From patchwork Tue Sep 7 22:00:38 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Keith Packard X-Patchwork-Id: 12479433 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=-16.0 required=3.0 tests=BAYES_00,DKIM_ADSP_ALL, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 C8888C433F5 for ; Tue, 7 Sep 2021 22:00:51 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6165261106 for ; Tue, 7 Sep 2021 22:00:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 6165261106 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=amazon.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id E3F5A6B007B; Tue, 7 Sep 2021 18:00:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DE8FD6B007D; Tue, 7 Sep 2021 18:00:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B7B8F6B007E; Tue, 7 Sep 2021 18:00:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0115.hostedemail.com [216.40.44.115]) by kanga.kvack.org (Postfix) with ESMTP id A27E26B007B for ; Tue, 7 Sep 2021 18:00:50 -0400 (EDT) Received: from smtpin32.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 6045C181EBA4E for ; Tue, 7 Sep 2021 22:00:50 +0000 (UTC) X-FDA: 78562147860.32.248EC41 Received: from elaine.keithp.com (home.keithp.com [63.227.221.253]) by imf26.hostedemail.com (Postfix) with ESMTP id 1100220019CF for ; Tue, 7 Sep 2021 22:00:49 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by elaine.keithp.com (Postfix) with ESMTP id 9155B3F30861; Tue, 7 Sep 2021 15:00:20 -0700 (PDT) X-Virus-Scanned: Debian amavisd-new at keithp.com Received: from elaine.keithp.com ([127.0.0.1]) by localhost (elaine.keithp.com [127.0.0.1]) (amavisd-new, port 10024) with LMTP id cyWcFQXC8t4y; Tue, 7 Sep 2021 15:00:20 -0700 (PDT) Received: from keithp.com (168-103-156-98.tukw.qwest.net [168.103.156.98]) by elaine.keithp.com (Postfix) with ESMTPSA id 71C3F3F30862; Tue, 7 Sep 2021 15:00:19 -0700 (PDT) Received: by keithp.com (Postfix, from userid 1000) id E25F31E6013D; Tue, 7 Sep 2021 15:00:40 -0700 (PDT) From: Keith Packard To: linux-kernel@vger.kernel.org Cc: Abbott Liu , Andrew Morton , Andrey Ryabinin , Anshuman Khandual , Ard Biesheuvel , Arnd Bergmann , Bjorn Andersson , Christoph Lameter , Dennis Zhou , Geert Uytterhoeven , Jens Axboe , Joe Perches , Kees Cook , Keith Packard , Krzysztof Kozlowski , Linus Walleij , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, Manivannan Sadhasivam , Marc Zyngier , Masahiro Yamada , Mike Rapoport , Nathan Chancellor , Nick Desaulniers , Nick Desaulniers , Nicolas Pitre , Russell King , Tejun Heo , Thomas Gleixner , =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= , Valentin Schneider , Viresh Kumar , "Wolfram Sang (Renesas)" , YiFei Zhu Subject: [PATCH 7/7] ARM: Move thread_info into task_struct (v7 only) Date: Tue, 7 Sep 2021 15:00:38 -0700 Message-Id: <20210907220038.91021-8-keithpac@amazon.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210907220038.91021-1-keithpac@amazon.com> References: <20210904060908.1310204-1-keithp@keithp.com> <20210907220038.91021-1-keithpac@amazon.com> MIME-Version: 1.0 X-Rspamd-Queue-Id: 1100220019CF Authentication-Results: imf26.hostedemail.com; dkim=none; dmarc=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=amazon.com (policy=quarantine); spf=pass (imf26.hostedemail.com: domain of keithp@keithp.com designates 63.227.221.253 as permitted sender) smtp.mailfrom=keithp@keithp.com X-Rspamd-Server: rspam01 X-Stat-Signature: brs5ku9fh7spq3ej6f943ots3zoxja6o X-Rspam: Yes X-HE-Tag: 1631052049-503475 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: This avoids many stack overflow attacks which modified the thread_info structure by moving that into the task_struct as is done is almost all other architectures. This depends on having 'current' stored in the TPIDRPRW register as that allows us to find thread_info and task_struct once the thread_info cannot be located using the kernel stack pointer. Signed-off-by: Keith Packard --- arch/arm/Kconfig | 1 + arch/arm/include/asm/assembler.h | 4 ++++ arch/arm/include/asm/thread_info.h | 12 +++++++++++- arch/arm/kernel/asm-offsets.c | 4 ++++ arch/arm/kernel/entry-armv.S | 4 ++++ arch/arm/vfp/vfpmodule.c | 9 +++++++++ 6 files changed, 33 insertions(+), 1 