From patchwork Sat Jun 10 09:13:10 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 13274791 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 1AB81C77B7A for ; Sat, 10 Jun 2023 09:13:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234156AbjFJJNf (ORCPT ); Sat, 10 Jun 2023 05:13:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33360 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233969AbjFJJNe (ORCPT ); Sat, 10 Jun 2023 05:13:34 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 95A5B3A98; Sat, 10 Jun 2023 02:13:33 -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 329C36153F; Sat, 10 Jun 2023 09:13:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2618EC4339E; Sat, 10 Jun 2023 09:13:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686388412; bh=PG6qM3vqxiF+KiiI8e2eBOByJ2994aew6fGGaTXEDyQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=S6Prepz6fIDlWpYHwo+9GvbzqBuM0yICauO1hNBqTYUTFjVwRJ2A0lsojWnWQfAW9 E+H/EcPwloHdGH8EOaFUCpZZaKRYY/nC3wUDs2wo9W8ZC7EJKYS0F7zHR/ofrmlh/v 7fRcIPItpQmvYMQK/mgnO3kGpfNEMZjqCNkhTJ3wf6ElyFdIRm9M7pDSJs0759DCuD G/WqKt24BtW4yNHYCFqDK5+RF7OMiSET7bdQXWtk0JtPjE7/fsD2+kH3G9V1tkragf Nb6cmBtVQvYyCeoJXlKlnvj3e5BbZJ2JyfDObDdF5aEQX2ccufJamt9+gRcPCHVze6 CfmWqoWkESXqg== From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nathan Chancellor , Nick Desaulniers , Nicolas Schier , linux-um@lists.infradead.org, Masahiro Yamada Subject: [PATCH v8 01/11] Revert "[PATCH] uml: export symbols added by GCC hardened" Date: Sat, 10 Jun 2023 18:13:10 +0900 Message-Id: <20230610091320.1054554-2-masahiroy@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230610091320.1054554-1-masahiroy@kernel.org> References: <20230610091320.1054554-1-masahiroy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org This reverts commit cead61a6717a9873426b08d73a34a325e3546f5d. It exported __stack_smash_handler and __guard, while they may not be defined by anyone. The code *declares* __stack_smash_handler and __guard. It does not create weak symbols. If no external library is linked, they are left undefined, but yet exported. If a loadable module tries to access non-existing symbols, bad things (a page fault, NULL pointer dereference, etc.) will happen. So, the current code is wrong and dangerous. If the code were written as follows, it would *define* them as weak symbols so modules would be able to get access to them. void (*__stack_smash_handler)(void *) __attribute__((weak)); EXPORT_SYMBOL(__stack_smash_handler); long __guard __attribute__((weak)); EXPORT_SYMBOL(__guard); In fact, modpost forbids exporting undefined symbols. It shows an error message if it detects such a mistake. ERROR: modpost: "..." [...] was exported without definition Unfortunately, it is checked only when the code is built as modular. The problem described above has been unnoticed for a long time because arch/um/os-Linux/user_syms.c is always built-in. With a planned change in Kbuild, exporting undefined symbols will always result in a build error instead of a run-time error. It is a good thing, but we need to fix the breakage in advance. One fix is to define weak symbols as shown above. An alternative is to export them conditionally as follows: #ifdef CONFIG_STACKPROTECTOR extern void __stack_smash_handler(void *); EXPORT_SYMBOL(__stack_smash_handler); external long __guard; EXPORT_SYMBOL(__guard); #endif This is what other architectures do; EXPORT_SYMBOL(__stack_chk_guard) is guarded by #ifdef CONFIG_STACKPROTECTOR. However, adding the #ifdef guard is not sensible because UML cannot enable the stack-protector in the first place! (Please note UML does not select HAVE_STACKPROTECTOR in Kconfig.) So, the code is already broken (and unused) in multiple ways. Just remove. Signed-off-by: Masahiro Yamada Reviewed-by: Nick Desaulniers --- (no changes since v7) Changes in v7: - New patch arch/um/os-Linux/user_syms.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/arch/um/os-Linux/user_syms.c b/arch/um/os-Linux/user_syms.c index 9b62a9d352b3..a310ae27b479 100644 --- a/arch/um/os-Linux/user_syms.c +++ b/arch/um/os-Linux/user_syms.c @@ -37,13 +37,6 @@ EXPORT_SYMBOL(vsyscall_ehdr); EXPORT_SYMBOL(vsyscall_end); #endif -/* Export symbols used by GCC for the stack protector. */ -extern void __stack_smash_handler(void *) __attribute__((weak)); -EXPORT_SYMBOL(__stack_smash_handler); - -extern long __guard __attribute__((weak)); -EXPORT_SYMBOL(__guard); - #ifdef _FORTIFY_SOURCE extern int __sprintf_chk(char *str, int flag, size_t len, const char *format); EXPORT_SYMBOL(__sprintf_chk); From patchwork Sat Jun 10 09:13:11 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 13274792 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 2B2F1C7EE43 for ; Sat, 10 Jun 2023 09:13:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234252AbjFJJNo (ORCPT ); Sat, 10 Jun 2023 05:13:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33378 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234197AbjFJJNh (ORCPT ); Sat, 10 Jun 2023 05:13:37 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AB8C63AA6; Sat, 10 Jun 2023 02:13:36 -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 417226112F; Sat, 10 Jun 2023 09:13:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 12B7CC4339C; Sat, 10 Jun 2023 09:13:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686388415; bh=Ly+sWm6TM1FV97DnfVYc+edRAEXC0kuE80+arR4Mn2I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GN6fr7O02dw/w8UlKq3m5oavUp5IwXvAZhiYjsmCnTMG8QlbqSOLpwMRs7zvBJZc3 t/qDlka+IZ5iYkN+k6iJvezINNBl2fbnfXfQdv38dLACaoVDunsEhorJGCXwKAR9Wx rfI61GcMj66s4+CaXBUmn05suIXS20FHx0cpavQPOIC+7v2rgr2mK70iYxYzb7XRCG Fx2QG55kOaDIWkH4MuSJPAo3ZUXSBf7proy56fAKCAYt2GOZV/Qy6DsTFw6Ul7jMj4 AUWXTJ1f7Z4/youyy8ihE6RZMMyUOYNwhabT1mYjcJJrNvWiOItALsKGNi/n5hm91q n+qQ5fmBS6szQ== From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nathan Chancellor , Nick Desaulniers , Nicolas Schier , linux-um@lists.infradead.org, Masahiro Yamada Subject: [PATCH v8 02/11] modpost: pass struct module pointer to check_section_mismatch() Date: Sat, 10 Jun 2023 18:13:11 +0900 Message-Id: <20230610091320.1054554-3-masahiroy@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230610091320.1054554-1-masahiroy@kernel.org> References: <20230610091320.1054554-1-masahiroy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org The next commit will use it. Signed-off-by: Masahiro Yamada Reviewed-by: Nick Desaulniers --- scripts/mod/modpost.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 8decf04633bc..403ba4d923f5 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -1211,7 +1211,7 @@ static void default_mismatch_handler(const char *modname, struct elf_info *elf, } } -static void check_section_mismatch(const char *modname, struct elf_info *elf, +static void check_section_mismatch(struct module *mod, struct elf_info *elf, Elf_Sym *sym, unsigned int fsecndx, const char *fromsec, Elf_Addr faddr, Elf_Addr taddr) @@ -1222,7 +1222,7 @@ static void check_section_mismatch(const char *modname, struct elf_info *elf, if (!mismatch) return; - default_mismatch_handler(modname, elf, mismatch, sym, + default_mismatch_handler(mod->name, elf, mismatch, sym, fsecndx, fromsec, faddr, tosec, taddr); } @@ -1406,7 +1406,7 @@ static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) #define R_LARCH_SUB32 55 #endif -static void section_rela(const char *modname, struct elf_info *elf, +static void section_rela(struct module *mod, struct elf_info *elf, Elf_Shdr *sechdr) { Elf_Rela *rela; @@ -1452,12 +1452,12 @@ static void section_rela(const char *modname, struct elf_info *elf, break; } - check_section_mismatch(modname, elf, elf->symtab_start + r_sym, + check_section_mismatch(mod, elf, elf->symtab_start + r_sym, fsecndx, fromsec, r.r_offset, r.r_addend); } } -static void section_rel(const char *modname, struct elf_info *elf, +static void section_rel(struct module *mod, struct elf_info *elf, Elf_Shdr *sechdr) { Elf_Rel *rel; @@ -1507,7 +1507,7 @@ static void section_rel(const char *modname, struct elf_info *elf, fatal("Please add code to calculate addend for this architecture\n"); } - check_section_mismatch(modname, elf, elf->symtab_start + r_sym, + check_section_mismatch(mod, elf, elf->symtab_start + r_sym, fsecndx, fromsec, r.r_offset, r.r_addend); } } @@ -1524,19 +1524,19 @@ static void section_rel(const char *modname, struct elf_info *elf, * to find all references to a section that reference a section that will * be discarded and warns about it. **/ -static void check_sec_ref(const char *modname, struct elf_info *elf) +static void check_sec_ref(struct module *mod, struct elf_info *elf) { int i; Elf_Shdr *sechdrs = elf->sechdrs; /* Walk through all sections */ for (i = 0; i < elf->num_sections; i++) { - check_section(modname, elf, &elf->sechdrs[i]); + check_section(mod->name, elf, &elf->sechdrs[i]); /* We want to process only relocation sections and not .init */ if (sechdrs[i].sh_type == SHT_RELA) - section_rela(modname, elf, &elf->sechdrs[i]); + section_rela(mod, elf, &elf->sechdrs[i]); else if (sechdrs[i].sh_type == SHT_REL) - section_rel(modname, elf, &elf->sechdrs[i]); + section_rel(mod, elf, &elf->sechdrs[i]); } } @@ -1707,7 +1707,7 @@ static void read_symbols(const char *modname) sym_get_data(&info, sym)); } - check_sec_ref(modname, &info); + check_sec_ref(mod, &info); if (!mod->is_vmlinux) { version = get_modinfo(&info, "version"); From patchwork Sat Jun 10 09:13:12 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 13274794 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 A6BADC7EE43 for ; Sat, 10 Jun 2023 09:13:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234194AbjFJJNr (ORCPT ); Sat, 10 Jun 2023 05:13:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33436 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234210AbjFJJNo (ORCPT ); Sat, 10 Jun 2023 05:13:44 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EE0893ABA; Sat, 10 Jun 2023 02:13:40 -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 72A5360FBD; Sat, 10 Jun 2023 09:13:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7F8DEC433EF; Sat, 10 Jun 2023 09:13:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686388419; bh=q11cUfTF9KNnjXIgS3iSVnOqodHM8m8M5Krc40jWfy4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=an6HM+pD1N66F+RBdNlDgaFVZNeFTfmTtWK/6WMkJBtMPR1CcHo2itOivAs/VAseJ r8a3m4gMvBEm2QQ3PtLACVU29aBWde3IYrkftSrcP3Sq5euhHIW+ePhdfTW10dDJLG NTJg4ej5D5LP56NuAOgJTC+hlOYVmjuICTGOYqqbAnf03HJ5VWd6PElfYXONhFaqQi xQQzvZ6GJKYTzowTFmvY1/duWLBWpBKPQlFWQtOhLCJPLSv9P6xm4i2zRPkPVJpOV3 