From nobody Fri Dec 19 04:54:27 2025 Received: from smtp-fw-52004.amazon.com (smtp-fw-52004.amazon.com [52.119.213.154]) (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 1B7571F8AC4 for ; Wed, 4 Dec 2024 14:20:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=52.119.213.154 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733322013; cv=none; b=BxuM+DuTbvuPsAKF99DPfqP1lobIxekV6i3vXWhTotRUeTcci3zI7yxYyt9DrGjcVyVknixyQhCcnkcJsDv2K5QubCADyiqES3o9MnqpUdko97Xj2/id3eII0YmHi615s/s+qmi6NEbfDsDSQKYk0S9QB3miNapxyGUXajPTtag= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733322013; c=relaxed/simple; bh=PdzN3Dh/ibgi1YnB8NJstOK1zIHw2+a8hUG3YJsMoC4=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ibUCCUGXBeKDK6Rdh9/uXkI9kzA6GiIKL1ID/WIpEotdouU3uu8P1+Mc6xN7IikI4adJqL7hidLXBrWwT1lf6TKV3yzja6UD9mDc57SxxTuChBu8MCnVFWRCE9n3H/kKpSffnIKp8SWSpEqATOJ76iNS2C+UhCnaZDo2RhhcBu4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com; spf=pass smtp.mailfrom=amazon.com; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b=iocfXi3I; arc=none smtp.client-ip=52.119.213.154 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=amazon.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="iocfXi3I" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1733322011; x=1764858011; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=5mJN0xDsc3RBo9kCI5VpP+8GDP08z7fNPcgv7+CVrqU=; b=iocfXi3ItbcYlxNY0+ZO5WmtcdJbS6pJFM1g04OBNBlXSiewrTMeI0SW s5NKtb+yq71m7Jzk4oS9mP8SRMZxuixHIwt/rUEltoMr+K1qM22hMmh67 PsMI+MObNTefeXZSnHPBgV/OzERiSJfURHWqYplJ5rTu532h/7SYzcSTZ Y=; X-IronPort-AV: E=Sophos;i="6.12,207,1728950400"; d="scan'208";a="252220900" Received: from iad6-co-svc-p1-lb1-vlan2.amazon.com (HELO smtpout.prod.us-west-2.prod.farcaster.email.amazon.dev) ([10.124.125.2]) by smtp-border-fw-52004.iad7.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Dec 2024 14:20:05 +0000 Received: from EX19MTAEUA001.ant.amazon.com [10.0.10.100:35215] by smtpin.naws.eu-west-1.prod.farcaster.email.amazon.dev [10.0.23.253:2525] with esmtp (Farcaster) id 4f701277-230b-4dbe-9bbd-a2fd4c729600; Wed, 4 Dec 2024 14:20:04 +0000 (UTC) X-Farcaster-Flow-ID: 4f701277-230b-4dbe-9bbd-a2fd4c729600 Received: from EX19D018EUA004.ant.amazon.com (10.252.50.85) by EX19MTAEUA001.ant.amazon.com (10.252.50.223) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1258.35; Wed, 4 Dec 2024 14:20:04 +0000 Received: from EX19MTAUEB002.ant.amazon.com (10.252.135.47) by EX19D018EUA004.ant.amazon.com (10.252.50.85) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1258.34; Wed, 4 Dec 2024 14:20:04 +0000 Received: from email-imr-corp-prod-iad-all-1b-1323ce6b.us-east-1.amazon.com (10.124.125.2) by mail-relay.amazon.com (10.252.135.97) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1258.34 via Frontend Transport; Wed, 4 Dec 2024 14:20:04 +0000 Received: from dev-dsk-farbere-1a-46ecabed.eu-west-1.amazon.com (dev-dsk-farbere-1a-46ecabed.eu-west-1.amazon.com [172.19.116.181]) by email-imr-corp-prod-iad-all-1b-1323ce6b.us-east-1.amazon.com (Postfix) with ESMTP id E07CC4056B; Wed, 4 Dec 2024 14:20:03 +0000 (UTC) Received: by dev-dsk-farbere-1a-46ecabed.eu-west-1.amazon.com (Postfix, from userid 14301484) id A058A7595; Wed, 4 Dec 2024 14:20:03 +0000 (UTC) From: Eliav Farber To: , , , , , , , , , , , , , , , , , , , , , , , CC: Subject: [PATCH v6 2/2] kexec: Prevent redundant IRQ masking by checking state before shutdown Date: Wed, 4 Dec 2024 14:20:03 +0000 Message-ID: <20241204142003.32859-3-farbere@amazon.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20241204142003.32859-1-farbere@amazon.com> References: <20241204142003.32859-1-farbere@amazon.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" During machine kexec, the function machine_kexec_mask_interrupts() is responsible for disabling or masking all interrupts. While the irq_disable hook ensures that an already-disabled IRQ is not disabled again, the current implementation unconditionally invokes the irq_mask() function for every interrupt descriptor, even when the interrupt is already masked. A specific issue was observed in the crash kernel flow after unbinding a device (prior to kexec) that used a GPIO as an IRQ source. The warning was triggered by the gpiochip_disable_irq() function, which attempted to clear the FLAG_IRQ_IS_ENABLED flag when FLAG_USED_AS_IRQ was not set: ``` void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset) { struct gpio_desc *desc =3D gpiochip_get_desc(gc, offset); if (!IS_ERR(desc) && !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags); } ``` This issue surfaced after commit a8173820f441 ("gpio: gpiolib: Allow GPIO IRQs to lazy disable") introduced lazy disablement for GPIO IRQs. It replaced disable/enable hooks with mask/unmask hooks. Unlike the disable hook, the mask hook doesn't handle already-masked IRQs. When a GPIO-IRQ driver is unbound, the IRQ is released, triggering __irq_disable() and irq_state_set_masked(). A subsequent call to machine_kexec_mask_interrupts() re-invokes chip->irq_mask(). This results in a call chain, including gpiochip_irq_mask() and gpiochip_disable_irq(). Since FLAG_USED_AS_IRQ was cleared earlier, a warning occurs. Replace calls to irq_mask() and irq_disable() hooks with a simplified call to irq_shutdown(), and check if the interrupt is started (irqd_is_started) before calling the shutdown. Signed-off-by: Eliav Farber --- V5 -> V6: No changes. kernel/irq/kexec.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/kernel/irq/kexec.c b/kernel/irq/kexec.c index 0f9548c1708d..1a3deffe6b5b 100644 --- a/kernel/irq/kexec.c +++ b/kernel/irq/kexec.c @@ -17,7 +17,7 @@ void machine_kexec_mask_interrupts(void) int check_eoi =3D 1; =20 chip =3D irq_desc_get_chip(desc); - if (!chip) + if (!chip || !irqd_is_started(&desc->irq_data)) continue; =20 if (IS_ENABLED(CONFIG_GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD)) { @@ -31,10 +31,6 @@ void machine_kexec_mask_interrupts(void) if (check_eoi && chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data)) chip->irq_eoi(&desc->irq_data); =20 - if (chip->irq_mask) - chip->irq_mask(&desc->irq_data); - - if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data)) - chip->irq_disable(&desc->irq_data); + irq_shutdown(desc); } } --=20 2.40.1