From patchwork Tue Feb 22 15:00:20 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 12755290 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 8C014C433EF for ; Tue, 22 Feb 2022 15:02:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233255AbiBVPCp (ORCPT ); Tue, 22 Feb 2022 10:02:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47620 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233076AbiBVPCS (ORCPT ); Tue, 22 Feb 2022 10:02:18 -0500 Received: from pegase2.c-s.fr (pegase2.c-s.fr [93.17.235.10]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3601D10EC46; Tue, 22 Feb 2022 07:00:54 -0800 (PST) Received: from localhost (mailhub3.si.c-s.fr [172.26.127.67]) by localhost (Postfix) with ESMTP id 4K32RK0RC9z9sSj; Tue, 22 Feb 2022 16:00:45 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase2.c-s.fr ([172.26.127.65]) by localhost (pegase2.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id dmkNAPq6bi6R; Tue, 22 Feb 2022 16:00:44 +0100 (CET) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase2.c-s.fr (Postfix) with ESMTP id 4K32RF2zyTz9sSh; Tue, 22 Feb 2022 16:00:41 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 56BDE8B778; Tue, 22 Feb 2022 16:00:41 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id hi9VJtzWf9Y1; Tue, 22 Feb 2022 16:00:41 +0100 (CET) Received: from PO20335.IDSI0.si.c-s.fr (unknown [192.168.7.78]) by messagerie.si.c-s.fr (Postfix) with ESMTP id C16228B779; Tue, 22 Feb 2022 16:00:40 +0100 (CET) Received: from PO20335.IDSI0.si.c-s.fr (localhost [127.0.0.1]) by PO20335.IDSI0.si.c-s.fr (8.17.1/8.16.1) with ESMTPS id 21MF0VGF1087072 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Tue, 22 Feb 2022 16:00:31 +0100 Received: (from chleroy@localhost) by PO20335.IDSI0.si.c-s.fr (8.17.1/8.17.1/Submit) id 21MF0Va51087071; Tue, 22 Feb 2022 16:00:31 +0100 X-Authentication-Warning: PO20335.IDSI0.si.c-s.fr: chleroy set sender to christophe.leroy@csgroup.eu using -f From: Christophe Leroy To: Luis Chamberlain , Aaron Tomlin Cc: Christophe Leroy , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kgdb-bugreport@lists.sourceforge.net, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-modules@vger.kernel.org Subject: [PATCH v5 3/6] module: Introduce data_layout Date: Tue, 22 Feb 2022 16:00:20 +0100 Message-Id: X-Mailer: git-send-email 2.34.1 In-Reply-To: References: MIME-Version: 1.0 X-Developer-Signature: v=1; a=ed25519-sha256; t=1645542019; l=7494; s=20211009; h=from:subject:message-id; bh=mnGJddV/VLufpq4mul7z0wxAfxM/ej4XLDRryeTGUBY=; b=ttQZbW5aANwVNLprjCMW7u0Ztg196JJwc6K6eP4mAPmWkhd+yyBXNW/OIHCFdGAPijD3DZK3Poz4 oQyQOiK/AXiAA4A770cUtq+alSh01BN9RL3+rZT00u6CQUKQHMOr X-Developer-Key: i=christophe.leroy@csgroup.eu; a=ed25519; pk=HIzTzUj91asvincQGOFx6+ZF5AoUuP9GdOtQChs7Mm0= Precedence: bulk List-ID: In order to allow separation of data from text, add another layout, called data_layout. For architectures requesting separation of text and data, only text will go in core_layout and data will go in data_layout. For architectures which keep text and data together, make data_layout an alias of core_layout, that way data_layout can be used for all data manipulations, regardless of whether data is in core_layout or data_layout. Signed-off-by: Christophe Leroy --- kernel/module/internal.h | 2 ++ kernel/module/kallsyms.c | 18 +++++++++--------- kernel/module/main.c | 20 ++++++++++++-------- kernel/module/strict_rwx.c | 10 +++++----- 4 files changed, 28 insertions(+), 22 deletions(-) diff --git a/kernel/module/internal.h b/kernel/module/internal.h index 99a5be36190c..5ad6233d409a 100644 --- a/kernel/module/internal.h +++ b/kernel/module/internal.h @@ -20,6 +20,8 @@ /* Maximum number of characters written by module_flags() */ #define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4) +#define data_layout core_layout + /* * Modules' sections will be aligned on page boundaries * to ensure complete separation of code and data, but diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c index b6d49bb5afed..850cc66bb28c 100644 --- a/kernel/module/kallsyms.c +++ b/kernel/module/kallsyms.c @@ -134,12 +134,12 @@ void layout_symtab(struct module *mod, struct load_info *info) } /* Append room for core symbols at end of core part. */ - info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1); - info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym); - mod->core_layout.size += strtab_size; - info->core_typeoffs = mod->core_layout.size; - mod->core_layout.size += ndst * sizeof(char); - mod->core_layout.size = debug_align(mod->core_layout.size); + info->symoffs = ALIGN(mod->data_layout.size, symsect->sh_addralign ?: 1); + info->stroffs = mod->data_layout.size = info->symoffs + ndst * sizeof(Elf_Sym); + mod->data_layout.size += strtab_size; + info->core_typeoffs = mod->data_layout.size; + mod->data_layout.size += ndst * sizeof(char); + mod->data_layout.size = debug_align(mod->data_layout.size); /* Put string table section at end of init part of module. */ strsect->sh_flags |= SHF_ALLOC; @@ -187,9 +187,9 @@ void add_kallsyms(struct module *mod, const struct load_info *info) * Now populate the cut down core kallsyms for after init * and set types up while we still have access to sections. */ - mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs; - mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs; - mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs; + mod->core_kallsyms.symtab = dst = mod->data_layout.base + info->symoffs; + mod->core_kallsyms.strtab = s = mod->data_layout.base + info->stroffs; + mod->core_kallsyms.typetab = mod->data_layout.base + info->core_typeoffs; src = rcu_dereference_sched(mod->kallsyms)->symtab; for (ndst = i = 0; i < rcu_dereference_sched(mod->kallsyms)->num_symtab; i++) { rcu_dereference_sched(mod->kallsyms)->typetab[i] = elf_type(src + i, info); diff --git a/kernel/module/main.c b/kernel/module/main.c index c0b961e02909..bd26280f2880 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -1229,7 +1229,7 @@ static void free_module(struct module *mod) percpu_modfree(mod); /* Free lock-classes; relies on the preceding sync_rcu(). */ - lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size); + lockdep_free_key_range(mod->data_layout.base, mod->data_layout.size); /* Finally, free the core (containing the module structure) */ module_memfree(mod->core_layout.base); @@ -1470,13 +1470,15 @@ static void layout_sections(struct module *mod, struct load_info *info) for (i = 0; i < info->hdr->e_shnum; ++i) { Elf_Shdr *s = &info->sechdrs[i]; const char *sname = info->secstrings + s->sh_name; + unsigned int *sizep; if ((s->sh_flags & masks[m][0]) != masks[m][0] || (s->sh_flags & masks[m][1]) || s->sh_entsize != ~0UL || module_init_layout_section(sname)) continue; - s->sh_entsize = module_get_offset(mod, &mod->core_layout.size, s, i); + sizep = m ? &mod->data_layout.size : &mod->core_layout.size; + s->sh_entsize = module_get_offset(mod, sizep, s, i); pr_debug("\t%s\n", sname); } switch (m) { @@ -1485,15 +1487,15 @@ static void layout_sections(struct module *mod, struct load_info *info) mod->core_layout.text_size = mod->core_layout.size; break; case 1: /* RO: text and ro-data */ - mod->core_layout.size = debug_align(mod->core_layout.size); - mod->core_layout.ro_size = mod->core_layout.size; + mod->data_layout.size = debug_align(mod->data_layout.size); + mod->data_layout.ro_size = mod->data_layout.size; break; case 2: /* RO after init */ - mod->core_layout.size = debug_align(mod->core_layout.size); - mod->core_layout.ro_after_init_size = mod->core_layout.size; + mod->data_layout.size = debug_align(mod->data_layout.size); + mod->data_layout.ro_after_init_size = mod->data_layout.size; break; case 4: /* whole core */ - mod->core_layout.size = debug_align(mod->core_layout.size); + mod->data_layout.size = debug_align(mod->data_layout.size); break; } } @@ -2173,6 +2175,8 @@ static int move_module(struct module *mod, struct load_info *info) if (shdr->sh_entsize & INIT_OFFSET_MASK) dest = mod->init_layout.base + (shdr->sh_entsize & ~INIT_OFFSET_MASK); + else if (!(shdr->sh_flags & SHF_EXECINSTR)) + dest = mod->data_layout.base + shdr->sh_entsize; else dest = mod->core_layout.base + shdr->sh_entsize; @@ -2863,7 +2867,7 @@ static int load_module(struct load_info *info, const char __user *uargs, mutex_unlock(&module_mutex); free_module: /* Free lock-classes; relies on the preceding sync_rcu() */ - lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size); + lockdep_free_key_range(mod->data_layout.base, mod->data_layout.size); module_deallocate(mod, info); free_copy: diff --git a/kernel/module/strict_rwx.c b/kernel/module/strict_rwx.c index 7949dfd449c2..1a6b9573260b 100644 --- a/kernel/module/strict_rwx.c +++ b/kernel/module/strict_rwx.c @@ -50,19 +50,19 @@ void module_enable_ro(const struct module *mod, bool after_init) set_vm_flush_reset_perms(mod->init_layout.base); frob_text(&mod->core_layout, set_memory_ro); - frob_rodata(&mod->core_layout, set_memory_ro); + frob_rodata(&mod->data_layout, set_memory_ro); frob_text(&mod->init_layout, set_memory_ro); frob_rodata(&mod->init_layout, set_memory_ro); if (after_init) - frob_ro_after_init(&mod->core_layout, set_memory_ro); + frob_ro_after_init(&mod->data_layout, set_memory_ro); } void module_enable_nx(const struct module *mod) { - frob_rodata(&mod->core_layout, set_memory_nx); - frob_ro_after_init(&mod->core_layout, set_memory_nx); - frob_writable_data(&mod->core_layout, set_memory_nx); + frob_rodata(&mod->data_layout, set_memory_nx); + frob_ro_after_init(&mod->data_layout, set_memory_nx); + frob_writable_data(&mod->data_layout, set_memory_nx); frob_rodata(&mod->init_layout, set_memory_nx); frob_writable_data(&mod->init_layout, set_memory_nx); }