_offsets->item = __data_size +                            \
                               offsetof(typeof(*entry), __data);        \
-       __data_offsets->item |= ((len) * sizeof(type)) << 16;           \
-       __data_size += (len) * sizeof(type);
+       __data_offsets->item |= __item_length << 16;                    \
+       __data_size += __item_length;
 
 #undef __string
 #define __string(item, src) __dynamic_array(char, item,                        
\
@@ -388,6 +389,7 @@ static inline notrace int ftrace_get_offsets_##call(        
                \
        struct ftrace_data_offsets_##call *__data_offsets, proto)       \
 {                                                                      \
        int __data_size = 0;                                            \
+       int __maybe_unused __item_length;                               \
        struct ftrace_raw_##call __maybe_unused *entry;                 \
                                                                        \
        tstruct;                                                        \
-- 
1.9.0.279.gdc9e3eb

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to