From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8727BCA9EC2 for ; Tue, 29 Oct 2019 04:21:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4D6A221721 for ; Tue, 29 Oct 2019 04:21:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=axtens.net header.i=@axtens.net header.b="P1vgWGkf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731587AbfJ2EV0 (ORCPT ); Tue, 29 Oct 2019 00:21:26 -0400 Received: from mail-pf1-f195.google.com ([209.85.210.195]:46051 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731556AbfJ2EVY (ORCPT ); Tue, 29 Oct 2019 00:21:24 -0400 Received: by mail-pf1-f195.google.com with SMTP id c7so7400188pfo.12 for ; Mon, 28 Oct 2019 21:21:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=axtens.net; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=WyYpZbWP6HUDQzKMRNpQV+55Z3UIHrq0rortvFyZDZM=; b=P1vgWGkf/BnwrZmL0q5T0WQPs38zAc66WR+8qieAC1hUtr621MHKjoSFdetsrm+m+r 1WBO50R1y8tyWsFHolAAgVsTlZD+eVmr/nnhrn2uSp4qiu5RVcZ1Rw4gDl/qFnm3gHfE dscZ0AqBNtSUNVCxp8EQZzW5AP021+KMshCs4= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=WyYpZbWP6HUDQzKMRNpQV+55Z3UIHrq0rortvFyZDZM=; b=EDBphYwrrmTH744zk2Xhhshn9yM2/kLnTyTzsIh3FEmvqs3v8djkhZ8gsiw522r7am Xcgn3H42fmZUvioESzqg5jA7qEWTcAvY53fHIhOgaxh8iLl65CyOeSldIVnrP+jTVw7Y iMqwUNTW6FjiyqWWhoSgfNVZp3QAzoj5UCReOWvihI+R1JHTxMyBYblj3acj4nL43Cwk 8ywQpAz99EJBfMuuR3bp2DeF4VKzgwvZ2dHvRdA2NQUEWIOYjIZRbSryBm9/Cg4LDfbL dLQg1ZX7J3jSvC90xCCMcPD5srVM+IhayvZd9qYH3wqqT5q+2TukZ8j0BGcLrOICMxEH hTxA== X-Gm-Message-State: APjAAAXCNBaobWK2MwrYIiirXaiGbZuXpHlEdU6CR8htudVM4YTFzHEY NEAe91IGf9ympdt9eZ/FLgm/iA== X-Google-Smtp-Source: APXvYqz089f1zvT/a0WmxOBM04w27sj2elEK1j7mV//9L+xZ/8smZxmsjO7tME/hRSZrcZUo6utVpQ== X-Received: by 2002:a17:90a:7608:: with SMTP id s8mr3568275pjk.75.1572322884077; Mon, 28 Oct 2019 21:21:24 -0700 (PDT) Received: from localhost ([2001:44b8:802:1120:783a:2bb9:f7cb:7c3c]) by smtp.gmail.com with ESMTPSA id t8sm1026995pjv.18.2019.10.28.21.21.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 28 Oct 2019 21:21:23 -0700 (PDT) From: Daniel Axtens To: kasan-dev@googlegroups.com, linux-mm@kvack.org, x86@kernel.org, aryabinin@virtuozzo.com, glider@google.com, luto@kernel.org, linux-kernel@vger.kernel.org, mark.rutland@arm.com, dvyukov@google.com, christophe.leroy@c-s.fr Cc: linuxppc-dev@lists.ozlabs.org, gor@linux.ibm.com, Daniel Axtens Subject: [PATCH v10 4/5] x86/kasan: support KASAN_VMALLOC Date: Tue, 29 Oct 2019 15:20:58 +1100 Message-Id: <20191029042059.28541-5-dja@axtens.net> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191029042059.28541-1-dja@axtens.net> References: <20191029042059.28541-1-dja@axtens.net> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In the case where KASAN directly allocates memory to back vmalloc space, don't map the early shadow page over it. We prepopulate pgds/p4ds for the range that would otherwise be empty. This is required to get it synced to hardware on boot, allowing the lower levels of the page tables to be filled dynamically. Acked-by: Dmitry Vyukov Signed-off-by: Daniel Axtens --- v5: fix some checkpatch