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References: <20230523122324.1668396-1-trix@redhat.com>
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From:   Doug Anderson <dianders@chromium.org>
Date:   Tue, 23 May 2023 07:12:07 -0700
Message-ID: <CAD=FV=W5HrBFakvoX-cQ5G=4xV1upkFPZ6aSR8me+d+aCpirgg@mail.gmail.com>
Subject: Re: [PATCH] watchdog: set variables watchdog_soft,hardlockup_user_enabled
 storage-class-specifier to static
To:     Tom Rix <trix@redhat.com>
Cc:     akpm@linux-foundation.org, pmladek@suse.com, kernelfans@gmail.com,
        lecopzer.chen@mediatek.com, ldufour@linux.ibm.com,
        linux-kernel@vger.kernel.org
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Hi,

On Tue, May 23, 2023 at 5:23=E2=80=AFAM Tom Rix <trix@redhat.com> wrote:
>
> smatch reports
> kernel/watchdog.c:40:19: warning: symbol
>   'watchdog_hardlockup_user_enabled' was not declared. Should it be stati=
c?
> kernel/watchdog.c:41:19: warning: symbol
>   'watchdog_softlockup_user_enabled' was not declared. Should it be stati=
c?
>
> These variabled are only used in their defining file, so it should be sta=
tic.

s/variabled/variables

>
> Signed-off-by: Tom Rix <trix@redhat.com>
> ---
>  kernel/watchdog.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

While your fix is valid (thanks!), it's only half the fix.

I wondered why smatch would have suddenly noticed this since the
change that touched this variable recently was only a rename. When I
dug deeper, I realized that the old names actually _were_ referenced
outside this file and my rename missed them. The reason I missed them
is that the only reference is an "extern" reference in
`include/linux/nmi.h`. The references in `include/linux/nmi.h`
probably should have been removed in commit dd0693fdf054 ("watchdog:
move watchdog sysctl interface to watchdog.c")

...so a more complete fix would also remove references to the old
names (nmi_watchdog_user_enabled and soft_watchdog_user_enabled) in
`include/linux/nmi.h`.

-Doug