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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 868CBC433EF for ; Fri, 25 Mar 2022 01:35:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355071AbiCYBgn (ORCPT ); Thu, 24 Mar 2022 21:36:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41822 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1357392AbiCYBfP (ORCPT ); Thu, 24 Mar 2022 21:35:15 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F35BC12F4 for ; Thu, 24 Mar 2022 18:32:55 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id C864160A75 for ; Fri, 25 Mar 2022 01:32:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 26E65C340EC; Fri, 25 Mar 2022 01:32:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1648171974; bh=007/FO7Mhn4jrriWKIGrBU9nf13KMMlj+AyAubajQ9U=; h=Date:To:From:Subject:From; b=z9bO00A3gA7BhYHxZ5jMqa9Ub9DsHcB/U1ZD1NKzMVgTitjW9Xye+qhxF1ZK3xwUp DXgWlUMSYQGH36OjiUmexrNb7zLoAXjI9ieOM58y5ICYXhIxY3RTTpyhQn0nkqiW9Y 8dUFYd0BuhRS+JBhr3YSlkGttyzwBm6PcQztAvxw= Date: Thu, 24 Mar 2022 18:32:53 -0700 To: mm-commits@vger.kernel.org, David.Laight@ACULAB.COM, anshuman.khandual@arm.com, christophe.leroy@csgroup.eu, akpm@linux-foundation.org From: Andrew Morton Subject: [merged] mm-uninline-copy_overflow.patch removed from -mm tree Message-Id: <20220325013254.26E65C340EC@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: mm: uninline copy_overflow() has been removed from the -mm tree. Its filename was mm-uninline-copy_overflow.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Christophe Leroy Subject: mm: uninline copy_overflow() While building a small config with CONFIG_CC_OPTIMISE_FOR_SIZE, I ended up with more than 50 times the following function in vmlinux because GCC doesn't honor the 'inline' keyword: c00243bc : c00243bc: 94 21 ff f0 stwu r1,-16(r1) c00243c0: 7c 85 23 78 mr r5,r4 c00243c4: 7c 64 1b 78 mr r4,r3 c00243c8: 3c 60 c0 62 lis r3,-16286 c00243cc: 7c 08 02 a6 mflr r0 c00243d0: 38 63 5e e5 addi r3,r3,24293 c00243d4: 90 01 00 14 stw r0,20(r1) c00243d8: 4b ff 82 45 bl c001c61c <__warn_printk> c00243dc: 0f e0 00 00 twui r0,0 c00243e0: 80 01 00 14 lwz r0,20(r1) c00243e4: 38 21 00 10 addi r1,r1,16 c00243e8: 7c 08 03 a6 mtlr r0 c00243ec: 4e 80 00 20 blr With -Winline, GCC tells: /include/linux/thread_info.h:212:20: warning: inlining failed in call to 'copy_overflow': call is unlikely and code size would grow [-Winline] copy_overflow() is a non conditional warning called by check_copy_size() on an error path. check_copy_size() have to remain inlined in order to benefit from constant folding, but copy_overflow() is not worth inlining. Uninline the warning when CONFIG_BUG is selected. When CONFIG_BUG is not selected, WARN() does nothing so skip it. This reduces the size of vmlinux by almost 4kbytes. Link: https://lkml.kernel.org/r/e1723b9cfa924bcefcd41f69d0025b38e4c9364e.1644819985.git.christophe.leroy@csgroup.eu Signed-off-by: Christophe Leroy Cc: David Laight Cc: Anshuman Khandual Signed-off-by: Andrew Morton --- include/linux/thread_info.h | 5 ++++- mm/maccess.c | 6 ++++++ 2 files changed, 10 insertions(+), 1 deletion(-) --- a/include/linux/thread_info.h~mm-uninline-copy_overflow +++ a/include/linux/thread_info.h @@ -209,9 +209,12 @@ __bad_copy_from(void); extern void __compiletime_error("copy destination size is too small") __bad_copy_to(void); +void __copy_overflow(int size, unsigned long count); + static inline void copy_overflow(int size, unsigned long count) { - WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count); + if (IS_ENABLED(CONFIG_BUG)) + __copy_overflow(size, count); } static __always_inline __must_check bool --- a/mm/maccess.c~mm-uninline-copy_overflow +++ a/mm/maccess.c @@ -335,3 +335,9 @@ long strnlen_user_nofault(const void __u return ret; } + +void __copy_overflow(int size, unsigned long count) +{ + WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count); +} +EXPORT_SYMBOL(__copy_overflow); _ Patches currently in -mm which might be from christophe.leroy@csgroup.eu are