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=-9.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_ADSP_CUSTOM_MED,DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=unavailable 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 5EA41C8B4DC for ; Mon, 16 Nov 2020 12:40:31 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EFFF020853 for ; Mon, 16 Nov 2020 12:40:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="HEKwWsWM"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=google.com header.i=@google.com header.b="Pt6jcPm5" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EFFF020853 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:To:Subject:Message-ID:Date:From:In-Reply-To: References:MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=EN3K83tQiXXt/EGG8pSWLm0kHWcB28ICh3x9ZI85/Yo=; b=HEKwWsWMW1oqpJh+vPB3/ibwt x7fGhPOwhGLhRLEqcUsqZMEBPKgtQop+z0ZoUcpKWU6NWjULSRnx8D430f+338u8N62+dWzx7BduV TYp/NbdjklO9+EYkG6Z8Tr0GVQkK8NQqzEyfS3tFJw/9WkD+MuueoRFPNNm9sd3LOgWHw7LonGjqP hO8NKGYQELAcez2cjEVgzhRlwmv87bx975U24uNa14WBUs9ReudtiSYPF9iuYeM/pUsrzx1w0wp3n RYuw7kfGi2bfKVcimYal2pYPP6XQrVy+Fsslqhzy9oegqgUqdcCWSGKff8fHcwdIqT41ijCpQtefU y0Z098esg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1ked1V-0002ml-U2; Mon, 16 Nov 2020 11:50:17 +0000 Received: from mail-ot1-x343.google.com ([2607:f8b0:4864:20::343]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1ked1T-0002lU-4O for linux-arm-kernel@lists.infradead.org; Mon, 16 Nov 2020 11:50:16 +0000 Received: by mail-ot1-x343.google.com with SMTP id l36so15708254ota.4 for ; Mon, 16 Nov 2020 03:50:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=fu3D6i8J61m+Cc7UW0OMX7Lqixc5Ynk1q+2LnV9wne0=; b=Pt6jcPm5dU+criPa9cicLUvdCVAqkzUHWd1Hci2dnjSRsBYRh/3+LAWeXMACgDyzfp X3VUJwro+hrGzVw+o5UzM8N8RHFFzHbYdGfQSYa/g7pXlgTE6ueKXT1FOiqLTMq3pKDS fROvtumY/Iroc0+exJFyugUD6zfyWkaQxe5B67uhHV+0939l3i25Kx8psdW0paPFgxj3 +T6P7CsedKrkcbSEBlZm2Go3sn3Uj+/WQk8Dx2FZ3qP5pmVMWZPZcJ9nCBZ/pN3L6iwN Y3ifA2JEguHbkSj6IeHkqk8IuKpu/B7/J9SOkZLacD9Qy8Yoo/CFykmmLOvoyZHFT6eq gWIg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=fu3D6i8J61m+Cc7UW0OMX7Lqixc5Ynk1q+2LnV9wne0=; b=BpVUzKzzXj2iDzWh21auRTqtmDor2RknQJR0+fReIDDB+LSbSvulKeOR51Fwzr0QqD NG8e+//8y10vuWJj7DlZWEpeCjU1yZFtFY17l+MUE9F5T/p8hXKcB0+WcEp6v8vRNBCD 7t5PJLj5q1eouz6fuykhK/5DXhDUS5TzbYvpURTaJsVEKOuKvi+pAU5DnFz2rCy8Ws23 IzjgzrFdHKMIyGPXagUZ4cvUyAq31ZlibZtj63J5z43VwbhH4MetY74nr2swt5y+/xul AeJKskEV21VBmcPTC6oXEN2xCl2l4QoJxBkrRKJhZmynUHn+J51QQMbcr9f7ZAaGb2OP UyQg== X-Gm-Message-State: AOAM531R4ByjQ0/k+MysQCdDxVhORiRVMQmTT0WdVRkW45C72cGw58lK pwUzLUW7EuuOnsRN15nAYpwikp583eXn3RbNgVhO8w== X-Google-Smtp-Source: ABdhPJz+UfTC8SjYm5XUzWC/G5ezY99GyqEI1qyVjf0RgCbCLEZvZQHFilyUs1hAtjFkctLuRk+6KIoRr8s/aujSQ1g= X-Received: by 2002:a9d:69:: with SMTP id 96mr6596676ota.233.1605527411731; Mon, 16 Nov 2020 03:50:11 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Marco Elver Date: Mon, 16 Nov 2020 12:50:00 +0100 Message-ID: Subject: Re: [PATCH RFC v2 04/21] kasan: unpoison stack only with CONFIG_KASAN_STACK To: Dmitry Vyukov X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201116_065015_199277_11642F03 X-CRM114-Status: GOOD ( 27.68 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Branislav Rankov , Elena Petrova , Linux-MM , Andrey Konovalov , Kevin Brodsky , Will Deacon , LKML , kasan-dev , Kostya Serebryany , Alexander Potapenko , Linux ARM , Serban Constantinescu , Catalin Marinas , Andrey Ryabinin , Andrew Morton , Vincenzo Frascino , Peter Collingbourne , Evgenii Stepanov Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, 16 Nov 2020 at 11:59, Dmitry Vyukov wrote: > > On Thu, Oct 29, 2020 at 8:57 PM 'Andrey Konovalov' via kasan-dev > wrote: > > > > On Tue, Oct 27, 2020 at 1:44 PM Dmitry Vyukov wrote: > > > > > > On Thu, Oct 