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=-9.9 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,USER_AGENT_GIT autolearn=ham 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 600C0ECDFB6 for ; Tue, 1 Oct 2019 06:59:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2D6E821835 for ; Tue, 1 Oct 2019 06:59:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=axtens.net header.i=@axtens.net header.b="HGfYh1Vy" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732787AbfJAG7E (ORCPT ); Tue, 1 Oct 2019 02:59:04 -0400 Received: from mail-pf1-f195.google.com ([209.85.210.195]:46876 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725777AbfJAG7D (ORCPT ); Tue, 1 Oct 2019 02:59:03 -0400 Received: by mail-pf1-f195.google.com with SMTP id q5so7209338pfg.13 for ; Mon, 30 Sep 2019 23:59:03 -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=nT2YfVWqLVVoMBBfkawFdkyFGk3ghEY3fSb+SzvkIKM=; b=HGfYh1VyCCRRrYjyyHksV5PtYqUEUQGZAzjuMeCow2Rb3lbgVQMLAwN7dOYK6q3x0d 3q5K8hsf4wYgSeFHQaeY5uV5uPTsa7dMcpYL+kEz8ZVjoV+m5Z2CYNTnACBP3nyl78WX aH+/6C6ji3wYROGNBbGc2VgFuXcqUP1SkXcx4= 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=nT2YfVWqLVVoMBBfkawFdkyFGk3ghEY3fSb+SzvkIKM=; b=Y9SvS09FEG68BOarOCwwILt4GT4GbcuLMCEFF312+M7Jnldigdy5+RhIXcCRT56J3M I3LKdTtIbxE7LvlBYt0N2P6N4RaVndpPeYhjefVzyRGw1mxIunlITpCjFxpHRJ1oRmlR oVGt/O79dgD0Cj+8gZ3oKhcvyDkILdqAj4zESWHYARQkYci0eRZ0BXGz6h1oi6E5aJCY 71rJg3kAaEwd6gnYxMNhOCI0ANF4sxrTQ25ypc1paCq+3CWrRL5lm4mvuRpnDVIgSdSR G6SGEX2wKzkiS7Xc71F6RZ5kw7A/O8Z+ugAi+3ta36Gl8qn/Fx0Nk9U/nxOzbVQWk1yV 3YFA== X-Gm-Message-State: APjAAAUmYqOtvKA2RnnATUDcpJpxnUyL/KNHV/TFJIQG9fXHlbnRSugO J+tTMWAxJEt6LbvXn2bLgkX7Ew== X-Google-Smtp-Source: APXvYqz8XN8M4FTvdMOasc3Ml6YeYUnTSf9Eg44o2IZlhuRJvc2uu7N4c7IKXOnVmqqQuB4RQFqXww== X-Received: by 2002:a62:8286:: with SMTP id w128mr1195213pfd.240.1569913142901; Mon, 30 Sep 2019 23:59:02 -0700 (PDT) Received: from localhost (ppp167-251-205.static.internode.on.net. [59.167.251.205]) by smtp.gmail.com with ESMTPSA id u11sm21284342pgb.75.2019.09.30.23.59.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 30 Sep 2019 23:59:02 -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 v8 4/5] x86/kasan: support KASAN_VMALLOC Date: Tue, 1 Oct 2019 16:58:33 +1000 Message-Id: <20191001065834.8880-5-dja@axtens.net> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191001065834.8880-1-dja@axtens.net> References: <20191001065834.8880-1-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 96ea2c7449ef..3590651e95f5 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