From patchwork Fri May 13 11:39:21 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 12848691 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 EE7B8C43219 for ; Fri, 13 May 2022 11:42:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1379952AbiEMLmP (ORCPT ); Fri, 13 May 2022 07:42:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39076 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1379934AbiEMLmO (ORCPT ); Fri, 13 May 2022 07:42:14 -0400 Received: from conuserg-07.nifty.com (conuserg-07.nifty.com [210.131.2.74]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BA8355A093; Fri, 13 May 2022 04:42:11 -0700 (PDT) Received: from grover.sesame (133-32-177-133.west.xps.vectant.ne.jp [133.32.177.133]) (authenticated) by conuserg-07.nifty.com with ESMTP id 24DBeEwa008349; Fri, 13 May 2022 20:40:15 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-07.nifty.com 24DBeEwa008349 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1652442016; bh=kJSj0j+AXEcFQ8ZaJqXjHFqZBXEeirnzJV86O9qeRSY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BM4uUUXsXYeQPGzbAMRpqzUkPiOPzds/ZOLS5bh+zuZDgEP2nI/NNf7yNqJxfA6Cz Gg6wjwC7OM7KG4v94307ziySprB77YRlGNhcX711XbNRLbgLlClKakCiHkJ+NE6E4A Q77Ed6tBm7MKC5X2qV754LARS9HXGVYYBhllVcLB4sCKzmwJ8vf4CH9FY1ScYq5D4r cEohXEUSQSaKSbS9/xqrv8um3z6KfEzWq7om/tWedC9rsC645DOoMUzYPrawm1lruN Pj+RkH0n6rZq8lqGP6cImO3s2poXi8fU0dVmPeFaOXTcOYEq00YklYl3fGKZcoHaiS 0TdVvBnoYohgQ== X-Nifty-SrcIP: [133.32.177.133] From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nathan Chancellor , Nick Desaulniers , Nicolas Schier , Peter Zijlstra , linux-modules@vger.kernel.org, llvm@lists.linux.dev, Ard Biesheuvel , Sami Tolvanen , Masahiro Yamada Subject: [PATCH v6 01/10] modpost: extract symbol versions from *.cmd files Date: Fri, 13 May 2022 20:39:21 +0900 Message-Id: <20220513113930.10488-2-masahiroy@kernel.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220513113930.10488-1-masahiroy@kernel.org> References: <20220513113930.10488-1-masahiroy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org Currently, CONFIG_MODVERSIONS needs extra link to embed the symbol versions into ELF objects. Then, modpost extracts the version CRCs from them. The following figures show how it currently works, and how I am trying to change it. Current implementation ====================== |----------| embed CRC -------------------------->| final | $(CC) $(LD) / |---------| | link for | -----> *.o -------> *.o -->| modpost | | vmlinux | / / | |-- *.mod.c -->| or | / genksyms / |---------| | module | *.c ------> *.symversions |----------| Genksyms outputs the calculated CRCs in the form of linker script (*.symversions), which is used by $(LD) to update the object. If CONFIG_LTO_CLANG=y, the build process is much more complex. Embedding the CRCs is postponed until the LLVM bitcode is converted into ELF, creating another intermediate *.prelink.o. However, this complexity is unneeded. There is no reason why we must embed version CRCs in objects so early. There is final link stage for vmlinux (scripts/link-vmlinux.sh) and modules (scripts/Makefile.modfinal). We can link CRCs at the very last moment. New implementation ================== |----------| --------------------------------------->| final | $(CC) / |---------| | link for | -----> *.o ---->| | | vmlinux | / | modpost |--- .vmlinux.export.c -->| or | / genksyms | |--- *.mod.c ------------>| module | *.c ------> *.cmd -->|---------| |----------| Pass the symbol versions to modpost as separate text data, which are available in *.cmd files. This commit changes modpost to extract CRCs from *.cmd files instead of from ELF objects. Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier Tested-by: Nathan Chancellor Reviewed-by: Sami Tolvanen --- Changes in v6: - Fix false-positive warnings when CONFIG_TRIM_UNUSED_KSYMS=y Changes in v2: - Simplify the implementation (parse .cmd files after ELF) scripts/mod/modpost.c | 179 +++++++++++++++++++++++++++++++----------- 1 file changed, 131 insertions(+), 48 deletions(-) diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index fc5db1f73cf1..213a130d1635 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -381,19 +381,10 @@ static struct symbol *sym_add_exported(const char *name, struct module *mod, return s; } -static void sym_set_crc(const char *name, unsigned int crc) +static void sym_set_crc(struct symbol *sym, unsigned int crc) { - struct symbol *s = find_symbol(name); - - /* - * Ignore stand-alone __crc_*, which might be auto-generated symbols - * such as __*_veneer in ARM ELF. - */ - if (!s) - return; - - s->crc = crc; - s->crc_valid = true; + sym->crc = crc; + sym->crc_valid = true; } static void *grab_file(const char *filename, size_t *size) @@ -616,33 +607,6 @@ static int ignore_undef_symbol(struct elf_info *info, const char *symname) return 0; } -static void handle_modversion(const struct module *mod, - const struct elf_info *info, - const Elf_Sym *sym, const char *symname) -{ - unsigned int crc; - - if (sym->st_shndx == SHN_UNDEF) { - warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n" - "Is \"%s\" prototyped in ?\n", - symname, mod->name, mod->is_vmlinux ? "" : ".ko", - symname); - - return; - } - - if (sym->st_shndx == SHN_ABS) { - crc = sym->st_value; - } else { - unsigned int *crcp; - - /* symbol points to the CRC in the ELF object */ - crcp = sym_get_data(info, sym); - crc = TO_NATIVE(*crcp); - } - sym_set_crc(symname, crc); -} - static void handle_symbol(struct module *mod, struct elf_info *info, const Elf_Sym *sym, const char *symname) { @@ -760,6 +724,104 @@ static char *remove_dot(char *s) return s; } +/* + * The CRCs are recorded in .*.cmd files in the form of: + * #SYMVER + */ +static void extract_crcs_for_object(const char *object, struct module *mod) +{ + char cmd_file[PATH_MAX]; + char *buf, *p; + const char *base; + int dirlen, ret; + + base = strrchr(object, '/'); + if (base) { + base++; + dirlen = base - object; + } else { + dirlen = 0; + base = object; + } + + ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd", + dirlen, object, base); + if (ret >= sizeof(cmd_file)) { + error("%s: too long path was truncated\n", cmd_file); + return; + } + + buf = read_text_file(cmd_file); + p = buf; + + while ((p = strstr(p, "\n#SYMVER "))) { + char *name; + size_t namelen; + unsigned int crc; + struct symbol *sym; + + name = p + strlen("\n#SYMVER "); + + p = strchr(name, ' '); + if (!p) + break; + + namelen = p - name; + p++; + + if (!isdigit(*p)) + continue; /* skip this line */ + + crc = strtol(p, &p, 0); + if (*p != '\n') + continue; /* skip this line */ + + name[namelen] = '\0'; + + /* + * sym_find_with_module() may return NULL here. + * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y. + * Since commit e1327a127703, genksyms calculates CRCs of all + * symbols, including trimmed ones. Ignore orphan CRCs. + */ + sym = sym_find_with_module(name, mod); + if (sym) + sym_set_crc(sym, crc); + } + + free(buf); +} + +/* + * The symbol versions (CRC) are recorded in the .