Re: [PATCH] locking/lockdep: Dump state of percpu_rwsem upon hung up.

[Will Deacon <will.deacon@arm.com>]

On Tue, Jul 10, 2018 at 03:10:51PM +0900, Tetsuo Handa wrote:
> From 2642b4a1904259384f2018ea8df03ac49509c57a Mon Sep 17 00:00:00 2001
> From: Tetsuo Handa <penguin-kernel@I-love.SKAURA.ne.jp>
> Date: Tue, 10 Jul 2018 15:01:20 +0900
> Subject: [PATCH] locking/rwsem: Convert the other sem->count to 'atomic_long_t'
> 
> Since "locking/rwsem: Convert sem->count to 'atomic_long_t'" forgot to
> convert "struct rw_semaphore"->count in linux/rwsem-spinlock.h which is
> used when CONFIG_RWSEM_GENERIC_SPINLOCK=y, trying to access it in MIPS
> architecture causes build error due to type mismatch.
> 
>   error: passing argument 1 of 'atomic_long_read' from incompatible pointer type [-Werror=incompatible-pointer-types]
>   note: expected 'const atomic_long_t * {aka const struct <anonymous> *}' but argument is of type '__s32 * {aka int *}'
> 
> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SKAURA.ne.jp>
> Reported-by: kbuild test robot <lkp@intel.com>
> Fixes: 8ee62b1870be8e63 ("locking/rwsem: Convert sem->count to 'atomic_long_t'")
> Cc: stable <stable@vger.kernel.org> # v4.8+
> Cc: Jason Low <jason.low2@hpe.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> ---
>  include/linux/rwsem-spinlock.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Hmm, how come you don't have to update kernel/locking/rwsem-spinlock.c
as well? I see stuff such as:

	sem->count += woken;

in there.

Will