From nobody Fri Jun 19 18:18:30 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 19B2DC433EF for ; Wed, 30 Mar 2022 21:44:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351315AbiC3Vp7 (ORCPT ); Wed, 30 Mar 2022 17:45:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43282 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351301AbiC3Vp6 (ORCPT ); Wed, 30 Mar 2022 17:45:58 -0400 Received: from esa6.hgst.iphmx.com (esa6.hgst.iphmx.com [216.71.154.45]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 575A75F76 for ; Wed, 30 Mar 2022 14:44:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1648676650; x=1680212650; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=lASKdYMSMbpY3YMCgBI+0wvBvlgBA48ZwyFm07zjWLU=; b=diCl5m2s8gvhgm8lThUxlyq1GenS0Y1pnOvVYFopGyVpc+XpLU0fzO9x 8evvmwgrnullhnCdF6/vZAf3ZaI8EMDJ+1rNagcNzF51PaI+YsdT8L+IR J/dU7sIT7bhjGK7hk7wvqnkhIM806hpU/K+GriBfowNrqjdWtSN6hNw0I 8LJoHsYdCV/W1v8k8ZfptIv74aMJNKl1MzEJC1LW1iy1/rukUV8hltNwe j0LyCdvkXEkmLnS8AcLHxC22J9Luxp0enFVOJpa3Yyrru7amcmqinkJH4 zQsQpuIFISehdWvvig7ylgBSSrmP4rcxdiyaS4xApov0VK7zGHcL8L82k g==; X-IronPort-AV: E=Sophos;i="5.90,223,1643644800"; d="scan'208";a="197584225" Received: from h199-255-45-15.hgst.com (HELO uls-op-cesaep02.wdc.com) ([199.255.45.15]) by ob1.hgst.iphmx.com with ESMTP; 31 Mar 2022 05:44:09 +0800 IronPort-SDR: 4GRIFdH9TMjeym8ZqTWhSxNqztqvcshb3t/93pNusSS/yeqXGZvjU3RRfJk8PlpxCl853gzCiS +y3aE+FuXflVesNUh24cwIMop0NdC9dwUFqV/3ICokl+1jCPnt5WKZ3qyL1IZ7m4YPRlAiJS9Y VW6vVjiFNcooxQMn5pvXjNR5agqO/mBll8SIn8VcKW4V4M1zWsH8uhzVLSXHZhkDy/fJdvSPM1 5Vs1odYJztkkE3UNGpcAtfTT7AQJR8EonU76TbTwViaVlpPlyXT0zxy88DvAFRWXo5zkqljXNL 3UNChpbmcl3PWXxSZPvmKVQj Received: from uls-op-cesaip02.wdc.com ([10.248.3.37]) by uls-op-cesaep02.wdc.com with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 30 Mar 2022 14:14:59 -0700 IronPort-SDR: nz9LRtCr74A5e9F8YpM0nyrSwbyZe0Y7xnAlxzV2ue48m5mOJRs4m4r2gjbmk8e6Ngv4rtHFKh SDNtWNfeOa2DiHSsgJQWRHq22nI3i0B3nW9jOILHKtBE75TlTUySnoGVk5ymPcZhOx9QOkHahs TBmcAKzXeYNcKXTeQSmqxZYd8s46AcFA5/HAroxC4mvQJSusIBenWPWKwToqvjDhP14BAWGlG1 ei4nQysu98Wh5h0+4I3e8eX6O0okOhAtGZp+UC0aaOWiV54ZWDdLBre0XQHDSVS89ccrIlIGAw TFU= WDCIronportException: Internal Received: from usg-ed-osssrv.wdc.com ([10.3.10.180]) by uls-op-cesaip02.wdc.com with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 30 Mar 2022 14:44:09 -0700 Received: from usg-ed-osssrv.wdc.com (usg-ed-osssrv.wdc.com [127.0.0.1]) by usg-ed-osssrv.wdc.com (Postfix) with ESMTP id 4KTKh84W68z1SVp1 for ; Wed, 30 Mar 2022 14:44:08 -0700 (PDT) Authentication-Results: usg-ed-osssrv.wdc.com (amavisd-new); dkim=pass reason="pass (just generated, assumed good)" header.d=opensource.wdc.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d= opensource.wdc.com; h=content-transfer-encoding:mime-version :x-mailer:message-id:date:subject:to:from; s=dkim; t=1648676647; x=1651268648; bh=lASKdYMSMbpY3YMCgBI+0wvBvlgBA48ZwyFm07zjWLU=; b= Gl5NzUDnqI0kjNfdRZ04swsSk5BP+Qbor+W1CKvXHkuYtfMz5Sr2Uc+zXsD8/K5X wkNbfhFMHxENsUtDUDTpeXpCaOa3QBVQbiqaRHSgPUAvP6JAdqavNTyVXscDSvT5 5zo6oyUJqiwR9zE9IykUfEA2JqIWpgyYn3HK/v69kjTJ16CbOL5/ec8/3HnTHkOI zlZnN6az9FT48zsbBiwWvInIWgf/e9ZwfAEwP9QkDwhUed9eQAcvIu8PQ/DsEHYk 4MWwaTTZU9E+R0Zg0O/BpnEBAcGfZZi1g/TYvYk/D9ZzKggBy7OFRv9cA882dlhn 2gBitXSNdzHk0rW1pmLV0A== X-Virus-Scanned: amavisd-new at usg-ed-osssrv.wdc.com Received: from usg-ed-osssrv.wdc.com ([127.0.0.1]) by