*.cmd files. + * Parse them to retrieve CRCs for the current module. + */ +static void mod_set_crcs(struct module *mod) +{ + char objlist[PATH_MAX]; + char *buf, *p, *obj; + int ret; + + if (mod->is_vmlinux) { + strcpy(objlist, ".vmlinux.objs"); + } else { + /* objects for a module are listed in the *.mod file. */ + ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name); + if (ret >= sizeof(objlist)) { + error("%s: too long path was truncated\n", objlist); + return; + } + } + + buf = read_text_file(objlist); + p = buf; + + while ((obj = strsep(&p, "\n")) && obj[0]) + extract_crcs_for_object(obj, mod); + + free(buf); +} + static void read_symbols(const char *modname) { const char *symname; @@ -820,9 +882,6 @@ static void read_symbols(const char *modname) if (strstarts(symname, "__kstrtabns_")) sym_update_namespace(symname + strlen("__kstrtabns_"), sym_get_data(&info, sym)); - if (strstarts(symname, "__crc_")) - handle_modversion(mod, &info, sym, - symname + strlen("__crc_")); } // check for static EXPORT_SYMBOL_* functions && global vars @@ -850,12 +909,17 @@ static void read_symbols(const char *modname) parse_elf_finish(&info); - /* Our trick to get versioning for module struct etc. - it's - * never passed as an argument to an exported function, so - * the automatic versioning doesn't pick it up, but it's really - * important anyhow */ - if (modversions) + if (modversions) { + /* + * Our trick to get versioning for module struct etc. - it's + * never passed as an argument to an exported function, so + * the automatic versioning doesn't pick it up, but it's really + * important anyhow. + */ sym_add_unresolved("module_layout", mod, false); + + mod_set_crcs(mod); + } } static void read_symbols_from_files(const char *filename) @@ -1012,6 +1076,23 @@ static void add_header(struct buffer *b, struct module *mod) buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); } +static void check_symversions(struct module *mod) +{ + struct symbol *sym; + + if (!modversions) + return; + + list_for_each_entry(sym, &mod->exported_symbols, list) { + if (!sym->crc_valid) { + warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n" + "Is \"%s\" prototyped in ?\n", + sym->name, mod->name, mod->is_vmlinux ? "" : ".ko", + sym->name); + } + } +} + /** * Record CRCs for unresolved symbols **/ @@ -1227,7 +1308,7 @@ static void read_dump(const char *fname) } s = sym_add_exported(symname, mod, gpl_only); s->is_static = false; - sym_set_crc(symname, crc); + sym_set_crc(s, crc); sym_update_namespace(symname, namespace); } free(buf); @@ -1353,6 +1434,8 @@ int main(int argc, char **argv) if (mod->from_dump) continue; + check_symversions(mod); + if (!mod->is_vmlinux) write_mod_c_file(mod); } From patchwork Fri May 13 11:39:22 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 12848703 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 30450C43219 for ; Fri, 13 May 2022 11:42:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1379978AbiEMLmU (ORCPT ); Fri, 13 May 2022 07:42:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39306 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1379960AbiEMLmQ (ORCPT ); Fri, 13 May 2022 07:42:16 -0400 Received: from conuserg-07.nifty.com (conuserg-07.nifty.com [210.131.2.74]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 495135C64A; Fri, 13 May 2022 04:42:12 -0700 (PDT) Received: from grover.sesame (133-32-177-133.west.xps.vectant.ne.jp [133.32.177.133]) (authenticated) by conuserg-07.nifty.com with ESMTP id 24DBeEwb008349; Fri, 13 May 2022 20:40:16 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-07.nifty.com 24DBeEwb008349 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1652442017; bh=J+ecGumYKrLqOydp2RzLw7ydsUNZpFMQQXUeORLeaeg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=r2zjcdBpMIVwvg2SASleLn6eWS51avhOZYGVzsrZs9C2aCm9gKyStiqpPP4GJ+7Vx j6SZ1nrNDQlBzBCXhkFCVx8ldzIBUByeGJIjO1g5X1415xDozM9PSi3WFlJLhhhEof PV/28BXVqn+Y504f+Qs9tpqV5ft6peEX8ekVFCcKTA0mqvMHkxMbJpRLEM6GO1HD4M XiM7Txd0ioiMzBptx/pYrxpq7C79vfKt5r1o9awFob6B3HY0M0bVdpmk5bmH6HFH3U 5pijVzRtDB52Hlswz20tP7ncrBalEH7Ojkv1wEAH+V8FSgYxOZECwO0aNYm2YF1iEQ wyVR4Ki5bNw8w== X-Nifty-SrcIP: [133.32.177.133] From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nathan Chancellor , Nick Desaulniers , Nicolas Schier , Peter Zijlstra , linux-modules@vger.kernel.org, llvm@lists.linux.dev, Ard Biesheuvel , Sami Tolvanen , Masahiro Yamada Subject: [PATCH v6 02/10] kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS Date: Fri, 13 May 2022 20:39:22 +0900 Message-Id: <20220513113930.10488-3-masahiroy@kernel.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220513113930.10488-1-masahiroy@kernel.org> References: <20220513113930.10488-1-masahiroy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org include/{linux,asm-generic}/export.h defines a weak symbol, __crc_* as a placeholder. Genksyms writes the version CRCs into the linker script, which will be used for filling the __crc_* symbols. The linker script format depends on CONFIG_MODULE_REL_CRCS. If it is enabled, __crc_* holds the offset to the reference of CRC. It is time to get rid of this complexity. Now that modpost parses text files (.*.cmd) to collect all the CRCs, it can generate C code that will be linked to the vmlinux or modules. Generate a new C file, .vmlinux.export.c, which contains the CRCs of symbols exported by vmlinux. It is compiled and linked to vmlinux in scripts/link-vmlinux.sh. Put the CRCs of symbols exported by modules into the existing *.mod.c files. No additional build step is needed for modules. As before, *.mod.c are compiled and linked to *.ko in scripts/Makefile.modfinal. No linker magic is used here. The new C implementation works in the same way, whether CONFIG_RELOCATABLE is enabled or not. CONFIG_MODULE_REL_CRCS is no longer needed. Previously, Kbuild invoked additional $(LD) to update the CRCs in objects, but this step is unneeded too. Signed-off-by: Masahiro Yamada Tested-by: Nathan Chancellor Tested-by: Nicolas Schier Reviewed-by: Nicolas Schier --- (no changes since v5) Changes in v5: - Fix the build error when CONFIG_DEBUG_INFO_BTF=y (reported by Nathan) - Clean up arch/m68k/include/asm/export.h (Nick) - Keep gen_symversions (and will be removed by a later patch) Changes in v4: - Rename .vmlinux-symver.c to .vmlinux.export.c because I notice this approach is useful for further cleanups, not only for modversioning but also for overall EXPORT_SYMBOL. Changes in v3: - New patch arch/m68k/include/asm/Kbuild | 1 + arch/m68k/include/asm/export.h | 2 -- arch/powerpc/Kconfig | 1 - arch/s390/Kconfig | 1 - arch/um/Kconfig | 1 - include/asm-generic/export.h | 22 ++++++++-------------- include/linux/export-internal.h | 16 ++++++++++++++++ include/linux/export.h | 30 ++++++++---------------------- init/Kconfig | 4 ---- kernel/module.c | 10 +--------- scripts/Makefile.build | 27 ++++----------------------- scripts/genksyms/genksyms.c | 18 ++++-------------- scripts/link-vmlinux.sh | 14 +++++++++++++- scripts/mod/modpost.c | 28 ++++++++++++++++++++++++---- 14 files changed, 79 insertions(+), 96 deletions(-) delete mode 100644 arch/m68k/include/asm/export.h create mode 100644 include/linux/export-internal.h diff --git a/arch/m68k/include/asm/Kbuild b/arch/m68k/include/asm/Kbuild index 0dbf9c5c6fae..1b720299deb1 100644 --- a/arch/m68k/include/asm/Kbuild +++ b/arch/m68k/include/asm/Kbuild @@ -1,5 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 generated-y += syscall_table.h +generic-y += export.h generic-y += extable.h generic-y += kvm_para.h generic-y += mcs_spinlock.h diff --git a/arch/m68k/include/asm/export.h b/arch/m68k/include/asm/export.h deleted file mode 100644 index b53008b67ce1..000000000000 --- a/arch/m68k/include/asm/export.h +++ /dev/null @@ -1,2 +0,0 @@ -#define KCRC_ALIGN 2 -#include diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 174edabb74fa..a4e8dd889e29 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -566,7 +566,6 @@ config RELOCATABLE bool "Build a relocatable kernel" depends on PPC64 || (FLATMEM && (44x || FSL_BOOKE)) select NONSTATIC_KERNEL - select MODULE_REL_CRCS if MODVERSIONS help This builds a kernel image that is capable of running at the location the kernel is loaded at. For ppc32, there is no any diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 77b5a03de13a..aa5848004c76 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -567,7 +567,6 @@ endchoice config RELOCATABLE bool "Build a relocatable kernel" - select MODULE_REL_CRCS if MODVERSIONS default y help This builds a kernel image that retains relocation information diff --git a/arch/um/Kconfig b/arch/um/Kconfig index 4d398b80aea8..e8983d098e73 100644 --- a/arch/um/Kconfig +++ b/arch/um/Kconfig @@ -106,7 +106,6 @@ config LD_SCRIPT_DYN bool default y depends on !LD_SCRIPT_STATIC - select MODULE_REL_CRCS if MODVERSIONS config LD_SCRIPT_DYN_RPATH bool "set rpath in the binary" if EXPERT diff --git a/include/asm-generic/export.h b/include/asm-generic/export.h index 07a36a874dca..5e4b1f2369d2 100644 --- a/include/asm-generic/export.h +++ b/include/asm-generic/export.h @@ -2,6 +2,14 @@ #ifndef __ASM_GENERIC_EXPORT_H #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. + */ + #ifndef KSYM_FUNC #define KSYM_FUNC(x) x #endif @@ -12,9 +20,6 @@ #else #define KSYM_ALIGN 4 #endif -#ifndef KCRC_ALIGN -#define KCRC_ALIGN 4 -#endif .macro __put, val, name #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS @@ -43,17 +48,6 @@ __ksymtab_\name: __kstrtab_\name: .asciz "\name" .previous -#ifdef CONFIG_MODVERSIONS - .section ___kcrctab\sec+\name,"a" - .balign KCRC_ALIGN -#if defined(CONFIG_MODULE_REL_CRCS) - .long __crc_\name - . -#else - .long __crc_\name -#endif - .weak __crc_\name - .previous -#endif #endif .endm diff --git a/include/linux/export-internal.h b/include/linux/export-internal.h new file mode 100644 index 000000000000..77175d561058 --- /dev/null +++ b/include/linux/export-internal.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Please do not include this explicitly. + * This is used by C files generated by modpost. + */ + +#ifndef __LINUX_EXPORT_INTERNAL_H__ +#define __LINUX_EXPORT_INTERNAL_H__ + +#include +#include + +#define SYMBOL_CRC(sym, crc, sec) \ + u32 __section("___kcrctab" sec "+" #sym) __crc_##sym = crc + +#endif /* __LINUX_EXPORT_INTERNAL_H__ */ diff --git a/include/linux/export.h b/include/linux/export.h index 27d848712b90..565c5ffcb26f 100644 --- a/include/linux/export.h +++ b/include/linux/export.h @@ -11,6 +11,14 @@ * hackers place grumpy comments in header files. */ +/* + * 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. + */ + #ifndef __ASSEMBLY__ #ifdef MODULE extern struct module __this_module; @@ -19,26 +27,6 @@ extern struct module __this_module; #define THIS_MODULE ((struct module *)0) #endif -#ifdef CONFIG_MODVERSIONS -/* Mark the CRC weak since genksyms apparently decides not to - * generate a checksums for some symbols */ -#if defined(CONFIG_MODULE_REL_CRCS) -#define __CRC_SYMBOL(sym, sec) \ - asm(" .section \"___kcrctab" sec "+" #sym "\", \"a\" \n" \ - " .weak __crc_" #sym " \n" \ - " .long __crc_" #sym " - . \n" \ - " .previous \n") -#else -#define __CRC_SYMBOL(sym, sec) \ - asm(" .section \"___kcrctab" sec "+" #sym "\", \"a\" \n" \ - " .weak __crc_" #sym " \n" \ - " .long __crc_" #sym " \n" \ - " .previous \n") -#endif -#else -#define __CRC_SYMBOL(sym, sec) -#endif - #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS #include /* @@ -85,7 +73,6 @@ struct kernel_symbol { /* * For every exported symbol, do the following: * - * - If applicable, place a CRC entry in the __kcrctab section. * - 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. @@ -98,7 +85,6 @@ struct kernel_symbol { extern typeof(sym) sym; \ extern const char __kstrtab_##sym[]; \ extern const char __kstrtabns_##sym[]; \ - __CRC_SYMBOL(sym, sec); \ asm(" .section \"__ksymtab_strings\",\"aMS\",%progbits,1 \n" \ "__kstrtab_" #sym ": \n" \ " .asciz \"" #sym "\" \n" \ diff --git a/init/Kconfig b/init/Kconfig index ddcbefe535e9..f5b14318dfcb 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -2136,10 +2136,6 @@ config ASM_MODVERSIONS assembly. This can be enabled only when the target architecture supports it. -config MODULE_REL_CRCS - bool - depends on MODVERSIONS - config MODULE_SRCVERSION_ALL bool "Source checksum for all modules" help diff --git a/kernel/module.c b/kernel/module.c index 6cea788fd965..c9e2342da28e 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1231,11 +1231,6 @@ static int try_to_force_load(struct module *mod, const char *reason) #ifdef CONFIG_MODVERSIONS -static u32 resolve_rel_crc(const s32 *crc) -{ - return *(u32 *)((void *)crc + *crc); -} - static int check_version(const struct load_info *info, const char *symname, struct module *mod, @@ -1264,10 +1259,7 @@ static int check_version(const struct load_info *info, if (strcmp(versions[i].name, symname) != 0) continue; - if (IS_ENABLED(CONFIG_MODULE_REL_CRCS)) - crcval = resolve_rel_crc(crc); - else - crcval = *crc; + crcval = *crc; if (versions[i].crc == crcval) return 1; pr_debug("Found checksum %X vs module %lX\n", diff --git a/scripts/Makefile.build b/scripts/Makefile.build index a1023868775f..ddd9080fc028 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -128,7 +128,6 @@ $(obj)/%.i: $(src)/%.c FORCE genksyms = scripts/genksyms/genksyms \ $(if $(1), -T $(2)) \ - $(if $(CONFIG_MODULE_REL_CRCS), -R) \ $(if $(KBUILD_PRESERVE), -p) \ -r $(or $(wildcard $(2:.symtypes=.symref)), /dev/null) @@ -162,19 +161,11 @@ ifdef CONFIG_MODVERSIONS # o if .o doesn't contain a __ksymtab version, 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 postprocess them in a way -# that they are usable as a linker script -# o generate .tmp_.o from .o using the linker to -# replace the unresolved symbols __crc_exported_symbol with -# the actual value of the checksum generated by genksyms -# o remove .tmp_.o to .o +# genksyms on the preprocessed source and dump them into the .cmd file. +# o modpost will extract versions from that file and create *.c files that will +# be compiled and linked to the kernel and/or modules. -# Generate .o.symversions files for each .o with exported symbols, and link these -# to the kernel and/or modules at the end. - -genksyms_format_rel_crc := [^_]*__crc_\([^ ]*\) = \.; LONG(\([^)]*\)).* -genksyms_format_normal := __crc_\(.*\) = \(.*\); -genksyms_format := $(if $(CONFIG_MODULE_REL_CRCS),$(genksyms_format_rel_crc),$(genksyms_format_normal)) +genksyms_format := __crc_\(.*\) = \(.