From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f73.google.com (mail-wm1-f73.google.com [209.85.128.73]) (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 7332D3E275F for ; Wed, 3 Jun 2026 16:11:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780503083; cv=none; b=We2cFQ8DVA/yGi1GZM4MSQKRbiDf/ltDH4ZDEPmdaHp2ctFxuEYxpwEnbMlB6LBil7zWfJzX6UuFmNtWQce1qlHt/8H+jKDh7etOn3mCwv6xcEu/cGxorXX1X4oBK/gpe6GwADYd20H26yKGyiV/Jd/gQPzkfK4LFaFKjMj6rj8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780503083; c=relaxed/simple; bh=dEmc5sV0UNjyYz4TuMmIs0aQ6UcAq2tyWsOVeh5s+Us=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=uAW/zYAQq4zVC34HwYudg6pD/V3IiI3xZYQQgWLdhBHbQZyUXpuL3/oLuTQfq5prCf/6e9AvYzdw2mRfnr+j9qnWw8IHTv7ePbat2eoJ0F0vscY7io/c1IjRDAC4lUA+N62pfXS028rUC7OoE4diYLKfcULKHfd35W1hEUyAcrk= 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=SJehfnNZ; arc=none smtp.client-ip=209.85.128.73 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="SJehfnNZ" Received: by mail-wm1-f73.google.com with SMTP id 5b1f17b1804b1-490a786f987so36909965e9.3 for ; Wed, 03 Jun 2026 09:11:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1780503081; x=1781107881; 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=TL4hLQqtTeIYj6fVsZXeAVFV7Zv0bhA39dqz5T4VWsY=; b=SJehfnNZoroL500wolBX28Emc0OCQkPa318+dCTOa1i3E2YugIj5CKy6nGIUH3IKe7 jTPGtowKqdtm0LS2J0PACmXK36jn4APbLktLasa+gnKiuLPxo21EYLROhojZJUvv6AHU 9ATWz74i+33mJb8I7+RhzcmuQZf/oSHrf92ik0M9Ao6Zyiae04i3tyexs8TzP3JfijuW F4ofCiPGAhXx/+W+xL4PzR7TtlM8pgGOLzmnA3mpd8WWL2IUFRcpyK2YgOM6g/Kiitml ERbXKrFNh0vR6GtAfuJFVmC3RboBpKfRF7PlOjHOrkej1jABk1AnDmgKJJLl4a2Ji9qa iK0g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1780503081; x=1781107881; 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=TL4hLQqtTeIYj6fVsZXeAVFV7Zv0bhA39dqz5T4VWsY=; b=ULl/H/uqiPBfz+yvU/6b/VtQGx9wnt5zkQUAvXvpTR/LijEkLZ3FAekovXrwRXU+tK NYWh+Mm51ewM+0ftBsFe2LjsF1tIPLfUQV4t1/firSTczgKUkJjCTqkt/xdYZR4Lr+72 /ecfDDknNf4Tf0fIh7GfTj8+KchHdSTK7Wr07jwXO15BIA0fdLgHSjChMUmIBSXQ1tku NTVlKHRyA+V9EAUckSTQDVRxbpSyyh904xE406TuGfezP50a6jUVZ/csZX0hVfMAy2vT QIruvOJQJrjnztJZDRKM199farwwBScow2nu0JeMKW4DGsCrYavVIoPXs/BwnYwvA9ZS D7KA== X-Gm-Message-State: AOJu0YxmjdTvMTKxfJAD64b61VDvaE/akMuSEPEArcoRH+AD3I0mxlFT t/5vvUC/YRWiDhf0tRgPsGnoRWu9rby5ZxY45+i3O4xkTnK8P/C+uU3hhYr16XdCDDkNNVnTpg= = X-Received: from wmoz18.prod.google.com ([2002:a05:600c:792:b0:490:b58a:2c80]) (user=ardb job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:820a:b0:490:9782:3eb8 with SMTP id 5b1f17b1804b1-490b5fd7378mr70201975e9.25.1780503080726; Wed, 03 Jun 2026 09:11:20 -0700 (PDT) Date: Wed, 3 Jun 2026 18:09:52 +0200 In-Reply-To: <20260603160949.3372482-6-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: <20260603160949.3372482-6-ardb+git@google.com> X-Developer-Key: i=ardb@kernel.org; a=openpgp; fpr=F43D03328115A198C90016883D200E9CA6329909 X-Developer-Signature: v=1; a=openpgp-sha256; l=2222; i=ardb@kernel.org; h=from:subject; bh=klTYuM9nrZaRSnTcs7Uaq38kYQvUy5mIsHZz1sf0jcw=; b=owGbwMvMwCVmkMcZplerG8N4Wi2JIUsh8KL6g/daO9pnK2+X3DhXPXKbsllExfMJs+ocW2KSW Y0fh0zoKGVhEONikBVTZBGY/ffdztMTpWqdZ8nCzGFlAhnCwMUpABOximD4p7Hz1NRnV46F1Zft DDxXyWkZcXf2ml3G5jNyAwOueKik6zAyHJklGVT4TXPNy8qLuzxbxG89qbH06y1pzigNu5+XEP2 THQA= X-Mailer: git-send-email 2.54.0.1013.g208068f2d8-goog Message-ID: <20260603160949.3372482-8-ardb+git@google.com> Subject: [PATCH 2/4] arm64: Avoid double evaluation of __ptep_get() From: Ard Biesheuvel To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, will@kernel.org, catalin.marinas@arm.com, maz@kernel.org, Ard Biesheuvel , Kevin Brodsky , Mark Brown Content-Type: text/plain; charset="UTF-8" From: Ard Biesheuvel Sashiko warns that the new pte_valid_noncont() macro is used in a manner where the argument (which performs a READ_ONCE() of the descriptor) is evaluated twice. Drop the macro that we just added, and move the check into the newly added users. Signed-off-by: Ard Biesheuvel --- arch/arm64/include/asm/pgtable.h | 4 ---- arch/arm64/mm/mmu.c | 14 ++++++++++---- 2 files changed, 10 insertions(+), 8 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 491ba0a6492d..c9e4e00a9af2 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -181,10 +181,6 @@ static inline pteval_t __phys_to_pte_val(phys_addr_t phys) * Returns true if the pte is valid and has the contiguous bit set. */ #define pte_valid_cont(pte) (pte_valid(pte) && pte_cont(pte)) -/* - * Returns true if the pte is valid and has the contiguous bit cleared. - */ -#define pte_valid_noncont(pte) (pte_valid(pte) && !pte_cont(pte)) /* * Could the pte be present in the TLB? We must check mm_tlb_flush_pending * so that we don't erroneously return false for pages that have been diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index be51f6cac86f..d68e691c093a 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -186,9 +186,12 @@ static void init_pte(pte_t *ptep, unsigned long addr, unsigned long end, static bool pte_range_has_valid_noncont(pte_t *ptep) { - for (int i = 0; i < CONT_PTES; i++) - if (pte_valid_noncont(__ptep_get(&ptep[i]))) + for (int i = 0; i < CONT_PTES; i++) { + pte_t pte = __ptep_get(&ptep[i]); + + if (pte_valid(pte) && !pte_cont(pte)) return true; + } return false; } @@ -291,9 +294,12 @@ static int init_pmd(pmd_t *pmdp, unsigned long addr, unsigned long end, static bool pmd_range_has_valid_noncont(pmd_t *pmdp) { - for (int i = 0; i < CONT_PMDS; i++) - if (pte_valid_noncont(pmd_pte(READ_ONCE(pmdp[i])))) + for (int i = 0; i < CONT_PMDS; i++) { + pte_t pte = pmd_pte(READ_ONCE(pmdp[i])); + + if (pte_valid(pte) && !pte_cont(pte)) return true; + } return false; } -- 2.54.0.1013.g208068f2d8-goog