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 B92AFFEFB70 for ; Fri, 27 Feb 2026 17:57:59 +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=EuTJwogsRPxq98iUSbWob8jNy/WUZB+Z5Sl2GVPFxdw=; b=1lTfBj3tJ0Rsk8LcIVOVzbsGdY gv0tbc6XRqA8/HdsbotYCuMciz6W/szm7FB3DkSsr8z0738r+yYr47TH+rlE/i2aHgMtaOYRdEKLb lBLhqm29g7C3t+3UaCCKjRiUFaFLItg1lWbScGU/ywOle3aFYszcgoRDk4F5vcpkwdm7s6PnAzsH/ LBmTTlzJNbwz7o4ZK8ho18dHiAlOEfjVU0efzTsOUNk41km4kEdDXGchpzJwV+rpqpjcA50WeLl87 a2tqcbIjJyXlbVOy0CWvUclDlYj75kzyFiIALJkOXQIRukxlHPp9ZhgVryXn7I68kpqCUCfFHyJFc UdIMCMIw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vw266-00000008s5c-3EqS; Fri, 27 Feb 2026 17:57:54 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vw25p-00000008roD-34mo for linux-arm-kernel@lists.infradead.org; Fri, 27 Feb 2026 17:57:48 +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 CE7E41516; Fri, 27 Feb 2026 09:57:29 -0800 (PST) Received: from e123572-lin.arm.com (e123572-lin.cambridge.arm.com [10.1.194.54]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B8C363F73B; Fri, 27 Feb 2026 09:57:31 -0800 (PST) From: Kevin Brodsky To: linux-hardening@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Kevin Brodsky , Andrew Morton , Andy Lutomirski , Catalin Marinas , Dave Hansen , David Hildenbrand , Ira Weiny , Jann Horn , Jeff Xu , Joey Gouly , Kees Cook , Linus Walleij , Lorenzo Stoakes , Marc Zyngier , Mark Brown , Matthew Wilcox , Maxwell Bland , "Mike Rapoport (IBM)" , Peter Zijlstra , Pierre Langlois , Quentin Perret , Rick Edgecombe , Ryan Roberts , Thomas Gleixner , Vlastimil Babka , Will Deacon , Yang Shi , Yeoreum Yun , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, x86@kernel.org Subject: [PATCH v6 24/30] arm64: kpkeys: Handle splitting of linear map Date: Fri, 27 Feb 2026 17:55:12 +0000 Message-ID: <20260227175518.3728055-25-kevin.brodsky@arm.com> X-Mailer: git-send-email 2.51.2 In-Reply-To: <20260227175518.3728055-1-kevin.brodsky@arm.com> References: <20260227175518.3728055-1-kevin.brodsky@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260227_095737_872141_460A026B X-CRM114-Status: GOOD ( 13.01 ) 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 When the kpkeys_hardened_pgtables feature is enabled, special care is required when allocating page table pages while splitting the linear map. Indicate that such pages are being allocated by passing __GFP_PGTABLE_SPLIT and use the appropriate interface to prepare the kpkeys_hardened_pgtables allocator in split_kernel_leaf_mapping(). Signed-off-by: Kevin Brodsky --- arch/arm64/mm/mmu.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index ea1cb1875257..2cee0b7f8a56 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -707,7 +707,7 @@ static int split_kernel_leaf_mapping_locked(unsigned long addr) if (!pud_present(pud)) goto out; if (pud_leaf(pud)) { - ret = split_pud(pudp, pud, GFP_PGTABLE_KERNEL, true); + ret = split_pud(pudp, pud, GFP_PGTABLE_KERNEL | __GFP_PGTABLE_SPLIT, true); if (ret) goto out; } @@ -732,7 +732,7 @@ static int split_kernel_leaf_mapping_locked(unsigned long addr) */ if (ALIGN_DOWN(addr, PMD_SIZE) == addr) goto out; - ret = split_pmd(pmdp, pmd, GFP_PGTABLE_KERNEL, true); + ret = split_pmd(pmdp, pmd, GFP_PGTABLE_KERNEL | __GFP_PGTABLE_SPLIT, true); if (ret) goto out; } @@ -800,7 +800,18 @@ int split_kernel_leaf_mapping(unsigned long start, unsigned long end) if (start != PAGE_ALIGN(start) || end != PAGE_ALIGN(end)) return -EINVAL; +kpkeys_retry: + ret = kpkeys_prepare_direct_map_split(); + if (ret) + return ret; + mutex_lock(&pgtable_split_lock); + + if (!kpkeys_ready_for_direct_map_split()) { + mutex_unlock(&pgtable_split_lock); + goto kpkeys_retry; + } + lazy_mmu_mode_enable(); /* -- 2.51.2