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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 040AEC44532 for ; Tue, 21 Jul 2026 16:23:59 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B5BD76B0095; Tue, 21 Jul 2026 12:23:58 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B338E6B0096; Tue, 21 Jul 2026 12:23:58 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A704D6B0098; Tue, 21 Jul 2026 12:23:58 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 7861C6B0095 for ; Tue, 21 Jul 2026 12:23:58 -0400 (EDT) Received: from smtpin10.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay04.hostedemail.com (Postfix) with ESMTP id D76EE1A01EB for ; Tue, 21 Jul 2026 16:23:57 +0000 (UTC) X-FDA: 85013305314.10.D6842BC Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf14.hostedemail.com (Postfix) with ESMTP id 332A310000D for ; Tue, 21 Jul 2026 16:23:56 +0000 (UTC) Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=Hhew6m2T; spf=pass (imf14.hostedemail.com: domain of rppt@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1784651036; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=ztzLHFgZF1pj4LHMu3VvIZzUHzFoGqe9tmkrlg/P0Q4=; b=wdL9dqGBj2ZiwJ8wuEXaNX14nL8qf6CbTukj4Ts06IdWGxQCW6N4qHNXsjnOYpHnW6k9nd 6YrJHYV9ViIihJ40YcpeYJH8C2BBxqCMLan6xiIYpVtjxVQXlUyqvcqshNWjF0YyhDdqL1 CF1rSWH/2Y/3RA4pefWwO6Nd1NyAprM= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1784651036; b=5FRGTSM7SlCLryAyHBNwiKEti0Hj9ZPT8rWeEooKsNBjjYWjHfeReGPiNfCFPJymraNvse WyWl8PWXQWKqtDkDO18+2WU/eJz67KIBfIlzjAds7WyBvTuzYmkg0zH+eRcmdmhuoxTJqK LinMaMJD5AqZhaPHj+n7DQQcM1kqSZc= ARC-Authentication-Results: i=1; imf14.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=Hhew6m2T; spf=pass (imf14.hostedemail.com: domain of rppt@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id BD59B60A5E; Tue, 21 Jul 2026 16:23:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E305A1F00A3D; Tue, 21 Jul 2026 16:23:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784651035; bh=ztzLHFgZF1pj4LHMu3VvIZzUHzFoGqe9tmkrlg/P0Q4=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=Hhew6m2TOv9DRY3CJ5gbegcSEoCRoBYhTbf45iQdRbrMKFcSNrw9pfJTGRkHal5DG pqwwjVVXbCK/99gt0PM3LFTF44MIq8GFR1Ln36lj/2CLq4/MQi2K/EbV75ihicS6s/ KZX9AWzzwaf86AoOavdoSUccw18O810scPylB6O2yn2ye8JoGgcA5FlxhKbcuTe+3g 0pt009M4LWj4WIRRFBSNZO1cvdBvD/JHkGsywJiS3euU2gHN7KcWgAo+3wnO1a4lJU kOE2hML+o2O5/WqOcYTGrDHVckMtRkBrIsMPIXn7dZVSzhO0n3VARhQSPwyFXlBaxH nLyf675udKYow== From: "Mike Rapoport (Microsoft)" Date: Tue, 21 Jul 2026 19:23:25 +0300 Subject: [PATCH RFC 02/18] x86/mm/pat: fix effective RW computation in lookup_address_in_pgd_attr() MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260721-generic-set-memory-v0-1-v1-2-2c1fc62306b3@kernel.org> References: <20260721-generic-set-memory-v0-1-v1-0-2c1fc62306b3@kernel.org> In-Reply-To: <20260721-generic-set-memory-v0-1-v1-0-2c1fc62306b3@kernel.org> To: linux-mm@kvack.org Cc: Albert Ou , Andrew Morton , Andy Lutomirski , Borislav Petkov , Brendan Jackman , Catalin Marinas , Dave Hansen , David Hildenbrand , Huacai Chen , Ingo Molnar , Ingo Molnar , Kevin Brodsky , "Liam R. Howlett" , Lorenzo Stoakes , Michal