B+WO0y/kNYIZE8plFA3zW7rEVriQAKKbzELcDpYkwmZnZn6wzJC1Nyf2H24H90hPrY oTmi5In94EciQ== From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nathan Chancellor , Nick Desaulniers , Nicolas Schier , linux-um@lists.infradead.org, Masahiro Yamada Subject: [PATCH v8 03/11] kbuild: generate KSYMTAB entries by modpost Date: Sat, 10 Jun 2023 18:13:12 +0900 Message-Id: <20230610091320.1054554-4-masahiroy@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230610091320.1054554-1-masahiroy@kernel.org> References: <20230610091320.1054554-1-masahiroy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org Commit 7b4537199a4a ("kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS") made modpost output CRCs in the same way whether the EXPORT_SYMBOL() is placed in *.c or *.S. For further cleanups, this commit applies a similar approach to the entire data structure of EXPORT_SYMBOL(). The EXPORT_SYMBOL() compilation is split into two stages. When a source file is compiled, EXPORT_SYMBOL() is converted into a dummy symbol in the .export_symbol section. For example, EXPORT_SYMBOL(foo); EXPORT_SYMBOL_NS_GPL(bar, BAR_NAMESPACE); will be encoded into the following assembly code: .section ".export_symbol","a" __export_symbol__foo: .asciz "" .balign 8 .quad foo .previous .section ".export_symbol","a" __export_symbol_gpl_bar: .asciz "BAR_NAMESPACE" .balign 8 .quad bar .previous They are mere markers to tell modpost the name, license, and namespace of the symbols. They will be dropped from the final vmlinux and modules because the *(.export_symbol) will go into /DISCARD/ in the linker script. Then, modpost extracts all the information about EXPORT_SYMBOL() from the .export_symbol section, and generates the final C code: KSYMTAB_FUNC(foo, "", ""); KSYMTAB_FUNC(bar, "_gpl", "BAR_NAMESPACE"); KSYMTAB_FUNC() (or KSYMTAB_DATA() if it is data) is expanded to struct kernel_symbol that will be linked to the vmlinux or a module. With this change, EXPORT_SYMBOL() works in the same way for *.c and *.S files, providing the following benefits. [1] Deprecate EXPORT_DATA_SYMBOL() In the old days, EXPORT_SYMBOL() was only available in C files. To export a symbol in *.S, EXPORT_SYMBOL() was placed in a separate *.c file. arch/arm/kernel/armksyms.c is one example written in the classic manner. Commit 22823ab419d8 ("EXPORT_SYMBOL() for asm") removed this limitation. Since then, EXPORT_SYMBOL() can be placed close to the symbol definition in *.S files. It was a nice improvement. However, as that commit mentioned, you need to use EXPORT_DATA_SYMBOL() for data objects on some architectures. In the new approach, modpost checks symbol's type (STT_FUNC or not), and outputs KSYMTAB_FUNC() or KSYMTAB_DATA() accordingly. There are only two users of EXPORT_DATA_SYMBOL: EXPORT_DATA_SYMBOL_GPL(empty_zero_page) (arch/ia64/kernel/head.S) EXPORT_DATA_SYMBOL(ia64_ivt) (arch/ia64/kernel/ivt.S) They are transformed as follows and output into .vmlinux.export.c KSYMTAB_DATA(empty_zero_page, "_gpl", ""); KSYMTAB_DATA(ia64_ivt, "", ""); The other EXPORT_SYMBOL users in ia64 assembly are output as KSYMTAB_FUNC(). EXPORT_DATA_SYMBOL() is now deprecated. [2] merge and There are two similar header implementations: include/linux/export.h for .c files include/asm-generic/export.h for .S files Ideally, the functionality should be consistent between them, but they tend to diverge. Commit 8651ec01daed ("module: add support for symbol namespaces.") did not support the namespace for *.S files. This commit shifts the essential implementation part to C, which supports EXPORT_SYMBOL_NS() for *.S files. and will remain as a wrapper of for a while. They will be removed after #include directives are all replaced with #include . [3] Implement CONFIG_TRIM_UNUSED_KSYMS in one-pass algorithm (by a later commit) When CONFIG_TRIM_UNUSED_KSYMS is enabled, Kbuild recursively traverses the directory tree to determine which EXPORT_SYMBOL to trim. If an EXPORT_SYMBOL turns out to be unused by anyone, Kbuild begins the second traverse, where some source files are recompiled with their EXPORT_SYMBOL() tuned into a no-op. We can do this better now; modpost can selectively emit KSYMTAB entries that are really used by modules. Signed-off-by: Masahiro Yamada Reviewed-by: Nick Desaulniers --- Changes in v8: - Fix the definition of ____EXPORT_SYMBOL() to v7. It seems to cause a regression for xtensa. (reported by 0day bot) Changes in v7: - Fix sparse warning reported by 0day bot https://lore.kernel.org/linux-kbuild/202305280830.Rj5ltc9M-lkp@intel.com/ Changes in v6: - Fix build error on UML Changes in v5: - Fix build error on ARM Changes in v4: - Version 3 did not work if a same name symbol exists in a different compilation unit Fix it. Changes in v3: - Move struct kernel_symbol to kernel/module/internal.h Changes in v2: - Use KSYMTAB_FUNC and KSYMTAB_DATA for functions and data, respectively This distinction is needed for ia64. arch/ia64/include/asm/Kbuild | 1 + arch/ia64/include/asm/export.h | 3 - include/asm-generic/export.h | 84 ++----------------------- include/asm-generic/vmlinux.lds.h | 1 + include/linux/export-internal.h | 49 +++++++++++++++ include/linux/export.h | 99 +++++++++++------------------ include/linux/pm.h | 8 +-- kernel/module/internal.h | 12 ++++ scripts/Makefile.build | 8 +-- scripts/check-local-export | 4 +- scripts/mod/modpost.c | 100 ++++++++++++++++++++---------- scripts/mod/modpost.h | 1 + 12 files changed, 182 insertions(+), 188 deletions(-) delete mode 100644 arch/ia64/include/asm/export.h diff --git a/arch/ia64/include/asm/Kbuild b/arch/ia64/include/asm/Kbuild index aefae2efde9f..33733245f42b 100644 --- a/arch/ia64/include/asm/Kbuild +++ b/arch/ia64/include/asm/Kbuild @@ -1,6 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 generated-y += syscall_table.h generic-y += agp.h +generic-y += export.h generic-y += kvm_para.h generic-y += mcs_spinlock.h generic-y += vtime.h diff --git a/arch/ia64/include/asm/export.h b/arch/ia64/include/asm/export.h deleted file mode 100644 index ad18c6583252..000000000000 --- a/arch/ia64/include/asm/export.h +++ /dev/null @@ -1,3 +0,0 @@ -/* EXPORT_DATA_SYMBOL != EXPORT_SYMBOL here */ -#define KSYM_FUNC(name) @fptr(name) -#include diff --git a/include/asm-generic/export.h b/include/asm-generic/export.h index 5e4b1f2369d2..0ae9f38a904c 100644 --- a/include/asm-generic/export.h +++ b/include/asm-generic/export.h @@ -3,86 +3,12 @@ #define __ASM_GENERIC_EXPORT_H /* - * This comment block is used by fixdep. Please do not remove. - * - * When CONFIG_MODVERSIONS is changed from n to y, all source files having - * EXPORT_SYMBOL variants must be re-compiled because genksyms is run as a - * side effect of the *.o build rule. + * and are deprecated. + * Please include directly. */ +#include -#ifndef KSYM_FUNC -#define KSYM_FUNC(x) x -#endif -#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS -#define KSYM_ALIGN 4 -#elif defined(CONFIG_64BIT) -#define KSYM_ALIGN 8 -#else -#define KSYM_ALIGN 4 -#endif - -.macro __put, val, name -#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS - .long \val - ., \name - ., 0 -#elif defined(CONFIG_64BIT) - .quad \val, \name, 0 -#else - .long \val, \name, 0 -#endif -.endm - -/* - * note on .section use: we specify progbits since usage of the "M" (SHF_MERGE) - * section flag requires it. Use '%progbits' instead of '@progbits' since the - * former apparently works on all arches according to the binutils source. - */ - -.macro ___EXPORT_SYMBOL name,val,sec -#if defined(CONFIG_MODULES) && !defined(__DISABLE_EXPORTS) - .section ___ksymtab\sec+\name,"a" - .balign KSYM_ALIGN -__ksymtab_\name: - __put \val, __kstrtab_\name - .previous - .section __ksymtab_strings,"aMS",%progbits,1 -__kstrtab_\name: - .asciz "\name" - .previous -#endif -.endm - -#if defined(CONFIG_TRIM_UNUSED_KSYMS) - -#include -#include - -.macro __ksym_marker sym - .section ".discard.ksym","a" -__ksym_marker_\sym: - .previous -.endm - -#define __EXPORT_SYMBOL(sym, val, sec) \ - __ksym_marker sym; \ - __cond_export_sym(sym, val, sec, __is_defined(__KSYM_##sym)) -#define __cond_export_sym(sym, val, sec, conf) \ - ___cond_export_sym(sym, val, sec, conf) -#define ___cond_export_sym(sym, val, sec, enabled) \ - __cond_export_sym_##enabled(sym, val, sec) -#define __cond_export_sym_1(sym, val, sec) ___EXPORT_SYMBOL sym, val, sec -#define __cond_export_sym_0(sym, val, sec) /* nothing */ - -#else -#define __EXPORT_SYMBOL(sym, val, sec) ___EXPORT_SYMBOL sym, val, sec -#endif - -#define EXPORT_SYMBOL(name) \ - __EXPORT_SYMBOL(name, KSYM_FUNC(name),) -#define EXPORT_SYMBOL_GPL(name) \ - __EXPORT_SYMBOL(name, KSYM_FUNC(name), _gpl) -#define EXPORT_DATA_SYMBOL(name) \ - __EXPORT_SYMBOL(name, name,) -#define EXPORT_DATA_SYMBOL_GPL(name) \ - __EXPORT_SYMBOL(name, name,_gpl) +#define EXPORT_DATA_SYMBOL(name) EXPORT_SYMBOL(name) +#define EXPORT_DATA_SYMBOL_GPL(name) EXPORT_SYMBOL_GPL(name) #endif diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index d1f57e4868ed..e65d55e8819c 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -1006,6 +1006,7 @@ PATCHABLE_DISCARDS \ *(.discard) \ *(.discard.*) \ + *(.export_symbol) \ *(.modinfo) \ /* ld.bfd warns about .gnu.version* even when not emitted */ \ *(.gnu.version*) \ diff --git a/include/linux/export-internal.h b/include/linux/export-internal.h index fe7e6ba918f1..1c849db953a5 100644 --- a/include/linux/export-internal.h +++ b/include/linux/export-internal.h @@ -10,6 +10,55 @@ #include #include +#if defined(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS) +/* + * relative reference: this reduces the size by half on 64-bit architectures, + * and eliminates the need for absolute relocations that require runtime + * processing on relocatable kernels. + */ +#define __KSYM_REF(sym) ".long " #sym "- ." +#elif defined(CONFIG_64BIT) +#define __KSYM_REF(sym) ".quad " #sym +#else +#define __KSYM_REF(sym) ".long " #sym +#endif + +/* + * For every exported symbol, do the following: + * + * - Put the name of the symbol and namespace (empty string "" for none) in + * __ksymtab_strings. + * - Place a struct kernel_symbol entry in the __ksymtab section. + * + * Note on .section use: we specify progbits since usage of the "M" (SHF_MERGE) + * section flag requires it. Use '%progbits' instead of '@progbits' since the + * former apparently works on all arches according to the binutils source. + */ +#define __KSYMTAB(name, sym, sec, ns) \ + asm(" .section \"__ksymtab_strings\",\"aMS\",%progbits,1" "\n" \ + "__kstrtab_" #name ":" "\n" \ + " .asciz \"" #name "\"" "\n" \ + "__kstrtabns_" #name ":" "\n" \ + " .asciz \"" ns "\"" "\n" \ + " .previous" "\n" \ + " .section \"___ksymtab" sec "+" #name "\", \"a\"" "\n" \ + " .balign 4" "\n" \ + "__ksymtab_" #name ":" "\n" \ + __KSYM_REF(sym) "\n" \ + __KSYM_REF(__kstrtab_ ##name) "\n" \ + __KSYM_REF(__kstrtabns_ ##name) "\n" \ + " .previous" "\n" \ + ) + +#ifdef CONFIG_IA64 +#define KSYM_FUNC(name) @fptr(name) +#else +#define KSYM_FUNC(name) name +#endif + +#define KSYMTAB_FUNC(name, sec, ns) __KSYMTAB(name, KSYM_FUNC(name), sec, ns) +#define KSYMTAB_DATA(name, sec, ns) __KSYMTAB(name, name, sec, ns) + #define SYMBOL_CRC(sym, crc, sec) \ asm(".section \"___kcrctab" sec "+" #sym "\",\"a\"" "\n" \ "__crc_" #sym ":" "\n" \ diff --git a/include/linux/export.h b/include/linux/export.h index 3f31ced0d977..245ecd342772 100644 --- a/include/linux/export.h +++ b/include/linux/export.h @@ -2,6 +2,7 @@ #ifndef _LINUX_EXPORT_H #define _LINUX_EXPORT_H +#include #include /* @@ -28,72 +29,36 @@ extern struct module __this_module; #else #define THIS_MODULE ((struct module *)0) #endif +#endif /* __ASSEMBLY__ */ -#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS -#include -/* - * Emit the ksymtab entry as a pair of relative references: this reduces - * the size by half on 64-bit architectures, and eliminates the need for - * absolute relocations that require runtime processing on relocatable - * kernels. - */ -#define __KSYMTAB_ENTRY(sym, sec) \ - __ADDRESSABLE(sym) \ - asm(" .section \"___ksymtab" sec "+" #sym "\", \"a\" \n" \ - " .balign 4 \n" \ - "__ksymtab_" #sym ": \n" \ - " .long " #sym "- . \n" \ - " .long __kstrtab_" #sym "- . \n" \ - " .long __kstrtabns_" #sym "- . \n" \ - " .previous \n") - -struct kernel_symbol { - int value_offset; - int name_offset; - int namespace_offset; -}; +#ifdef CONFIG_64BIT +#define __EXPORT_SYMBOL_REF(sym) .balign 8; .quad sym #else -#define __KSYMTAB_ENTRY(sym, sec) \ - static const struct kernel_symbol __ksymtab_##sym \ - __attribute__((section("___ksymtab" sec "+" #sym), used)) \ - __aligned(sizeof(void *)) \ - = { (unsigned long)&sym, __kstrtab_##sym, __kstrtabns_##sym } - -struct kernel_symbol { - unsigned long value; - const char *name; - const char *namespace; -}; +#define __EXPORT_SYMBOL_REF(sym) .balign 4; .long sym #endif +#define ____EXPORT_SYMBOL(sym, license, ns) \ + .section ".export_symbol","a" ; \ + __export_symbol_##license##_##sym: ; \ + .asciz ns ; \ + __EXPORT_SYMBOL_REF(sym) ; \ + .previous + #ifdef __GENKSYMS__ #define ___EXPORT_SYMBOL(sym, sec, ns) __GENKSYMS_EXPORT_SYMBOL(sym) +#elif defined(__ASSEMBLY__) + +#define ___EXPORT_SYMBOL(sym, license, ns) \ + ____EXPORT_SYMBOL(sym, license, ns) + #else -/* - * For every exported symbol, do the following: - * - * - Put the name of the symbol and namespace (empty string "" for none) in - * __ksymtab_strings. - * - Place a struct kernel_symbol entry in the __ksymtab section. - * - * note on .section use: we specify progbits since usage of the "M" (SHF_MERGE) - * section flag requires it. Use '%progbits' instead of '@progbits' since the - * former apparently works on all arches according to the binutils source. - */ -#define ___EXPORT_SYMBOL(sym, sec, ns) \ - extern typeof(sym) sym; \ - extern const char __kstrtab_##sym[]; \ - extern const char __kstrtabns_##sym[]; \ - asm(" .section \"__ksymtab_strings\",\"aMS\",%progbits,1 \n" \ - "__kstrtab_" #sym ": \n" \ - " .asciz \"" #sym "\" \n" \ - "__kstrtabns_" #sym ": \n" \ - " .asciz \"" ns "\" \n" \ - " .previous \n"); \ - __KSYMTAB_ENTRY(sym, sec) +#define ___EXPORT_SYMBOL(sym, license, ns) \ + extern typeof(sym) sym; \ + __ADDRESSABLE(sym) \ + asm(__stringify(____EXPORT_SYMBOL(sym, license, ns))) #endif @@ -117,9 +82,21 @@ struct kernel_symbol { * from the $(NM) output (see scripts/gen_ksymdeps.sh). These symbols are * discarded in the final link stage. */ + +#ifdef __ASSEMBLY__ + +#define __ksym_marker(sym) \ + .section ".discard.ksym","a" ; \ +__ksym_marker_##sym: ; \ + .previous + +#else + #define __ksym_marker(sym) \ static int __ksym_marker_##sym[0] __section(".discard.ksym") __used +#endif + #define __EXPORT_SYMBOL(sym, sec, ns) \ __ksym_marker(sym); \ __cond_export_sym(sym, sec, ns, __is_defined(__KSYM_##sym)) @@ -147,11 +124,9 @@ struct kernel_symbol { #define _EXPORT_SYMBOL(sym, sec) __EXPORT_SYMBOL(sym, sec, "") #endif -#define EXPORT_SYMBOL(sym) _EXPORT_SYMBOL(sym, "") -#define EXPORT_SYMBOL_GPL(sym) _EXPORT_SYMBOL(sym, "_gpl") -#define EXPORT_SYMBOL_NS(sym, ns) __EXPORT_SYMBOL(sym, "", __stringify(ns)) -#define EXPORT_SYMBOL_NS_GPL(sym, ns) __EXPORT_SYMBOL(sym, "_gpl", __stringify(ns)) - -#endif /* !__ASSEMBLY__ */ +#define EXPORT_SYMBOL(sym) _EXPORT_SYMBOL(sym,) +#define EXPORT_SYMBOL_GPL(sym) _EXPORT_SYMBOL(sym,gpl) +#define EXPORT_SYMBOL_NS(sym, ns) __EXPORT_SYMBOL(sym,, __stringify(ns)) +#define EXPORT_SYMBOL_NS_GPL(sym, ns) __EXPORT_SYMBOL(sym,gpl, __stringify(ns)) #endif /* _LINUX_EXPORT_H */ diff --git a/include/linux/pm.h b/include/linux/pm.h index 035d9649eba4..aabb6bd8f89e 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -388,10 +388,10 @@ const struct dev_pm_ops name = { \ #define EXPORT_PM_FN_NS_GPL(name, ns) #endif -#define EXPORT_DEV_PM_OPS(name) _EXPORT_DEV_PM_OPS(name, "", "") -#define EXPORT_GPL_DEV_PM_OPS(name) _EXPORT_DEV_PM_OPS(name, "_gpl", "") -#define EXPORT_NS_DEV_PM_OPS(name, ns) _EXPORT_DEV_PM_OPS(name, "", #ns) -#define EXPORT_NS_GPL_DEV_PM_OPS(name, ns) _EXPORT_DEV_PM_OPS(name, "_gpl", #ns) +#define EXPORT_DEV_PM_OPS(name) _EXPORT_DEV_PM_OPS(name,, "") +#define EXPORT_GPL_DEV_PM_OPS(name) _EXPORT_DEV_PM_OPS(name,gpl, "") +#define EXPORT_NS_DEV_PM_OPS(name, ns) _EXPORT_DEV_PM_OPS(name,, #ns) +#define EXPORT_NS_GPL_DEV_PM_OPS(name, ns) _EXPORT_DEV_PM_OPS(name,gpl, #ns) /* * Use this if you want to use the same suspend and resume callbacks for suspend diff --git a/kernel/module/internal.h b/kernel/module/internal.h index dc7b0160c480..c8b7b4dcf782 100644 --- a/kernel/module/internal.h +++ b/kernel/module/internal.h @@ -32,6 +32,18 @@ /* Maximum number of characters written by module_flags() */ #define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4) +struct kernel_symbol { +#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS + int value_offset; + int name_offset; + int namespace_offset; +#else + unsigned long value; + const char *name; + const char *namespace; +#endif +}; + extern struct mutex module_mutex; extern struct list_head modules; diff --git a/scripts/Makefile.build b/scripts/Makefile.build index ddd644bd032d..4af35997007b 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -163,7 +163,7 @@ quiet_cmd_cc_o_c = CC $(quiet_modtag) $@ ifdef CONFIG_MODVERSIONS # When module versioning is enabled the following steps are executed: # o compile a .o from .c -# o if .o doesn't contain a __ksymtab version, i.e. does +# o if .o doesn't contain a __export_symbol*, i.e. does # not export symbols, it's done. # o otherwise, we calculate symbol versions using the good old # genksyms on the preprocessed source and dump them into the .cmd file. @@ -171,7 +171,7 @@ ifdef CONFIG_MODVERSIONS # be compiled and linked to the kernel and/or modules. gen_symversions = \ - if $(NM) $@ 2>/dev/null | grep -q __ksymtab; then \ + if $(NM) $@ 2>/dev/null | grep -q '__export_symbol_[^_]*_'; then \ $(call cmd_gensymtypes_$(1),$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \ >> $(dot-target).cmd; \ fi @@ -342,9 +342,7 @@ $(obj)/%.ll: $(src)/%.rs FORCE cmd_gensymtypes_S = \ { echo "\#include " ; \ echo "\#include " ; \ - $(CPP) $(a_flags) $< | \ - grep "\<___EXPORT_SYMBOL\>" | \ - sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ; } | \ + $(NM) $@ | sed -n 's/.*__export_symbol_[^_]*_\(.*\)/EXPORT_SYMBOL(\1);/p' ; } | \ $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | $(genksyms) quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@ diff --git a/scripts/check-local-export b/scripts/check-local-export index f90b5a9c67b3..969a313b9299 100755 --- a/scripts/check-local-export +++ b/scripts/check-local-export @@ -46,9 +46,9 @@ BEGIN { { symbol_types[$3]=$2 } # append the exported symbol to the array -($3 ~ /^__ksymtab_/) { +($3 ~ /^__export_symbol_(gpl)?_.*/) { export_symbols[i] = $3 - sub(/^__ksymtab_/, "", export_symbols[i]) + sub(/^__export_symbol_(gpl)?_/, "", export_symbols[i]) i++ } diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 403ba4d923f5..0ae6c9c5bdf6 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -217,6 +217,7 @@ struct symbol { unsigned int crc; bool crc_valid; bool weak; + bool is_func; bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */ char name[]; }; @@ -533,6 +534,8 @@ static int parse_elf(struct elf_info *info, const char *filename) fatal("%s has NOBITS .modinfo\n", filename); info->modinfo = (void *)hdr + sechdrs[i].sh_offset; info->modinfo_len = sechdrs[i].sh_size; + } else if (!strcmp(secname, ".export_symbol")) { + info->export_symbol_secndx = i; } if (sechdrs[i].sh_type == SHT_SYMTAB) { @@ -655,18 +658,6 @@ static void handle_symbol(struct module *mod, struct elf_info *info, ELF_ST_BIND(sym->st_info) == STB_WEAK); break; default: - /* All exported symbols */ - if (strstarts(symname, "__ksymtab_")) { - const char *name, *secname; - - name = symname + strlen("__ksymtab_"); - secname = sec_name(info, get_secindex(info, sym)); - - if (strstarts(secname, "___ksymtab_gpl+")) - sym_add_exported(name, mod, true); - else if (strstarts(secname, "___ksymtab+")) - sym_add_exported(name, mod, false); - } if (strcmp(symname, "init_module") == 0) mod->has_init = true; if (strcmp(symname, "cleanup_module") == 0) @@ -848,7 +839,6 @@ enum mismatch { XXXEXIT_TO_SOME_EXIT, ANY_INIT_TO_ANY_EXIT, ANY_EXIT_TO_ANY_INIT, - EXPORT_TO_INIT_EXIT, EXTABLE_TO_NON_TEXT, }; @@ -920,12 +910,6 @@ static const struct sectioncheck sectioncheck[] = { .bad_tosec = { INIT_SECTIONS, NULL }, .mismatch = ANY_INIT_TO_ANY_EXIT, }, -/* Do not export init/exit functions or data */ -{ - .fromsec = { "___ksymtab*", NULL }, - .bad_tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL }, - .mismatch = EXPORT_TO_INIT_EXIT, -}, { .fromsec = { "__ex_table", NULL }, /* If you're adding any new black-listed sections in here, consider @@ -1180,10 +1164,6 @@ static void default_mismatch_handler(const char *modname, struct elf_info *elf, warn("%s: section mismatch in reference: %s (section: %s) -> %s (section: %s)\n", modname, fromsym, fromsec, tosym, tosec); break; - case EXPORT_TO_INIT_EXIT: - warn("%s: EXPORT_SYMBOL used for init/exit symbol: %s (section: %s)\n", - modname, tosym, tosec); - break; case EXTABLE_TO_NON_TEXT: warn("%s(%s+0x%lx): Section mismatch in reference to the %s:%s\n", modname, fromsec, (long)faddr, tosec, tosym); @@ -1211,14 +1191,69 @@ static void default_mismatch_handler(const char *modname, struct elf_info *elf, } } +static void check_export_symbol(struct module *mod, struct elf_info *elf, + Elf_Addr faddr, const char *secname, + Elf_Sym *sym) +{ + const char *label_name, *name, *prefix; + Elf_Sym *label; + struct symbol *s; + bool is_gpl; + + label = find_fromsym(elf, faddr, elf->export_symbol_secndx); + label_name = sym_name(elf, label); + + name = sym_name(elf, sym); + + if (strstarts(label_name, "__export_symbol_gpl_")) { + prefix = "__export_symbol_gpl_"; + is_gpl = true; + } else if (strstarts(label_name, "__export_symbol__")) { + prefix = "__export_symbol__"; + is_gpl = false; + } else { + error("%s: .export_symbol section contains strange symbol '%s'\n", + mod->name, label_name); + return; + } + + if (strcmp(label_name + strlen(prefix), name)) { + error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n", + mod->name, name); + return; + } + + s = sym_add_exported(name, mod, is_gpl); + sym_update_namespace(name, sym_get_data(elf, label)); + + /* + * We need to be aware whether we are exporting a function or + * a data on some architectures. + */ + s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC); + + if (match(secname, PATTERNS(INIT_SECTIONS))) + error("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n", + mod->name, name); + else if (match(secname, PATTERNS(EXIT_SECTIONS))) + error("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n", + mod->name, name); +} + static void check_section_mismatch(struct module *mod, struct elf_info *elf, Elf_Sym *sym, unsigned int fsecndx, const char *fromsec, Elf_Addr faddr, Elf_Addr taddr) { const char *tosec = sec_name(elf, get_secindex(elf, sym)); - const struct sectioncheck *mismatch = section_mismatch(fromsec, tosec); + const struct sectioncheck *mismatch; + if (elf->export_symbol_secndx == fsecndx) { + check_export_symbol(mod, elf, faddr, tosec, sym); + return; + } + + mismatch = section_mismatch(fromsec, tosec); if (!mismatch) return; @@ -1698,15 +1733,6 @@ static void read_symbols(const char *modname) handle_moddevtable(mod, &info, sym, symname); } - for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { - symname = remove_dot(info.strtab + sym->st_name); - - /* Apply symbol namespaces from __kstrtabns_ entries. */ - if (strstarts(symname, "__kstrtabns_")) - sym_update_namespace(symname + strlen("__kstrtabns_"), - sym_get_data(&info, sym)); - } - check_sec_ref(mod, &info); if (!mod->is_vmlinux) { @@ -1890,6 +1916,14 @@ static void add_exported_symbols(struct buffer *buf, struct module *mod) { struct symbol *sym; + /* generate struct for exported symbols */ + buf_printf(buf, "\n"); + list_for_each_entry(sym, &mod->exported_symbols, list) + buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n", + sym->is_func ? "FUNC" : "DATA", sym->name, + sym->is_gpl_only ? "_gpl" : "", + sym->namespace ?: ""); + if (!modversions) return; diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h index b1e2d95f8047..dfdb9484e325 100644 --- a/scripts/mod/modpost.h +++ b/scripts/mod/modpost.h @@ -137,6 +137,7 @@ struct elf_info { Elf_Shdr *sechdrs; Elf_Sym *symtab_start; Elf_Sym *symtab_stop; + unsigned int export_symbol_secndx; /* .export_symbol section */ char *strtab; char *modinfo; unsigned int modinfo_len; From patchwork Sat Jun 10 09:13:13 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 13274793 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 C8093C83005 for ; Sat, 10 Jun 2023 09:13:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234380AbjFJJNs (ORCPT ); Sat, 10 Jun 2023 05:13:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33444 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234222AbjFJJNp (ORCPT ); Sat, 10 Jun 2023 05:13:45 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A784B3A9B; Sat, 10 Jun 2023 02:13:43 -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 433A562065; Sat, 10 Jun 2023 09:13:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 689D4C4339B; Sat, 10 Jun 2023 09:13:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686388422; bh=zr+yJCwaIX4mMIACmjYkguIW6MMvumzYzdZSlBPO+AQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cAI3a/zwJxAnwFNnICsvEGmj/0sZtcnOLgGN8tCTdTI+sS7beZOMQpJXxhTN5+O5M p/w3uwmCb/b/joojpNUKy9Vw53Fx+KkrM4CBggRONaJeK+OrJa03OChNEszFwXTU9W ibOx7IG/KK6dno/q3/mnVQIDwmMRPgYeNHItOo18zph4vsTFmlN7WdGB0Bu7vwAb41 H8b7elmL2jxuliiyNfZ6I0h1aqVXfP2BQ15QetoMmA/+8XHEpl1K2rgVnVntZ+vAsq s2ooJ900Czb7wXePlvChY3aQdcpRb7HlBMId5p7MKaDgeXCUr9AnDk4Qx0J3LGx6RG FGD4xVW7szcTQ== From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nathan Chancellor , Nick Desaulniers , Nicolas Schier , linux-um@lists.infradead.org, Masahiro Yamada Subject: [PATCH v8 04/11] ia64,export.h: replace EXPORT_DATA_SYMBOL* with EXPORT_SYMBOL* Date: Sat, 10 Jun 2023 18:13:13 +0900 Message-Id: <20230610091320.1054554-5-masahiroy@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230610091320.1054554-1-masahiroy@kernel.org> References: <20230610091320.1054554-1-masahiroy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org With the previous refactoring, you can always use EXPORT_SYMBOL*. Replace two instances in ia64, then remove EXPORT_DATA_SYMBOL*. Signed-off-by: Masahiro Yamada Reviewed-by: Nick Desaulniers --- arch/ia64/kernel/head.S | 2 +- arch/ia64/kernel/ivt.S | 2 +- include/asm-generic/export.h | 3 --- 3 files changed, 2 insertions(+), 5 deletions(-) diff --git a/arch/ia64/kernel/head.S b/arch/ia64/kernel/head.S index f22469f1c1fc..c096500590e9 100644 --- a/arch/ia64/kernel/head.S +++ b/arch/ia64/kernel/head.S @@ -170,7 +170,7 @@ RestRR: \ __PAGE_ALIGNED_DATA .global empty_zero_page -EXPORT_DATA_SYMBOL_GPL(empty_zero_page) +EXPORT_SYMBOL_GPL(empty_zero_page) empty_zero_page: .skip PAGE_SIZE diff --git a/arch/ia64/kernel/ivt.S b/arch/ia64/kernel/ivt.S index d6d4229b28db..7a418e324d30 100644 --- a/arch/ia64/kernel/ivt.S +++ b/arch/ia64/kernel/ivt.S @@ -87,7 +87,7 @@ .align 32768 // align on 32KB boundary .global ia64_ivt - EXPORT_DATA_SYMBOL(ia64_ivt) + EXPORT_SYMBOL(ia64_ivt) ia64_ivt: ///////////////////////////////////////////////////////////////////////////////////////// // 0x0000 Entry 0 (size 64 bundles) VHPT Translation (8,20,47) diff --git a/include/asm-generic/export.h b/include/asm-generic/export.h index 0ae9f38a904c..570cd4da7210 100644 --- a/include/asm-generic/export.h +++ b/include/asm-generic/export.h @@ -8,7 +8,4 @@ */ #include -#define EXPORT_DATA_SYMBOL(name) EXPORT_SYMBOL(name) -#define EXPORT_DATA_SYMBOL_GPL(name) EXPORT_SYMBOL_GPL(name) - #endif From patchwork Sat Jun 10 09:13:14 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 13274795 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 DD587C7EE2E for ; Sat, 10 Jun 2023 09:14:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234512AbjFJJOD (ORCPT ); Sat, 10 Jun 2023 05:14:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33518 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234280AbjFJJNs (ORCPT ); Sat, 10 Jun 2023 05:13:48 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 36B163C1B; Sat, 10 Jun 2023 02:13:47 -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 BECF261EFC; Sat, 10 Jun 2023 09:13:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4394AC4339E; Sat, 10 Jun 2023 09:13:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686388426; bh=W5GU/ZLzGNLqfZHu55u3amZ0uNTqo90d6vPAinl/0zo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sax95FXe+7gU8fc6TNx+TFw5JXYJ+N2lXneSCZB/RyO4BVdpZvdPW3buUGgLGUfcY IISU96O/mImxT15xLAN1fNrWRBPMPagEfQ/CrscP2/y8I5WHX0QCVoE/vZNjzihYtp 0/A5a0wTF8t8tNsJwrKUmVKIXtMsZoDoLtoySX66hkwI4/9ardRwfUrf97VonaWREK ZYo8UlkBDU/IVRrcJIa7nr68IFAu8aLMzpkhwMaLwLD5yQr5MeeKK5PkPhKkyu4qDp LE1nxGNTblYYWAmWJml2huPju27r4bnz81Vsp2Xq+er5/6HXu1qHUxDMVR1NP68xr0 SYzB1REs65szw== From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nathan Chancellor , Nick Desaulniers , Nicolas Schier , linux-um@lists.infradead.org, Masahiro Yamada Subject: [PATCH v8 05/11] modpost: check static EXPORT_SYMBOL* by modpost again Date: Sat, 10 Jun 2023 18:13:14 +0900 Message-Id: <20230610091320.1054554-6-masahiroy@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230610091320.1054554-1-masahiroy@kernel.org> References: <20230610091320.1054554-1-masahiroy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org Commit 31cb50b5590f ("kbuild: check static EXPORT_SYMBOL* by script instead of modpost") moved the static EXPORT_SYMBOL* check from the mostpost to a shell script because I thought it must be checked per compilation unit to avoid false negatives. I came up with an idea to do this in modpost, against combined ELF files. The relocation entries in ELF will find the correct exported symbol even if there exist symbols with the same name in different compilation units. Again, the same sample code. Makefile: obj-y += foo1.o foo2.o foo1.c: #include static void foo(void) {} EXPORT_SYMBOL(foo); foo2.c: void foo(void) {} Then, modpost can catch it correctly. MODPOST Module.symvers ERROR: modpost: vmlinux: local symbol 'foo' was exported Signed-off-by: Masahiro Yamada Reviewed-by: Nick Desaulniers --- (no changes since v6) Changes in v6: - Make the symbol name in the warning more precise scripts/Makefile.build | 4 --- scripts/check-local-export | 70 -------------------------------------- scripts/mod/modpost.c | 7 ++++ 3 files changed, 7 insertions(+), 74 deletions(-) delete mode 100755 scripts/check-local-export diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 4af35997007b..d676bc15e4e7 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -222,8 +222,6 @@ cmd_gen_ksymdeps = \ $(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd endif -cmd_check_local_export = $(srctree)/scripts/check-local-export $@ - ifneq ($(findstring 1, $(KBUILD_EXTRA_WARN)),) cmd_warn_shared_object = $(if $(word 2, $(modname-multi)),$(warning $(kbuild-file): $*.o is added to multiple modules: $(modname-multi))) endif @@ -231,7 +229,6 @@ endif define rule_cc_o_c $(call cmd_and_fixdep,cc_o_c) $(call cmd,gen_ksymdeps) - $(call cmd,check_local_export) $(call cmd,checksrc) $(call cmd,checkdoc) $(call cmd,gen_objtooldep) @@ -243,7 +240,6 @@ endef define rule_as_o_S $(call cmd_and_fixdep,as_o_S) $(call cmd,gen_ksymdeps) - $(call cmd,check_local_export) $(call cmd,gen_objtooldep) $(call cmd,gen_symversions_S) $(call cmd,warn_shared_object) diff --git a/scripts/check-local-export b/scripts/check-local-export deleted file mode 100755 index 969a313b9299..000000000000 --- a/scripts/check-local-export +++ /dev/null @@ -1,70 +0,0 @@ -#!