From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f74.google.com (mail-wr1-f74.google.com [209.85.221.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7AE7C403E97 for ; Tue, 19 May 2026 15:18:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779203913; cv=none; b=Ko2i2ing17neTov1OpikDCojUeE3Hsl9B8u4ZnWMjJXalCW9kxCesl1ceiM7J62l1TGhA6arADNZCZiAxyTjtiBlgkvxXC1YDCqBF5jVkmwgX745CxhHg4+aN6TKSU4dSYBijVxlQAz7HMfiqmDzih4sSoXu99AxynU+DMuPHBo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779203913; c=relaxed/simple; bh=jjYhcW/kbMDe/UK3BjYp/roCAIoFYhxhPdWkrX5A06k=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=FNUyE2vhihrxBr1GH+QpjAw+6vbehlkJhaddESSOHHmS/b/d1mUfGFmNQqiMIKY8K1ZU7mu5e439TtPZX7Cm4Tavvamwaq4itswEW9xYXoTAyttOQspfzF1gF0xGrGh188Jbjha5f8/FMBvMgUv0zVnqIN343PiPIeVAmlv+Z5E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--ardb.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=kzkNmIE/; arc=none smtp.client-ip=209.85.221.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--ardb.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="kzkNmIE/" Received: by mail-wr1-f74.google.com with SMTP id ffacd0b85a97d-447f2ce5556so3173272f8f.2 for ; Tue, 19 May 2026 08:18:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1779203905; x=1779808705; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=EjHc0cb+NE/2F+UEf5a5kfxEL68f5+QTn7aAzw8hvjg=; b=kzkNmIE/f6woXRLWC7RjhzEH6PZSgJA0ZdZ1OgryFCZBDsP2/sCfObgnjPRY7fT9aI xL19lFCSJNXpOSPtBi6VCno1b63rhj9jSGzJOAXl5dyvFuPD06355UwkmEuVLd9/rl3C Nb6/9Ot38Vfx3P6OBcOfvucIPGHCvloK1pgqA8Y/gz26Awq4MGmLGxZuF4oE6nW8xx+a Q/P7yfdtWK2HOwyesbhN5sjC+IMuQx2WNrswxcKw/ndo01w53FfgtcrjuwJloRjFywtZ 1U2bUZjslbrUqHRYYJanAAevPrqTL5dyRb0O4MDpDRQlXzaU17LnON1GKM3iyPVSMFOD 84hA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779203905; x=1779808705; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=EjHc0cb+NE/2F+UEf5a5kfxEL68f5+QTn7aAzw8hvjg=; b=mfrXp79URbaFpkeTneVco8L0PTXpAlFPahkLSLh7QUxVWarl2q3/k4RIEeUJTRx7KU mNeIipfvDIbze5wza2qqW8EOd7+89/mnSZ/TNyqZ1G9B7xwDpw+2hFattW3g7XfyJZ+J pD8fmRLHcfM1XFBzPMfj4428LV9nEQV/hR/tMoWaDS2zgTApGE3ETx/eMNNCPlOQ2uZR 3BoHim0CKGu4B/eFTZKxno75aNT5hZMQ3rVQjciTamnhMiyhp8stOrKH3kSpjnMDDFBe HnsBJBSdN4NPQ4gQqAclAlQobZIiyN95StkOQqcTXbp8zW9Eojzxxmyc67xKPW6q2VbM gR5Q== X-Gm-Message-State: AOJu0YydCPLthbWhET1v8JbFw1WSyRM+zAle8li09S6gzqIRN5AreT/j GX7vMwpWma+pIeB3cs0VzDnPSLK0m37d8NjJ22lh2HQiUkMEkwpg9+QaPgeOk7GXwtaAtbhZPA= = X-Received: from wrjb13.prod.google.com ([2002:adf:e30d:0:b0:45b:cad1:2df1]) (user=ardb job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6000:2c06:b0:45d:4fc0:fe0a with SMTP id ffacd0b85a97d-45e5c5dd346mr33349921f8f.32.1779203905296; Tue, 19 May 2026 08:18:25 -0700 (PDT) Date: Tue, 19 May 2026 17:16:24 +0200 In-Reply-To: <20260519151616.2557018-15-ardb+git@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260519151616.2557018-15-ardb+git@google.com> X-Developer-Key: i=ardb@kernel.org; a=openpgp; fpr=F43D03328115A198C90016883D200E9CA6329909 X-Developer-Signature: v=1; a=openpgp-sha256; l=914; i=ardb@kernel.org; h=from:subject; bh=DzlMi7mku98t808/4L/IevsaqNhHNBA7ZPaOWGTKp3M=; b=owGbwMvMwCVmkMcZplerG8N4Wi2JIYun7ozjx5JHO2c9Tvz2bbb1UYGuFVGxfyOk/Lcl39l/K H2HsKVMRykLgxgXg6yYIovA7L/vdp6eKFXrPEsWZg4rE8gQBi5OAZjI0z2MDCcD0w4yfjZVbdjI l/1mdYzWeoF7uf/65CXWOutIPTyn6s7wz/CboZoY8yGh2dyvFDVyd1ef1EtQfpqkvm298dz7pw+ +ZwAA X-Mailer: git-send-email 2.54.0.563.g4f69b47b94-goog Message-ID: <20260519151616.2557018-22-ardb+git@google.com> Subject: [PATCH v5 07/13] arm64: mm: Permit contiguous descriptors to be rewritten From: Ard Biesheuvel To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, will@kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com, Ard Biesheuvel , Ryan Roberts , Anshuman Khandual , Liz Prucka , Seth Jenkins , Kees Cook , Mike Rapoport , David Hildenbrand , Andrew Morton , Jann Horn , linux-mm@kvack.org, linux-hardening@vger.kernel.org Content-Type: text/plain; charset="UTF-8" From: Ard Biesheuvel Currently, pgattr_change_is_safe() is overly pedantic when it comes to descriptors with the contiguous hint attribute set, as it rejects assignments even if the old and the new value are the same. So relax the check to allow that. Signed-off-by: Ard Biesheuvel --- arch/arm64/mm/mmu.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 0405fac18959..7cecd25aa83b 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -134,10 +134,6 @@ bool pgattr_change_is_safe(pteval_t old, pteval_t new) if (pte_pfn(__pte(old)) != pte_pfn(__pte(new))) return false; - /* live contiguous mappings may not be manipulated at all */ - if ((old | new) & PTE_CONT) - return false; - /* Transitioning from Non-Global to Global is unsafe */ if (old & ~new & PTE_NG) return false; -- 2.54.0.563.g4f69b47b94-goog