[for-next][PATCH 12/20] tracing: Correctly expand len expressions from __dynamic_array macro

From: Steven Rostedt
Date: Fri Mar 07 2014 - 10:16:11 EST


From: Filipe Brandenburger <filbranden@xxxxxxxxxx>

This fixes expansion of the len argument in __dynamic_array macros.
The previous code from commit 7d536cb3f would not fully evaluate the
expression before multiplying its result by the size of the type.

This went unnoticed because the length stored in the high 16 bits of the
offset (which is the one that was broken here) is only used by
filter_pred_strloc which only acts on strings for which the size of the
type is 1.

Link: http://lkml.kernel.org/r/1393651938-16418-2-git-send-email-filbranden@xxxxxxxxxx

Signed-off-by: Filipe Brandenburger <filbranden@xxxxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
include/trace/ftrace.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 1cc2265..2125005 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -363,7 +363,7 @@ ftrace_define_fields_##call(struct ftrace_event_call *event_call) \
#define __dynamic_array(type, item, len) \
__data_offsets->item = __data_size + \
offsetof(typeof(*entry), __data); \
- __data_offsets->item |= (len * sizeof(type)) << 16; \
+ __data_offsets->item |= ((len) * sizeof(type)) << 16; \
__data_size += (len) * sizeof(type);

#undef __string
--
1.8.5.3


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