On Thu, Mar 2, 2017 at 5:36 PM, Ingo Molnar <mi...@kernel.org> wrote:
>
> I tried to test as many build configurations as possible, but some build
> breakage
> is probably still left - but it should be mostly limited to architectures that
> have no cross-compiler binaries available on kernel.org, and non-default
> configurations.
So I merged this, and it's pushed out, but it showed a real annoyance
almost immediately.
That annoyance is also pushed out - it's the pull of the overlayfs
updates. And the reason that was annoying was that that pull caused
this build error due to a subtle semantic clash:
fs/overlayfs/util.c: In function ‘ovl_copy_up_start’:
./include/linux/wait.h:634:7: error: implicit declaration of
function ‘signal_pending’ [-Werror=implicit-function-declaration]
if (signal_pending(current)) { \
^
./include/linux/wait.h:679:9: note: in expansion of macro
‘__wait_event_interruptible_locked’
? 0 : __wait_event_interruptible_locked(wq, condition, 0, 0))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fs/overlayfs/util.c:275:8: note: in expansion of macro
‘wait_event_interruptible_locked’
err = wait_event_interruptible_locked(ofs->copyup_wq, !oe->copying);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
and that's just complete bullshit.
The thing is, fs/overlayfs/util.c included <linux/fs.h>, which in turn
includes <linux/wait.h>
So using "wait_event_interruptible_locked()" should damn well have worked.
The fact that you can include <linux/wait.h>, and then cannot use the
wait event functions because you're missing "signal_pending()" is
complete garbage. This needs to be fixed.
The most obvious way to fix it is likely to just shrink that
__wait_event_interruptible_locked() macro.
Yes, yes, some of it absolutely does need to remain as a macro,
because it has that
do { .. } while (condition);
part of it, but I think the stuff inside that while loop could be made
into a function of its own. Actually, maybe two different functions
(for the "irq" case on/off).
Anyway, I fixed the semantic merge error by just including thar
<linux/sched/signal.h> file, but this is just not acceptable.
Having to have files know that if they use the wait-event functins
(well, _some_ of them), they not only need to include <linux/wait.h>,
they need to completely illogically also include
<linux/sched/signal.h> is just not maintainable.
And who knows what similar semantic cases I _won't_ notice, because
they occur in code I don't build even with my allmodconfig builds?
Linus
