From nobody Sun Feb 8 04:11:49 2026 Received: from smtp-fw-2101.amazon.com (smtp-fw-2101.amazon.com [72.21.196.25]) (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 20CA81AAE37 for ; Sat, 30 Nov 2024 20:11:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=72.21.196.25 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732997515; cv=none; b=iMQ/yDvihdO6E/IPHn7y9nHt7q+s9M3yEsMlCWYlrzi/hAPSmOcJUkCMnoZ6E4MVQyzZoxiTqzQ503Kx+OgHSc1dF/K3yfJ4ytLnE5bIbMjsyLUz0uTbSJxo3Kf6B4ops4rRASppDbQnsQ8S4O+CdfKv6m3KR8B5XcK3CFymYpc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732997515; c=relaxed/simple; bh=g92KyX6CAIPOtrfBng7B/GZYyEPmh6nGdN2J1VAHcy8=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Wj+MqcH7q/d3B7TM2TKrUFC4OEcVxDGlFhcnJvE43G4yxI4NPWuZ4ogR0tySZBK0R+TeNVs02cdVmS+JYiYFtuEBrKt0lV9REeFTpRRZT99ZxN/Vdb2KPtkmO6G8FEfvPnKtr/T02NvNMuAOgHmaQGUMJ6qMm4Wf7PBQptyvYNI= 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=JRaoZ/aK; arc=none smtp.client-ip=72.21.196.25 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="JRaoZ/aK" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1732997515; x=1764533515; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=zoZ/+qDc221WdsVhvoxlHSC6W9U8KUsHn4lZh61HM1Y=; b=JRaoZ/aKsQXXtXy+x7uwDNs9T0bzx+25VcyoKLkDwAR0yZaePhUVu4de mA5/eWJ0gxYpGzDe1FkhqoQXsAmNHIQH8CENhXIMAYKkwnRJLkNKJAjcW HFcC+Pu2YIRVgny4DvPxJtFng+BRbr3Q4P2+p2AD0ovo6rg7XQRlOsZv8 k=; X-IronPort-AV: E=Sophos;i="6.12,199,1728950400"; d="scan'208";a="447165625" Received: from iad6-co-svc-p1-lb1-vlan3.amazon.com (HELO smtpout.prod.us-west-2.prod.farcaster.email.amazon.dev) ([10.124.125.6]) by smtp-border-fw-2101.iad2.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Nov 2024 20:11:50 +0000 Received: from EX19MTAUWA002.ant.amazon.com [10.0.21.151:19230] by smtpin.naws.us-west-2.prod.farcaster.email.amazon.dev [10.0.32.230:2525] with esmtp (Farcaster) id a6a52d1b-8c83-4dfa-ade4-e0f66ee20537; Sat, 30 Nov 2024 20:11:48 +0000 (UTC) X-Farcaster-Flow-ID: a6a52d1b-8c83-4dfa-ade4-e0f66ee20537 Received: from EX19D013UWB003.ant.amazon.com (10.13.138.111) by EX19MTAUWA002.ant.amazon.com (10.250.64.202) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1258.34; Sat, 30 Nov 2024 20:11:44 +0000 Received: from EX19MTAUWB001.ant.amazon.com (10.250.64.248) by EX19D013UWB003.ant.amazon.com (10.13.138.111) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1258.34; Sat, 30 Nov 2024 20:11:44 +0000 Received: from email-imr-corp-prod-iad-all-1a-47ca2651.us-east-1.amazon.com (10.25.36.214) by mail-relay.amazon.com (10.250.64.254) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1258.34 via Frontend Transport; Sat, 30 Nov 2024 20:11:44 +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-1a-47ca2651.us-east-1.amazon.com (Postfix) with ESMTP id D7D6F404CE; Sat, 30 Nov 2024 20:11:43 +0000 (UTC) Received: by dev-dsk-farbere-1a-46ecabed.eu-west-1.amazon.com (Postfix, from userid 14301484) id 96751719D; Sat, 30 Nov 2024 20:11:43 +0000 (UTC) From: Eliav Farber To: , , , , , , , , , , , , , , , , , , , , , , , CC: Subject: [PATCH v5 2/2] kexec: Prevent redundant IRQ masking by checking state before shutdown Date: Sat, 30 Nov 2024 20:11:43 +0000 Message-ID: <20241130201143.48808-3-farbere@amazon.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20241130201143.48808-1-farbere@amazon.com> References: <20241130201143.48808-1-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 --- V4 -> V5: - The phrase 'This patch' has been removed from the commit message. 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