From patchwork Wed Dec 11 21:01:51 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tejun Heo X-Patchwork-Id: 13904197 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BFD261D88D3; Wed, 11 Dec 2024 21:01:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733950912; cv=none; b=StZWLz+35SXgxGNguMSeVaiMRENxYqaYhaSIHIkODrEx7zFrvR61+lxu+bOcQlTPP0lDp6/p1R+NpTOyXqEN/9/YnzEtGweXwRMeskAPK4ly+aKDvKK5tmObqbR8HcD9DSFT0xXey+0f+CezVRuYnGdmjJCEWmn6k70vwqQvRyU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733950912; c=relaxed/simple; bh=dQnmoWONT5Zo+IkP2sm37LSCIsWrY5YPNyx39MAvgBI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=s4IfQBsHWTELYKp49p5sOEOLj0KIvc8nJ6e4leswoIPpYJ7eN7zRzgZpsYfrZ3NhFKYHUbNWiCC3ADXga6WIan5XJkTf6sFlBh/LPfSqCJQI8f9JMyAJ2M5Histeks76TtAJnoqYvV/2t/19k0yg8AVrsr8zTDgM3cozclXzXRc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GMZ6hcwL; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="GMZ6hcwL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 29D72C4CED2; Wed, 11 Dec 2024 21:01:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1733950912; bh=dQnmoWONT5Zo+IkP2sm37LSCIsWrY5YPNyx39MAvgBI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=GMZ6hcwLgY5CuexEHbWUkzg9oEtO4r82tLO75t7aa+WBwtCIIzBYMwboKaX8U7SXE babeq9B+PtSh4DoAHGI5WLO3fNJ9qra8LlC+wlwR+oeJw66cDlEkdemeMzyr2t4ogc lUtN/oXzatlxclTdclt/nfCbZJ6vrtzS7HOiHS/vKNrHRK8ZmZCTEeJvrNgH534E+B xcAkUqiahziRV+RLcoq8AtLAG9zSJIewEbMcSRYLcnZx+YkoKg/NxNNqxM95poZkMG /Hy8tmpPHXoHTL7Dzzi2a6Yjwow2F6UShuy3ba5DfqteBYkJcBAduuHKIWEpOgAyjI JRyS+dNVazqww== Date: Wed, 11 Dec 2024 11:01:51 -1000 From: Tejun Heo To: Ihor Solodrai Cc: David Vernet , sched-ext@meta.com, kernel-team@meta.com, linux-kernel@vger.kernel.org, bpf Subject: [PATCH sched_ext/for-6.13-fixes] sched_ext: Fix invalid irq restore in scx_ops_bypass() Message-ID: References: <20241209152924.4508-1-void@manifault.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: While adding outer irqsave/restore locking, 0e7ffff1b811 ("scx: Fix raciness in scx_ops_bypass()") forgot to convert an inner rq_unlock_irqrestore() to rq_unlock() which could re-enable IRQ prematurely leading to the following warning: raw_local_irq_restore() called with IRQs enabled WARNING: CPU: 1 PID: 96 at kernel/locking/irqflag-debug.c:10 warn_bogus_irq_restore+0x30/0x40 ... Sched_ext: create_dsq (enabling) pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : warn_bogus_irq_restore+0x30/0x40 lr : warn_bogus_irq_restore+0x30/0x40 ... Call trace: warn_bogus_irq_restore+0x30/0x40 (P) warn_bogus_irq_restore+0x30/0x40 (L) scx_ops_bypass+0x224/0x3b8 scx_ops_enable.isra.0+0x2c8/0xaa8 bpf_scx_reg+0x18/0x30 ... irq event stamp: 33739 hardirqs last enabled at (33739): [] scx_ops_bypass+0x174/0x3b8 hardirqs last disabled at (33738): [] _raw_spin_lock_irqsave+0xb4/0xd8 Drop the stray _irqrestore(). Signed-off-by: Tejun Heo Reported-by: Ihor Solodrai Link: http://lkml.kernel.org/r/qC39k3UsonrBYD_SmuxHnZIQLsuuccoCrkiqb_BT7DvH945A1_LZwE4g-5Pu9FcCtqZt4lY1HhIPi0homRuNWxkgo1rgP3bkxa0donw8kV4=@pm.me Fixes: 0e7ffff1b811 ("scx: Fix raciness in scx_ops_bypass()") Cc: stable@vger.kernel.org # v6.12 Tested-by: Ihor Solodrai ihor.solodrai@pm.me --- kernel/sched/ext.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index 7fff1d045477..98519e6d0dcd 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -4763,7 +4763,7 @@ static void scx_ops_bypass(bool bypass) * sees scx_rq_bypassing() before moving tasks to SCX. */ if (!scx_enabled()) { - rq_unlock_irqrestore(rq, &rf); + rq_unlock(rq, &rf); continue; }