On Thu, 7 Mar 2024 11:07:17 +1100
Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
> Hi all,
>
> After merging the ext3 tree, today's linux-next build (x86_64
> allmodconfig) failed like this:
>
> In file included from include/linux/sysctl.h:27,
> from include/linux/fanotify.h:5,
> from fs/notify/fanotify/fanotify.c:2:
> fs/notify/fanotify/fanotify.c: In function 'fanotify_get_response':
> fs/notify/fanotify/fanotify.c:233:48: error: suggest parentheses
> around arithmetic in operand of '|' [-Werror=parentheses] 233 |
> TASK_KILLABLE|TASK_FREEZABLE); |
> ^ include/linux/wait.h:283:11:
> note: in definition of macro '___wait_is_interruptible' 283 |
> (state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL))) | ^~~~~
> include/linux/wait.h:935:9: note: in expansion of macro
> '___wait_event' 935 | ___wait_event(wq, condition, state, 0,
> 0, schedule()) | ^~~~~~~~~~~~~
> include/linux/wait.h:958:25: note: in expansion of macro
> '__wait_event_state' 958 | __ret =
> __wait_event_state(wq_head, condition, state); \ |
> ^~~~~~~~~~~~~~~~~~
> fs/notify/fanotify/fanotify.c:231:15: note: in expansion of macro
> 'wait_event_state' 231 | ret =
> wait_event_state(group->fanotify_data.access_waitq, |
> ^~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors
>
> Caused by commit
>
> 3440e7e55ced ("fanotify: allow freeze when waiting response for
> permission events")
>
> Though, I guess, you could argue that the ___wait_is_interruptible
> macro should parenthesise the use of its "state" argument.
>
> I have used the ext3 tree from next-20240306 for today.
>
Sorry I missed this warning. And agreed! I can add parentheses on the
call side, but it may be more reasonable to add them in the macro.
Hey Peter,
Could you please take a look at the patch attached at your convenience?
Thanks!
--
Thanks,
Winston
>From 17bdb67492823e90e77f4e3159d631efc4cdd865 Mon Sep 17 00:00:00 2001
From: Winston Wen <wentao@xxxxxxxxxxxxx>
Date: Thu, 7 Mar 2024 10:59:59 +0800
Subject: [PATCH 1/2] wait: add parentheses to "state" argument in macro
Now if we use macro wait_event_state() like this:
wait_event_state(waitq, condition,
TASK_KILLABLE|TASK_FREEZABLE);
we'll get a build warning in __wait_is_interruptible because of:
((state) & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
Parenthesise the use of "state" argument to avoid this warning as
it's very common to use "TASK_*|TASK_*" as function parameter in kernel.
Signed-off-by: Winston Wen <wentao@xxxxxxxxxxxxx>
---
include/linux/wait.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/wait.h b/include/linux/wait.h
index 8aa3372f21a0..a4e57865aded 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -280,7 +280,7 @@ static inline void wake_up_pollfree(struct wait_queue_head *wq_head)
#define ___wait_is_interruptible(state) \
(!__builtin_constant_p(state) || \
- (state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
+ ((state) & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
extern void init_wait_entry(struct wait_queue_entry *wq_entry, int flags);
--
2.43.0
