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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 9F792C433E0 for ; Mon, 6 Jul 2020 14:35:30 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 61F3520715 for ; Mon, 6 Jul 2020 14:35:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 61F3520715 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id DAE496B0002; Mon, 6 Jul 2020 10:35:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D370D6B0005; Mon, 6 Jul 2020 10:35:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BFF776B0006; Mon, 6 Jul 2020 10:35:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0209.hostedemail.com [216.40.44.209]) by kanga.kvack.org (Postfix) with ESMTP id A5C916B0002 for ; Mon, 6 Jul 2020 10:35:29 -0400 (EDT) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 5F0478248047 for ; Mon, 6 Jul 2020 14:35:29 +0000 (UTC) X-FDA: 77007899178.25.meat88_0615e5626eac Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin25.hostedemail.com (Postfix) with ESMTP id 274FC1804E3A8 for ; Mon, 6 Jul 2020 14:35:29 +0000 (UTC) X-HE-Tag: meat88_0615e5626eac X-Filterd-Recvd-Size: 3943 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf35.hostedemail.com (Postfix) with ESMTP for ; Mon, 6 Jul 2020 14:35:28 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A7A7630E; Mon, 6 Jul 2020 07:35:27 -0700 (PDT) Received: from e119884-lin.cambridge.arm.com (e119884-lin.cambridge.arm.com [10.1.196.72]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 709E53F71E; Mon, 6 Jul 2020 07:35:26 -0700 (PDT) From: Vincenzo Frascino To: kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: vincenzo.frascino@arm.com, mark.rutland@arm.com, Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , Andrew Morton Subject: [PATCH] kasan: Remove kasan_unpoison_stack_above_sp_to() Date: Mon, 6 Jul 2020 15:35:05 +0100 Message-Id: <20200706143505.23299-1-vincenzo.frascino@arm.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 X-Rspamd-Queue-Id: 274FC1804E3A8 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam04 Content-Transfer-Encoding: quoted-printable 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: The function kasan_unpoison_stack_above_sp_to() is defined in kasan code but never used. The function was introduced as part of the commit: commit 9f7d416c36124667 ("kprobes: Unpoison stack in jprobe_return() f= or KASAN") ... where it was necessary because x86's jprobe_return() would leave stale shadow on the stack, and was an oddity in that regard. Since then, jprobes were removed entirely, and as of commit: commit 80006dbee674f9fa ("kprobes/x86: Remove jprobe implementation") ... there have been no callers of this function. Remove the declaration and the implementation. Cc: Andrey Ryabinin Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: Andrew Morton Signed-off-by: Vincenzo Frascino --- include/linux/kasan.h | 2 -- mm/kasan/common.c | 15 --------------- 2 files changed, 17 deletions(-) diff --git a/include/linux/kasan.h b/include/linux/kasan.h index 82522e996c76..0ebf2fab8567 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -38,7 +38,6 @@ extern void kasan_disable_current(void); void kasan_unpoison_shadow(const void *address, size_t size); =20 void kasan_unpoison_task_stack(struct task_struct *task); -void kasan_unpoison_stack_above_sp_to(const void *watermark); =20 void kasan_alloc_pages(struct page *page, unsigned int order); void kasan_free_pages(struct page *page, unsigned int order); @@ -101,7 +100,6 @@ void kasan_restore_multi_shot(bool enabled); static inline void kasan_unpoison_shadow(const void *address, size_t siz= e) {} =20 static inline void kasan_unpoison_task_stack(struct task_struct *task) {= } -static inline void kasan_unpoison_stack_above_sp_to(const void *watermar= k) {} =20 static inline void kasan_enable_current(void) {} static inline void kasan_disable_current(void) {} diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 757d4074fe28..6339179badb2 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -180,21 +180,6 @@ asmlinkage void kasan_unpoison_task_stack_below(cons= t void *watermark) kasan_unpoison_shadow(base, watermark - base); } =20 -/* - * Clear all poison for the region between the current SP and a provided - * watermark value, as is sometimes required prior to hand-crafted asm f= unction - * returns in the middle of functions. - */ -void kasan_unpoison_stack_above_sp_to(const void *watermark) -{ - const void *sp =3D __builtin_frame_address(0); - size_t size =3D watermark - sp; - - if (WARN_ON(sp > watermark)) - return; - kasan_unpoison_shadow(sp, size); -} - void kasan_alloc_pages(struct page *page, unsigned int order) { u8 tag; --=20 2.27.0