*\); gen_symversions = \ if $(NM) $@ 2>/dev/null | grep -q __ksymtab; then \ @@ -188,12 +179,6 @@ gen_symversions = \ cmd_gen_symversions_c = $(call gen_symversions,c) -cmd_modversions = \ - if [ -r $@.symversions ]; then \ - $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ \ - -T $@.symversions; \ - mv -f $(@D)/.tmp_$(@F) $@; \ - fi endif ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT @@ -273,7 +258,6 @@ define rule_cc_o_c $(call cmd,checkdoc) $(call cmd,gen_objtooldep) $(call cmd,gen_symversions_c) - $(if $(CONFIG_LTO_CLANG),,$(call cmd,modversions)) $(call cmd,record_mcount) endef @@ -282,7 +266,6 @@ define rule_as_o_S $(call cmd,gen_ksymdeps) $(call cmd,gen_objtooldep) $(call cmd,gen_symversions_S) - $(call cmd,modversions) endef # Built-in and composite module parts @@ -296,8 +279,6 @@ ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),) quiet_cmd_cc_prelink_modules = LD [M] $@ cmd_cc_prelink_modules = \ $(LD) $(ld_flags) -r -o $@ \ - $(shell [ -s $(@:.prelink.o=.o.symversions) ] && \ - echo -T $(@:.prelink.o=.o.symversions)) \ --whole-archive $(filter-out FORCE,$^) \ $(cmd_objtool) diff --git a/scripts/genksyms/genksyms.c b/scripts/genksyms/genksyms.c index 4827c5abe5b7..67b23cc0df0f 100644 --- a/scripts/genksyms/genksyms.c +++ b/scripts/genksyms/genksyms.c @@ -33,7 +33,7 @@ char *cur_filename; int in_source_file; static int flag_debug, flag_dump_defs, flag_reference, flag_dump_types, - flag_preserve, flag_warnings, flag_rel_crcs; + flag_preserve, flag_warnings; static int errors; static int nsyms; @@ -680,11 +680,7 @@ void export_symbol(const char *name) if (flag_dump_defs) fputs(">\n", debugfile); - /* Used as a linker script. */ - printf(!flag_rel_crcs ? "__crc_%s = 0x%08lx;\n" : - "SECTIONS { .rodata : ALIGN(4) { " - "__crc_%s = .; LONG(0x%08lx); } }\n", - name, crc); + printf("__crc_%s = 0x%08lx;\n", name, crc); } } @@ -733,7 +729,6 @@ static void genksyms_usage(void) " -q, --quiet Disable warnings (default)\n" " -h, --help Print this message\n" " -V, --version Print the release version\n" - " -R, --relative-crc Emit section relative symbol CRCs\n" #else /* __GNU_LIBRARY__ */ " -s Select symbol prefix\n" " -d Increment the debug level (repeatable)\n" @@ -745,7 +740,6 @@ static void genksyms_usage(void) " -q Disable warnings (default)\n" " -h Print this message\n" " -V Print the release version\n" - " -R Emit section relative symbol CRCs\n" #endif /* __GNU_LIBRARY__ */ , stderr); } @@ -766,14 +760,13 @@ int main(int argc, char **argv) {"preserve", 0, 0, 'p'}, {"version", 0, 0, 'V'}, {"help", 0, 0, 'h'}, - {"relative-crc", 0, 0, 'R'}, {0, 0, 0, 0} }; - while ((o = getopt_long(argc, argv, "s:dwqVDr:T:phR", + while ((o = getopt_long(argc, argv, "s:dwqVDr:T:ph", &long_opts[0], NULL)) != EOF) #else /* __GNU_LIBRARY__ */ - while ((o = getopt(argc, argv, "s:dwqVDr:T:phR")) != EOF) + while ((o = getopt(argc, argv, "s:dwqVDr:T:ph")) != EOF) #endif /* __GNU_LIBRARY__ */ switch (o) { case 'd': @@ -813,9 +806,6 @@ int main(int argc, char **argv) case 'h': genksyms_usage(); return 0; - case 'R': - flag_rel_crcs = 1; - break; default: genksyms_usage(); return 1; diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index eceb3ee7ec06..7313cbd755df 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -90,7 +90,6 @@ modpost_link() if is_enabled CONFIG_MODVERSIONS; then gen_symversions - lds="${lds} -T .tmp_symversions.lds" fi # This might take a while, so indicate that we're doing @@ -183,6 +182,10 @@ vmlinux_link() libs="${KBUILD_VMLINUX_LIBS}" fi + if is_enabled CONFIG_MODULES; then + objs="${objs} .vmlinux.export.o" + fi + if [ "${SRCARCH}" = "um" ]; then wl=-Wl, ld="${CC}" @@ -312,6 +315,7 @@ cleanup() rm -f vmlinux.o rm -f .vmlinux.d rm -f .vmlinux.objs + rm -f .vmlinux.export.c } # Use "make V=1" to debug this script @@ -363,6 +367,14 @@ info GEN modules.builtin tr '\0' '\n' < modules.builtin.modinfo | sed -n 's/^[[:alnum:]:_]*\.file=//p' | tr ' ' '\n' | uniq | sed -e 's:^:kernel/:' -e 's/$/.ko/' > modules.builtin +if is_enabled CONFIG_MODULES; then + info CC .vmlinux.export.c + ${CC} ${NOSTDINC_FLAGS} ${LINUXINCLUDE} \ + ${KBUILD_CPPFLAGS} ${KBUILD_CFLAGS} \ + ${KBUILD_CFLAGS_KERNEL} ${CFLAGS_KERNEL} \ + -c -o .vmlinux.export.o .vmlinux.export.c +fi + btf_vmlinux_bin_o="" if is_enabled CONFIG_DEBUG_INFO_BTF; then btf_vmlinux_bin_o=.btf.vmlinux.bin.o diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 213a130d1635..2313bdae91bf 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -1042,6 +1042,7 @@ static void add_header(struct buffer *b, struct module *mod) buf_printf(b, "#define INCLUDE_VERMAGIC\n"); buf_printf(b, "#include \n"); buf_printf(b, "#include \n"); + buf_printf(b, "#include \n"); buf_printf(b, "#include \n"); buf_printf(b, "#include \n"); buf_printf(b, "\n"); @@ -1076,20 +1077,26 @@ static void add_header(struct buffer *b, struct module *mod) buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); } -static void check_symversions(struct module *mod) +static void add_exported_symbols(struct buffer *buf, struct module *mod) { struct symbol *sym; if (!modversions) return; + /* record CRCs for exported symbols */ + buf_printf(buf, "\n"); list_for_each_entry(sym, &mod->exported_symbols, list) { if (!sym->crc_valid) { warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n" "Is \"%s\" prototyped in ?\n", sym->name, mod->name, mod->is_vmlinux ? "" : ".ko", sym->name); + continue; } + + buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n", + sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : ""); } } @@ -1226,6 +1233,18 @@ static void write_if_changed(struct buffer *b, const char *fname) write_buf(b, fname); } +static void write_vmlinux_export_c_file(struct module *mod) +{ + struct buffer buf = { }; + + buf_printf(&buf, + "#include \n"); + + add_exported_symbols(&buf, mod); + write_if_changed(&buf, ".vmlinux.export.c"); + free(buf.p); +} + /* do sanity checks, and generate *.mod.c file */ static void write_mod_c_file(struct module *mod) { @@ -1237,6 +1256,7 @@ static void write_mod_c_file(struct module *mod) check_exports(mod); add_header(&buf, mod); + add_exported_symbols(&buf, mod); add_versions(&buf, mod); add_depends(&buf, mod); add_moddevtable(&buf, mod); @@ -1434,9 +1454,9 @@ int main(int argc, char **argv) if (mod->from_dump) continue; - check_symversions(mod); - - if (!mod->is_vmlinux) + if (mod->is_vmlinux) + write_vmlinux_export_c_file(mod); + else write_mod_c_file(mod); } From patchwork Fri May 13 11:39:23 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 12848702 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 EED9BC433F5 for ; Fri, 13 May 2022 11:42:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1379933AbiEMLmV (ORCPT ); Fri, 13 May 2022 07:42:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39314 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1379963AbiEMLmR (ORCPT ); Fri, 13 May 2022 07:42:17 -0400 Received: from conuserg-07.nifty.com (conuserg-07.nifty.com [210.131.2.74]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1041453A50; Fri, 13 May 2022 04:42:13 -0700 (PDT) Received: from grover.sesame (133-32-177-133.west.xps.vectant.ne.jp [133.32.177.133]) (authenticated) by conuserg-07.nifty.com with ESMTP id 24DBeEwc008349; Fri, 13 May 2022 20:40:17 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-07.nifty.com 24DBeEwc008349 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1652442018; bh=cga2j3/RnX95UXo6+4HyPv/WWKGxfQZ0xpYK4BVs9G8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=p5ftmnST03FxjYRjjdJDBeXs1RhWVX7sEj20o6h2lFkAVs15LD1gYUdS+kWEJMdL5 MLb11fpAipT++S44EFXq3/PS6tTfaBrqtn75TgVO0yORnZoqj8I4topwBsyynYgYr2 MkT68Pxjy0ae+j/tZcpYGZzPmFuB7yVd4ulEip6sX2Zm9V8OyvUtoe7/7rN1gBovqk sYlkruGLARitLMDo/zZwMuqKEUQfPksHfRv7c5VxaRH5iTO6CJUy+hxYw2VAPlDWZY TJQE0xnYgcTEsNQF+b8WM9Sr6xPJSG7QP1df1B1kifECu8jVFRo8s6fCEBE4PxdR2c aXWgWnQ/ledng== X-Nifty-SrcIP: [133.32.177.133] From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nathan Chancellor , Nick Desaulniers , Nicolas Schier , Peter Zijlstra , linux-modules@vger.kernel.org, llvm@lists.linux.dev, Ard Biesheuvel , Sami Tolvanen , Masahiro Yamada Subject: [PATCH v6 03/10] kbuild: stop merging *.symversions Date: Fri, 13 May 2022 20:39:23 +0900 Message-Id: <20220513113930.10488-4-masahiroy@kernel.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220513113930.10488-1-masahiroy@kernel.org> References: <20220513113930.10488-1-masahiroy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org Now modpost reads symbol versions from .*.cmd files. The merged *.symversions are no longer needed. Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier Tested-by: Nathan Chancellor --- (no changes since v1) scripts/Makefile.build | 21 ++------------------- scripts/link-vmlinux.sh | 19 ------------------- 2 files changed, 2 insertions(+), 38 deletions(-) diff --git a/scripts/Makefile.build b/scripts/Makefile.build index ddd9080fc028..dff9220135c4 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -390,17 +390,6 @@ $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler $(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ; $(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ; -# combine symversions for later processing -ifeq ($(CONFIG_LTO_CLANG) $(CONFIG_MODVERSIONS),y y) - cmd_update_lto_symversions = \ - rm -f $@.symversions \ - $(foreach n, $(filter-out FORCE,$^), \ - $(if $(shell test -s $(n).symversions && echo y), \ - ; cat $(n).symversions >> $@.symversions)) -else - cmd_update_lto_symversions = echo >/dev/null -endif - # # Rule to compile a set of .o files into one .a file (without symbol table) # @@ -408,11 +397,8 @@ endif quiet_cmd_ar_builtin = AR $@ cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs) -quiet_cmd_ar_and_symver = AR $@ - cmd_ar_and_symver = $(cmd_update_lto_symversions); $(cmd_ar_builtin) - $(obj)/built-in.a: $(real-obj-y) FORCE - $(call if_changed,ar_and_symver) + $(call if_changed,ar_builtin) # # Rule to create modules.order file @@ -432,16 +418,13 @@ $(obj)/modules.order: $(obj-m) FORCE # # Rule to compile a set of .o files into one .a file (with symbol table) # -quiet_cmd_ar_lib = AR $@ - cmd_ar_lib = $(cmd_update_lto_symversions); $(cmd_ar) $(obj)/lib.a: $(lib-y) FORCE - $(call if_changed,ar_lib) + $(call if_changed,ar) ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),) quiet_cmd_link_multi-m = AR [M] $@ cmd_link_multi-m = \ - $(cmd_update_lto_symversions); \ rm -f $@; \ $(AR) cDPrsT $@ @$(patsubst %.o,%.mod,$@) else diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index 7313cbd755df..47e5336d0c75 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -56,20 +56,6 @@ gen_initcalls() > .tmp_initcalls.lds } -# If CONFIG_LTO_CLANG is selected, collect generated symbol versions into -# .tmp_symversions.lds -gen_symversions() -{ - info GEN .tmp_symversions.lds - rm -f .tmp_symversions.lds - - for o in ${KBUILD_VMLINUX_OBJS} ${KBUILD_VMLINUX_LIBS}; do - if [ -f ${o}.symversions ]; then - cat ${o}.symversions >> .tmp_symversions.lds - fi - done -} - # Link of vmlinux.o used for section mismatch analysis # ${1} output file modpost_link() @@ -88,10 +74,6 @@ modpost_link() gen_initcalls lds="-T .tmp_initcalls.lds" - if is_enabled CONFIG_MODVERSIONS; then - gen_symversions - fi - # This might take a while, so indicate that we're doing # an LTO link info LTO ${1} @@ -307,7 +289,6 @@ cleanup() rm -f .btf.* rm -f .tmp_System.map rm -f .tmp_initcalls.lds - rm -f .tmp_symversions.lds rm -f .tmp_vmlinux* rm -f System.map rm -f vmlinux From patchwork Fri May 13 11:39:24 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 12848701 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 BEEE0C433FE for ; Fri, 13 May 2022 11:42:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1379970AbiEMLmT (ORCPT ); Fri, 13 May 2022 07:42:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39312 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1379962AbiEMLmR (ORCPT ); Fri, 13 May 2022 07:42:17 -0400 Received: from conuserg-07.nifty.com (conuserg-07.nifty.com [210.131.2.74]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 703F041611; Fri, 13 May 2022 04:42:13 -0700 (PDT) Received: from grover.sesame (133-32-177-133.west.xps.vectant.ne.jp [133.32.177.133]) (authenticated) by conuserg-07.nifty.com with ESMTP id 24DBeEwd008349; Fri, 13 May 2022 20:40:18 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-07.nifty.com 24DBeEwd008349 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1652442019; bh=9Q6mTn1bAGbkjgZhALJ6nTHBDHzsRRSkgxWQCfuUF6o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=whFtsEspc/QO7yhgWHzcrhF8CSTpr4/K7GubZ1k3pXPHngIOmWX1Bg3G3E9BT4G9r vDeq+KtUyMHJrUQ2RXmTnWl7x4Q0J+gBTbmDWLOXqm0/eyW70pi6CydWhjWMnbTOR5 LXln7JkIpyWBgqy+4Wr14rjvy5vF44LDFeEVCtkFGmP/xVHhoRc0UdKYSFRxQBb6LE tExxXn0tiIRu2Oqt5frj98+5mgfKw4kcHfI+CXZIrle/imk4dKBi0gRMX2Wq2z0kk8 G8xgM/60nUIb5oxj6Onyc4jifXi23ZJ0NxCENT7C4BC2AA3k+g2462IvHOUh5WmF7S iv4XkKxDnM6lw== X-Nifty-SrcIP: [133.32.177.133] From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nathan Chancellor , Nick Desaulniers , Nicolas Schier , Peter Zijlstra , linux-modules@vger.kernel.org, llvm@lists.linux.dev, Ard Biesheuvel , Sami Tolvanen , Masahiro Yamada Subject: [PATCH v6 04/10] genksyms: adjust the output format to modpost Date: Fri, 13 May 2022 20:39:24 +0900 Message-Id: <20220513113930.10488-5-masahiroy@kernel.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220513113930.10488-1-masahiroy@kernel.org> References: <20220513113930.10488-1-masahiroy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org Make genksyms output symbol versions in the format modpost expects, so the 'sed' is unneeded. This commit makes *.symversions completely unneeded. I will keep *.symversions in .gitignore and 'make clean' for a while. Otherwise, 'git status' might be surprising. Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier Tested-by: Nathan Chancellor --- (no changes since v2) Changes in v2: - New patch scripts/Makefile.build | 6 ------ scripts/genksyms/genksyms.c | 2 +- 2 files changed, 1 insertion(+), 7 deletions(-) diff --git a/scripts/Makefile.build b/scripts/Makefile.build index dff9220135c4..461998a2ad2b 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -165,16 +165,10 @@ ifdef CONFIG_MODVERSIONS # o modpost will extract versions from that file and create *.c files that will # be compiled and linked to the kernel and/or modules. -genksyms_format := __crc_\(.