From patchwork Fri Nov 3 16:04:10 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yuan Tan X-Patchwork-Id: 13444684 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CA5F1C4332F for ; Fri, 3 Nov 2023 16:04:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=3O1iBlrnK1DLtDN9FVgiEtyFNbq5fertkfHPLrRbN4g=; b=EdPtfItTTyPzkC wMEJgjDWqD5F1K6AC4Zj6c6JfKYHgW2u7GYB4m+EpUx/jAF4VLe1uS0hTfU3kmSaqZo03EuzqVAhH Ybw824NMom9AfLXEYuVorZOq4Ke7uJ80D4rsnABdAkwsVPNaDt5wcR3pP729MJegI6zYZKA9PdHqU LjrsqGvRkMrGZBqNQy28k3Bq+m+0cKvFC+3mUh3pPTMj3Vd0LhwCOJ9gAdguCj1fmsTC6Zey2o0SV Gfn4IuiE0PlvJfQxgYwLv0K2pcPi1Gq+J5JAXWPhf5tyvhhkOJGErCf9ihhPEjMhNqFOUd9Dh8JlL ddD9Fi7xLYEhUJ90oY7g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qywf2-00BlGg-0J; Fri, 03 Nov 2023 16:04:40 +0000 Received: from bg4.exmail.qq.com ([43.154.221.58]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qywey-00BlEa-0Z for linux-riscv@lists.infradead.org; Fri, 03 Nov 2023 16:04:37 +0000 X-QQ-mid: bizesmtp78t1699027456tnrc347s Received: from main2-ubuntu.tail147f4.ts.net ( [202.201.15.117]) by bizesmtp.qq.com (ESMTP) with id ; Sat, 04 Nov 2023 00:04:13 +0800 (CST) X-QQ-SSF: 01200000000000B06000000A0000000 X-QQ-FEAT: mot7IUESEd/O3Ye3RvUm0u0JfDP8ilGw6DJ+bg2ku9yW02xqru4czyWnDR4JC EQdnw8q1TsviTHclgFaJRSxxEJSFDKoZfMUzfWIOoWQW5FI9+0rOhbgL2xFjAIQLOk/WiNb Ze0d8K6zH/AYLaKpQIAtAZG4jS7M72shuT9euUEJaCCA/CcImxoiQrXkdoAg+grDS7lI/xU DnpaZjUvJet9LH1I1tXUT2k+8t0nGwPGjmBS7XYMcEABQ3GlVXZx8/iDCsrMmgIy1Mf4YxT 25ig0IbUsLLwVXn/38HbQVCzou/49TJyeRhZOCpzf0rKiNfEg1KrsIRdd33Cz5XTnn7Ws/O zQ60yzEUchZNK3VB1+XcP3Ha7KKHjs9ib0py4O2 X-QQ-GoodBg: 0 X-BIZMAIL-ID: 6096022325544553150 From: Yuan Tan To: falcon@tinylab.org, arnd@arndb.de, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, luc.vanoostenryck@gmail.com, linux-sparse@vger.kernel.org Cc: linux@weissschuh.net, palmer@rivosinc.com, paul.walmsley@sifive.com, paulburton@kernel.org, paulmck@kernel.org, tim.bird@sony.com, tsbogend@alpha.franken.de, w@1wt.eu, tanyuan@tinylab.org, i@maskray.me Subject: [PATCH v1 13/14] DCE/DSE: add SECTION_NO_KEEP_SUPPORT option Date: Sat, 4 Nov 2023 00:04:10 +0800 Message-Id: <4ad1b8cb7cd54c57e74e877235f64b5be5bbbe8f.1699025537.git.tanyuan@tinylab.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: References: MIME-Version: 1.0 X-QQ-SENDSIZE: 520 Feedback-ID: bizesmtp:tinylab.org:qybglogicsvrgz:qybglogicsvrgz5a-1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231103_090436_525453_F944DBF1 X-CRM114-Status: UNSURE ( 8.41 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org It is able to drop the brute KEEP() keyword for some sections, when the sections are able to link or group together with one of the used sections. Some syscalls are actually orphan sections. SECTION_SHF_LINK_ORDER_SUPPORT or SECTION_SHF_GROUP_SUPPORT creates references for these sections, eliminating the need for the KEEP() directive. Signed-off-by: Yuan Tan Signed-off-by: Zhangjin Wu --- include/asm-generic/vmlinux.lds.h | 24 ++++++++++++++++++------ init/Kconfig | 9 +++++++++ 2 files changed, 27 insertions(+), 6 deletions(-) diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index ea8170e11ab1..f10afc42a1ac 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -201,18 +201,30 @@ # endif #endif -#define BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, _BEGIN_, _END_) \ +#ifdef CONFIG_SECTION_NO_KEEP_SUPPORT +#define NO_KEEP(sec) sec +#else +#define NO_KEEP(sec) KEEP(sec) +#endif + +#define _BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, _BEGIN_, _END_, _KEEP_, ...) \ _BEGIN_##_label_ = .; \ - KEEP(*(BSEC_MAIN(_sec_))) \ + _KEEP_(*(BSEC_MAIN(_sec_))) \ _END_##_label_ = .; -#define BOUNDED_SECTION_POST_LABEL(_sec_, _label_, _BEGIN_, _END_) \ +#define BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, _BEGIN_, _END_, ...) \ + _BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, _BEGIN_, _END_, ##__VA_ARGS__, KEEP) + +#define _BOUNDED_SECTION_POST_LABEL(_sec_, _label_, _BEGIN_, _END_, _KEEP_, ...)\ _label_##_BEGIN_ = .; \ - KEEP(*(BSEC_MAIN(_sec_))) \ + _KEEP_(*(BSEC_MAIN(_sec_))) \ _label_##_END_ = .; -#define BOUNDED_SECTION_BY(_sec_, _label_) \ - BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, __start, __stop) +#define BOUNDED_SECTION_POST_LABEL(_sec_, _label_, _BEGIN_, _END_, ...) \ + _BOUNDED_SECTION_POST_LABEL(_sec_, _label_, _BEGIN_, _END_, ##__VA_ARGS__, KEEP) + +#define BOUNDED_SECTION_BY(_sec_, _label_, ...) \ + _BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, __start, __stop, ##__VA_ARGS__, KEEP) #define BOUNDED_SECTION(_sec) BOUNDED_SECTION_BY(_sec, _sec) diff --git a/init/Kconfig b/init/Kconfig index 9599d2de44e8..aeb859e410b2 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1467,6 +1467,13 @@ config HAVE_SECTION_NO_KEEP_SUPPORT depends on HAVE_SECTION_SHF_LINK_ORDER_SUPPORT || HAVE_SECTION_SHF_GROUP_SUPPORT default y +config SECTION_NO_KEEP_SUPPORT + bool + depends on SECTION_SHF_LINK_ORDER_SUPPORT || SECTION_SHF_GROUP_SUPPORT + default y + help + This option allows some sections unkept so they can be GC + config HAVE_SECTION_SHF_LINK_ORDER_SUPPORT bool depends on AS_IS_GNU && AS_VERSION >= 23500 @@ -1765,6 +1772,7 @@ config RESTRICTED_TRIM_UNUSED_SYSCALLS config SECTION_SHF_LINK_ORDER_SUPPORT bool "Using SHF_LINK_ORDER attribute (EXPERIMENTAL)" if EXPERT depends on HAVE_SECTION_SHF_LINK_ORDER_SUPPORT + select SECTION_NO_KEEP_SUPPORT help Say Y here to trim more 'unused' syscalls wrongly kept by __ex_table like sections in kernel space. @@ -1778,6 +1786,7 @@ config SECTION_SHF_LINK_ORDER_SUPPORT config SECTION_SHF_GROUP_SUPPORT bool "Using SHF_GROUP attribute (EXPERIMENTAL)" if EXPERT depends on HAVE_SECTION_SHF_GROUP_SUPPORT + select SECTION_NO_KEEP_SUPPORT help Say Y here to trim more 'unused' syscalls wrongly kept by __ex_table like sections in kernel space.