[for-linus][PATCH 1/5] tracing: xen: Ordered comparison of function pointers

Steven Rostedt
2020-01-21T14:40:17Z

From: Changbin Du <changbin.du@gmail.com>

Just as commit 0566e40ce7 ("tracing: initcall: Ordered comparison of
function pointers"), this patch fixes another remaining one in xen.h
found by clang-9.

In file included from arch/x86/xen/trace.c:21:
In file included from ./include/trace/events/xen.h:475:
In file included from ./include/trace/define_trace.h:102:
In file included from ./include/trace/trace_events.h:473:
./include/trace/events/xen.h:69:7: warning: ordered comparison of function \
pointers ('xen_mc_callback_fn_t' (aka 'void (*)(void *)') and 'xen_mc_callback_fn_t') [-Wordered-compare-function-pointers]
__field(xen_mc_callback_fn_t, fn)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
./include/trace/trace_events.h:421:29: note: expanded from macro '__field'
^
./include/trace/trace_events.h:407:6: note: expanded from macro '__field_ext'
is_signed_type(type), filter_type); \
^
./include/linux/trace_events.h:554:44: note: expanded from macro 'is_signed_type'
^

Fixes: c796f213a6934 ("xen/trace: add multicall tracing")
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
include/trace/events/xen.h | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/include/trace/events/xen.h b/include/trace/events/xen.h
index 9a0e8af21310..a5ccfa67bc5c 100644
--- a/include/trace/events/xen.h
+++ b/include/trace/events/xen.h
@@ -66,7 +66,11 @@ TRACE_EVENT(xen_mc_callback,
TP_PROTO(xen_mc_callback_fn_t fn, void *data),
TP_ARGS(fn, data),
TP_STRUCT__entry(
- __field(xen_mc_callback_fn_t, fn)
+ /*
+ * Use field_struct to avoid is_signed_type()
+ * comparison of a function pointer.
+ */
+ __field_struct(xen_mc_callback_fn_t, fn)
__field(void *, data)
),
TP_fast_assign(
--
2.24.1