usg-ed-osssrv.wdc.com (usg-ed-osssrv.wdc.com [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id aSWGep7J0jfO for ; Wed, 30 Mar 2022 14:44:07 -0700 (PDT) Received: from toolbox.alistair23.me (unknown [10.225.165.114]) by usg-ed-osssrv.wdc.com (Postfix) with ESMTPSA id 4KTKh31mLtz1Rvlx; Wed, 30 Mar 2022 14:44:02 -0700 (PDT) From: Alistair Francis To: paul.walmsley@sifive.com, palmer@dabbelt.com, linux-riscv@lists.infradead.org, aou@eecs.berkeley.edu Cc: linux-kernel@vger.kernel.org, anup@brainfault.org, atishp@rivosinc.com, guoren@kernel.org, Alistair Francis Subject: [PATCH v2] riscv: Ensure only ASIDLEN is used for sfence.vma Date: Thu, 31 Mar 2022 07:43:58 +1000 Message-Id: <20220330214358.3409766-1-alistair.francis@opensource.wdc.com> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Alistair Francis When we set the value of context.id using __new_context() we set both the asid and the current_version with this return statement in __new_context(): return asid | ver; This means that when local_flush_tlb_all_asid() is called with the asid specified from context.id we can write the incorrect value. We get away with this as hardware ignores the extra bits, as the RISC-V specification states: "bits SXLEN-1:ASIDMAX of the value held in rs2 are reserved for future standard use. Until their use is defined by a standard extension, they should be zeroed by software and ignored by current implementations." but it is still a bug and worth addressing as we are incorrectly setting extra bits. This patch uses asid_mask when calling sfence.vma to ensure the asid is always the correct len (ASIDLEN). This is similar to what we do in arch/riscv/mm/context.c. Fixes: 3f1e782998cd ("riscv: add ASID-based tlbflushing methods") Signed-off-by: Alistair Francis --- arch/riscv/mm/context.c | 2 +- arch/riscv/mm/tlbflush.c | 2 +- include/linux/mm_types.h | 2 ++ 3 files changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/riscv/mm/context.c b/arch/riscv/mm/context.c index 7acbfbd14557..4329fe54176b 100644 --- a/arch/riscv/mm/context.c +++ b/arch/riscv/mm/context.c @@ -22,7 +22,7 @@ DEFINE_STATIC_KEY_FALSE(use_asid_allocator); =20 static unsigned long asid_bits; static unsigned long num_asids; -static unsigned long asid_mask; +unsigned long asid_mask; =20 static atomic_long_t current_version; =20 diff --git a/arch/riscv/mm/tlbflush.c b/arch/riscv/mm/tlbflush.c index 37ed760d007c..ef701fa83f36 100644 --- a/arch/riscv/mm/tlbflush.c +++ b/arch/riscv/mm/tlbflush.c @@ -42,7 +42,7 @@ static void __sbi_tlb_flush_range(struct mm_struct *mm, u= nsigned long start, /* check if the tlbflush needs to be sent to other CPUs */ broadcast =3D cpumask_any_but(cmask, cpuid) < nr_cpu_ids; if (static_branch_unlikely(&use_asid_allocator)) { - unsigned long asid =3D atomic_long_read(&mm->context.id); + unsigned long asid =3D atomic_long_read(&mm->context.id) & asid_mask; =20 if (broadcast) { sbi_remote_sfence_vma_asid(cmask, start, size, asid); diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 8834e38c06a4..5fa7cc0af853 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -666,6 +666,8 @@ struct mm_struct { =20 extern struct mm_struct init_mm; =20 +extern unsigned long asid_mask; + /* Pointer magic because the dynamic array size confuses some compilers. */ static inline void mm_init_cpumask(struct mm_struct *mm) { --=20 2.35.1