22, 2020 at 3:19 PM Andrey Konovalov wrote: > > > > > > > > There's a config option CONFIG_KASAN_STACK that has to be enabled for > > > > KASAN to use stack instrumentation and perform validity checks for > > > > stack variables. > > > > > > > > There's no need to unpoison stack when CONFIG_KASAN_STACK is not enabled. > > > > Only call kasan_unpoison_task_stack[_below]() when CONFIG_KASAN_STACK is > > > > enabled. > > > > > > > > Signed-off-by: Andrey Konovalov > > > > Link: https://linux-review.googlesource.com/id/If8a891e9fe01ea543e00b576852685afec0887e3 > > > > --- > > > > arch/arm64/kernel/sleep.S | 2 +- > > > > arch/x86/kernel/acpi/wakeup_64.S | 2 +- > > > > include/linux/kasan.h | 10 ++++++---- > > > > mm/kasan/common.c | 2 ++ > > > > 4 files changed, 10 insertions(+), 6 deletions(-) > > > > > > > > diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S > > > > index ba40d57757d6..bdadfa56b40e 100644 > > > > --- a/arch/arm64/kernel/sleep.S > > > > +++ b/arch/arm64/kernel/sleep.S > > > > @@ -133,7 +133,7 @@ SYM_FUNC_START(_cpu_resume) > > > > */ > > > > bl cpu_do_resume > > > > > > > > -#ifdef CONFIG_KASAN > > > > +#if defined(CONFIG_KASAN) && CONFIG_KASAN_STACK > > > > mov x0, sp > > > > bl kasan_unpoison_task_stack_below > > > > #endif > > > > diff --git a/arch/x86/kernel/acpi/wakeup_64.S b/arch/x86/kernel/acpi/wakeup_64.S > > > > index c8daa92f38dc..5d3a0b8fd379 100644 > > > > --- a/arch/x86/kernel/acpi/wakeup_64.S > > > > +++ b/arch/x86/kernel/acpi/wakeup_64.S > > > > @@ -112,7 +112,7 @@ SYM_FUNC_START(do_suspend_lowlevel) > > > > movq pt_regs_r14(%rax), %r14 > > > > movq pt_regs_r15(%rax), %r15 > > > > > > > > -#ifdef CONFIG_KASAN > > > > +#if defined(CONFIG_KASAN) && CONFIG_KASAN_STACK > > > > /* > > > > * The suspend path may have poisoned some areas deeper in the stack, > > > > * which we now need to unpoison. > > > > diff --git a/include/linux/kasan.h b/include/linux/kasan.h > > > > index 3f3f541e5d5f..7be9fb9146ac 100644 > > > > --- a/include/linux/kasan.h > > > > +++ b/include/linux/kasan.h > > > > @@ -68,8 +68,6 @@ static inline void kasan_disable_current(void) {} > > > > > > > > void kasan_unpoison_memory(const void *address, size_t size); > > > > > > > > -void kasan_unpoison_task_stack(struct task_struct *task); > > > > - > > > > void kasan_alloc_pages(struct page *page, unsigned int order); > > > > void kasan_free_pages(struct page *page, unsigned int order); > > > > > > > > @@ -114,8 +112,6 @@ void kasan_restore_multi_shot(bool enabled); > > > > > > > > static inline void kasan_unpoison_memory(const void *address, size_t size) {} > > > > > > > > -static inline void kasan_unpoison_task_stack(struct task_struct *task) {} > > > > - > > > > static inline void kasan_alloc_pages(struct page *page, unsigned int order) {} > > > > static inline void kasan_free_pages(struct page *page, unsigned int order) {} > > > > > > > > @@ -167,6 +163,12 @@ static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; } > > > > > > > > #endif /* CONFIG_KASAN */ > > > > > > > > +#if defined(CONFIG_KASAN) && CONFIG_KASAN_STACK > > > > > > && defined(CONFIG_KASAN_STACK) for consistency > > > > CONFIG_KASAN_STACK is different from other KASAN configs. It's always > > defined, and its value is what controls whether stack instrumentation > > is enabled. > > Not sure why we did this instead of the following, but okay. > > config KASAN_STACK > - int > - default 1 if KASAN_STACK_ENABLE || CC_IS_GCC > - default 0 > + bool > + default y if KASAN_STACK_ENABLE || CC_IS_GCC > + default n I wondered the same, but then looking at scripts/Makefile.kasan I think it's because we directly pass it to the compiler: ... $(call cc-param,asan-stack=$(CONFIG_KASAN_STACK)) \ ... _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel