From patchwork Mon May 15 08:19:33 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Wenlong X-Patchwork-Id: 13240944 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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 18B48C7EE26 for ; Mon, 15 May 2023 08:20:41 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.534603.831765 (Exim 4.92) (envelope-from ) id 1pyTRX-00018L-P9; Mon, 15 May 2023 08:20:31 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 534603.831765; Mon, 15 May 2023 08:20:31 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pyTRX-00018C-LU; Mon, 15 May 2023 08:20:31 +0000 Received: by outflank-mailman (input) for mailman id 534603; Mon, 15 May 2023 08:20:30 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pyTRW-0000Zb-O6 for xen-devel@lists.xenproject.org; Mon, 15 May 2023 08:20:30 +0000 Received: from out0-207.mail.aliyun.com (out0-207.mail.aliyun.com [140.205.0.207]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 591fb455-f2f9-11ed-b229-6b7b168915f2; Mon, 15 May 2023 10:20:29 +0200 (CEST) Received: from localhost(mailfrom:houwenlong.hwl@antgroup.com fp:SMTPD_---.T2G7nz7_1684138818) by smtp.aliyun-inc.com; Mon, 15 May 2023 16:20:19 +0800 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 591fb455-f2f9-11ed-b229-6b7b168915f2 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R621e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018047194;MF=houwenlong.hwl@antgroup.com;NM=1;PH=DS;RN=12;SR=0;TI=SMTPD_---.T2G7nz7_1684138818; From: "Hou Wenlong" To: linux-kernel@vger.kernel.org Cc: "Lai Jiangshan" , "Hou Wenlong" , "Juergen Gross" , "Boris Ostrovsky" , "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "Dave Hansen" , , "H. Peter Anvin" , Subject: [PATCH RFC 2/4] x86/xen: Pin up to VSYSCALL_ADDR when vsyscall page is out of fixmap area Date: Mon, 15 May 2023 16:19:33 +0800 Message-Id: X-Mailer: git-send-email 2.31.1 In-Reply-To: References: MIME-Version: 1.0 If the vsyscall page is moved out of the fixmap area, then FIXADDR_TOP would be below the vsyscall page. Therefore, it should be pinned up to VSYSCALL_ADDR if vsyscall is enabled. Suggested-by: Lai Jiangshan Signed-off-by: Hou Wenlong --- arch/x86/xen/mmu_pv.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c index c42c60faa3bb..c1f298c31e64 100644 --- a/arch/x86/xen/mmu_pv.c +++ b/arch/x86/xen/mmu_pv.c @@ -587,6 +587,12 @@ static void xen_p4d_walk(struct mm_struct *mm, p4d_t *p4d, xen_pud_walk(mm, pud, func, last, limit); } +#ifdef CONFIG_X86_VSYSCALL_EMULATION +#define __KERNEL_MAP_TOP (VSYSCALL_ADDR + PAGE_SIZE) +#else +#define __KERNEL_MAP_TOP FIXADDR_TOP +#endif + /* * (Yet another) pagetable walker. This one is intended for pinning a * pagetable. This means that it walks a pagetable and calls the @@ -594,7 +600,7 @@ static void xen_p4d_walk(struct mm_struct *mm, p4d_t *p4d, * at every level. It walks the entire pagetable, but it only bothers * pinning pte pages which are below limit. In the normal case this * will be STACK_TOP_MAX, but at boot we need to pin up to - * FIXADDR_TOP. + * __KERNEL_MAP_TOP. * * We must skip the Xen hole in the middle of the address space, just after * the big x86-64 virtual hole. @@ -609,7 +615,7 @@ static void __xen_pgd_walk(struct mm_struct *mm, pgd_t *pgd, /* The limit is the last byte to be touched */ limit--; - BUG_ON(limit >= FIXADDR_TOP); + BUG_ON(limit >= __KERNEL_MAP_TOP); /* * 64-bit has a great big hole in the middle of the address @@ -797,7 +803,7 @@ static void __init xen_after_bootmem(void) #ifdef CONFIG_X86_VSYSCALL_EMULATION SetPagePinned(virt_to_page(level3_user_vsyscall)); #endif - xen_pgd_walk(&init_mm, xen_mark_pinned, FIXADDR_TOP); + xen_pgd_walk(&init_mm, xen_mark_pinned, __KERNEL_MAP_TOP); } static void xen_unpin_page(struct mm_struct *mm, struct page *page,