From nobody Wed Nov 5 00:52:04 2025 Received: from mail-pg1-f202.google.com (mail-pg1-f202.google.com [209.85.215.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A4AB4185614 for ; Tue, 9 Jul 2024 20:32:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720557154; cv=none; b=d3NbQRuB91TSicd+Qbej+kgfmR1FyabAG43daPMqPY6UxLbrC6THZqYD1u2F95KjWD/F9fMOTSQl3rJ6N23t1PipcY39hxucypDNp/HDIUqt4HSFu0OPaflJ6zIrlQ9pQiWm9aNlsDoeEnePyqEyzKhs1PF6dRLfIin1R02rBqU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720557154; c=relaxed/simple; bh=8WwFP5CCf9stN1FiTOlKvBC5zqi6xiZP0UDWiU8fL0k=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=t5E24m11nQhScZI/e+oVaEUAsxkCdTJfWiK5PxYrAG2t6wyxAqBCoDrkT554sqmjYXWpzcqz6517uXs5QYYl+SNkfFyMniZqlzXnaItgxca3swqcMYNWQd3YvH/F3PHa6JRE4te6XQiRCsmJa9k2KxDiUlIivFReS3F+HVfca2A= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--jstultz.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=kRriDddW; arc=none smtp.client-ip=209.85.215.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--jstultz.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="kRriDddW" Received: by mail-pg1-f202.google.com with SMTP id 41be03b00d2f7-5e4df21f22dso84516a12.0 for ; Tue, 09 Jul 2024 13:32:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1720557151; x=1721161951; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=dLvTAbNH73dBrl7bNnyR5edCKfFkbAVRdkATgKgoksk=; b=kRriDddWYlXlgFyqUDT6O5yMU+O7f1xMIClEigxPga0u5tVetcpX++Fzf+1h8JqwKP N9tM1fOmvduAZytY50/dsUiDsgpF24s824T5by2S3pCsYK6vb818TlFyLIw9YZ5svr/M nu30flUOuGbxaqVQU1EAoPYCt0zKUJnDEYMiI1M1nTZmqSkaUteWWMwYkxKfgBA3HziE WnyEM83I2Ab/0fb3if1Xmij1qaEkjbiOOZubR8NUqrMdANVhPzMkXa8k+TWJlqoBiwCV 8yr2YJc48Lb56KA7Ejs2W0qzViJ9ACKL89BNJMLfXjIdel8JIpyFPS/ocKOr/94R+qLK kF2w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1720557151; x=1721161951; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=dLvTAbNH73dBrl7bNnyR5edCKfFkbAVRdkATgKgoksk=; b=KHOiDssZOWURzFsslrVFyYV5ucLru5yk0aXCgo0SliyYrN1xzuoVNFfNaepBmhzOuX 25VuybLLVgDR5ZL/xHVGr6/MchOwnqiLVcuzdr5AYFwQ99NTLHAIYMKO3udwcpSkwha7 u7rq2XcA8IOGyJFnlAfyUXzGaDk8XO0aTES3jtlk3UegXrW/ClsaFp9PYKL9FoqT3qwN dgpGWAI6kLCPeE76fPrrLYD4jdb44v49/7z1N00xjB/AnFFAELnD/wScVpFxX0c5NQGV tS9b2kmEzW+4kDoZTlxwAKBgP7KGlrSNIfrDtzSYDgbU1sFoM5BpbOrfdFV3HNx7Wkg1 iu+Q== X-Gm-Message-State: AOJu0YwfOETly6t5c9XANuH2FcvEkKF6wxGR4eh18w05XLfnoouXVc7I KYhfWL0OsKN8lQDHgeVcYGFthpe+m2X87Q5j8EoFfyqZq1dlpyr0Qe5XjKJovs1rYENKtqwRReP uQSZaX478SLIM6qXfkzEQqkfqc778MVM6YLqPDjRiFReaOqwOf3cESgDxI9km/Ih6SdUC+JBoLT qXHqDfQTtVn/hfdbeom5ePVt2DcOflACiRvNX3Y31CsrbF X-Google-Smtp-Source: AGHT+IGMvCZToZeHj65S2vUnjRIIe0nCFMOuJ9QbdPNkwAiB09LaXZrmLtpISjk6zta7Lvx8LztCl8RRgrDp X-Received: from jstultz-noogler2.c.googlers.com ([fda3:e722:ac3:cc00:24:72f4:c0a8:600]) (user=jstultz job=sendgmr) by 2002:a65:67da:0:b0:70e:1058:e16c with SMTP id 41be03b00d2f7-77dfededd53mr8536a12.1.1720557148168; Tue, 09 Jul 2024 13:32:28 -0700 (PDT) Date: Tue, 9 Jul 2024 13:31:45 -0700 In-Reply-To: <20240709203213.799070-1-jstultz@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240709203213.799070-1-jstultz@google.com> X-Mailer: git-send-email 2.45.2.993.g49e7a77208-goog Message-ID: <20240709203213.799070-3-jstultz@google.com> Subject: [PATCH v11 2/7] locking/mutex: Make mutex::wait_lock irq safe From: John Stultz To: LKML Cc: Juri Lelli , Joel Fernandes , Qais Yousef , Ingo Molnar , Peter Zijlstra , Vincent Guittot , Dietmar Eggemann , Valentin Schneider , Steven Rostedt , Ben Segall , Zimuzo Ezeozue , Youssef Esmat , Mel Gorman , Will Deacon , Waiman Long , Boqun Feng , "Paul E. McKenney" , Metin Kaya , Xuewen Yan , K Prateek Nayak , Thomas Gleixner , Daniel Lezcano , kernel-team@android.com, "Connor O'Brien" , John Stultz , Metin Kaya Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Juri Lelli mutex::wait_lock might be nested under rq->lock. Make it irq safe then. Cc: Joel Fernandes Cc: Qais Yousef Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Juri Lelli Cc: Vincent Guittot Cc: Dietmar Eggemann Cc: Valentin Schneider Cc: Steven Rostedt Cc: Ben Segall Cc: Zimuzo Ezeozue Cc: Youssef Esmat Cc: Mel Gorman Cc: Will Deacon Cc: Waiman Long Cc: Boqun Feng Cc: "Paul E. McKenney" Cc: Metin Kaya Cc: Xuewen Yan Cc: K Prateek Nayak Cc: Thomas Gleixner Cc: Daniel Lezcano Cc: kernel-team@android.com Signed-off-by: Juri Lelli Signed-off-by: Peter Zijlstra (Intel) [rebase & fix {un,}lock_wait_lock helpers in ww_mutex.h] Signed-off-by: Connor O'Brien Signed-off-by: John Stultz Tested-by: K Prateek Nayak Tested-by: Metin Kaya Reviewed-by: Metin Kaya Reviewed-by: Valentin Schneider --- v3: * Re-added this patch after it was dropped in v2 which caused lockdep warnings to trip. v7: * Fix function definition for PREEMPT_RT case, as pointed out by Metin Kaya. * Fix incorrect flags handling in PREEMPT_RT case as found by Metin Kaya --- kernel/locking/mutex.c | 18 ++++++++++-------- kernel/locking/ww_mutex.h | 22 +++++++++++----------- 2 files changed, 21 insertions(+), 19 deletions(-) diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c index 4269da1f3ef5..6d843a0978a5 100644 --- a/kernel/locking/mutex.c +++ b/kernel/locking/mutex.c @@ -578,6 +578,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int st= ate, unsigned int subclas DEFINE_WAKE_Q(wake_q); struct mutex_waiter waiter; struct ww_mutex *ww; + unsigned long flags; int ret; =20 if (!use_ww_ctx) @@ -620,7 +621,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int st= ate, unsigned int subclas return 0; } =20 - raw_spin_lock(&lock->wait_lock); + raw_spin_lock_irqsave(&lock->wait_lock, flags); /* * After waiting to acquire the wait_lock, try again. */ @@ -681,7 +682,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int st= ate, unsigned int subclas goto err; } =20 - raw_spin_unlock(&lock->wait_lock); + raw_spin_unlock_irqrestore(&lock->wait_lock, flags); /* Make sure we do wakeups before calling schedule */ if (!wake_q_empty(&wake_q)) { wake_up_q(&wake_q); @@ -707,9 +708,9 @@ __mutex_lock_common(struct mutex *lock, unsigned int st= ate, unsigned int subclas trace_contention_begin(lock, LCB_F_MUTEX); } =20 - raw_spin_lock(&lock->wait_lock); + raw_spin_lock_irqsave(&lock->wait_lock, flags); } - raw_spin_lock(&lock->wait_lock); + raw_spin_lock_irqsave(&lock->wait_lock, flags); acquired: __set_current_state(TASK_RUNNING); =20 @@ -735,7 +736,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int st= ate, unsigned int subclas if (ww_ctx) ww_mutex_lock_acquired(ww, ww_ctx); =20 - raw_spin_unlock(&lock->wait_lock); + raw_spin_unlock_irqrestore(&lock->wait_lock, flags); wake_up_q(&wake_q); preempt_enable(); return 0; @@ -745,7 +746,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int