From patchwork Wed Nov 3 20:57:14 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Fainelli X-Patchwork-Id: 12601617 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8E5C8C433EF for ; Wed, 3 Nov 2021 20:57:46 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3916F61156 for ; Wed, 3 Nov 2021 20:57:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 3916F61156 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id D22F194000C; Wed, 3 Nov 2021 16:57:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CFA9C940008; Wed, 3 Nov 2021 16:57:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B9A9394000C; Wed, 3 Nov 2021 16:57:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0037.hostedemail.com [216.40.44.37]) by kanga.kvack.org (Postfix) with ESMTP id A7BAC940008 for ; Wed, 3 Nov 2021 16:57:45 -0400 (EDT) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 6F40A8249980 for ; Wed, 3 Nov 2021 20:57:45 +0000 (UTC) X-FDA: 78768830490.08.3FDB0EF Received: from mail-pl1-f181.google.com (mail-pl1-f181.google.com [209.85.214.181]) by imf29.hostedemail.com (Postfix) with ESMTP id 1D4A8900024F for ; Wed, 3 Nov 2021 20:57:45 +0000 (UTC) Received: by mail-pl1-f181.google.com with SMTP id b13so3639749plg.2 for ; Wed, 03 Nov 2021 13:57:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=gp+q+Dp9Rg8+gbw0JzqtKDIoOTrQCdiRZcY/99hfXto=; b=URmpnGWL791dLOnO2PzfX4IQbFW2IlgqhpCLMVShp4wPT6hwXU/zpYC9/2hz5RXQd8 uFCaD6M6Cu8K7WHuDbHT7S+BcNVOU2S1wK4t0D3FoJYLYYNhJa/7my7Skw3arb387ZSU g49Ha2Oc8PcqGVFRw3Qxw9svIWJDiclovUF3/Ql07dJNjheCkir+jDna0JX3BYPplNAl P9MoHa8zCt+Hep1au1Cf3SA4GceWH74J23cdFSUkajkIHV1NCKV+gP22KIIhAC7YKyU+ kqTog0GqtReKoJb2NaJlvQR5LOZ6lHEfk9jfzrNJFG+JJaNFPDACHRAhAacDkvbudy2j Bc+A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=gp+q+Dp9Rg8+gbw0JzqtKDIoOTrQCdiRZcY/99hfXto=; b=jO3nl9/DbaF4hi/0MAWxAPLlSJFjarkj13wS4vUD3g33Fl9G5ZhDSqCm/BPm2buByl VjSZDR85WyWtgpslwZOPU36PKGw0MrAT6VBTVcmye+GcM/xY/KXkko/N2UZWzsmuwGFB 7wHJSq0hXMnu0ueJFAO4UHRKEcmR/YiYxiiLumN67oEdqapNblMSKkFTfb/pY7CThgxx 4kROQd4VUB8fLW2Yx2QHcIu8bhpQm66ZCoMb8JCYp6s1UtzhUIQJVqEEBzfqLHbm3HH+ oTSJIywI4H7b445El04vBbrDHvkX3jhaIf62VklURR+1RzO4kmgkTvrdtlyXhJMXb3wg 7ZVw== X-Gm-Message-State: AOAM533bh4ERofoo8VYo2uWyYBFqXfy26by9++X5tppVuXnUDQMTcSC+ WoZPa7EEwBWhDTqou86XdrE= X-Google-Smtp-Source: ABdhPJxaQhs3rUPf+5wXCB1IY4jfT140BDfhG5OoHFaRDoUG46SqIjVMSeFPILH71toODyyhkdhUQg== X-Received: by 2002:a17:90a:cf85:: with SMTP id i5mr17320338pju.101.1635973064168; Wed, 03 Nov 2021 13:57:44 -0700 (PDT) Received: from fainelli-desktop.igp.broadcom.net ([192.19.223.252]) by smtp.gmail.com with ESMTPSA id n14sm2512073pgd.68.2021.11.03.13.57.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 03 Nov 2021 13:57:40 -0700 (PDT) From: Florian Fainelli To: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org, Greg Kroah-Hartman , Sasha Levin , Arnd Bergmann , Thomas Bogendoerfer , Stefan Agner , Mike Rapoport , Florian Fainelli , Vineet Gupta , Russell King , Ralf Baechle , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)), Minchan Kim , Nitin Gupta , Sergey Senozhatsky , "Kirill A. Shutemov" , linux-snps-arc@lists.infradead.org (open list:SYNOPSYS ARC ARCHITECTURE), linux-arm-kernel@lists.infradead.org (moderated list:ARM PORT), linux-mips@linux-mips.org (open list:MIPS), linuxppc-dev@lists.ozlabs.org (open list:LINUX FOR POWERPC (32-BIT AND 64-BIT)), linux-arch@vger.kernel.org (open list:GENERIC INCLUDE/ASM HEADER FILES), linux-mm@kvack.org (open list:ZSMALLOC COMPRESSED SLAB MEMORY ALLOCATOR) Subject: [PATCH stable 4.9 2/2] arch: pgtable: define