/bin/sh -# SPDX-License-Identifier: GPL-2.0-only -# -# Copyright (C) 2022 Masahiro Yamada -# Copyright (C) 2022 Owen Rafferty -# -# Exit with error if a local exported symbol is found. -# EXPORT_SYMBOL should be used for global symbols. - -set -e -pid=$$ - -# If there is no symbol in the object, ${NM} (both GNU nm and llvm-nm) shows -# 'no symbols' diagnostic (but exits with 0). It is harmless and hidden by -# '2>/dev/null'. However, it suppresses real error messages as well. Add a -# hand-crafted error message here. -# -# TODO: -# Use --quiet instead of 2>/dev/null when we upgrade the minimum version of -# binutils to 2.37, llvm to 13.0.0. -# Then, the following line will be simpler: -# { ${NM} --quiet ${1} || kill 0; } | - -{ ${NM} ${1} 2>/dev/null || { echo "${0}: ${NM} failed" >&2; kill $pid; } } | -${AWK} -v "file=${1}" ' -BEGIN { - i = 0 -} - -# Skip the line if the number of fields is less than 3. -# -# case 1) -# For undefined symbols, the first field (value) is empty. -# The outout looks like this: -# " U _printk" -# It is unneeded to record undefined symbols. -# -# case 2) -# For Clang LTO, llvm-nm outputs a line with type t but empty name: -# "---------------- t" -!length($3) { - next -} - -# save (name, type) in the associative array -{ symbol_types[$3]=$2 } - -# append the exported symbol to the array -($3 ~ /^__export_symbol_(gpl)?_.*/) { - export_symbols[i] = $3 - sub(/^__export_symbol_(gpl)?_/, "", export_symbols[i]) - i++ -} - -END { - exit_code = 0 - for (j = 0; j < i; ++j) { - name = export_symbols[j] - # nm(3) says "If lowercase, the symbol is usually local" - if (symbol_types[name] ~ /[a-z]/) { - printf "%s: error: local symbol %s was exported\n", - file, name | "cat 1>&2" - exit_code = 1 - } - } - - exit exit_code -}' - -exit $? diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 0ae6c9c5bdf6..a3185ee6ec1a 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -1217,6 +1217,13 @@ static void check_export_symbol(struct module *mod, struct elf_info *elf, return; } + if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && + ELF_ST_BIND(sym->st_info) != STB_WEAK) { + error("%s: local symbol '%s' was exported\n", mod->name, + label_name + strlen(prefix)); + return; + } + if (strcmp(label_name + strlen(prefix), name)) { error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n", mod->name, name); From patchwork Sat Jun 10 09:13:15 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 13274796 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 394C1C83005 for ; Sat, 10 Jun 2023 09:14:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234222AbjFJJOG (ORCPT ); Sat, 10 Jun 2023 05:14:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33470 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234233AbjFJJNw (ORCPT ); Sat, 10 Jun 2023 05:13:52 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A9973C28; Sat, 10 Jun 2023 02:13:49 -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 095BE61EFC; Sat, 10 Jun 2023 09:13:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E1F9EC433D2; Sat, 10 Jun 2023 09:13:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686388428; bh=WxsbZJQWaT5jCsrdDCJG6B1Ekj8QHp6BWQx+hm3BcWA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IiVRdteGCFlLKvr6PB4BCZgVXVjEWdD61C3XUb06yo/CsMmc4UWgAdOTV5m1U2nhB zWm617SOqSOTnqPDMiX2W7FX1GzhNVhTWvbKLleGHtqtftwS/Yl++6e7FhyL1r4d4Y eu+XqhXwGgPROTiKzc6lYC3ZK6idH6uEN5g0m68Gd4HqC4wh9FNJNU7/S/7TfXYYzF yL/Y/KQcDirTKqUUhGJLwR2NFl+yT36PPuaQlDjWjfD5VmUeX6vCtP9TSBXxwAWQyL 8YTlhHv6426s6URkTD/oOmtFU4fN383j74r9PCZ0VS+9E0F7v4enw4Ble3k0LjncGh +7euzpAbwJkig== From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nathan Chancellor , Nick Desaulniers , Nicolas Schier , linux-um@lists.infradead.org, Masahiro Yamada Subject: [PATCH v8 06/11] modpost: squash sym_update_namespace() into sym_add_exported() Date: Sat, 10 Jun 2023 18:13:15 +0900 Message-Id: <20230610091320.1054554-7-masahiroy@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230610091320.1054554-1-masahiroy@kernel.org> References: <20230610091320.1054554-1-masahiroy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org Pass a set of the name, license, and namespace to sym_add_exported(). sym_update_namespace() is unneeded. Signed-off-by: Masahiro Yamada Reviewed-by: Nick Desaulniers --- scripts/mod/modpost.c | 27 ++++----------------------- 1 file changed, 4 insertions(+), 23 deletions(-) diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index a3185ee6ec1a..4b0a009de0fb 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -355,26 +355,8 @@ static const char *sec_name(const struct elf_info *info, unsigned int secindex) #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0) -static void sym_update_namespace(const char *symname, const char *namespace) -{ - struct symbol *s = find_symbol(symname); - - /* - * That symbol should have been created earlier and thus this is - * actually an assertion. - */ - if (!s) { - error("Could not update namespace(%s) for symbol %s\n", - namespace, symname); - return; - } - - free(s->namespace); - s->namespace = namespace[0] ? NOFAIL(strdup(namespace)) : NULL; -} - static struct symbol *sym_add_exported(const char *name, struct module *mod, - bool gpl_only) + bool gpl_only, const char *namespace) { struct symbol *s = find_symbol(name); @@ -387,6 +369,7 @@ static struct symbol *sym_add_exported(const char *name, struct module *mod, s = alloc_symbol(name); s->module = mod; s->is_gpl_only = gpl_only; + s->namespace = namespace[0] ? NOFAIL(strdup(namespace)) : NULL; list_add_tail(&s->list, &mod->exported_symbols); hash_add_symbol(s); @@ -1230,8 +1213,7 @@ static void check_export_symbol(struct module *mod, struct elf_info *elf, return; } - s = sym_add_exported(name, mod, is_gpl); - sym_update_namespace(name, sym_get_data(elf, label)); + s = sym_add_exported(name, mod, is_gpl, sym_get_data(elf, label)); /* * We need to be aware whether we are exporting a function or @@ -2174,9 +2156,8 @@ static void read_dump(const char *fname) mod = new_module(modname, strlen(modname)); mod->from_dump = true; } - s = sym_add_exported(symname, mod, gpl_only); + s = sym_add_exported(symname, mod, gpl_only, namespace); sym_set_crc(s, crc); - sym_update_namespace(symname, namespace); } free(buf); return; From patchwork Sat Jun 10 09:13:16 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 13274797 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 976B5C77B7A for ; Sat, 10 Jun 2023 09:14:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234484AbjFJJOS (ORCPT ); Sat, 10 Jun 2023 05:14:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33890 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234495AbjFJJOD (ORCPT ); Sat, 10 Jun 2023 05:14:03 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E1D034202; Sat, 10 Jun 2023 02:13:52 -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 773B060CA4; Sat, 10 Jun 2023 09:13:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 48724C433EF; Sat, 10 Jun 2023 09:13:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686388431; bh=Ap3GuMqINZf2WdIT1xsNL1OzEvsLgkbr6RhrjaSFN2U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nP8/MpiNzNy6yeqR8dbxaAnpVDSSoo3qY417NEK4RQd9NKUvZSPMzRA5cn/Df0D7q 7A72aMZjxbwGbVW/3aBk56MiDOsN+OcGe6kYvgPm2f6F3gKT/ZdC3I1SgWn/kKYVUE skMlKo5hKcNkzg1szdEKt8uWRkEoa5AesUv+tdGldplIMswWj1mjPhlLFDMEc7vb6G ahLZ7YHFS0nFnigd6vvA+EFX9yg4DaE/ikO/6XfZZTFjDg1HG5A4eEegvtM2OKijgi FhSw0bJig3AHk5uuww7kLyD1jwNwx5ugoak/u6Eq6JsHuZOmhKMu7M3MQ05wm+2Edp BYJAu3c45vgbw== From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nathan Chancellor , Nick Desaulniers , Nicolas Schier , linux-um@lists.infradead.org, Masahiro Yamada Subject: [PATCH v8 07/11] modpost: use null string instead of NULL pointer for default namespace Date: Sat, 10 Jun 2023 18:13:16 +0900 Message-Id: <20230610091320.1054554-8-masahiroy@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230610091320.1054554-1-masahiroy@kernel.org> References: <20230610091320.1054554-1-masahiroy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org The default namespace is the null string, "". When set, the null string "" is converted to NULL: s->namespace = namespace[0] ? NOFAIL(strdup(namespace)) : NULL; When printed, the NULL pointer is get back to the null string: sym->namespace ?: "" This saves 1 byte memory allocated for "", but loses the readability. In kernel-space, we strive to save memory, but modpost is a userspace tool used to build the kernel. On modern systems, such small piece of memory is not a big deal. Handle the namespace string as is. Signed-off-by: Masahiro Yamada Reviewed-by: Nick Desaulniers --- scripts/mod/modpost.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 4b0a009de0fb..7044b257424a 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -300,6 +300,13 @@ static bool contains_namespace(struct list_head *head, const char *namespace) { struct namespace_list *list; + /* + * The default namespace is null string "", which is always implicitly + * contained. + */ + if (!namespace[0]) + return true; + list_for_each_entry(list, head, list) { if (!strcmp(list->namespace, namespace)) return true; @@ -369,7 +376,7 @@ static struct symbol *sym_add_exported(const char *name, struct module *mod, s = alloc_symbol(name); s->module = mod; s->is_gpl_only = gpl_only; - s->namespace = namespace[0] ? NOFAIL(strdup(namespace)) : NULL; + s->namespace = NOFAIL(strdup(namespace)); list_add_tail(&s->list, &mod->exported_symbols); hash_add_symbol(s); @@ -1823,8 +1830,7 @@ static void check_exports(struct module *mod) else basename = mod->name; - if (exp->namespace && - !contains_namespace(&mod->imported_namespaces, exp->namespace)) { + if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) { modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR, "module %s uses symbol %s from namespace %s, but does not import it.