st= ate, unsigned int subclas __mutex_remove_waiter(lock, &waiter); err_early_kill: trace_contention_end(lock, ret); - raw_spin_unlock(&lock->wait_lock); + raw_spin_unlock_irqrestore(&lock->wait_lock, flags); debug_mutex_free_waiter(&waiter); mutex_release(&lock->dep_map, ip); wake_up_q(&wake_q); @@ -916,6 +917,7 @@ static noinline void __sched __mutex_unlock_slowpath(st= ruct mutex *lock, unsigne struct task_struct *next =3D NULL; DEFINE_WAKE_Q(wake_q); unsigned long owner; + unsigned long flags; =20 mutex_release(&lock->dep_map, ip); =20 @@ -942,7 +944,7 @@ static noinline void __sched __mutex_unlock_slowpath(st= ruct mutex *lock, unsigne } } =20 - raw_spin_lock(&lock->wait_lock); + raw_spin_lock_irqsave(&lock->wait_lock, flags); debug_mutex_unlock(lock); if (!list_empty(&lock->wait_list)) { /* get the first entry from the wait-list: */ @@ -960,7 +962,7 @@ static noinline void __sched __mutex_unlock_slowpath(st= ruct mutex *lock, unsigne __mutex_handoff(lock, next); =20 preempt_disable(); - raw_spin_unlock(&lock->wait_lock); + raw_spin_unlock_irqrestore(&lock->wait_lock, flags); wake_up_q(&wake_q); preempt_enable(); } diff --git a/kernel/locking/ww_mutex.h b/kernel/locking/ww_mutex.h index 7189c6631d90..9facc0ddfdd3 100644 --- a/kernel/locking/ww_mutex.h +++ b/kernel/locking/ww_mutex.h @@ -70,14 +70,14 @@ __ww_mutex_has_waiters(struct mutex *lock) return atomic_long_read(&lock->owner) & MUTEX_FLAG_WAITERS; } =20 -static inline void lock_wait_lock(struct mutex *lock) +static inline void lock_wait_lock(struct mutex *lock, unsigned long *flags) { - raw_spin_lock(&lock->wait_lock); + raw_spin_lock_irqsave(&lock->wait_lock, *flags); } =20 -static inline void unlock_wait_lock(struct mutex *lock) +static inline void unlock_wait_lock(struct mutex *lock, unsigned long *fla= gs) { - raw_spin_unlock(&lock->wait_lock); + raw_spin_unlock_irqrestore(&lock->wait_lock, *flags); } =20 static inline void lockdep_assert_wait_lock_held(struct mutex *lock) @@ -144,14 +144,14 @@ __ww_mutex_has_waiters(struct rt_mutex *lock) return rt_mutex_has_waiters(&lock->rtmutex); } =20 -static inline void lock_wait_lock(struct rt_mutex *lock) +static inline void lock_wait_lock(struct rt_mutex *lock, unsigned long *fl= ags) { - raw_spin_lock(&lock->rtmutex.wait_lock); + raw_spin_lock_irqsave(&lock->rtmutex.wait_lock, *flags); } =20 -static inline void unlock_wait_lock(struct rt_mutex *lock) +static inline void unlock_wait_lock(struct rt_mutex *lock, unsigned long *= flags) { - raw_spin_unlock(&lock->rtmutex.wait_lock); + raw_spin_unlock_irqrestore(&lock->rtmutex.wait_lock, *flags); } =20 static inline void lockdep_assert_wait_lock_held(struct rt_mutex *lock) @@ -380,6 +380,7 @@ static __always_inline void ww_mutex_set_context_fastpath(struct ww_mutex *lock, struct ww_acquire_ctx= *ctx) { DEFINE_WAKE_Q(wake_q); + unsigned long flags; =20 ww_mutex_lock_acquired(lock, ctx); =20 @@ -408,10 +409,9 @@ ww_mutex_set_context_fastpath(struct ww_mutex *lock, s= truct ww_acquire_ctx *ctx) * Uh oh, we raced in fastpath, check if any of the waiters need to * die or wound us. */ - lock_wait_lock(&lock->base); + lock_wait_lock(&lock->base, &flags); __ww_mutex_check_waiters(&lock->base, ctx, &wake_q); - unlock_wait_lock(&lock->base); - + unlock_wait_lock(&lock->base, &flags); wake_up_q(&wake_q); } =20 --=20 2.45.2.993.g49e7a77208-goog