MAX_POSSIBLE_PHYSMEM_BITS where needed Date: Wed, 3 Nov 2021 13:57:14 -0700 Message-Id: <20211103205714.374801-3-f.fainelli@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211103205714.374801-1-f.fainelli@gmail.com> References: <20211103205714.374801-1-f.fainelli@gmail.com> MIME-Version: 1.0 X-Stat-Signature: 7j9bqtejwempp5rj6m6fcf4aw8ex33mj X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 1D4A8900024F Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=URmpnGWL; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf29.hostedemail.com: domain of f.fainelli@gmail.com designates 209.85.214.181 as permitted sender) smtp.mailfrom=f.fainelli@gmail.com X-HE-Tag: 1635973064-354667 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Arnd Bergmann [ Upstream commit cef397038167ac15d085914493d6c86385773709 ] Stefan Agner reported a bug when using zsram on 32-bit Arm machines with RAM above the 4GB address boundary: Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = a27bd01c [00000000] *pgd=236a0003, *pmd=1ffa64003 Internal error: Oops: 207 [#1] SMP ARM Modules linked in: mdio_bcm_unimac(+) brcmfmac cfg80211 brcmutil raspberrypi_hwmon hci_uart crc32_arm_ce bcm2711_thermal phy_generic genet CPU: 0 PID: 123 Comm: mkfs.ext4 Not tainted 5.9.6 #1 Hardware name: BCM2711 PC is at zs_map_object+0x94/0x338 LR is at zram_bvec_rw.constprop.0+0x330/0xa64 pc : [] lr : [] psr: 60000013 sp : e376bbe0 ip : 00000000 fp : c1e2921c r10: 00000002 r9 : c1dda730 r8 : 00000000 r7 : e8ff7a00 r6 : 00000000 r5 : 02f9ffa0 r4 : e3710000 r3 : 000fdffe r2 : c1e0ce80 r1 : ebf979a0 r0 : 00000000 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5383d Table: 235c2a80 DAC: fffffffd Process mkfs.ext4 (pid: 123, stack limit = 0x495a22e6) Stack: (0xe376bbe0 to 0xe376c000) As it turns out, zsram needs to know the maximum memory size, which is defined in MAX_PHYSMEM_BITS when CONFIG_SPARSEMEM is set, or in MAX_POSSIBLE_PHYSMEM_BITS on the x86 architecture. The same problem will be hit on all 32-bit architectures that have a physical address space larger than 4GB and happen to not enable sparsemem and include asm/sparsemem.h from asm/pgtable.h. After the initial discussion, I suggested just always defining MAX_POSSIBLE_PHYSMEM_BITS whenever CONFIG_PHYS_ADDR_T_64BIT is set, or provoking a build error otherwise. This addresses all configurations that can currently have this runtime bug, but leaves all other configurations unchanged. I looked up the possible number of bits in source code and datasheets, here is what I found: - on ARC, CONFIG_ARC_HAS_PAE40 controls whether 32 or 40 bits are used - on ARM, CONFIG_LPAE enables 40 bit addressing, without it we never support more than 32 bits, even though supersections in theory allow up to 40 bits as well. - on MIPS, some MIPS32r1 or later chips support 36 bits, and MIPS32r5 XPA supports up to 60 bits in theory, but 40 bits are more than anyone will ever ship - On PowerPC, there are three different implementations of 36 bit addressing, but 32-bit is used without CONFIG_PTE_64BIT - On RISC-V, the normal page table format can support 34 bit addressing. There is no highmem support on RISC-V, so anything above 2GB is unused, but it might be useful to eventually support CONFIG_ZRAM for high pages. Fixes: 61989a80fb3a ("staging: zsmalloc: zsmalloc memory allocation library") Fixes: 02390b87a945 ("mm/zsmalloc: Prepare to variable MAX_PHYSMEM_BITS") Acked-by: Thomas Bogendoerfer Reviewed-by: Stefan Agner Tested-by: Stefan Agner Acked-by: Mike Rapoport Link: https://lore.kernel.org/linux-mm/bdfa44bf1c570b05d6c70898e2bbb0acf234ecdf.1604762181.git.stefan@agner.ch/ Signed-off-by: Arnd Bergmann Signed-off-by: Sasha Levin [florian: patch arch/powerpc/include/asm/pte-common.h for 4.9.y removed arch/riscv/include/asm/pgtable.h which does not exist] Signed-off-by: Florian Fainelli --- arch/arc/include/asm/pgtable.h | 2 ++ arch/arm/include/asm/pgtable-2level.h | 2 ++ arch/arm/include/asm/pgtable-3level.h | 2 ++ arch/mips/include/asm/pgtable-32.h | 3 +++ arch/powerpc/include/asm/pte-common.h | 2 ++ include/asm-generic/pgtable.h | 13 +++++++++++++ 6 files changed, 24 insertions(+) diff --git a/arch/arc/include/asm/pgtable.h b/arch/arc/include/asm/pgtable.h index c10f5cb203e6..81198a6773c6 100644 --- a/arch/arc/include/asm/pgtable.h +++ b/arch/arc/include/asm/pgtable.h @@ -137,8 +137,10 @@ #ifdef CONFIG_ARC_HAS_PAE40 #define PTE_BITS_NON_RWX_IN_PD1 (0xff00000000 | PAGE_MASK | _PAGE_CACHEABLE) +#define MAX_POSSIBLE_PHYSMEM_BITS 40 #else #define PTE_BITS_NON_RWX_IN_PD1 (PAGE_MASK | _PAGE_CACHEABLE) +#define MAX_POSSIBLE_PHYSMEM_BITS 32 #endif /************************************************************************** diff --git a/arch/arm/include/asm/pgtable-2level.h b/arch/arm/include/asm/pgtable-2level.h index 92fd2c8a9af0..6154902bed83 100644 --- a/arch/arm/include/asm/pgtable-2level.h +++ b/arch/arm/include/asm/pgtable-2level.h @@ -78,6 +78,8 @@ #define PTE_HWTABLE_OFF (PTE_HWTABLE_PTRS * sizeof(pte_t)) #define PTE_HWTABLE_SIZE (PTRS_PER_PTE * sizeof(u32)) +#define MAX_POSSIBLE_PHYSMEM_BITS 32 + /* * PMD_SHIFT determines the size of the area a second-level page table can map * PGDIR_SHIFT determines what a third-level page table entry can map diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h index 2a029bceaf2f..35807e611b6e 100644 --- a/arch/arm/include/asm/pgtable-3level.h +++ b/arch/arm/include/asm/pgtable-3level.h @@ -37,6 +37,8 @@ #define PTE_HWTABLE_OFF (0) #define PTE_HWTABLE_SIZE (PTRS_PER_PTE * sizeof(u64)) +#define MAX_POSSIBLE_PHYSMEM_BITS 40 + /* * PGDIR_SHIFT determines the size a top-level page table entry can map. */ diff --git a/arch/mips/include/asm/pgtable-32.h b/arch/mips/include/asm/pgtable-32.h index c0be540e83cb..2c6df5a92e1e 100644 --- a/arch/mips/include/asm/pgtable-32.h +++ b/arch/mips/include/asm/pgtable-32.h @@ -110,6 +110,7 @@ static inline void pmd_clear(pmd_t *pmdp) #if defined(CONFIG_XPA) +#define MAX_POSSIBLE_PHYSMEM_BITS 40 #define pte_pfn(x) (((unsigned long)((x).pte_high >> _PFN_SHIFT)) | (unsigned long)((x).pte_low << _PAGE_PRESENT_SHIFT)) static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot) @@ -125,6 +126,7 @@ pfn_pte(unsigned long pfn, pgprot_t prot) #elif defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32) +#define MAX_POSSIBLE_PHYSMEM_BITS 36 #define pte_pfn(x) ((unsigned long)((x).pte_high >> 6)) static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot) @@ -139,6 +141,7 @@ static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot) #else +#define MAX_POSSIBLE_PHYSMEM_BITS 32 #ifdef CONFIG_CPU_VR41XX #define pte_pfn(x) ((unsigned long)((x).pte >> (PAGE_SHIFT + 2))) #define pfn_pte(pfn, prot) __pte(((pfn) << (PAGE_SHIFT + 2)) | pgprot_val(prot)) diff --git a/arch/powerpc/include/asm/pte-common.h b/arch/powerpc/include/asm/pte-common.h index 4ba26dd259fd..0d81cd9dd60e 100644 --- a/arch/powerpc/include/asm/pte-common.h +++ b/arch/powerpc/include/asm/pte-common.h @@ -101,8 +101,10 @@ static inline bool pte_user(pte_t pte) */ #if defined(CONFIG_PPC32) && defined(CONFIG_PTE_64BIT) #define PTE_RPN_MASK (~((1ULL<