*\) = \(.*\); - gen_symversions = \ if $(NM) $@ 2>/dev/null | grep -q __ksymtab; then \ $(call cmd_gensymtypes_$(1),$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \ - > $@.symversions; \ - sed -n 's/$(genksyms_format)/$(pound)SYMVER \1 \2/p' $@.symversions \ >> $(dot-target).cmd; \ - else \ - rm -f $@.symversions; \ fi cmd_gen_symversions_c = $(call gen_symversions,c) diff --git a/scripts/genksyms/genksyms.c b/scripts/genksyms/genksyms.c index 67b23cc0df0f..f5dfdb9d80e9 100644 --- a/scripts/genksyms/genksyms.c +++ b/scripts/genksyms/genksyms.c @@ -680,7 +680,7 @@ void export_symbol(const char *name) if (flag_dump_defs) fputs(">\n", debugfile); - printf("__crc_%s = 0x%08lx;\n", name, crc); + printf("#SYMVER %s 0x%08lx\n", name, crc); } } From patchwork Fri May 13 11:39:25 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 12848700 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 2958CC433EF for ; Fri, 13 May 2022 11:42:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1379964AbiEMLmR (ORCPT ); Fri, 13 May 2022 07:42:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39258 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1379955AbiEMLmQ (ORCPT ); Fri, 13 May 2022 07:42:16 -0400 Received: from conuserg-07.nifty.com (conuserg-07.nifty.com [210.131.2.74]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 883FB5C659; Fri, 13 May 2022 04:42:13 -0700 (PDT) Received: from grover.sesame (133-32-177-133.west.xps.vectant.ne.jp [133.32.177.133]) (authenticated) by conuserg-07.nifty.com with ESMTP id 24DBeEwe008349; Fri, 13 May 2022 20:40:19 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-07.nifty.com 24DBeEwe008349 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1652442020; bh=ril7znayTMbxC8UAEJWKwvHJ9mz9JyJMl2sfYS140MA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PwNW+8H1eLkalggUU6D31depod/zHYyFUM/ykihCkuYUsBhnbqcrP6trfxPDT9EvK l7WCZE/OmN9/7NyxNQAv6nxK4+1CFnPAoE3rr9mY+tBNA5/v/MCtlSSVVvAXX20ke1 YpE360DWJQ02grObnodmQaKEo5KxHfveLDWZI2Jw75Yhz0pIovzhf/ETHMZBzAnKXX 4uBf5GtJOrTThk4C8E76g3+pesLA/YeFU8z4of4Whm/mAeSkXLjEF8doIUilucxyvW PvkunRnSpFkXelHKUle9UJf08j2yqPYQ8GZgUGj0N40rvUm7i58GY/BGLi9P9r9rdc MOipMbhtCYnYQ== X-Nifty-SrcIP: [133.32.177.133] From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nathan Chancellor , Nick Desaulniers , Nicolas Schier , Peter Zijlstra , linux-modules@vger.kernel.org, llvm@lists.linux.dev, Ard Biesheuvel , Sami Tolvanen , Masahiro Yamada Subject: [PATCH v6 05/10] kbuild: do not create *.prelink.o for Clang LTO or IBT Date: Fri, 13 May 2022 20:39:25 +0900 Message-Id: <20220513113930.10488-6-masahiroy@kernel.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220513113930.10488-1-masahiroy@kernel.org> References: <20220513113930.10488-1-masahiroy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org When CONFIG_LTO_CLANG=y, additional intermediate *.prelink.o is created for each module. Also, objtool is postponed until LLVM IR is converted to ELF. CONFIG_X86_KERNEL_IBT works in a similar way to postpone objtool until objects are merged together. This commit stops generating *.prelink.o, so the build flow will look similar with/without LTO. The following figures show how the LTO build currently works, and how this commit is changing it. Current build flow ================== [1] single-object module $(LD) $(CC) +objtool $(LD) foo.c --------------------> foo.o -----> foo.prelink.o -----> foo.ko (LLVM IR) (ELF) | | foo.mod.o --/ [2] multi-object module $(LD) $(CC) $(AR) +objtool $(LD) foo1.c -----> foo1.o -----> foo.o -----> foo.prelink.o -----> foo.ko | (archive) (ELF) | foo2.c -----> foo2.o --/ | (LLVM IR) foo.mod.o --/ One confusion is foo.o in multi-object module is an archive despite of its suffix. New build flow ============== [1] single-object module Since there is only one object, there is no need to keep the LLVM IR. Use $(CC)+$(LD) to generate an ELF object in one build rule. When LTO is disabled, $(LD) is unneeded because $(CC) produces an ELF object. $(CC)+$(LD)+objtool $(LD) foo.c ----------------------------> foo.o ---------> foo.ko (ELF) | | foo.mod.o --/ [2] multi-object module Previously, $(AR) was used to combine LLVM bitcode into an archive, but there was no technical reason to do so. Use $(LD) to merge them into a single ELF object. $(LD) $(CC) +objtool $(LD) foo1.c ---------> foo1.o ---------> foo.o ---------> foo.ko | (ELF) | foo2.c ---------> foo2.o ----/ | (LLVM IR) foo.mod.o --/ Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier Tested-by: Nathan Chancellor Reviewed-by: Sami Tolvanen --- (no changes since v2) Changes in v2: - replace the chain of $(if ...) with $(and ) scripts/Kbuild.include | 4 +++ scripts/Makefile.build | 58 ++++++++++++--------------------------- scripts/Makefile.lib | 7 ----- scripts/Makefile.modfinal | 5 ++-- scripts/Makefile.modpost | 9 ++---- scripts/mod/modpost.c | 7 ----- 6 files changed, 25 insertions(+), 65 deletions(-) diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index 3514c2149e9d..455a0a6ce12d 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -15,6 +15,10 @@ pound := \# # Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o dot-target = $(dir $@).$(notdir $@) +### +# Name of target with a '.tmp_' as filename prefix. foo/bar.o => foo/.tmp_bar.o +tmp-target = $(dir $@).tmp_$(notdir $@) + ### # The temporary file to save gcc -MMD generated dependencies must not # contain a comma diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 461998a2ad2b..838ea5e83174 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -88,10 +88,6 @@ endif targets-for-modules := $(foreach x, o mod $(if $(CONFIG_TRIM_UNUSED_KSYMS), usyms), \ $(patsubst %.o, %.$x, $(filter %.o, $(obj-m)))) -ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),) -targets-for-modules += $(patsubst %.o, %.prelink.o, $(filter %.o, $(obj-m))) -endif - ifdef need-modorder targets-for-modules += $(obj)/modules.order endif @@ -152,8 +148,16 @@ $(obj)/%.ll: $(src)/%.c FORCE # The C file is compiled and updated dependency information is generated. # (See cmd_cc_o_c + relevant part of rule_cc_o_c) +is-single-obj-m = $(and $(part-of-module),$(filter $@, $(obj-m)),y) + +ifdef CONFIG_LTO_CLANG +cmd_ld_single_m = $(if $(is-single-obj-m), ; $(LD) $(ld_flags) -r -o $(tmp-target) $@; mv $(tmp-target) $@) +endif + quiet_cmd_cc_o_c = CC $(quiet_modtag) $@ - cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< $(cmd_objtool) + cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< \ + $(cmd_ld_single_m) \ + $(cmd_objtool) ifdef CONFIG_MODVERSIONS # When module versioning is enabled the following steps are executed: @@ -224,21 +228,16 @@ cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(o endif # CONFIG_STACK_VALIDATION -ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),) - -# Skip objtool for LLVM bitcode -$(obj)/%.o: objtool-enabled := - -else # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file -$(obj)/%.o: objtool-enabled = $(if $(filter-out y%, \ - $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n),y) +is-standard-object = $(if $(filter-out y%, $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n),y) -endif +delay-objtool := $(or $(CONFIG_LTO_CLANG),$(CONFIG_X86_KERNEL_IBT)) + +$(obj)/%.o: objtool-enabled = $(if $(is-standard-object),$(if $(delay-objtool),$(is-single-obj-m),y)) ifdef CONFIG_TRIM_UNUSED_KSYMS cmd_gen_ksymdeps = \ @@ -267,24 +266,6 @@ $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE $(call if_changed_rule,cc_o_c) $(call cmd,force_checksrc) -ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),) -# Module .o files may contain LLVM bitcode, compile them into native code -# before ELF processing -quiet_cmd_cc_prelink_modules = LD [M] $@ - cmd_cc_prelink_modules = \ - $(LD) $(ld_flags) -r -o $@ \ - --whole-archive $(filter-out FORCE,$^) \ - $(cmd_objtool) - -# objtool was skipped for LLVM bitcode, run it now that we have compiled -# modules into native code -$(obj)/%.prelink.o: objtool-enabled = y -$(obj)/%.prelink.o: part-of-module := y - -$(obj)/%.prelink.o: $(obj)/%.o FORCE - $(call if_changed,cc_prelink_modules) -endif - cmd_mod = echo $(addprefix $(obj)/, $(call real-search, $*.o, .o, -objs -y -m)) | \ $(AWK) -v RS='( |\n)' '!x[$$0]++' > $@ @@ -294,7 +275,7 @@ $(obj)/%.mod: FORCE # List module undefined symbols cmd_undefined_syms = $(NM) $< | sed -n 's/^ *U //p' > $@ -$(obj)/%.usyms: $(obj)/%$(mod-prelink-ext).o FORCE +$(obj)/%.usyms: $(obj)/%.o FORCE $(call if_changed,undefined_syms) quiet_cmd_cc_lst_c = MKLST $@ @@ -416,16 +397,11 @@ $(obj)/modules.order: $(obj-m) FORCE $(obj)/lib.a: $(lib-y) FORCE $(call if_changed,ar) -ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),) -quiet_cmd_link_multi-m = AR [M] $@ -cmd_link_multi-m = \ - rm -f $@; \ - $(AR) cDPrsT $@ @$(patsubst %.o,%.mod,$@) -else quiet_cmd_link_multi-m = LD [M] $@ - cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ @$(patsubst %.o,%.mod,$@) -endif + cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ @$(patsubst %.o,%.mod,$@) $(cmd_objtool) +$(multi-obj-m): objtool-enabled := $(delay-objtool) +$(multi-obj-m): part-of-module := y $(multi-obj-m): %.o: %.mod FORCE $(call if_changed,link_multi-m) $(call multi_depend, $(multi-obj-m), .o, -objs -y -m) diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 0453a1904646..f75138385449 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -225,13 +225,6 @@ dtc_cpp_flags = -Wp,-MMD,$(depfile).pre.tmp -nostdinc \ $(addprefix -I,$(DTC_INCLUDE)) \ -undef -D__DTS__ -ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),) -# With CONFIG_LTO_CLANG, .o files in modules might be LLVM bitcode, so we -# need to run LTO to compile them into native code (.lto.o) before further -# processing. -mod-prelink-ext := .prelink -endif - # Useful for describing the dependency of composite objects # Usage: # $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add) diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal index 7f39599e9fae..35100e981f4a 100644 --- a/scripts/Makefile.modfinal +++ b/scripts/Makefile.modfinal @@ -9,7 +9,7 @@ __modfinal: include include/config/auto.conf include $(srctree)/scripts/Kbuild.include -# for c_flags and mod-prelink-ext +# for c_flags include $(srctree)/scripts/Makefile.lib # find all modules listed in modules.order @@ -54,9 +54,8 @@ if_changed_except = $(if $(call newer_prereqs_except,$(2))$(cmd-check), \ $(cmd); \ printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:) - # Re-generate module BTFs if either module's .ko or vmlinux changed -$(modules): %.ko: %$(mod-prelink-ext).o %.mod.o scripts/module.lds $(if $(KBUILD_BUILTIN),vmlinux) FORCE +$(modules): %.ko: %.o %.mod.o scripts/module.lds $(if $(KBUILD_BUILTIN),vmlinux) FORCE +$(call if_changed_except,ld_ko_o,vmlinux) ifdef CONFIG_DEBUG_INFO_BTF_MODULES +$(if $(newer-prereqs),$(call cmd,btf_ko)) diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost index 48585c4d04ad..f2ce411acd59 100644 --- a/scripts/Makefile.modpost +++ b/scripts/Makefile.modpost @@ -41,9 +41,6 @@ __modpost: include include/config/auto.conf include $(srctree)/scripts/Kbuild.include -# for mod-prelink-ext -include $(srctree)/scripts/Makefile.lib - MODPOST = scripts/mod/modpost \ $(if $(CONFIG_MODVERSIONS),-m) \ $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \ @@ -118,8 +115,6 @@ $(input-symdump): @echo >&2 ' Modules may not have dependencies or modversions.' @echo >&2 ' You may get many unresolved symbol warnings.' -modules := $(sort $(shell cat $(MODORDER))) - # KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined symbols ifneq ($(KBUILD_MODPOST_WARN)$(filter-out $(existing-input-symdump), $(input-symdump)),) MODPOST += -w @@ -128,9 +123,9 @@ endif # Read out modules.order to pass in modpost. # Otherwise, allmodconfig would fail with "Argument list too long". quiet_cmd_modpost = MODPOST $@ - cmd_modpost = sed 's/\.ko$$/$(mod-prelink-ext)\.o/' $< | $(MODPOST) -T - + cmd_modpost = sed 's/ko$$/o/' $< | $(MODPOST) -T - -$(output-symdump): $(MODORDER) $(input-symdump) $(modules:.ko=$(mod-prelink-ext).o) FORCE +$(output-symdump): $(MODORDER) $(input-symdump) FORCE $(call if_changed,modpost) targets += $(output-symdump) diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 2313bdae91bf..27c45427d989 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -716,10 +716,6 @@ static char *remove_dot(char *s) size_t m = strspn(s + n + 1, "0123456789"); if (m && (s[n + m] == '.' || s[n + m] == 0)) s[n] = 0; - - /* strip trailing .prelink */ - if (strends(s, ".prelink")) - s[strlen(s) - 8] = '\0'; } return s; } @@ -841,9 +837,6 @@ static void read_symbols(const char *modname) /* strip trailing .o */ tmp = NOFAIL(strdup(modname)); tmp[strlen(tmp) - 2] = '\0'; - /* strip trailing .prelink */ - if (strends(tmp, ".prelink")) - tmp[strlen(tmp) - 8] = '\0'; mod = new_module(tmp); free(tmp); } From patchwork Fri May 13 11:39:26 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 12848690 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 5CD53C433EF for ; Fri, 13 May 2022 11:42:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1379949AbiEMLmP (ORCPT ); Fri, 13 May 2022 07:42:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39074 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1379933AbiEMLmO (ORCPT ); Fri, 13 May 2022 07:42:14 -0400 Received: from conuserg-07.nifty.com (conuserg-07.nifty.com [210.131.2.74]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 52A0C5AA79; Fri, 13 May 2022 04:42:12 -0700 (PDT) Received: from grover.sesame (133-32-177-133.west.xps.vectant.ne.jp [133.32.177.133]) (authenticated) by conuserg-07.nifty.com with ESMTP id 24DBeEwf008349; Fri, 13 May 2022 20:40:20 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-07.nifty.com 24DBeEwf008349 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1652442021; bh=cqElzDKYpcUrgO4yHYvWdPTzjbjG7knRZ4i2745IA+I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Sc3Y3caE/J1wed4rFYZnaCpQhbTPOPyo6Eo0nM+FrQSyiMx9UMcAK4hL4C/M5w8Ze oLEckYtJTNT6qK4yaUuHkqrpjubN5bDQ47zCTsArPk352eWo2JqJVkCejliOY0ZDAQ a5jNXw0kyOkiYbsbMQKHs9i1LjATm9v7pj0z5/1aXLsZxDhNNV3ViOdeG8S1jZrodG bxHebxebti4fji1Czx/yAHQSgu6OMbfYJzhpyhLUBtwrEgt4lcrFcDhjA7rZs8RvLa ba2itORo7C46mX1ysaHXHu73CYPEcGlmaXkBJs8//kpYZyYQYsqtLiLKtrHey91YRo P7yxqNo9PrLsQ== X-Nifty-SrcIP: [133.32.177.133] From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nathan Chancellor , Nick Desaulniers , Nicolas Schier , Peter Zijlstra , linux-modules@vger.kernel.org, llvm@lists.linux.dev, Ard Biesheuvel , Sami Tolvanen , Masahiro Yamada Subject: [PATCH v6 06/10] kbuild: check static EXPORT_SYMBOL* by script instead of modpost Date: Fri, 13 May 2022 20:39:26 +0900 Message-Id: <20220513113930.10488-7-masahiroy@kernel.