deletion(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 414fe23fd5ac..5846b4f5444b 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -128,6 +128,7 @@ config ARM select RTC_LIB select SET_FS select SYS_SUPPORTS_APM_EMULATION + select THREAD_INFO_IN_TASK if CURRENT_POINTER_IN_TPIDRPRW # Above selects are sorted alphabetically; please add new ones # according to that. Thanks. help diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h index ea12fe3bb589..b23d2b87184a 100644 --- a/arch/arm/include/asm/assembler.h +++ b/arch/arm/include/asm/assembler.h @@ -203,10 +203,14 @@ * Get current thread_info. */ .macro get_thread_info, rd +#ifdef CONFIG_THREAD_INFO_IN_TASK + mrc p15, 0, \rd, c13, c0, 4 +#else ARM( mov \rd, sp, lsr #THREAD_SIZE_ORDER + PAGE_SHIFT ) THUMB( mov \rd, sp ) THUMB( lsr \rd, \rd, #THREAD_SIZE_ORDER + PAGE_SHIFT ) mov \rd, \rd, lsl #THREAD_SIZE_ORDER + PAGE_SHIFT +#endif .endm /* diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h index 70d4cbc49ae1..6b67703ca16a 100644 --- a/arch/arm/include/asm/thread_info.h +++ b/arch/arm/include/asm/thread_info.h @@ -55,8 +55,10 @@ struct thread_info { unsigned long flags; /* low level flags */ int preempt_count; /* 0 => preemptable, <0 => bug */ mm_segment_t addr_limit; /* address limit */ +#ifndef CONFIG_THREAD_INFO_IN_TASK struct task_struct *task; /* main task structure */ __u32 cpu; /* cpu */ +#endif __u32 cpu_domain; /* cpu domain */ #ifdef CONFIG_STACKPROTECTOR_PER_TASK unsigned long stack_canary; @@ -75,14 +77,21 @@ struct thread_info { #endif }; +#ifdef CONFIG_THREAD_INFO_IN_TASK +#define INIT_THREAD_INFO_TASK(tsk) +#else +#define INIT_THREAD_INFO_TASK(tsk) .task = &tsk, +#endif + #define INIT_THREAD_INFO(tsk) \ { \ - .task = &tsk, \ + INIT_THREAD_INFO_TASK(tsk) \ .flags = 0, \ .preempt_count = INIT_PREEMPT_COUNT, \ .addr_limit = KERNEL_DS, \ } +#ifndef CONFIG_THREAD_INFO_IN_TASK /* * how to get the thread information struct from C */ @@ -93,6 +102,7 @@ static inline struct thread_info *current_thread_info(void) return (struct thread_info *) (current_stack_pointer & ~(THREAD_SIZE - 1)); } +#endif #define thread_saved_pc(tsk) \ ((unsigned long)(task_thread_info(tsk)->cpu_context.pc)) diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c index 70993af22d80..2a6745f7423e 100644 --- a/arch/arm/kernel/asm-offsets.c +++ b/arch/arm/kernel/asm-offsets.c @@ -44,8 +44,12 @@ int main(void) DEFINE(TI_FLAGS, offsetof(struct thread_info, flags)); DEFINE(TI_PREEMPT, offsetof(struct thread_info, preempt_count)); DEFINE(TI_ADDR_LIMIT, offsetof(struct thread_info, addr_limit)); +#ifdef CONFIG_THREAD_INFO_IN_TASK + DEFINE(TI_CPU, offsetof(struct task_struct, cpu)); +#else DEFINE(TI_TASK, offsetof(struct thread_info, task)); DEFINE(TI_CPU, offsetof(struct thread_info, cpu)); +#endif DEFINE(TI_CPU_DOMAIN, offsetof(struct thread_info, cpu_domain)); DEFINE(TI_CPU_SAVE, offsetof(struct thread_info, cpu_context)); DEFINE(TI_USED_CP, offsetof(struct thread_info, used_cp)); diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index db3947ee9c3e..5ae687c8c7b8 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -762,9 +762,13 @@ ENTRY(__switch_to) #endif switch_tls r1, r4, r5, r3, r7 #ifdef CONFIG_CURRENT_POINTER_IN_TPIDRPRW +#ifdef CONFIG_THREAD_INFO_IN_TASK + set_current r2 +#else ldr r7, [r2, #TI_TASK] set_current r7 #endif +#endif #if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP) ldr r7, [r2, #TI_TASK] ldr r8, =__stack_chk_guard diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c index d7a3818da671..84a691da59fa 100644 --- a/arch/arm/vfp/vfpmodule.c +++ b/arch/arm/vfp/vfpmodule.c @@ -158,7 +158,12 @@ static void vfp_thread_copy(struct thread_info *thread) */ static int vfp_notifier(struct notifier_block *self, unsigned long cmd, void *v) { +#ifdef CONFIG_THREAD_INFO_IN_TASK + struct task_struct *tsk = v; + struct thread_info *thread = &tsk->thread_info; +#else struct thread_info *thread = v; +#endif u32 fpexc; #ifdef CONFIG_SMP unsigned int cpu; @@ -169,7 +174,11 @@ static int vfp_notifier(struct notifier_block *self, unsigned long cmd, void *v) fpexc = fmrx(FPEXC); #ifdef CONFIG_SMP +#ifdef CONFIG_THREAD_INFO_IN_TASK + cpu = tsk->cpu; +#else cpu = thread->cpu; +#endif /* * On SMP, if VFP is enabled, save the old state in