From patchwork Thu Aug 18 10:02:40 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 9287201 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 6BE02607FF for ; Thu, 18 Aug 2016 10:04:59 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5B39128969 for ; Thu, 18 Aug 2016 10:04:59 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4E52C28AAF; Thu, 18 Aug 2016 10:04:59 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id D756428969 for ; Thu, 18 Aug 2016 10:04:58 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1baKAg-0001BY-Bi; Thu, 18 Aug 2016 10:03:34 +0000 Received: from mail-wm0-x230.google.com ([2a00:1450:400c:c09::230]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1baKAL-00012M-Lt for linux-arm-kernel@lists.infradead.org; Thu, 18 Aug 2016 10:03:15 +0000 Received: by mail-wm0-x230.google.com with SMTP id o80so24281187wme.1 for ; Thu, 18 Aug 2016 03:02:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=8scsndMIkuUi/TBBkMl8QK1S1+Fyw5FWolyxo6Hv7gg=; b=fiMYUpqmnkRfyP/ga+k1Bzkuuw7cgGZx5HeAluNNRy18GqmKR0c1hh+lu9oYqKxwDT 7G35eBm1Wj1/oYD9ZPBOnjlSlfYO0F9l2+EMbLf+b0QEb8mE9z2j1SwlBtfh8O4v9lHz nV6Hq0z8GvmnaLK+eDb3VB8Fz5wSETNZoBITU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=8scsndMIkuUi/TBBkMl8QK1S1+Fyw5FWolyxo6Hv7gg=; b=m49fRTyk02Bp3FaU9x2PohF3gSqVSTtFoyafh3T+GMOdfFGuepaFWuk6NojotIMhI1 CraZKSoymuz++ePcqKleNKnY6+2JxTLY4W5XvBLNH820qP453fLNPlgNkTHQi2z96BBY RsWlTU4UkvErrrbiFecniJ7Ro1AVKbz+CL6QQkZA57bX0jJydBsutl3VDvUk0VWLEGqK Pn4yMmrEMAW4vU5IHAqRIgnEbrYORzSxN2jSwaqBMq0+jSfEsPKK/JvWuOpAl6TqAMj2 OAiZ4WB4fIXfFU1TZ04BQzd/5wFsbIdxiHZQ2hkskDUur8X/jcTikY+D5sLfbrMWPv5e UQmw== X-Gm-Message-State: AEkooutJJQWu1fgMlXoT917nf5zyZfVHWV0TXQPGCiHBXD+vBx3x9ni6jU8xp1lkLG0JkiNU X-Received: by 10.28.20.139 with SMTP id 133mr1689531wmu.78.1471514571706; Thu, 18 Aug 2016 03:02:51 -0700 (PDT) Received: from localhost.localdomain (46.red-81-37-107.dynamicip.rima-tde.net. [81.37.107.46]) by smtp.gmail.com with ESMTPSA id b130sm1860450wmg.19.2016.08.18.03.02.49 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 18 Aug 2016 03:02:50 -0700 (PDT) From: Ard Biesheuvel To: linux-arm-kernel@lists.infradead.org, linux@arm.linux.org.uk, dave.martin@arm.com Subject: [PATCH v3 1/4] ARM: kernel: merge core and init PLTs Date: Thu, 18 Aug 2016 12:02:40 +0200 Message-Id: <1471514563-28172-2-git-send-email-ard.biesheuvel@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1471514563-28172-1-git-send-email-ard.biesheuvel@linaro.org> References: <1471514563-28172-1-git-send-email-ard.biesheuvel@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160818_030314_072055_13F47B53 X-CRM114-Status: GOOD ( 19.12 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: namhyung.kim@lge.com, youngho.shin@lge.com, arnd@arndb.de, Ard Biesheuvel , neidhard.kim@lge.com, chanho.min@lge.com MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP The PLT code uses a separate .init.plt section to allocate PLT entries for jump and call instructions in __init code. However, even for fairly sizable modules like mac80211.ko, we only end up with a couple of PLT entries in the .init section, and so we can simplify the code significantly by emitting all PLT entries into the same section. Signed-off-by: Ard Biesheuvel --- arch/arm/include/asm/module.h | 6 +- arch/arm/kernel/module-plts.c | 68 +++++++------------- arch/arm/kernel/module.lds | 3 +- 3 files changed, 25 insertions(+), 52 deletions(-) diff --git a/arch/arm/include/asm/module.h b/arch/arm/include/asm/module.h index e358b7966c06..464748b9fd7d 100644 --- a/arch/arm/include/asm/module.h +++ b/arch/arm/include/asm/module.h @@ -23,10 +23,8 @@ struct mod_arch_specific { struct unwind_table *unwind[ARM_SEC_MAX]; #endif #ifdef CONFIG_ARM_MODULE_PLTS - struct elf32_shdr *core_plt; - struct elf32_shdr *init_plt; - int core_plt_count; - int init_plt_count; + struct elf32_shdr *plt; + int plt_count; #endif }; diff --git a/arch/arm/kernel/module-plts.c b/arch/arm/kernel/module-plts.c index 0c7efc3446c0..6832d1d6444e 100644 --- a/arch/arm/kernel/module-plts.c +++ b/arch/arm/kernel/module-plts.c @@ -30,28 +30,16 @@ struct plt_entries { u32 lit[PLT_ENT_COUNT]; }; -static bool in_init(const struct module *mod, u32 addr) -{ - return addr - (u32)mod->init_layout.base < mod->init_layout.size; -} - u32 get_module_plt(struct module *mod, unsigned long loc, Elf32_Addr val) { struct plt_entries *plt, *plt_end; - int c, *count; - - if (in_init(mod, loc)) { - plt = (void *)mod->arch.init_plt->sh_addr; - plt_end = (void *)plt + mod->arch.init_plt->sh_size; - count = &mod->arch.init_plt_count; - } else { - plt = (void *)mod->arch.core_plt->sh_addr; - plt_end = (void *)plt + mod->arch.core_plt->sh_size; - count = &mod->arch.core_plt_count; - } + int c; + + plt = (void *)mod->arch.plt->sh_addr; + plt_end = (void *)plt + mod->arch.plt->sh_size; /* Look for an existing entry pointing to 'val' */ - for (c = *count; plt < plt_end; c -= PLT_ENT_COUNT, plt++) { + for (c = mod->arch.plt_count; plt < plt_end; c -= PLT_ENT_COUNT, plt++) { int i; if (!c) { @@ -60,13 +48,13 @@ u32 get_module_plt(struct module *mod, unsigned long loc, Elf32_Addr val) { [0 ... PLT_ENT_COUNT - 1] = PLT_ENT_LDR, }, { val, } }; - ++*count; + mod->arch.plt_count++; return (u32)plt->ldr; } for (i = 0; i < PLT_ENT_COUNT; i++) { if (!plt->lit[i]) { plt->lit[i] = val; - ++*count; + mod->arch.plt_count++; } if (plt->lit[i] == val) return (u32)&plt->ldr[i]; @@ -132,21 +120,19 @@ static unsigned int count_plts(Elf32_Addr base, const Elf32_Rel *rel, int num) int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, char *secstrings, struct module *mod) { - unsigned long core_plts = 0, init_plts = 0; + unsigned long plts = 0; Elf32_Shdr *s, *sechdrs_end = sechdrs + ehdr->e_shnum; /* * To store the PLTs, we expand the .text section for core module code - * and the .init.text section for initialization code. + * and for initialization code. */ for (s = sechdrs; s < sechdrs_end; ++s) - if (strcmp(".core.plt", secstrings + s->sh_name) == 0) - mod->arch.core_plt = s; - else if (strcmp(".init.plt", secstrings + s->sh_name) == 0) - mod->arch.init_plt = s; + if (strcmp(".plt", secstrings + s->sh_name) == 0) + mod->arch.plt = s; - if (!mod->arch.core_plt || !mod->arch.init_plt) { - pr_err("%s: sections missing\n", mod->name); + if (!mod->arch.plt) { + pr_err("%s: module PLT section missing\n", mod->name); return -ENOEXEC; } @@ -158,26 +144,16 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, if (s->sh_type != SHT_REL) continue; - if (strstr(secstrings + s->sh_name, ".init")) - init_plts += count_plts(dstsec->sh_addr, rels, numrels); - else - core_plts += count_plts(dstsec->sh_addr, rels, numrels); + plts += count_plts(dstsec->sh_addr, rels, numrels); } - mod->arch.core_plt->sh_type = SHT_NOBITS; - mod->arch.core_plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC; - mod->arch.core_plt->sh_addralign = L1_CACHE_BYTES; - mod->arch.core_plt->sh_size = round_up(core_plts * PLT_ENT_SIZE, - sizeof(struct plt_entries)); - mod->arch.core_plt_count = 0; - - mod->arch.init_plt->sh_type = SHT_NOBITS; - mod->arch.init_plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC; - mod->arch.init_plt->sh_addralign = L1_CACHE_BYTES; - mod->arch.init_plt->sh_size = round_up(init_plts * PLT_ENT_SIZE, - sizeof(struct plt_entries)); - mod->arch.init_plt_count = 0; - pr_debug("%s: core.plt=%x, init.plt=%x\n", __func__, - mod->arch.core_plt->sh_size, mod->arch.init_plt->sh_size); + mod->arch.plt->sh_type = SHT_NOBITS; + mod->arch.plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC; + mod->arch.plt->sh_addralign = L1_CACHE_BYTES; + mod->arch.plt->sh_size = round_up(plts * PLT_ENT_SIZE, + sizeof(struct plt_entries)); + mod->arch.plt_count = 0; + + pr_debug("%s: plt=%x\n", __func__, mod->arch.plt->sh_size); return 0; } diff --git a/arch/arm/kernel/module.lds b/arch/arm/kernel/module.lds index 3682fa107918..05881e2b414c 100644 --- a/arch/arm/kernel/module.lds +++ b/arch/arm/kernel/module.lds @@ -1,4 +1,3 @@ SECTIONS { - .core.plt : { BYTE(0) } - .init.plt : { BYTE(0) } + .plt : { BYTE(0) } }