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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 3EEA2C433E0 for ; Fri, 15 May 2020 17:28:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 193CF207C3 for ; Fri, 15 May 2020 17:28:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589563700; bh=3rT3Y1nllLXurlUajpsDUcgeYtZ6W1gs3Ys8kPvelUA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Dpy9zJYJPt/hbN6HC3V68UTf8XVWa2or+252vfa+hF5pVNXcqD1MZEWg5lX+ovIOG 50IKZD9b200umWy8fxpE4eA/KiKjmPmVb3yuI+NJBcWVos4Wl09DYDRJCSVdcBzFRE KMHhaBoNtjpLvCsdBQjdadssCPRQMBi4yDTzRHqw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726722AbgEOR2T (ORCPT ); Fri, 15 May 2020 13:28:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:53290 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726653AbgEOR2Q (ORCPT ); Fri, 15 May 2020 13:28:16 -0400 Received: from localhost.localdomain (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A08B3207C3; Fri, 15 May 2020 17:28:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589563695; bh=3rT3Y1nllLXurlUajpsDUcgeYtZ6W1gs3Ys8kPvelUA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iflLaAfznSBNzehiCR0qdxs9AXdnlMcpDZJeKjJJDdOdOFYot//rRZ+qIoILzuKzm gmjibbc5QcONQwYXD8nX/9SH7TkOq2PI4aajQoEFRc0ir4oSjeZdCP8fC/Y1I4QeMN UdFJLXmI4zW87VTFTxOfi/3Q66IBl8DdKl++oSgQ= From: Will Deacon To: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, Will Deacon , Sami Tolvanen , Kees Cook , Catalin Marinas , Mark Rutland , Jann Horn , Ard Biesheuvel , Peter Zijlstra , kernel-team@android.com Subject: [PATCH 4/6] scs: Move scs_overflow_check() out of architecture code Date: Fri, 15 May 2020 18:27:54 +0100 Message-Id: <20200515172756.27185-5-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200515172756.27185-1-will@kernel.org> References: <20200515172756.27185-1-will@kernel.org> 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 There is nothing architecture-specific about scs_overflow_check() as it's just a trivial wrapper around scs_corrupted(). For parity with task_stack_end_corrupted(), rename scs_corrupted() to task_scs_end_corrupted() and call it from schedule_debug() when CONFIG_SCHED_STACK_END_CHECK_is enabled. Finally, remove the unused scs_overflow_check() function entirely. This has absolutely no impact on architectures that do not support SCS (currently arm64 only). Signed-off-by: Will Deacon --- arch/arm64/include/asm/scs.h | 18 ------------------ arch/arm64/kernel/process.c | 2 -- arch/arm64/kernel/scs.c | 2 +- include/linux/scs.h | 4 ++-- kernel/sched/core.c | 3 +++ kernel/scs.c | 3 ++- 6 files changed, 8 insertions(+), 24 deletions(-) diff --git a/arch/arm64/include/asm/scs.h b/arch/arm64/include/asm/scs.h index d46efdd2060a..eaa2cd92e4c1 100644 --- a/arch/arm64/include/asm/scs.h +++ b/arch/arm64/include/asm/scs.h @@ -24,24 +24,6 @@ .endm #endif /* CONFIG_SHADOW_CALL_STACK */ -#else /* __ASSEMBLY__ */ - -#include - -#ifdef CONFIG_SHADOW_CALL_STACK - -static inline void scs_overflow_check(struct task_struct *tsk) -{ - if (unlikely(scs_corrupted(tsk))) - panic("corrupted shadow stack detected inside scheduler\n"); -} - -#else /* CONFIG_SHADOW_CALL_STACK */ - -static inline void scs_overflow_check(struct task_struct *tsk) {} - -#endif /* CONFIG_SHADOW_CALL_STACK */ - #endif /* __ASSEMBLY __ */ #endif /* _ASM_SCS_H */ diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index a35d3318492c..56be4cbf771f 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -52,7 +52,6 @@ #include #include #include -#include #include #if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_STACKPROTECTOR_PER_TASK) @@ -516,7 +515,6 @@ __notrace_funcgraph struct task_struct *__switch_to(struct task_struct *prev, entry_task_switch(next); uao_thread_switch(next); ssbs_thread_switch(next); - scs_overflow_check(next); /* * Complete any pending TLB or cache maintenance on this CPU in case diff --git a/arch/arm64/kernel/scs.c b/arch/arm64/kernel/scs.c index adc97f826fab..955875dff9e1 100644 --- a/arch/arm64/kernel/scs.c +++ b/arch/arm64/kernel/scs.c @@ -6,7 +6,7 @@ */ #include -#include +#include /* Allocate a static per-CPU shadow stack */ #define DEFINE_SCS(name) \ diff --git a/include/linux/scs.h b/include/linux/scs.h index 0eb2485ef832..2fd3df50e93e 100644 --- a/include/linux/scs.h +++ b/include/linux/scs.h @@ -47,7 +47,7 @@ static inline unsigned long *__scs_magic(void *s) return (unsigned long *)(s + SCS_SIZE) - 1; } -static inline bool scs_corrupted(struct task_struct *tsk) +static inline bool task_scs_end_corrupted(struct task_struct *tsk) { unsigned long *magic = __scs_magic(task_scs(tsk)); unsigned long sz = task_scs_sp(tsk) - task_scs(tsk); @@ -60,8 +60,8 @@ static inline bool scs_corrupted(struct task_struct *tsk) static inline void scs_init(void) {} static inline void scs_task_reset(struct task_struct *tsk) {} static inline int scs_prepare(struct task_struct *tsk, int node) { return 0; } -static inline bool scs_corrupted(struct task_struct *tsk) { return false; } static inline void scs_release(struct task_struct *tsk) {} +static inline bool task_scs_end_corrupted(struct task_struct *tsk) { return false; } #endif /* CONFIG_SHADOW_CALL_STACK */ diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 934e03cfaec7..a1d815a11b90 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3878,6 +3878,9 @@ static inline void schedule_debug(struct task_struct *prev, bool preempt) #ifdef CONFIG_SCHED_STACK_END_CHECK if (task_stack_end_corrupted(prev)) panic("corrupted stack end detected inside scheduler\n"); + + if (task_scs_end_corrupted(prev)) + panic("corrupted shadow stack detected inside scheduler\n"); #endif #ifdef CONFIG_DEBUG_ATOMIC_SLEEP diff --git a/kernel/scs.c b/kernel/scs.c index aea841cd7586..faf0ecd7b893 100644 --- a/kernel/scs.c +++ b/kernel/scs.c @@ -98,7 +98,8 @@ void scs_release(struct task_struct *tsk) if (!s) return; - WARN(scs_corrupted(tsk), "corrupted shadow stack detected when freeing task\n"); + WARN(task_scs_end_corrupted(tsk), + "corrupted shadow stack detected when freeing task\n"); scs_check_usage(tsk); scs_free(s); } -- 2.26.2.761.g0e0b3e54be-goog