From patchwork Sat Jan 16 15:02:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Lobakin X-Patchwork-Id: 12024997 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,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 3EF27C433DB for ; Sat, 16 Jan 2021 18:13:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EDDA72255F for ; Sat, 16 Jan 2021 18:13:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726114AbhAPSL7 (ORCPT ); Sat, 16 Jan 2021 13:11:59 -0500 Received: from mail-41103.protonmail.ch ([185.70.41.103]:23431 "EHLO mail-41103.protonmail.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727226AbhAPSLq (ORCPT ); Sat, 16 Jan 2021 13:11:46 -0500 Received: from mail-02.mail-europe.com (mail-02.mail-europe.com [51.89.119.103]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by mail-41103.protonmail.ch (Postfix) with ESMTPS id 1E8FF2000A6E; Sat, 16 Jan 2021 15:04:11 +0000 (UTC) Authentication-Results: mail-41103.protonmail.ch; dkim=pass (2048-bit key) header.d=pm.me header.i=@pm.me header.b="W2c3xXYW" Date: Sat, 16 Jan 2021 15:02:40 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pm.me; s=protonmail; t=1610809366; bh=szQc7ok2ZUzEIxdMp0cTbpcM6sRv6WQkySAgozBWZyU=; h=Date:To:From:Cc:Reply-To:Subject:In-Reply-To:References:From; b=W2c3xXYWubUtOxfVEZfaO5twJlLniiEDoWstyU8bubpsvOYvTuY3cT31B0bLCpKLq wgehgIqwGbo13PYmsbwFoToxOsePdIok0tCeQsG6h28iSZ64I2HbzsXK12ijFjBVFa 0EUpeuwG/ibwbCtDcEIV5VESmghvsyxScCQXJL7DB86a8o3GUXqmb+sJqcnZaUij2X Ieg0s+k3SCkQ589OVGed1UQxEzDzWd+fmro1yxIViNO32hOXYDHdoM0VTMgANqeC+w Z9b3dwMN1Nz+PmpQxVbCtp+c4S0f6aE9l2c+vanPP9xblS9/ZBETUICIXWS0JY/hjH /oCVL2nAqXulg== To: Thomas Bogendoerfer From: Alexander Lobakin Cc: Nathan Chancellor , Nick Desaulniers , Kees Cook , Andrew Morton , Mike Rapoport , Alexander Lobakin , Jinyang He , linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org Reply-To: Alexander Lobakin Subject: [PATCH mips-next 1/2] MIPS: module: optimize module relocations processing Message-ID: <20210116150225.21127-1-alobakin@pm.me> In-Reply-To: <20210116150126.20693-1-alobakin@pm.me> References: <20210116150126.20693-1-alobakin@pm.me> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org For now, module relocation functions are implemented as an array of handlers of type reloc_handler_t. Convert that array into a single switch-case function to: - remove unused arguments; - change the return type of simple handlers to void; - remove the array and don't use any data at all; - avoid using indirect calls; - allow the compiler to inline and greatly optimize the relocation function[s]. The result on MIPS32 R2 with GCC 10.2 -O2 is: scripts/bloat-o-meter -c arch/mips/kernel/__module.o arch/mips/kernel/module.o add/remove: 1/11 grow/shrink: 1/0 up/down: 876/-1436 (-560) Function old new delta apply_relocate 456 1148 +692 apply_r_mips_pc - 184 +184 apply_r_mips_none 8 - -8 apply_r_mips_32 16 - -16 apply_r_mips_64 76 - -76 apply_r_mips_highest 88 - -88 apply_r_mips_higher 108 - -108 apply_r_mips_26 132 - -132 apply_r_mips_pc26 160 - -160 apply_r_mips_pc21 160 - -160 apply_r_mips_pc16 160 - -160 apply_r_mips_hi16 172 - -172 apply_r_mips_lo16 356 - -356 Total: Before=2608, After=2048, chg -21.47% add/remove: 0/0 grow/shrink: 0/0 up/down: 0/0 (0) Data old new delta Total: Before=12, After=12, chg +0.00% add/remove: 0/1 grow/shrink: 0/0 up/down: 0/-248 (-248) RO Data old new delta reloc_handlers 248 - -248 Total: Before=248, After=0, chg -100.00% All functions were collapsed into a single one that is called directly by $(srctree)/kernel/module.c. Signed-off-by: Alexander Lobakin Reviewed-by: Jiaxun Yang --- arch/mips/kernel/module.c | 109 ++++++++++++++++++-------------------- 1 file changed, 52 insertions(+), 57 deletions(-) diff --git a/arch/mips/kernel/module.c b/arch/mips/kernel/module.c index 3c0c3d1260c1..14f46d17500a 100644 --- a/arch/mips/kernel/module.c +++ b/arch/mips/kernel/module.c @@ -40,22 +40,13 @@ void *module_alloc(unsigned long size) } #endif -static int apply_r_mips_none(struct module *me, u32 *location, - u32 base, Elf_Addr v, bool rela) -{ - return 0; -} - -static int apply_r_mips_32(struct module *me, u32 *location, - u32 base, Elf_Addr v, bool rela) +static void apply_r_mips_32(u32 *location, u32 base, Elf_Addr v) { *location = base + v; - - return 0; } -static int apply_r_mips_26(struct module *me, u32 *location, - u32 base, Elf_Addr v, bool rela) +static int apply_r_mips_26(struct module *me, u32 *location, u32 base, + Elf_Addr v) { if (v % 4) { pr_err("module %s: dangerous R_MIPS_26 relocation\n", @@ -75,8 +66,8 @@ static int apply_r_mips_26(struct module *me, u32 *location, return 0; } -static int apply_r_mips_hi16(struct module *me, u32 *location, - u32 base, Elf_Addr v, bool rela) +static int apply_r_mips_hi16(struct module *me, u32 *location, Elf_Addr v, + bool rela) { struct mips_hi16 *n; @@ -217,26 +208,25 @@ static int apply_r_mips_pc(struct module *me, u32 *location, u32 base, return 0; } -static int apply_r_mips_pc16(struct module *me, u32 *location, - u32 base, Elf_Addr v, bool rela) +static int apply_r_mips_pc16(struct module *me, u32 *location, u32 base, + Elf_Addr v) { return apply_r_mips_pc(me, location, base, v, 16); } -static int apply_r_mips_pc21(struct module *me, u32 *location, - u32 base, Elf_Addr v, bool rela) +static int apply_r_mips_pc21(struct module *me, u32 *location, u32 base, + Elf_Addr v) { return apply_r_mips_pc(me, location, base, v, 21); } -static int apply_r_mips_pc26(struct module *me, u32 *location, - u32 base, Elf_Addr v, bool rela) +static int apply_r_mips_pc26(struct module *me, u32 *location, u32 base, + Elf_Addr v) { return apply_r_mips_pc(me, location, base, v, 26); } -static int apply_r_mips_64(struct module *me, u32 *location, - u32 base, Elf_Addr v, bool rela) +static int apply_r_mips_64(u32 *location, Elf_Addr v, bool rela) { if (WARN_ON(!rela)) return -EINVAL; @@ -246,8 +236,7 @@ static int apply_r_mips_64(struct module *me, u32 *location, return 0; } -static int apply_r_mips_higher(struct module *me, u32 *location, - u32 base, Elf_Addr v, bool rela) +static int apply_r_mips_higher(u32 *location, Elf_Addr v, bool rela) { if (WARN_ON(!rela)) return -EINVAL; @@ -258,8 +247,7 @@ static int apply_r_mips_higher(struct module *me, u32 *location, return 0; } -static int apply_r_mips_highest(struct module *me, u32 *location, - u32 base, Elf_Addr v, bool rela) +static int apply_r_mips_highest(u32 *location, Elf_Addr v, bool rela) { if (WARN_ON(!rela)) return -EINVAL; @@ -272,12 +260,14 @@ static int apply_r_mips_highest(struct module *me, u32 *location, /** * reloc_handler() - Apply a particular relocation to a module + * @type: type of the relocation to apply * @me: the module to apply the reloc to * @location: the address at which the reloc is to be applied * @base: the existing value at location for REL-style; 0 for RELA-style * @v: the value of the reloc, with addend for RELA-style + * @rela: indication of is this a RELA (true) or REL (false) relocation * - * Each implemented reloc_handler function applies a particular type of + * Each implemented relocation function applies a particular type of * relocation to the module @me. Relocs that may be found in either REL or RELA * variants can be handled by making use of the @base & @v parameters which are * set to values which abstract the difference away from the particular reloc @@ -285,23 +275,40 @@ static int apply_r_mips_highest(struct module *me, u32 *location, * * Return: 0 upon success, else -ERRNO */ -typedef int (*reloc_handler)(struct module *me, u32 *location, - u32 base, Elf_Addr v, bool rela); - -/* The handlers for known reloc types */ -static reloc_handler reloc_handlers[] = { - [R_MIPS_NONE] = apply_r_mips_none, - [R_MIPS_32] = apply_r_mips_32, - [R_MIPS_26] = apply_r_mips_26, - [R_MIPS_HI16] = apply_r_mips_hi16, - [R_MIPS_LO16] = apply_r_mips_lo16, - [R_MIPS_PC16] = apply_r_mips_pc16, - [R_MIPS_64] = apply_r_mips_64, - [R_MIPS_HIGHER] = apply_r_mips_higher, - [R_MIPS_HIGHEST] = apply_r_mips_highest, - [R_MIPS_PC21_S2] = apply_r_mips_pc21, - [R_MIPS_PC26_S2] = apply_r_mips_pc26, -}; +static int reloc_handler(u32 type, struct module *me, u32 *location, u32 base, + Elf_Addr v, bool rela) +{ + switch (type) { + case R_MIPS_NONE: + break; + case R_MIPS_32: + apply_r_mips_32(location, base, v); + break; + case R_MIPS_26: + return apply_r_mips_26(me, location, base, v); + case R_MIPS_HI16: + return apply_r_mips_hi16(me, location, v, rela); + case R_MIPS_LO16: + return apply_r_mips_lo16(me, location, base, v, rela); + case R_MIPS_PC16: + return apply_r_mips_pc16(me, location, base, v); + case R_MIPS_PC21_S2: + return apply_r_mips_pc21(me, location, base, v); + case R_MIPS_PC26_S2: + return apply_r_mips_pc26(me, location, base, v); + case R_MIPS_64: + return apply_r_mips_64(location, v, rela); + case R_MIPS_HIGHER: + return apply_r_mips_higher(location, v, rela); + case R_MIPS_HIGHEST: + return apply_r_mips_highest(location, v, rela); + default: + pr_err("%s: Unknown relocation type %u\n", me->name, type); + return -EINVAL; + } + + return 0; +} static int __apply_relocate(Elf_Shdr *sechdrs, const char *strtab, unsigned int symindex, unsigned int relsec, @@ -311,7 +318,6 @@ static int __apply_relocate(Elf_Shdr *sechdrs, const char *strtab, Elf_Mips_Rel *rel; Elf_Mips_Rela *rela; } r; - reloc_handler handler; Elf_Sym *sym; u32 *location, base; unsigned int i, type; @@ -343,17 +349,6 @@ static int __apply_relocate(Elf_Shdr *sechdrs, const char *strtab, } type = ELF_MIPS_R_TYPE(*r.rel); - if (type < ARRAY_SIZE(reloc_handlers)) - handler = reloc_handlers[type]; - else - handler = NULL; - - if (!handler) { - pr_err("%s: Unknown relocation type %u\n", - me->name, type); - err = -EINVAL; - goto out; - } if (rela) { v = sym->st_value + r.rela->r_addend; @@ -365,7 +360,7 @@ static int __apply_relocate(Elf_Shdr *sechdrs, const char *strtab, r.rel = &r.rel[1]; } - err = handler(me, location, base, v, rela); + err = reloc_handler(type, me, location, base, v, rela); if (err) goto out; }