From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from abb.hmeau.com (abb.hmeau.com [144.6.53.87]) (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 0500E1F1522; Mon, 23 Jun 2025 09:24:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=144.6.53.87 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750670698; cv=none; b=Pcpvu2MDymTyYnoD5JhsRK2hOTk0gaxTFzK/VI/GHeuibijlx5XQNU0OLEYR7YlzQkyLTtkPu0nx4aaPqlmFfEgeG0ao8VqQT9VQSygMo3YuFY1hqQHga0riH8va/AkHnOJHlAa0VQfE4L25jNVNMV7ix7PjlFzWZVbAbPi+V38= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750670698; c=relaxed/simple; bh=yxximNRZg10fk70Q/eGnQ3KnoNbsSsD9NHTqlJs2ZC4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=AlvwVVTG67aZqHEPjEJRh5O1DfvWuiDoda4sb4qryrws/eGXzByZBWzSEeKGvlpRrgzGBQ0wo3bza5poX5qFGzGbIMcuJeGHByMcu3zXTHJrtcGaj4AqsvW0og+F+tZ8aDIVMabSO9nueyV3Mtv4pCtrovW/GtF8fj3ga5YkpCg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=gondor.apana.org.au; spf=pass smtp.mailfrom=gondor.apana.org.au; dkim=pass (2048-bit key) header.d=hmeau.com header.i=@hmeau.com header.b=l9AhgzrC; arc=none smtp.client-ip=144.6.53.87 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=gondor.apana.org.au Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gondor.apana.org.au Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=hmeau.com header.i=@hmeau.com header.b="l9AhgzrC" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=hmeau.com; s=formenos; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=WYO6dUwunWcz7wqIiPUd0m6sJh2n71+M5Cw939+rQ/c=; b=l9AhgzrCOXC/8F7TPB047C1Yzn k8leIX5hUWqLGKBzUTl2CgMFmuO/+PLau/3cGqmFsM0o3nfrA4Y/c3lDJvqZu2zoTbFJ9uprXYokD McBEWZnFs7yheb1sZrk2WNnagX7WrGtIDcA+/DjiPdgtWFCB8Ybta4iG6ScV+5MNB8NKcAq4JaL4c 4yD1qQOIEqucvjwevfRNhKAuDA5EvCRIltfWN3/L0HmXy8+Hx5yaX9TPumhH4KJbJ4NPwjWYYd8pu k5FiU8bvFRfmMOeIkG2/eUafbx7SsIhYKYqBCWyc4nKqKuV24VR1cM9krjKZeDCoPoKBJgyuSfzds RVpMzAkg==; Received: from loth.rohan.me.apana.org.au ([192.168.167.2]) by formenos.hmeau.com with smtp (Exim 4.96 #2 (Debian)) id 1uTdAa-000FeC-2O; Mon, 23 Jun 2025 17:24:50 +0800 Received: by loth.rohan.me.apana.org.au (sSMTP sendmail emulation); Mon, 23 Jun 2025 17:24:49 +0800 Date: Mon, 23 Jun 2025 17:24:49 +0800 From: Herbert Xu To: Ashish Kalra Cc: thomas.lendacky@amd.com, john.allen@amd.com, davem@davemloft.net, aik@amd.com, dionnaglaze@google.com, michael.roth@amd.com, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [RESEND PATCH v3] crypto: ccp: Fix SNP panic notifier unregistration Message-ID: References: <20250616215027.68768-1-Ashish.Kalra@amd.com> Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250616215027.68768-1-Ashish.Kalra@amd.com> On Mon, Jun 16, 2025 at 09:50:27PM +0000, Ashish Kalra wrote: > From: Ashish Kalra > > Panic notifiers are invoked with RCU read lock held and when the > SNP panic notifier tries to unregister itself from the panic > notifier callback itself it causes a deadlock as notifier > unregistration does RCU synchronization. > > Code flow for SNP panic notifier: > snp_shutdown_on_panic() -> > __sev_firmware_shutdown() -> > __sev_snp_shutdown_locked() -> > atomic_notifier_chain_unregister(.., &snp_panic_notifier) > > Fix SNP panic notifier to unregister itself during SNP shutdown > only if panic is not in progress. > > Reviewed-by: Tom Lendacky > Cc: stable@vger.kernel.org > Fixes: 19860c3274fb ("crypto: ccp - Register SNP panic notifier only if SNP is enabled") > Signed-off-by: Ashish Kalra > --- > drivers/crypto/ccp/sev-dev.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) Patch applied. Thanks. -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt