From patchwork Tue May 12 18:44:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mike Rapoport X-Patchwork-Id: 11543779 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 46A8A92A for ; Tue, 12 May 2020 18:46:33 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 05F6420784 for ; Tue, 12 May 2020 18:46:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="FlkStUOf" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 05F6420784 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 385529000E3; Tue, 12 May 2020 14:46:32 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 35B2B900036; Tue, 12 May 2020 14:46:32 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 24AF19000E3; Tue, 12 May 2020 14:46:32 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0197.hostedemail.com [216.40.44.197]) by kanga.kvack.org (Postfix) with ESMTP id 0C2C3900036 for ; Tue, 12 May 2020 14:46:32 -0400 (EDT) Received: from smtpin01.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id BD23B181AEF07 for ; Tue, 12 May 2020 18:46:31 +0000 (UTC) X-FDA: 76808947782.01.use60_1bd4778b78f60 X-Spam-Summary: 2,0,0,7629d5470f06da47,d41d8cd98f00b204,rppt@kernel.org,,RULES_HIT:2:41:69:355:379:541:800:960:973:988:989:1260:1311:1314:1345:1359:1437:1515:1535:1605:1730:1747:1777:1792:1981:2194:2199:2393:2559:2562:3138:3139:3140:3141:3142:3865:3866:3867:3868:3870:3871:4049:4120:4250:4321:4605:5007:6117:6119:6261:6630:6653:6742:6743:7576:7903:9592:10004:11026:11473:11657:11658:11914:12043:12219:12291:12296:12297:12438:12517:12519:12555:12679:12683:12895:12986:13141:13161:13229:13230:13894:14096:14394:21080:21433:21451:21627:21966:21990:30012:30054:30074:30079,0,RBL:198.145.29.99:@kernel.org:.lbl8.mailshell.net-64.100.201.201 62.2.0.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:26,LUA_SUMMARY:none X-HE-Tag: use60_1bd4778b78f60 X-Filterd-Recvd-Size: 9333 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf18.hostedemail.com (Postfix) with ESMTP for ; Tue, 12 May 2020 18:46:31 +0000 (UTC) Received: from aquarius.haifa.ibm.com (nesher1.haifa.il.ibm.com [195.110.40.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 47CAC20673; Tue, 12 May 2020 18:46:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589309190; bh=AQUJn6mfzeNGdr4PJCFIJ/VJeHCNxPfcmfbaSimbRTk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FlkStUOfxg2XidXXkPETlQBTEywMyia/LTgxg4q7Dzwj4/scd/IOqNS0FX4FdPne6 hdQC26B46vkm/CAAnLsu+j6YvUdXBfTwW3bT3abkPzHmPelfNFfG0LEeFZxv40RUZi Cah4ENld4CoU+xFamDONbiLpiwhMjnTGO/VyxIdI= From: Mike Rapoport To: linux-kernel@vger.kernel.org Cc: Andrew Morton , Arnd Bergmann , Borislav Petkov , Brian Cain , Catalin Marinas , Chris Zankel , "David S. Miller" , Geert Uytterhoeven , Greentime Hu , Greg Ungerer , Guan Xuetao , Guo Ren , Heiko Carstens , Helge Deller , Ingo Molnar , Ley Foon Tan , Mark Salter , Matt Turner , Max Filippov , Michael Ellerman , Michal Simek , Mike Rapoport , Nick Hu , Paul Walmsley , Richard Weinberger , Rich Felker , Russell King , Stafford Horne , Thomas Bogendoerfer , Thomas Gleixner , Tony Luck , Vincent Chen , Vineet Gupta , Will Deacon , Yoshinori Sato , linux-alpha@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-c6x-dev@linux-c6x.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-um@lists.infradead.org, linux-xtensa@linux-xtensa.org, openrisc@lists.librecores.org, sparclinux@vger.kernel.org, x86@kernel.org, Mike Rapoport Subject: [PATCH 07/12] x86/mm: simplify init_trampoline() and surrounding logic Date: Tue, 12 May 2020 21:44:17 +0300 Message-Id: <20200512184422.12418-8-rppt@kernel.org> X-Mailer: git-send-email 2.26.1 In-Reply-To: <20200512184422.12418-1-rppt@kernel.org> References: <20200512184422.12418-1-rppt@kernel.org> MIME-Version: 1.0 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: Mike Rapoport There are three cases for the trampoline initialization: * 32-bit does nothing * 64-bit with kaslr disabled simply copies a PGD entry from the direct map to the trampoline PGD * 64-bit with kaslr enabled maps the real mode trampoline at PUD level These cases are currently differentiated by a bunch of ifdefs inside asm/include/pgtable.h and the case of 64-bits with kaslr on uses pgd_index() helper. Replacing the ifdefs with a static function in arch/x86/mm/init.c gives clearer code and allows moving pgd_index() to the generic implementation in include/linux/pgtable.h Signed-off-by: Mike Rapoport --- arch/x86/include/asm/kaslr.h | 2 ++ arch/x86/include/asm/pgtable.h | 15 +-------------- arch/x86/include/asm/setup.h | 9 +++++++++ arch/x86/mm/init.c | 22 ++++++++++++++++++++++ arch/x86/mm/kaslr.c | 33 +-------------------------------- 5 files changed, 35 insertions(+), 46 deletions(-) diff --git a/arch/x86/include/asm/kaslr.h b/arch/x86/include/asm/kaslr.h index db7ba2feb947..0648190467ba 100644 --- a/arch/x86/include/asm/kaslr.h +++ b/arch/x86/include/asm/kaslr.h @@ -6,8 +6,10 @@ unsigned long kaslr_get_random_long(const char *purpose); #ifdef CONFIG_RANDOMIZE_MEMORY void kernel_randomize_memory(void); +void init_trampoline_kaslr(void); #else static inline void kernel_randomize_memory(void) { } +static inline void init_trampoline_kaslr(void) {} #endif /* CONFIG_RANDOMIZE_MEMORY */ #endif diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index d24f8e1f7250..6366136b0e46 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -1070,27 +1070,14 @@ void init_mem_mapping(void); void early_alloc_pgt_buf(void); extern void memblock_find_dma_reserve(void); + #ifdef CONFIG_X86_64 -/* Realmode trampoline initialization. */ extern pgd_t trampoline_pgd_entry; -static inline void __meminit init_trampoline_default(void) -{ - /* Default trampoline pgd value */ - trampoline_pgd_entry = init_top_pgt[pgd_index(__PAGE_OFFSET)]; -} void __init poking_init(void); unsigned long init_memory_mapping(unsigned long start, unsigned long end, pgprot_t prot); - -# ifdef CONFIG_RANDOMIZE_MEMORY -void __meminit init_trampoline(void); -# else -# define init_trampoline init_trampoline_default -# endif -#else -static inline void init_trampoline(void) { } #endif /* local pte updates need not use xchg for locking */ diff --git a/arch/x86/include/asm/setup.h b/arch/x86/include/asm/setup.h index ed8ec011a9fd..d95cacf210bb 100644 --- a/arch/x86/include/asm/setup.h +++ b/arch/x86/include/asm/setup.h @@ -78,6 +78,15 @@ static inline bool kaslr_enabled(void) return !!(boot_params.hdr.loadflags & KASLR_FLAG); } +/* + * Apply no randomization if KASLR was disabled at boot or if KASAN + * is enabled. KASAN shadow mappings rely on regions being PGD aligned. + */ +static inline bool kaslr_memory_enabled(void) +{ + return kaslr_enabled() && !IS_ENABLED(CONFIG_KASAN); +} + static inline unsigned long kaslr_offset(void) { return (unsigned long)&_text - __START_KERNEL; diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 235dd0e35741..e225ebb25197 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -682,6 +682,28 @@ static void __init memory_map_bottom_up(unsigned long map_start, } } +/* + * The real mode trampoline, which is required for bootstrapping CPUs + * occupies only a small area under the low 1MB. See reserve_real_mode() + * for details. + * + * If KASLR is disabled the first PGD entry of the direct mapping is copied + * to map the real mode trampoline. + * + * If KASLR is enabled, copy only the PUD which covers the low 1MB + * area. This limits the randomization granularity to 1GB for both 4-level + * and 5-level paging. + */ +static void __init init_trampoline(void) +{ +#ifdef CONFIG_X86_64 + if (!kaslr_memory_enabled()) + trampoline_pgd_entry = init_top_pgt[pgd_index(__PAGE_OFFSET)]; + else + init_trampoline_kaslr(); +#endif +} + void __init init_mem_mapping(void) { unsigned long end; diff --git a/arch/x86/mm/kaslr.c b/arch/x86/mm/kaslr.c index faf02e1e1517..fb620fd9dae9 100644 --- a/arch/x86/mm/kaslr.c +++ b/arch/x86/mm/kaslr.c @@ -61,15 +61,6 @@ static inline unsigned long get_padding(struct kaslr_memory_region *region) return (region->size_tb << TB_SHIFT); } -/* - * Apply no randomization if KASLR was disabled at boot or if KASAN - * is enabled. KASAN shadow mappings rely on regions being PGD aligned. - */ -static inline bool kaslr_memory_enabled(void) -{ - return kaslr_enabled() && !IS_ENABLED(CONFIG_KASAN); -} - /* Initialize base and padding for each memory region randomized with KASLR */ void __init kernel_randomize_memory(void) { @@ -148,7 +139,7 @@ void __init kernel_randomize_memory(void) } } -static void __meminit init_trampoline_pud(void) +void __meminit init_trampoline_kaslr(void) { pud_t *pud_page_tramp, *pud, *pud_tramp; p4d_t *p4d_page_tramp, *p4d, *p4d_tramp; @@ -189,25 +180,3 @@ static void __meminit init_trampoline_pud(void) __pgd(_KERNPG_TABLE | __pa(pud_page_tramp))); } } - -/* - * The real mode trampoline, which is required for bootstrapping CPUs - * occupies only a small area under the low 1MB. See reserve_real_mode() - * for details. - * - * If KASLR is disabled the first PGD entry of the direct mapping is copied - * to map the real mode trampoline. - * - * If KASLR is enabled, copy only the PUD which covers the low 1MB - * area. This limits the randomization granularity to 1GB for both 4-level - * and 5-level paging. - */ -void __meminit init_trampoline(void) -{ - if (!kaslr_memory_enabled()) { - init_trampoline_default(); - return; - } - - init_trampoline_pud(); -}