\n", basename, exp->name, exp->namespace); @@ -1910,8 +1916,7 @@ static void add_exported_symbols(struct buffer *buf, struct module *mod) list_for_each_entry(sym, &mod->exported_symbols, list) buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n", sym->is_func ? "FUNC" : "DATA", sym->name, - sym->is_gpl_only ? "_gpl" : "", - sym->namespace ?: ""); + sym->is_gpl_only ? "_gpl" : "", sym->namespace); if (!modversions) return; @@ -2179,7 +2184,7 @@ static void write_dump(const char *fname) buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n", sym->crc, sym->name, mod->name, sym->is_gpl_only ? "_GPL" : "", - sym->namespace ?: ""); + sym->namespace); } } write_buf(&buf, fname); From patchwork Sat Jun 10 09:13:17 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 13274798 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 9C500C7EE2E for ; Sat, 10 Jun 2023 09:14:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234431AbjFJJO2 (ORCPT ); Sat, 10 Jun 2023 05:14:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33804 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234457AbjFJJOI (ORCPT ); Sat, 10 Jun 2023 05:14:08 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E7FFE4213; Sat, 10 Jun 2023 02:13:56 -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 5FB946217E; Sat, 10 Jun 2023 09:13:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 067EFC433EF; Sat, 10 Jun 2023 09:13:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686388435; bh=rLYwIF6pk3gbhbFAZvnFsEVEHXPxI9dFIwA+I9BIpuA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OpeHRfRNjxwX7ILRo0V70TADgZpj9fzmi3pjthUtgsjw9IUyMVf4I4BRMdlWROvmi kx3dR4UFzrXNYGrK8HUTTAGfk2US8ccCXlq5dT76HpRU/uFbpOagDgAAmKHc7NspON GahOX/0Y84MyqhtW9Qojm2pckrQnmJQq3P7rLSEHtN3KHUen7gxOuZWiWRryWpD/2l ksiG9MeUwThUfF2hwM1l2203YG6BaxzVWmPZYgPdJumxJXR6/3T1rCz2wgMNKHx/Cm H5VTTHzJrVMpV4BidlBuoSy26aQN2/AtkE58WQQr3LffVDysLm35T4zxdlZMWtoRyp r89pX43CPUvTw== From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nathan Chancellor , Nick Desaulniers , Nicolas Schier , linux-um@lists.infradead.org, Masahiro Yamada Subject: [PATCH v8 08/11] kbuild: implement CONFIG_TRIM_UNUSED_KSYMS without recursion Date: Sat, 10 Jun 2023 18:13:17 +0900 Message-Id: <20230610091320.1054554-9-masahiroy@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230610091320.1054554-1-masahiroy@kernel.org> References: <20230610091320.1054554-1-masahiroy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org When CONFIG_TRIM_UNUSED_KSYMS is enabled, Kbuild recursively traverses the directory tree to determine which EXPORT_SYMBOL to trim. If an EXPORT_SYMBOL turns out to be unused by anyone, Kbuild begins the second traverse, where some source files are recompiled with their EXPORT_SYMBOL() tuned into a no-op. Linus stated negative opinions about this slowness in commits: - 5cf0fd591f2e ("Kbuild: disable TRIM_UNUSED_KSYMS option") - a555bdd0c58c ("Kbuild: enable TRIM_UNUSED_KSYMS again, with some guarding") We can do this better now. The final data structures of EXPORT_SYMBOL are generated by the modpost stage, so modpost can selectively emit KSYMTAB entries that are really used by modules. Commit f73edc8951b2 ("kbuild: unify two modpost invocations") is another ground-work to do this in a one-pass algorithm. With the list of modules, modpost sets sym->used if it is used by a module. modpost emits KSYMTAB only for symbols with sym->used==true. BTW, Nicolas explained why the trimming was implemented with recursion: https://lore.kernel.org/all/2o2rpn97-79nq-p7s2-nq5-8p83391473r@syhkavp.arg/ Actually, we never achieved that level of optimization where the chain reaction of trimming comes into play because: - CONFIG_LTO_CLANG cannot remove any unused symbols - CONFIG_LD_DEAD_CODE_DATA_ELIMINATION is enabled only for vmlinux, but not modules If deeper trimming is required, we need to revisit this, but I guess that is unlikely to happen. Signed-off-by: Masahiro Yamada --- (no changes since v7) Changes in v7: - Remove *.usyms Changes in v5: - Clean up more .gitignore | 2 - Makefile | 22 ++--------- include/linux/export.h | 67 +++++----------------------------- scripts/Makefile.build | 15 +------- scripts/Makefile.modpost | 7 ++++ scripts/adjust_autoksyms.sh | 73 ------------------------------------- scripts/basic/fixdep.c | 3 +- scripts/gen_autoksyms.sh | 62 ------------------------------- scripts/gen_ksymdeps.sh | 30 --------------- scripts/mod/modpost.c | 54 ++++++++++++++++++++++++--- scripts/remove-stale-files | 4 ++ 11 files changed, 75 insertions(+), 264 deletions(-) delete mode 100755 scripts/adjust_autoksyms.sh delete mode 100755 scripts/gen_autoksyms.sh delete mode 100755 scripts/gen_ksymdeps.sh diff --git a/.gitignore b/.gitignore index 7f86e0837909..c3ce78ca20d2 100644 --- a/.gitignore +++ b/.gitignore @@ -51,7 +51,6 @@ *.symversions *.tab.[ch] *.tar -*.usyms *.xz *.zst Module.symvers @@ -112,7 +111,6 @@ modules.order # /include/config/ /include/generated/ -/include/ksym/ /arch/*/include/generated/ # stgit generated dirs diff --git a/Makefile b/Makefile index f836936fb4d8..cc3fe09c4dec 100644 --- a/Makefile +++ b/Makefile @@ -1193,28 +1193,12 @@ endif export KBUILD_VMLINUX_LIBS export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds -# Recurse until adjust_autoksyms.sh is satisfied -PHONY += autoksyms_recursive ifdef CONFIG_TRIM_UNUSED_KSYMS # For the kernel to actually contain only the needed exported symbols, # we have to build modules as well to determine what those symbols are. -# (this can be evaluated only once include/config/auto.conf has been included) KBUILD_MODULES := 1 - -autoksyms_recursive: $(build-dir) modules.order - $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \ - "$(MAKE) -f $(srctree)/Makefile autoksyms_recursive" endif -autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h) - -quiet_cmd_autoksyms_h = GEN $@ - cmd_autoksyms_h = mkdir -p $(dir $@); \ - $(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@ - -$(autoksyms_h): - $(call cmd,autoksyms_h) - # '$(AR) mPi' needs 'T' to workaround the bug of llvm-ar <= 14 quiet_cmd_ar_vmlinux.a = AR $@ cmd_ar_vmlinux.a = \ @@ -1223,7 +1207,7 @@ quiet_cmd_ar_vmlinux.a = AR $@ $(AR) mPiT $$($(AR) t $@ | sed -n 1p) $@ $$($(AR) t $@ | grep -F -f $(srctree)/scripts/head-object-list.txt) targets += vmlinux.a -vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt autoksyms_recursive FORCE +vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt FORCE $(call if_changed,ar_vmlinux.a) PHONY += vmlinux_o @@ -1279,7 +1263,7 @@ scripts: scripts_basic scripts_dtc PHONY += prepare archprepare archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \ - asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \ + asm-generic $(version_h) include/generated/utsrelease.h \ include/generated/compile.h include/generated/autoconf.h remove-stale-files prepare0: archprepare @@ -2039,7 +2023,7 @@ clean: $(clean-dirs) -o -name '*.dtb.S' -o -name '*.dtbo.S' \ -o -name '*.dt.yaml' \ -o -name '*.dwo' -o -name '*.lst' \ - -o -name '*.su' -o -name '*.mod' -o -name '*.usyms' \ + -o -name '*.su' -o -name '*.mod' \ -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \ -o -name '*.lex.c' -o -name '*.tab.[ch]' \ -o -name '*.asn1.[ch]' \ diff --git a/include/linux/export.h b/include/linux/export.h index 245ecd342772..8a9b72386fff 100644 --- a/include/linux/export.h +++ b/include/linux/export.h @@ -37,31 +37,13 @@ extern struct module __this_module; #define __EXPORT_SYMBOL_REF(sym) .balign 4; .long sym #endif -#define ____EXPORT_SYMBOL(sym, license, ns) \ +#define ___EXPORT_SYMBOL(sym, license, ns) \ .section ".export_symbol","a" ; \ __export_symbol_##license##_##sym: ; \ .asciz ns ; \ __EXPORT_SYMBOL_REF(sym) ; \ .previous -#ifdef __GENKSYMS__ - -#define ___EXPORT_SYMBOL(sym, sec, ns) __GENKSYMS_EXPORT_SYMBOL(sym) - -#elif defined(__ASSEMBLY__) - -#define ___EXPORT_SYMBOL(sym, license, ns) \ - ____EXPORT_SYMBOL(sym, license, ns) - -#else - -#define ___EXPORT_SYMBOL(sym, license, ns) \ - extern typeof(sym) sym; \ - __ADDRESSABLE(sym) \ - asm(__stringify(____EXPORT_SYMBOL(sym, license, ns))) - -#endif - #if !defined(CONFIG_MODULES) || defined(__DISABLE_EXPORTS) /* @@ -71,50 +53,21 @@ extern struct module __this_module; */ #define __EXPORT_SYMBOL(sym, sec, ns) -#elif defined(CONFIG_TRIM_UNUSED_KSYMS) +#elif defined(__GENKSYMS__) -#include +#define __EXPORT_SYMBOL(sym, sec, ns) __GENKSYMS_EXPORT_SYMBOL(sym) -/* - * For fine grained build dependencies, we want to tell the build system - * about each possible exported symbol even if they're not actually exported. - * We use a symbol pattern __ksym_marker_ that the build system filters - * from the $(NM) output (see scripts/gen_ksymdeps.sh). These symbols are - * discarded in the final link stage. - */ +#elif defined(__ASSEMBLY__) -#ifdef __ASSEMBLY__ - -#define __ksym_marker(sym) \ - .section ".discard.ksym","a" ; \ -__ksym_marker_##sym: ; \ - .previous +#define __EXPORT_SYMBOL(sym, license, ns) \ + ___EXPORT_SYMBOL(sym, license, ns) #else -#define __ksym_marker(sym) \ - static int __ksym_marker_##sym[0] __section(".discard.ksym") __used - -#endif - -#define __EXPORT_SYMBOL(sym, sec, ns) \ - __ksym_marker(sym); \ - __cond_export_sym(sym, sec, ns, __is_defined(__KSYM_##sym)) -#define __cond_export_sym(sym, sec, ns, conf) \ - ___cond_export_sym(sym, sec, ns, conf) -#define ___cond_export_sym(sym, sec, ns, enabled) \ - __cond_export_sym_##enabled(sym, sec, ns) -#define __cond_export_sym_1(sym, sec, ns) ___EXPORT_SYMBOL(sym, sec, ns) - -#ifdef __GENKSYMS__ -#define __cond_export_sym_0(sym, sec, ns) __GENKSYMS_EXPORT_SYMBOL(sym) -#else -#define __cond_export_sym_0(sym, sec, ns) /* nothing */ -#endif - -#else - -#define __EXPORT_SYMBOL(sym, sec, ns) ___EXPORT_SYMBOL(sym, sec, ns) +#define __EXPORT_SYMBOL(sym, license, ns) \ + extern typeof(sym) sym; \ + __ADDRESSABLE(sym) \ + asm(__stringify(___EXPORT_SYMBOL(sym, license, ns))) #endif /* CONFIG_MODULES */ diff --git a/scripts/Makefile.build b/scripts/Makefile.build index d676bc15e4e7..51477dd71427 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -82,7 +82,7 @@ ifdef need-builtin targets-for-builtin += $(obj)/built-in.a endif -targets-for-modules := $(foreach x, o mod $(if $(CONFIG_TRIM_UNUSED_KSYMS), usyms), \ +targets-for-modules := $(foreach x, o mod, \ $(patsubst %.o, %.