From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 13D9CC79FA0 for ; Mon, 7 Sep 2026 16:22:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=D49O1NeemyQmd2xxB1EDTbL7eRgYjkwJtwKVF5+rHbk=; b=Dw5oMrrHN9dQlT7z336Iub64C6 +5ot4v1kd5iCPizWjQK6La8dval6WCK9tW8+ZFIJddnrwwHdNz1mRa1ZKhDNZyeON8t42popgXOnR PvPKRGqHYX8gdzLhmJozHG71Ypw4RSi83hg1XwyRUmj89Nc0XKldqCAGlbGc+bdMfUu1KmWRjnKbw fdP6Lw9QU1IuBNwDkObERI3gxdEdpBQ1EwOZge5CAGKrVwH4Czzsih/Vzsl/9/sWB90ii2vzWblE9 7Hwkftm3n51MwLgabJfopfFE0wJlZ/aIWST+QqioHk5VxIZUrYZ0lWNOxg3tm7FJ7Ltx6vDWTzZqk 5om1BklA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x3c72-00000007Hl2-2dlV; Mon, 07 Sep 2026 16:22:28 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x3c6y-00000007Hje-0XWN for linux-arm-kernel@lists.infradead.org; Mon, 07 Sep 2026 16:22:25 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2F85D1477; Mon, 7 Sep 2026 09:22:19 -0700 (PDT) Received: from ewhatever.cambridge.arm.com (ewhatever.cambridge.arm.com [10.2.197.99]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 0316C3F528; Mon, 7 Sep 2026 09:22:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1788798142; bh=XAeqWuHc9jnj7EF+rIUKhmu4pAbQvhgD5GDfn5hHh9I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=G+J91P19HVXLKxQXd9uRL/DwKTix2YtsSCBzkyKxR8RVFksiU9e5ONFoRnN0cHFb+ r7LbJ6PFOT/WA4xYbR3enBx7EemQ4YVFW9gqTSpCOKZlLAqlVh13rLfOefjg1Pb34H Rp7oau2DGEt7l8MfqiGL0PlM7uZCudjBa2uycWsM= From: Suzuki K Poulose To: linux-arm-kernel@lists.infradead.org Cc: catalin.marinas@arm.com, will@kernel.org, linux-kernel@vger.kernel.org, maz@kernel.org, pavan.kondeti@oss.qualcomm.com, tabba@google.com, aneesh.kumar@kernel.org, mark.rutland@arm.com, sdonthineni@nvidia.com, steven.price@arm.com, gshan@redhat.com, yuzenghui@huawei.com, kvmarm@lists.linux.dev, Suzuki K Poulose Subject: [PATCH v17 1/1] arm64: mm: Handle Granule Protection Faults (GPFs) Date: Mon, 7 Sep 2026 17:22:04 +0100 Message-ID: <20260907162204.1479401-2-suzuki.poulose@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260907162204.1479401-1-suzuki.poulose@arm.com> References: <20260907162204.1479401-1-suzuki.poulose@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260907_092224_257830_DE1CB2B9 X-CRM114-Status: GOOD ( 15.03 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Steven Price If the host attempts to access granules that have been delegated for use in a realm these accesses will be caught and will trigger a Granule Protection Fault (GPF). A fault during a page walk signals a bug in the kernel and is handled by oopsing the kernel. A non-page walk fault could be caused by user space having access to a page which has been delegated to the kernel and will trigger a SIGBUS to allow debugging why user space is trying to access a delegated page. Also, until we unmap the "private" memory pages from the linear map, we could get spurious GPFs from within the kernel, e.g., load_unaligned_zeropad(). So, try to fix them up for now. Reviewed-by: Suzuki K Poulose Reviewed-by: Gavin Shan Signed-off-by: Steven Price Signed-off-by: Suzuki K Poulose --- Changes since v16: * Update the commit description to indicate why we try to fixup GPFs Changes since v10: * Don't call arm64_notify_die() in do_gpf() but simply return 1. Changes since v2: * Include missing "Granule Protection Fault at level -1" --- arch/arm64/mm/fault.c | 28 ++++++++++++++++++++++------ 1 file changed, 22 insertions(+), 6 deletions(-) diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 0b52557652be6..ad00997b1a873 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -910,6 +910,22 @@ static int do_tag_check_fault(unsigned long far, unsigned long esr, return 0; } +static int do_gpf_ptw(unsigned long far, unsigned long esr, struct pt_regs *regs) +{ + const struct fault_info *inf = esr_to_fault_info(esr); + + die_kernel_fault(inf->name, far, esr, regs); + return 0; +} + +static int do_gpf(unsigned long far, unsigned long esr, struct pt_regs *regs) +{ + if (!is_el1_instruction_abort(esr) && fixup_exception(regs, esr)) + return 0; + + return 1; +} + static const struct fault_info fault_info[] = { { do_bad, SIGKILL, SI_KERNEL, "ttbr address size fault" }, { do_bad, SIGKILL, SI_KERNEL, "level 1 address size fault" }, @@ -946,12 +962,12 @@ static const struct fault_info fault_info[] = { { do_bad, SIGKILL, SI_KERNEL, "unknown 32" }, { do_alignment_fault, SIGBUS, BUS_ADRALN, "alignment fault" }, { do_bad, SIGKILL, SI_KERNEL, "unknown 34" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 35" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 36" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 37" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 38" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 39" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 40" }, + { do_gpf_ptw, SIGKILL, SI_KERNEL, "level -1 granule protection fault (translation table walk)" }, + { do_gpf_ptw, SIGKILL, SI_KERNEL, "level 0 granule protection fault (translation table walk)" }, + { do_gpf_ptw, SIGKILL, SI_KERNEL, "level 1 granule protection fault (translation table walk)" }, + { do_gpf_ptw, SIGKILL, SI_KERNEL, "level 2 granule protection fault (translation table walk)" }, + { do_gpf_ptw, SIGKILL, SI_KERNEL, "level 3 granule protection fault (translation table walk)" }, + { do_gpf, SIGBUS, SI_KERNEL, "granule protection fault" }, { do_bad, SIGKILL, SI_KERNEL, "level -1 address size fault" }, { do_bad, SIGKILL, SI_KERNEL, "unknown 42" }, { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level -1 translation fault" }, -- 2.43.0