From nobody Thu Feb 12 04:51:36 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 52B9CC77B60 for ; Fri, 28 Apr 2023 09:56:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345952AbjD1J4Q (ORCPT ); Fri, 28 Apr 2023 05:56:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37136 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345954AbjD1JzY (ORCPT ); Fri, 28 Apr 2023 05:55:24 -0400 Received: from out187-17.us.a.mail.aliyun.com (out187-17.us.a.mail.aliyun.com [47.90.187.17]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B677465AB for ; Fri, 28 Apr 2023 02:55:07 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R121e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018047190;MF=houwenlong.hwl@antgroup.com;NM=1;PH=DS;RN=17;SR=0;TI=SMTPD_---.STFoGjm_1682675641; Received: from localhost(mailfrom:houwenlong.hwl@antgroup.com fp:SMTPD_---.STFoGjm_1682675641) by smtp.aliyun-inc.com; Fri, 28 Apr 2023 17:54:02 +0800 From: "Hou Wenlong" To: linux-kernel@vger.kernel.org Cc: "Thomas Garnier" , "Lai Jiangshan" , "Kees Cook" , "Hou Wenlong" , "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "Dave Hansen" , , "H. Peter Anvin" , "Andy Lutomirski" , "Peter Zijlstra" , "Juergen Gross" , "Anshuman Khandual" , "Josh Poimboeuf" , "Pasha Tatashin" Subject: [PATCH RFC 39/43] x86/fixmap: Unify FIXADDR_TOP Date: Fri, 28 Apr 2023 17:51:19 +0800 Message-Id: X-Mailer: git-send-email 2.31.1 In-Reply-To: References: 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" Now FIXADDR_TOP is nothing to do with vsyscall page, it can be declared as variable too for x86_64, so unify it for x86. Suggested-by: Lai Jiangshan Signed-off-by: Hou Wenlong Cc: Thomas Garnier Cc: Kees Cook --- arch/x86/include/asm/fixmap.h | 13 ------------- arch/x86/kernel/head64.c | 1 - arch/x86/mm/dump_pagetables.c | 3 ++- arch/x86/mm/ioremap.c | 5 ++--- arch/x86/mm/pgtable.c | 13 +++++++++++++ arch/x86/mm/pgtable_32.c | 3 --- 6 files changed, 17 insertions(+), 21 deletions(-) diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h index eeb152ad9682..9433109e4853 100644 --- a/arch/x86/include/asm/fixmap.h +++ b/arch/x86/include/asm/fixmap.h @@ -40,21 +40,8 @@ #include #endif =20 -/* - * We can't declare FIXADDR_TOP as variable for x86_64 because vsyscall - * uses fixmaps that relies on FIXADDR_TOP for proper address calculation. - * Because of this, FIXADDR_TOP x86 integration was left as later work. - */ -#ifdef CONFIG_X86_32 -/* - * Leave one empty page between vmalloc'ed areas and - * the start of the fixmap. - */ extern unsigned long __FIXADDR_TOP; #define FIXADDR_TOP ((unsigned long)__FIXADDR_TOP) -#else -#define FIXADDR_TOP (0xffffffffff600000UL - PAGE_SIZE) -#endif =20 /* * Here we define all the compile-time 'special' virtual diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index ef7ad96f2154..8295b547b64f 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -499,7 +499,6 @@ asmlinkage __visible void __init __noreturn x86_64_star= t_kernel(char * real_mode BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL)); MAYBE_BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) =3D=3D (__START_KERNEL & PGDIR_MASK))); - BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <=3D MODULES_END); =20 cr4_init_shadow(); =20 diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c index e1b599ecbbc2..df1a708a038a 100644 --- a/arch/x86/mm/dump_pagetables.c +++ b/arch/x86/mm/dump_pagetables.c @@ -104,7 +104,7 @@ static struct addr_marker address_markers[] =3D { [HIGH_KERNEL_NR] =3D { __START_KERNEL_map, "High Kernel Mapping" }, [MODULES_VADDR_NR] =3D { MODULES_VADDR, "Modules" }, [MODULES_END_NR] =3D { MODULES_END, "End Modules" }, - [FIXADDR_START_NR] =3D { FIXADDR_START, "Fixmap Area" }, + [FIXADDR_START_NR] =3D { 0UL, "Fixmap Area" }, [END_OF_SPACE_NR] =3D { -1, NULL } }; =20 @@ -453,6 +453,7 @@ static int __init pt_dump_init(void) address_markers[KASAN_SHADOW_START_NR].start_address =3D KASAN_SHADOW_STA= RT; address_markers[KASAN_SHADOW_END_NR].start_address =3D KASAN_SHADOW_END; #endif + address_markers[FIXADDR_START_NR].start_address =3D FIXADDR_START; #endif #ifdef CONFIG_X86_32 address_markers[VMALLOC_START_NR].start_address =3D VMALLOC_START; diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index aa7d279321ea..44f9c6781c15 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -879,10 +879,9 @@ void __init early_ioremap_init(void) pmd_t *pmd; =20 #ifdef CONFIG_X86_64 - BUILD_BUG_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1)); -#else - WARN_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1)); + BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <=3D MODULES_END); #endif + WARN_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1)); =20 early_ioremap_setup(); =20 diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index afab0bc7862b..726c0c369676 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -627,6 +627,19 @@ pmd_t pmdp_invalidate_ad(struct vm_area_struct *vma, u= nsigned long address, } #endif =20 +#ifdef CONFIG_X86_32 +/* + * Leave one empty page between vmalloc'ed areas and + * the start of the fixmap. + */ +#define __FIXADDR_TOP_BASE 0xfffff000 +#else +#define __FIXADDR_TOP_BASE (0xffffffffff600000UL - PAGE_SIZE) +#endif + +unsigned long __FIXADDR_TOP =3D __FIXADDR_TOP_BASE; +EXPORT_SYMBOL(__FIXADDR_TOP); + /** * reserve_top_address - reserves a hole in the top of kernel address space * @reserve - size of hole to reserve diff --git a/arch/x86/mm/pgtable_32.c b/arch/x86/mm/pgtable_32.c index c234634e26ba..2b9a00976fee 100644 --- a/arch/x86/mm/pgtable_32.c +++ b/arch/x86/mm/pgtable_32.c @@ -65,9 +65,6 @@ void set_pte_vaddr(unsigned long vaddr, pte_t pteval) flush_tlb_one_kernel(vaddr); } =20 -unsigned long __FIXADDR_TOP =3D 0xfffff000; -EXPORT_SYMBOL(__FIXADDR_TOP); - /* * vmalloc=3Dsize forces the vmalloc area to be exactly 'size' * bytes. This can be used to increase (or decrease) the --=20 2.31.1