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 889BB3368BF for ; Thu, 4 Jun 2026 15:12:21 +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=1780585942; cv=none; b=H6jE7og/qjGDc8JuxTZ6d3b9UhfdRCwu53b3VCP87x7qxEbDnjpeHbAtogcjDyl8kaAjLVTCco3ZQ2rnUCPF6AVmUqyh7ww42s45a1eZI375y7IgjnIjemjISoJ3+4svQebC79YLZZxiTu8KvgYJcQ8kOYXX7Rla4E6WIJO/0IQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780585942; c=relaxed/simple; bh=UMjgCmB1f7tn+ZahT/zZLL/dtSIsvXofK5mm+isFSCY=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=O09KTm4YkAfbJFcw9sOfmYxXl7YbA0fvIXlvyfckiJ1qdWc7nhgb9d6cZmJgzeWWMeV8qqd2tlp5s2/CaYrp4PD9hXPGgds7Gy4FSxz4Oujx4HRsT/ZR2WtfmIpp4nQug8JUWCQjnp4eawp3VWPGZxI94LllT9s4mAPxhoKIY1M= 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=jdco4+17; 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="jdco4+17" Received: by mail-wr1-f74.google.com with SMTP id ffacd0b85a97d-4600c8cb13aso508662f8f.1 for ; Thu, 04 Jun 2026 08:12:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1780585940; x=1781190740; 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=CasHJuCvieisWqL8kBoseI3vU+9nQuNqwVDXJ6YMA3Y=; b=jdco4+17ax6Fx0BlNf2uQ/9vMy4FAV7ncjWihFfkKUr63/vS+oHNzNQn0YVr2LX1g4 2qj6E0V1WOi/461L8SzGARqmrCMlHautPMLyO+N4sBrJk6Y8gnAdG892ok0AWu+aguwu b10OM06MJVfIq+JsN6Gj01+PA8eQehS24JggM04BBwCuXG5H5lgu2m/2WmLfLe/DxbGN yDnu+3ekGZdTVS/2b0jQgoT2klKeMY4AxwxNkj6G7KnkPcdNEkEJWglSsyvUpzYX0hYw rlH5xgy/sNBgcS5SGAUDzVCmSiEeC3v3cP+ix5hq707p4WWJj+7AffMO9GZ+2gfleDUa tiaQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1780585940; x=1781190740; 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=CasHJuCvieisWqL8kBoseI3vU+9nQuNqwVDXJ6YMA3Y=; b=cONVaEp4S++nwna3CTzo6UlzaURnN7rVPPBc2uoIOeeEk8Af31eGX0yor+lSG2j319 EG/GNnsfLseFVKC9bVtT6eUzJfW274y6PYx0kemgVK1bSfOHYL4GQem7Ioz4XDtpJ4xf ZSzn3NcC8iVhnZgWnjjIQTZmaVcak5nboiI3z1LpNrTFipnOThxR9p+Rd8lFMv/0uyHD GQKHmoL+9pd3Cw6WKvKOZlcnsxYSUPaiT6geoqx7X2RMvK2g78OPSF3qXVO74YliVdtX oI6+YmL+j/LKanky9GshWUPZ161QsSaI6dZzvYLj978Y1afCMPu1K1EU0GuN6CAG57mt TzNw== X-Gm-Message-State: AOJu0YyaqG8GSJWt+bGocXYiFaqlBtncAPnVDx8Vo0v9f7LFl06cHOJK tELXrjUD2CvhQtt9haaGnxIrblxnGe5KpAF/CsRHMrnMKe/d4xhg9eZ+X7K83WU7vX1kf+Qwxg= = X-Received: from wmdd20.prod.google.com ([2002:a05:600c:a214:b0:490:bfa7:ad27]) (user=ardb job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:c0dc:b0:490:6869:ef13 with SMTP id 5b1f17b1804b1-490b5ecce34mr98325645e9.14.1780585939840; Thu, 04 Jun 2026 08:12:19 -0700 (PDT) Date: Thu, 4 Jun 2026 17:11:55 +0200 In-Reply-To: <20260604151151.150377-7-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: <20260604151151.150377-7-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=5MfAD19ZZ8C7D6B6Oy/cwSyuECR6YirB5JgWa4RaF1A=; b=owGbwMvMwCVmkMcZplerG8N4Wi2JIUtx6t5nXSbvtmssWHykqergKUuNdIPnnZdr+ryTDS53S 7jGn33bUcrCIMbFICumyCIw+++7nacnStU6z5KFmcPKBDKEgYtTACZi1sbIsL7hgJ21icadQ4wl sxnry3xtJ/07HvBR97lbm9TvPofDdxkZGrY625Vtydmry5tzLfeG1mlt6aTZH8/6z3E2iPt4uDi NDQA= X-Mailer: git-send-email 2.54.0.1032.g2f8565e1d1-goog Message-ID: <20260604151151.150377-10-ardb+git@google.com> Subject: [PATCH v2 3/5] 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, Ard Biesheuvel , Kevin Brodsky , Mark Brown , Marc Zyngier 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; } -- 2.54.0.1032.g2f8565e1d1-goog