Hocko , Mike Rapoport , Palmer Dabbelt , Paul Walmsley , Peter Zijlstra , "H. Peter Anvin" , Suren Baghdasaryan , Thomas Gleixner , Vlastimil Babka , Will Deacon , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, loongarch@lists.linux.dev, x86@kernel.org, Juergen Gross X-Mailer: b4 0.16-dev X-Rspam-User: X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 332A310000D X-Stat-Signature: bg1m8tynqwuxxitsbxg7btfp3ng63deu X-HE-Tag: 1784651036-747392 X-HE-Meta: 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 5M3EQVel G6gccyRtFZmYfrtgsaoQwgKFFT3c+Ue/ztlXhca0RIcPlejLYLM1Ji9Fp82Bo7+l5kvybz1QVFXefqe7m/ppJSJ4YENHn8RK+YUgMG/3FbAelpN92MdMqIDEsApfXaOkypR8tIChUAcWdesOgokJZk3cCwI6ufZbbCiIceKygdbmf/ChX5Xp6/Cn9IbObsw0iv8fn+jz7hDAW/vhan110+FRaEvE5xfmTyvZTepCr07CRydge9OKlcTzJvYsK77BpXQbSx8jj+2vRGdpMw8i4ZmCsDDF7l8wlpJBCs03ZmVyNMpefpYkMHd2/hJ0yPa9WmEhfXu6yxoDOFGe6I7MqzXNLvmYPzFFP3syZ Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: lookup_address_in_pgd_attr() accumulates the effective NX and RW bits of the walked page table levels so that verify_rwx() can detect mappings that are both writable and executable. The RW bits are folded into a bool with rw &= pXd_flags(*pXd) & _PAGE_RW; but _PAGE_RW is 0x2. So consider the accumulation line: rw &= pXd_flags(*pXd) & _PAGE_RW; where rw=0x1 and the right side evaluates down to 0x2. It'll end up doing: rw = 0x1 & 0x2 and rw always ends up 0. This way rw becomes false at the first level walked, regardless of the actual permissions, and verify_rwx() treats every mapping as non-writable and never reports a W^X violation. Add double negation to the right side to normalize the _PAGE_RW flag to 0 or 1. Fixes: ceb647b4b529 ("x86/pat: Introduce lookup_address_in_pgd_attr()") Assisted-by: Copilot:claude-opus-4.8 Signed-off-by: Mike Rapoport (Microsoft) Reviewed-by: Juergen Gross --- arch/x86/mm/pat/set_memory.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c index e8316f5ffa8a..9382f1d6194f 100644 --- a/arch/x86/mm/pat/set_memory.c +++ b/arch/x86/mm/pat/set_memory.c @@ -730,7 +730,7 @@ pte_t *lookup_address_in_pgd_attr(pgd_t *pgd, unsigned long address, *level = PG_LEVEL_512G; *nx |= pgd_flags(*pgd) & _PAGE_NX; - *rw &= pgd_flags(*pgd) & _PAGE_RW; + *rw &= !!(pgd_flags(*pgd) & _PAGE_RW); p4d = p4d_offset(pgd, address); if (p4d_none(*p4d)) @@ -741,7 +741,7 @@ pte_t *lookup_address_in_pgd_attr(pgd_t *pgd, unsigned long address, *level = PG_LEVEL_1G; *nx |= p4d_flags(*p4d) & _PAGE_NX; - *rw &= p4d_flags(*p4d) & _PAGE_RW; + *rw &= !!(p4d_flags(*p4d) & _PAGE_RW); pud = pud_offset(p4d, address); if (pud_none(*pud)) @@ -752,7 +752,7 @@ pte_t *lookup_address_in_pgd_attr(pgd_t *pgd, unsigned long address, *level = PG_LEVEL_2M; *nx |= pud_flags(*pud) & _PAGE_NX; - *rw &= pud_flags(*pud) & _PAGE_RW; + *rw &= !!(pud_flags(*pud) & _PAGE_RW); pmd = pmd_offset(pud, address); if (pmd_none(*pmd)) @@ -763,7 +763,7 @@ pte_t *lookup_address_in_pgd_attr(pgd_t *pgd, unsigned long address, *level = PG_LEVEL_4K; *nx |= pmd_flags(*pmd) & _PAGE_NX; - *rw &= pmd_flags(*pmd) & _PAGE_RW; + *rw &= !!(pmd_flags(*pmd) & _PAGE_RW); return pte_offset_kernel(pmd, address); } -- 2.53.0