CHECK warnings. There are some that remain around lines ending with '(': I have not changed these because it's consistent with the rest of the file and it's not easy to see how to fix it without creating an overlong line or lots of temporary variables. v2: move from faulting in shadow pgds to prepopulating --- arch/x86/Kconfig | 1 + arch/x86/mm/kasan_init_64.c | 60 +++++++++++++++++++++++++++++++++++++ 2 files changed, 61 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 45699e458057..d65b0fcc9bc0 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -135,6 +135,7 @@ config X86 select HAVE_ARCH_JUMP_LABEL select HAVE_ARCH_JUMP_LABEL_RELATIVE select HAVE_ARCH_KASAN if X86_64 + select HAVE_ARCH_KASAN_VMALLOC if X86_64 select HAVE_ARCH_KGDB select HAVE_ARCH_MMAP_RND_BITS if MMU select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c index 296da58f3013..8f00f462709e 100644 --- a/arch/x86/mm/kasan_init_64.c +++ b/arch/x86/mm/kasan_init_64.c @@ -245,6 +245,51 @@ static void __init kasan_map_early_shadow(pgd_t *pgd) } while (pgd++, addr = next, addr != end); } +static void __init kasan_shallow_populate_p4ds(pgd_t *pgd, + unsigned long addr, + unsigned long end, + int nid) +{ + p4d_t *p4d; + unsigned long next; + void *p; + + p4d = p4d_offset(pgd, addr); + do { + next = p4d_addr_end(addr, end); + + if (p4d_none(*p4d)) { + p = early_alloc(PAGE_SIZE, nid, true); + p4d_populate(&init_mm, p4d, p); + } + } while (p4d++, addr = next, addr != end); +} + +static void __init kasan_shallow_populate_pgds(void *start, void *end) +{ + unsigned long addr, next; + pgd_t *pgd; + void *p; + int nid = early_pfn_to_nid((unsigned long)start); + + addr = (unsigned long)start; + pgd = pgd_offset_k(addr); + do { + next = pgd_addr_end(addr, (unsigned long)end); + + if (pgd_none(*pgd)) { + p = early_alloc(PAGE_SIZE, nid, true); + pgd_populate(&init_mm, pgd, p); + } + + /* + * we need to populate p4ds to be synced when running in + * four level mode - see sync_global_pgds_l4() + */ + kasan_shallow_populate_p4ds(pgd, addr, next, nid); + } while (pgd++, addr = next, addr != (unsigned long)end); +} + #ifdef CONFIG_KASAN_INLINE static int kasan_die_handler(struct notifier_block *self, unsigned long val, @@ -352,9 +397,24 @@ void __init kasan_init(void) shadow_cpu_entry_end = (void *)round_up( (unsigned long)shadow_cpu_entry_end, PAGE_SIZE); + /* + * If we're in full vmalloc mode, don't back vmalloc space with early + * shadow pages. Instead, prepopulate pgds/p4ds so they are synced to + * the global table and we can populate the lower levels on demand. + */ +#ifdef CONFIG_KASAN_VMALLOC + kasan_shallow_populate_pgds( + kasan_mem_to_shadow((void *)PAGE_OFFSET + MAXMEM), + kasan_mem_to_shadow((void *)VMALLOC_END)); + + kasan_populate_early_shadow( + kasan_mem_to_shadow((void *)VMALLOC_END + 1), + shadow_cpu_entry_begin); +#else kasan_populate_early_shadow( kasan_mem_to_shadow((void *)PAGE_OFFSET + MAXMEM), shadow_cpu_entry_begin); +#endif kasan_populate_shadow((unsigned long)shadow_cpu_entry_begin, (unsigned long)shadow_cpu_entry_end, 0); -- 2.20.1