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Fri, 29 May 2026 13:21:50 -0400 X-MC-Unique: CGkRtYNWMaS4VWvGCBj3QQ-1 X-Mimecast-MFC-AGG-ID: CGkRtYNWMaS4VWvGCBj3QQ_1780075309 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 57C491956089; Fri, 29 May 2026 17:21:49 +0000 (UTC) Received: from [10.22.64.54] (unknown [10.22.64.54]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id BE1D31800347; Fri, 29 May 2026 17:21:47 +0000 (UTC) Message-ID: <12e4a916-fb6c-459b-8c96-2fe2872155e0@redhat.com> Date: Fri, 29 May 2026 13:21:46 -0400 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] locking/rwsem: add scoped guard for down_read_killable() To: Oleg Nesterov , Peter Zijlstra , Ingo Molnar , Will Deacon , Boqun Feng Cc: Marco Elver , Christian Brauner , linux-kernel@vger.kernel.org References: Content-Language: en-US From: Waiman Long In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 On 5/29/26 10:16 AM, Oleg Nesterov wrote: > We have lock guards for down_read_trylock/interruptible() but > down_read_killable() is missing. > > At least scoped_cond_guard(rwsem_read_kill, signal->exec_update_lock) > can have a lot of users: __pidfd_fget(), mm_access(), find_mm_struct(), > kernel_migrate_pages(), and probably more. > > Signed-off-by: Oleg Nesterov > --- > include/linux/rwsem.h | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h > index 6a1a7bae5f81..f0cc72d8f0f2 100644 > --- a/include/linux/rwsem.h > +++ b/include/linux/rwsem.h > @@ -259,6 +259,7 @@ extern void up_write(struct rw_semaphore *sem) __releases(sem); > DEFINE_LOCK_GUARD_1(rwsem_read, struct rw_semaphore, down_read(_T->lock), up_read(_T->lock)) > DEFINE_LOCK_GUARD_1_COND(rwsem_read, _try, down_read_trylock(_T->lock)) > DEFINE_LOCK_GUARD_1_COND(rwsem_read, _intr, down_read_interruptible(_T->lock), _RET == 0) > +DEFINE_LOCK_GUARD_1_COND(rwsem_read, _kill, down_read_killable(_T->lock), _RET == 0) > > DECLARE_LOCK_GUARD_1_ATTRS(rwsem_read, __acquires_shared(_T), __releases_shared(*(struct rw_semaphore **)_T)) > #define class_rwsem_read_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(rwsem_read, _T) > @@ -266,6 +267,8 @@ DECLARE_LOCK_GUARD_1_ATTRS(rwsem_read_try, __acquires_shared(_T), __releases_sha > #define class_rwsem_read_try_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(rwsem_read_try, _T) > DECLARE_LOCK_GUARD_1_ATTRS(rwsem_read_intr, __acquires_shared(_T), __releases_shared(*(struct rw_semaphore **)_T)) > #define class_rwsem_read_intr_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(rwsem_read_intr, _T) > +DECLARE_LOCK_GUARD_1_ATTRS(rwsem_read_kill, __acquires_shared(_T), __releases_shared(*(struct rw_semaphore **)_T)) > +#define class_rwsem_read_kill_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(rwsem_read_kill, _T) > > DEFINE_LOCK_GUARD_1(rwsem_write, struct rw_semaphore, down_write(_T->lock), up_write(_T->lock)) > DEFINE_LOCK_GUARD_1_COND(rwsem_write, _try, down_write_trylock(_T->lock)) Acked-by: Waiman Long