$x, $(filter %.o, $(obj-m)))) ifdef need-modorder @@ -217,18 +217,12 @@ is-standard-object = $(if $(filter-out y%, $(OBJECT_FILES_NON_STANDARD_$(basetar $(obj)/%.o: objtool-enabled = $(if $(is-standard-object),$(if $(delay-objtool),$(is-single-obj-m),y)) -ifdef CONFIG_TRIM_UNUSED_KSYMS -cmd_gen_ksymdeps = \ - $(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd -endif - ifneq ($(findstring 1, $(KBUILD_EXTRA_WARN)),) cmd_warn_shared_object = $(if $(word 2, $(modname-multi)),$(warning $(kbuild-file): $*.o is added to multiple modules: $(modname-multi))) endif define rule_cc_o_c $(call cmd_and_fixdep,cc_o_c) - $(call cmd,gen_ksymdeps) $(call cmd,checksrc) $(call cmd,checkdoc) $(call cmd,gen_objtooldep) @@ -239,7 +233,6 @@ endef define rule_as_o_S $(call cmd_and_fixdep,as_o_S) - $(call cmd,gen_ksymdeps) $(call cmd,gen_objtooldep) $(call cmd,gen_symversions_S) $(call cmd,warn_shared_object) @@ -258,12 +251,6 @@ cmd_mod = printf '%s\n' $(call real-search, $*.o, .o, -objs -y -m) | \ $(obj)/%.mod: FORCE $(call if_changed,mod) -# List module undefined symbols -cmd_undefined_syms = $(NM) $< | sed -n 's/^ *U //p' > $@ - -$(obj)/%.usyms: $(obj)/%.o FORCE - $(call if_changed,undefined_syms) - quiet_cmd_cc_lst_c = MKLST $@ cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \ $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \ diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost index 074e27c0c140..65133fcdd5b8 100644 --- a/scripts/Makefile.modpost +++ b/scripts/Makefile.modpost @@ -91,6 +91,13 @@ targets += .vmlinux.objs .vmlinux.objs: vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE $(call if_changed,vmlinux_objs) +ifdef CONFIG_TRIM_UNUSED_KSYMS +ksym-wl := $(CONFIG_UNUSED_KSYMS_WHITELIST) +ksym-wl := $(if $(filter-out /%, $(ksym-wl)),$(srctree)/)$(ksym-wl) +modpost-args += -t $(addprefix -u, $(ksym-wl)) +modpost-deps += $(ksym-wl) +endif + ifeq ($(wildcard vmlinux.o),) missing-input := vmlinux.o output-symdump := modules-only.symvers diff --git a/scripts/adjust_autoksyms.sh b/scripts/adjust_autoksyms.sh deleted file mode 100755 index f1b5ac818411..000000000000 --- a/scripts/adjust_autoksyms.sh +++ /dev/null @@ -1,73 +0,0 @@ -#!/bin/sh -# SPDX-License-Identifier: GPL-2.0-only - -# Script to update include/generated/autoksyms.h and dependency files -# -# Copyright: (C) 2016 Linaro Limited -# Created by: Nicolas Pitre, January 2016 -# - -# Update the include/generated/autoksyms.h file. -# -# For each symbol being added or removed, the corresponding dependency -# file's timestamp is updated to force a rebuild of the affected source -# file. All arguments passed to this script are assumed to be a command -# to be exec'd to trigger a rebuild of those files. - -set -e - -cur_ksyms_file="include/generated/autoksyms.h" -new_ksyms_file="include/generated/autoksyms.h.tmpnew" - -info() { - if [ "$quiet" != "silent_" ]; then - printf " %-7s %s\n" "$1" "$2" - fi -} - -info "CHK" "$cur_ksyms_file" - -# Use "make V=1" to debug this script. -case "$KBUILD_VERBOSE" in -*1*) - set -x - ;; -esac - -# Generate a new symbol list file -$CONFIG_SHELL $srctree/scripts/gen_autoksyms.sh --modorder "$new_ksyms_file" - -# Extract changes between old and new list and touch corresponding -# dependency files. -changed=$( -count=0 -sort "$cur_ksyms_file" "$new_ksyms_file" | uniq -u | -sed -n 's/^#define __KSYM_\(.*\) 1/\1/p' | -while read sympath; do - if [ -z "$sympath" ]; then continue; fi - depfile="include/ksym/${sympath}" - mkdir -p "$(dirname "$depfile")" - touch "$depfile" - # Filesystems with coarse time precision may create timestamps - # equal to the one from a file that was very recently built and that - # needs to be rebuild. Let's guard against that by making sure our - # dep files are always newer than the first file we created here. - while [ ! "$depfile" -nt "$new_ksyms_file" ]; do - touch "$depfile" - done - echo $((count += 1)) -done | tail -1 ) -changed=${changed:-0} - -if [ $changed -gt 0 ]; then - # Replace the old list with tne new one - old=$(grep -c "^#define __KSYM_" "$cur_ksyms_file" || true) - new=$(grep -c "^#define __KSYM_" "$new_ksyms_file" || true) - info "KSYMS" "symbols: before=$old, after=$new, changed=$changed" - info "UPD" "$cur_ksyms_file" - mv -f "$new_ksyms_file" "$cur_ksyms_file" - # Then trigger a rebuild of affected source files - exec $@ -else - rm -f "$new_ksyms_file" -fi diff --git a/scripts/basic/fixdep.c b/scripts/basic/fixdep.c index fa562806c2be..84b6efa849f4 100644 --- a/scripts/basic/fixdep.c +++ b/scripts/basic/fixdep.c @@ -246,8 +246,7 @@ static void *read_file(const char *filename) /* Ignore certain dependencies */ static int is_ignored_file(const char *s, int len) { - return str_ends_with(s, len, "include/generated/autoconf.h") || - str_ends_with(s, len, "include/generated/autoksyms.h"); + return str_ends_with(s, len, "include/generated/autoconf.h"); } /* Do not parse these files */ diff --git a/scripts/gen_autoksyms.sh b/scripts/gen_autoksyms.sh deleted file mode 100755 index 12bcfae940ee..000000000000 --- a/scripts/gen_autoksyms.sh +++ /dev/null @@ -1,62 +0,0 @@ -#!/bin/sh -# SPDX-License-Identifier: GPL-2.0-only - -# Create an autoksyms.h header file from the list of all module's needed symbols -# as recorded in *.usyms files and the user-provided symbol whitelist. - -set -e - -# Use "make V=1" to debug this script. -case "$KBUILD_VERBOSE" in -*1*) - set -x - ;; -esac - -read_modorder= - -if [ "$1" = --modorder ]; then - shift - read_modorder=1 -fi - -output_file="$1" - -needed_symbols= - -# Special case for modversions (see modpost.c) -if grep -q "^CONFIG_MODVERSIONS=y$" include/config/auto.conf; then - needed_symbols="$needed_symbols module_layout" -fi - -ksym_wl=$(sed -n 's/^CONFIG_UNUSED_KSYMS_WHITELIST=\(.*\)$/\1/p' include/config/auto.conf) -if [ -n "$ksym_wl" ]; then - [ "${ksym_wl}" != "${ksym_wl#/}" ] || ksym_wl="$abs_srctree/$ksym_wl" - if [ ! -f "$ksym_wl" ] || [ ! -r "$ksym_wl" ]; then - echo "ERROR: '$ksym_wl' whitelist file not found" >&2 - exit 1 - fi -fi - -# Generate a new ksym list file with symbols needed by the current -# set of modules. -cat > "$output_file" << EOT -/* - * Automatically generated file; DO NOT EDIT. - */ - -EOT - -{ - [ -n "${read_modorder}" ] && sed 's/o$/usyms/' modules.order | xargs cat - echo "$needed_symbols" - [ -n "$ksym_wl" ] && cat "$ksym_wl" -} | sed -e 's/ /\n/g' | sed -n -e '/^$/!p' | -# Remove the dot prefix for ppc64; symbol names with a dot (.) hold entry -# point addresses. -sed -e 's/^\.//' | -sort -u | -# Ignore __this_module. It's not an exported symbol, and will be resolved -# when the final .ko's are linked. -grep -v '^__this_module$' | -sed -e 's/\(.*\)/#define __KSYM_\1 1/' >> "$output_file" diff --git a/scripts/gen_ksymdeps.sh b/scripts/gen_ksymdeps.sh deleted file mode 100755 index 8ee533f33659..000000000000 --- a/scripts/gen_ksymdeps.sh +++ /dev/null @@ -1,30 +0,0 @@ -#!/bin/sh -# SPDX-License-Identifier: GPL-2.0 - -set -e - -# List of exported symbols -# -# If the object has no symbol, $NM warns 'no symbols'. -# Suppress the stderr. -# TODO: -# Use -q instead of 2>/dev/null when we upgrade the minimum version of -# binutils to 2.37, llvm to 13.0.0. -ksyms=$($NM $1 2>/dev/null | sed -n 's/.*__ksym_marker_\(.*\)/\1/p') - -if [ -z "$ksyms" ]; then - exit 0 -fi - -echo -echo "ksymdeps_$1 := \\" - -for s in $ksyms -do - printf ' $(wildcard include/ksym/%s) \\\n' "$s" -done - -echo -echo "$1: \$(ksymdeps_$1)" -echo -echo "\$(ksymdeps_$1):" diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 7044b257424a..decb7d23ef9f 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -35,6 +35,9 @@ static bool warn_unresolved; static int sec_mismatch_count; static bool sec_mismatch_warn_only = true; +/* Trim EXPORT_SYMBOLs that are unused by in-tree modules */ +static bool trim_unused_exports; + /* ignore missing files */ static bool ignore_missing_files; /* If set to 1, only warn (instead of error) about missing ns imports */ @@ -219,6 +222,7 @@ struct symbol { bool weak; bool is_func; bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */ + bool used; /* there exists a user of this symbol */ char name[]; }; @@ -1820,6 +1824,7 @@ static void check_exports(struct module *mod) continue; } + exp->used = true; s->module = exp->module; s->crc_valid = exp->crc_valid; s->crc = exp->crc; @@ -1843,6 +1848,23 @@ static void check_exports(struct module *mod) } } +static void handle_white_list_exports(const char *white_list) +{ + char *buf, *p, *name; + + buf = read_text_file(white_list); + p = buf; + + while ((name = strsep(&p, "\n"))) { + struct symbol *sym = find_symbol(name); + + if (sym) + sym->used = true; + } + + free(buf); +} + static void check_modname_len(struct module *mod) { const char *mod_name; @@ -1913,10 +1935,14 @@ static void add_exported_symbols(struct buffer *buf, struct module *mod) /* generate struct for exported symbols */ buf_printf(buf, "\n"); - list_for_each_entry(sym, &mod->exported_symbols, list) + list_for_each_entry(sym, &mod->exported_symbols, list) { + if (trim_unused_exports && !sym->used) + continue; + buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n", sym->is_func ? "FUNC" : "DATA", sym->name, sym->is_gpl_only ? "_gpl" : "", sym->namespace); + } if (!modversions) return; @@ -1924,6 +1950,9 @@ static void add_exported_symbols(struct buffer *buf, struct module *mod) /* record CRCs for exported symbols */ buf_printf(buf, "\n"); list_for_each_entry(sym, &mod->exported_symbols, list) { + if (trim_unused_exports && !sym->used) + continue; + if (!sym->crc_valid) warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n" "Is \"%s\" prototyped in ?\n", @@ -2087,9 +2116,6 @@ static void write_mod_c_file(struct module *mod) char fname[PATH_MAX]; int ret; - check_modname_len(mod); - check_exports(mod); - add_header(&buf, mod); add_exported_symbols(&buf, mod); add_versions(&buf, mod); @@ -2223,12 +2249,13 @@ int main(int argc, char **argv) { struct module *mod; char *missing_namespace_deps = NULL; + char *unused_exports_white_list = NULL; char *dump_write = NULL, *files_source = NULL; int opt; LIST_HEAD(dump_lists); struct dump_list *dl, *dl2; - while ((opt = getopt(argc, argv, "ei:mnT:o:aWwENd:")) != -1) { + while ((opt = getopt(argc, argv, "ei:mnTt:o:auWwENd:")) != -1) { switch (opt) { case 'e': external_module = true; @@ -2253,6 +2280,12 @@ int main(int argc, char **argv) case 'T': files_source = optarg; break; + case 't': + trim_unused_exports = true; + break; + case 'u': + unused_exports_white_list = optarg; + break; case 'W': extra_warn = true; break; @@ -2285,6 +2318,17 @@ int main(int argc, char **argv) if (files_source) read_symbols_from_files(files_source); + list_for_each_entry(mod, &modules, list) { + if (mod->from_dump || mod->is_vmlinux) + continue; + + check_modname_len(mod); + check_exports(mod); + } + + if (unused_exports_white_list) + handle_white_list_exports(unused_exports_white_list); + list_for_each_entry(mod, &modules, list) { if (mod->from_dump) continue; diff --git a/scripts/remove-stale-files b/scripts/remove-stale-files index 7f432900671a..f3659ea0335b 100755 --- a/scripts/remove-stale-files +++ b/scripts/remove-stale-files @@ -33,3 +33,7 @@ rm -f rust/target.json rm -f scripts/bin2c rm -f .scmversion + +rm -rf include/ksym + +find . -name '*.usyms' | xargs rm -f From patchwork Sat Jun 10 09:13:18 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 13274799 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 8AE57C7EE43 for ; Sat, 10 Jun 2023 09:14:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234542AbjFJJOa (ORCPT ); Sat, 10 Jun 2023 05:14:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34054 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234458AbjFJJOK (ORCPT ); Sat, 10 Jun 2023 05:14:10 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DDC004220; Sat, 10 Jun 2023 02:13:59 -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 5BA6F61E22; Sat, 10 Jun 2023 09:13:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A76B1C433EF; Sat, 10 Jun 2023 09:13:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686388438; bh=Tv49Wx2718uLurHeG8QRHYpB10Ur4mWH5TKdeB3r3Yo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pF+3eVrLOKZc36SGrL1YuGnZKfORbIAal/gwsSYOtHaI9IfK13Wo14NYdB68UKFpu fSj80VrG7tqNx//4ahG59mVJ6bfGLIILVLaEznbHcK4X8QIjfQJF7uNdAEhawTgeWv 8CmH6X0+5LhKS2jN7al/EfxMYpGg24I0a3FPqENmKQa8Gt7JM69DdI0tXGf0w4t/1b 1dbcd+YgeNuk82CPvmpvhQqJNXTNnapi3S4+9Vps2ctxtKGLt2/w0mADYLmhBsyJrb cW6V/IEy8I4yM3wm0kgIhC1h90X/RQ1hNLW7dymzDKpAshOeua2DyTUgO2mVc2OLny Q7Ssaq8h811BA== From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nathan Chancellor , Nick Desaulniers , Nicolas Schier , linux-um@lists.infradead.org, Masahiro Yamada Subject: [PATCH v8 09/11] modpost: merge two similar section mismatch warnings Date: Sat, 10 Jun 2023 18:13:18 +0900 Message-Id: <20230610091320.1054554-10-masahiroy@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230610091320.1054554-1-masahiroy@kernel.org> References: <20230610091320.1054554-1-masahiroy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org In case of section mismatch, modpost shows slightly different messages. For extable section mismatch: "%s(%s+0x%lx): Section mismatch in reference to the %s:%s\n" For the other cases: "%s: section mismatch in reference: %s (section: %s) -> %s (section: %s)\n" They are similar. Merge them. Signed-off-by: Masahiro Yamada Reviewed-by: Nick Desaulniers --- scripts/mod/modpost.c | 18 +++--------------- 1 file changed, 3 insertions(+), 15 deletions(-) diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index decb7d23ef9f..85df3f3ba9ee 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -1147,21 +1147,10 @@ static void default_mismatch_handler(const char *modname, struct elf_info *elf, sec_mismatch_count++; - switch (mismatch->mismatch) { - case TEXT_TO_ANY_INIT: - case DATA_TO_ANY_INIT: - case TEXTDATA_TO_ANY_EXIT: - case XXXINIT_TO_SOME_INIT: - case XXXEXIT_TO_SOME_EXIT: - case ANY_INIT_TO_ANY_EXIT: - case ANY_EXIT_TO_ANY_INIT: - warn("%s: section mismatch in reference: %s (section: %s) -> %s (section: %s)\n", - modname, fromsym, fromsec, tosym, tosec); - break; - case EXTABLE_TO_NON_TEXT: - warn("%s(%s+0x%lx): Section mismatch in reference to the %s:%s\n", - modname, fromsec, (long)faddr, tosec, tosym); + warn("%s: section mismatch in reference: %s (section: %s) -> %s (section: %s)\n", + modname, fromsym, fromsec, tosym, tosec); + if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) { if (match(tosec, mismatch->bad_tosec)) fatal("The relocation at %s+0x%lx references\n" "section \"%s\" which is black-listed.\n" @@ -1181,7 +1170,6 @@ static void default_mismatch_handler(const char *modname, struct elf_info *elf, else error("%s+0x%lx references non-executable section '%s'\n", fromsec, (long)faddr, tosec); - break; } } From patchwork Sat Jun 10 09:13:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 13274800 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 9A173C7EE2E for ; Sat, 10 Jun 2023 09:14:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234793AbjFJJOp (ORCPT ); Sat, 10 Jun 2023 05:14:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33454 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234273AbjFJJOS (ORCPT ); Sat, 10 Jun 2023 05:14:18 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 195483C12; Sat, 10 Jun 2023 02:14:02 -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 6210760B9A; Sat, 10 Jun 2023 09:14:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 96415C433D2; Sat, 10 Jun 2023 09:13:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686388441; bh=bSgiFXb7ZTjwLTsJwq+dnf6gUoYaRAfD7X61i4sz3V8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Hv8O9+nc+vktReYdxDm4KB3gyGRtONLjgrcTDTVxRRW85xNwf1HWmKH//k61Z+pDj iP7E6VsZBFfxZuKuqix+YFGkkKA2BE4bjUP4I4H3KsFHNHb4wcm44cZh+/0WGpP288 EYpwyZm0D6mPYdWfmOOKjNzzNvJkMCuEC5D4DcbQQGs9aHsgFze0++EH+Zkh8Bi4tJ ulS1aYe4CZYHL5pyHU8wJB441JQveiDXFB3Ocp+8q/p26D9vRFO7IOS9aYziL3ZDG4 C7Td6mMkaa0PUF3RncOQZ0HxczaQCffx36G3c1US88x4bFgOitvhmVepVCbeu8v+w2 SxvM7fWV3qJvg== From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nathan Chancellor , Nick Desaulniers , Nicolas Schier , linux-um@lists.infradead.org, Masahiro Yamada Subject: [PATCH v8 10/11] modpost: show offset from symbol for section mismatch warnings Date: Sat, 10 Jun 2023 18:13:19 +0900 Message-Id: <20230610091320.1054554-11-masahiroy@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230610091320.1054554-1-masahiroy@kernel.org> References: <20230610091320.1054554-1-masahiroy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org Currently, modpost only shows the symbol names and section names, so it repeats the same message if there are multiple relocations in the same symbol. It is common the relocation spans across multiple instructions. It is better to show the offset from the symbol. Signed-off-by: Masahiro Yamada Reviewed-by: Nick Desaulniers --- scripts/mod/modpost.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 85df3f3ba9ee..40967ed816df 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -1147,8 +1147,8 @@ static void default_mismatch_handler(const char *modname, struct elf_info *elf, sec_mismatch_count++; - warn("%s: section mismatch in reference: %s (section: %s) -> %s (section: %s)\n", - modname, fromsym, fromsec, tosym, tosec); + warn("%s: section mismatch in reference: %s+0x%x (section: %s) -> %s (section: %s)\n", + modname, fromsym, (unsigned int)(faddr - from->st_value), fromsec, tosym, tosec); if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) { if (match(tosec, mismatch->bad_tosec)) From patchwork Sat Jun 10 09:13:20 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 13274801 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 7952CC77B7A for ; Sat, 10 Jun 2023 09:15:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234273AbjFJJPE (ORCPT ); Sat, 10 Jun 2023 05:15:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34234 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234667AbjFJJOW (ORCPT ); Sat, 10 Jun 2023 05:14:22 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C390A3AA8; Sat, 10 Jun 2023 02:14:05 -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 3353F62062; Sat, 10 Jun 2023 09:14:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 48329C433EF; Sat, 10 Jun 2023 09:14:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686388444; bh=xcoBBS4j2RIAWnyNGP0DVmJUBsQUOVbHeiB3BEvgdeI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=k5AyddC6WuJ2wCTIZvBnbcNAvKQ008GAVGl9rorjCUXw9Mslqnt50+r6RzzE7rq4Q g0n5U82WFmlYSudoCvrhx99mRsHWbaIFy6SshHVyHZ+euh64J/Nj6qrDXxb7CIqx15 X0YlOH/uv10l9arls+EbM8wTnML3hStVenUMAOmbPztsR+zaR9RrYkuUBqiEybN5xL jRTEX9pjEjF6hXPh0EvWooDO5IIaWyj1hpFAKtOuM+3hVPyT7JyLJTimDYpZHLKiio 0hfl/OtpmdwMHVuDW6Gwe++oD4+UbUeDq9Z0m0/UAU+h/vvjKYmIl2vJjph7Inl5kx +l4dG9CQGI2bw== From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nathan Chancellor , Nick Desaulniers , Nicolas Schier , linux-um@lists.infradead.org, Masahiro Yamada Subject: [PATCH v8 11/11] linux/export.h: rename 'sec' argument to 'license' Date: Sat, 10 Jun 2023 18:13:20 +0900 Message-Id: <20230610091320.1054554-12-masahiroy@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230610091320.1054554-1-masahiroy@kernel.org> References: <20230610091320.1054554-1-masahiroy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org Now, EXPORT_SYMBOL() is populated in two stages. In the first stage, all of EXPORT_SYMBOL/EXPORT_SYMBOL_GPL go into the same section, '.export_symbol'. 'sec' does not make sense any more. Rename it to 'license'. Signed-off-by: Masahiro Yamada Reviewed-by: Nick Desaulniers --- (no changes since v7) Changes in v7: - New patch include/linux/export.h | 8 ++++---- include/linux/pm.h | 6 +++--- 2 files changed, 7 insertions(+), 7 deletions(-) diff --git a/include/linux/export.h b/include/linux/export.h index 8a9b72386fff..427f5517217f 100644 --- a/include/linux/export.h +++ b/include/linux/export.h @@ -51,11 +51,11 @@ extern struct module __this_module; * be reused in other execution contexts such as the UEFI stub or the * decompressor. */ -#define __EXPORT_SYMBOL(sym, sec, ns) +#define __EXPORT_SYMBOL(sym, license, ns) #elif defined(__GENKSYMS__) -#define __EXPORT_SYMBOL(sym, sec, ns) __GENKSYMS_EXPORT_SYMBOL(sym) +#define __EXPORT_SYMBOL(sym, license, ns) __GENKSYMS_EXPORT_SYMBOL(sym) #elif defined(__ASSEMBLY__) @@ -72,9 +72,9 @@ extern struct module __this_module; #endif /* CONFIG_MODULES */ #ifdef DEFAULT_SYMBOL_NAMESPACE -#define _EXPORT_SYMBOL(sym, sec) __EXPORT_SYMBOL(sym, sec, __stringify(DEFAULT_SYMBOL_NAMESPACE)) +#define _EXPORT_SYMBOL(sym, license) __EXPORT_SYMBOL(sym, license, __stringify(DEFAULT_SYMBOL_NAMESPACE)) #else -#define _EXPORT_SYMBOL(sym, sec) __EXPORT_SYMBOL(sym, sec, "") +#define _EXPORT_SYMBOL(sym, license) __EXPORT_SYMBOL(sym, license, "") #endif #define EXPORT_SYMBOL(sym) _EXPORT_SYMBOL(sym,) diff --git a/include/linux/pm.h b/include/linux/pm.h index aabb6bd8f89e..1810d776e84a 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -375,14 +375,14 @@ const struct dev_pm_ops name = { \ } #ifdef CONFIG_PM -#define _EXPORT_DEV_PM_OPS(name, sec, ns) \ +#define _EXPORT_DEV_PM_OPS(name, license, ns) \ const struct dev_pm_ops name; \ - __EXPORT_SYMBOL(name, sec, ns); \ + __EXPORT_SYMBOL(name, license, ns); \ const struct dev_pm_ops name #define EXPORT_PM_FN_GPL(name) EXPORT_SYMBOL_GPL(name) #define EXPORT_PM_FN_NS_GPL(name, ns) EXPORT_SYMBOL_NS_GPL(name, ns) #else -#define _EXPORT_DEV_PM_OPS(name, sec, ns) \ +#define _EXPORT_DEV_PM_OPS(name, license, ns) \ static __maybe_unused const struct dev_pm_ops __static_##name #define EXPORT_PM_FN_GPL(name) #define EXPORT_PM_FN_NS_GPL(name, ns)