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220513113930.10488-1-masahiroy@kernel.org> References: <20220513113930.10488-1-masahiroy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org The 'static' specifier and EXPORT_SYMBOL() are an odd combination. Commit 15bfc2348d54 ("modpost: check for static EXPORT_SYMBOL* functions") tried to detect it, but this check has false negatives. Here is the sample code. Makefile: obj-y += foo1.o foo2.o foo1.c: #include static void foo(void) {} EXPORT_SYMBOL(foo); foo2.c: void foo(void) {} foo1.c exports the static symbol 'foo', but modpost cannot catch it because it is fooled by foo2.c, which has a global symbol with the same name. s->is_static is cleared if a global symbol with the same name is found somewhere, but EXPORT_SYMBOL() and the global symbol do not necessarily belong to the same compilation unit. This check should be done per compilation unit, but I do not know how to do it in modpost. modpost runs against vmlinux.o or modules, which merges multiple objects, then forgets their origin. It is true modpost gets access to the lists of all the member objects (.vmlinux.objs and *.mod), but modpost cannot parse individual objects because they may not be ELF but LLVM IR when CONFIG_LTO_CLANG=y. Add a simple bash script to parse the output from ${NM}. This works for CONFIG_LTO_CLANG=y because llvm-nm can dump symbols of LLVM IR files. Revert 15bfc2348d54. Signed-off-by: Masahiro Yamada Reviewed-by: Nick Desaulniers Tested-by: Nathan Chancellor Tested-by: Jon Hunter --- (no changes since v5) Changes in v5: - Add more comments in the script Changes in v4: - New patch scripts/Makefile.build | 4 +++ scripts/check-local-export | 64 ++++++++++++++++++++++++++++++++++++++ scripts/mod/modpost.c | 28 +---------------- 3 files changed, 69 insertions(+), 27 deletions(-) create mode 100755 scripts/check-local-export diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 838ea5e83174..c2a173b3fd60 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -244,9 +244,12 @@ cmd_gen_ksymdeps = \ $(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd endif +cmd_check_local_export = $(srctree)/scripts/check-local-export $@ + 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) @@ -257,6 +260,7 @@ 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) endef diff --git a/scripts/check-local-export b/scripts/check-local-export new file mode 100755 index 000000000000..829e0591c0be --- /dev/null +++ b/scripts/check-local-export @@ -0,0 +1,64 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0-only +# +# Copyright (C) 2022 Masahiro Yamada +# +# Exit with error if a local exported symbol is found. +# EXPORT_SYMBOL should be used for global symbols. + +set -e + +declare -A symbol_types +declare -a export_symbols + +exit_code=0 + +while read value type name +do + # Exceptional case for Clang LTO. + # llvm-nm outputs this: + # "---------------- t" + # Skip this line because the name is empty. + if [[ ${value} = -* && -z ${name} ]]; then + continue + fi + + # For undefined symbols, the first field (value) is empty. + # The outout looks like this: + # " U _printk" + # Shift the fields. + if [[ -z ${name} ]]; then + name=${type} + type=${value} + fi + + # save (name, type) in the associative array + symbol_types[${name}]=${type} + + # append the exported symbol to the array + if [[ ${name} == __ksymtab_* ]]; then + export_symbols+=(${name#__ksymtab_}) + fi + + # If there is no symbol in the object, ${NM} (both GNU nm and llvm-nm) + # shows 'no symbols' diagnostic (but exits with 0). It is harmless and + # hidden by '2>/dev/null'. However, it suppresses real error messages + # as well. Add a hand-crafted error message here. + # + # Use -q instead of 2>/dev/null when we upgrade the minimum version of + # binutils to 2.37, llvm to 13.0.0. +done < <(${NM} ${1} 2>/dev/null || { echo "${0}: ${NM} failed" >&2; false; } ) + +# Catch error in the process substitution +wait $! + +for name in "${export_symbols[@]}" +do + # nm(3) says "If lowercase, the symbol is usually local" + if [[ ${symbol_types[$name]} =~ [a-z] ]]; then + echo "$@: error: local symbol '${name}' was exported" >&2 + exit_code=1 + fi +done + +exit ${exit_code} diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 27c45427d989..2328522f8a78 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -212,7 +212,6 @@ struct symbol { unsigned int crc; bool crc_valid; bool weak; - bool is_static; /* true if symbol is not global */ bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */ char name[]; }; @@ -242,7 +241,7 @@ static struct symbol *alloc_symbol(const char *name) memset(s, 0, sizeof(*s)); strcpy(s->name, name); - s->is_static = true; + return s; } @@ -877,20 +876,6 @@ static void read_symbols(const char *modname) sym_get_data(&info, sym)); } - // check for static EXPORT_SYMBOL_* functions && global vars - for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { - unsigned char bind = ELF_ST_BIND(sym->st_info); - - if (bind == STB_GLOBAL || bind == STB_WEAK) { - struct symbol *s = - find_symbol(remove_dot(info.strtab + - sym->st_name)); - - if (s) - s->is_static = false; - } - } - check_sec_ref(mod, modname, &info); if (!mod->is_vmlinux) { @@ -1320,7 +1305,6 @@ static void read_dump(const char *fname) mod->from_dump = true; } s = sym_add_exported(symname, mod, gpl_only); - s->is_static = false; sym_set_crc(s, crc); sym_update_namespace(symname, namespace); } @@ -1385,7 +1369,6 @@ int main(int argc, char **argv) char *missing_namespace_deps = NULL; char *dump_write = NULL, *files_source = NULL; int opt; - int n; LIST_HEAD(dump_lists); struct dump_list *dl, *dl2; @@ -1461,15 +1444,6 @@ int main(int argc, char **argv) if (sec_mismatch_count && !sec_mismatch_warn_only) error("Section mismatches detected.\n" "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n"); - for (n = 0; n < SYMBOL_HASH_SIZE; n++) { - struct symbol *s; - - for (s = symbolhash[n]; s; s = s->next) { - if (s->is_static) - error("\"%s\" [%s] is a static EXPORT_SYMBOL\n", - s->name, s->module->name); - } - } if (nr_unresolved > MAX_UNRESOLVED_REPORTS) warn("suppressed %u unresolved symbol warnings because there were too many)\n", From patchwork Fri May 13 11:39:27 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 12848689 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 A2B4DC433F5 for ; Fri, 13 May 2022 11:42:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1379941AbiEMLmO (ORCPT ); Fri, 13 May 2022 07:42:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39020 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1379936AbiEMLmN (ORCPT ); Fri, 13 May 2022 07:42:13 -0400 Received: from conuserg-07.nifty.com (conuserg-07.nifty.com [210.131.2.74]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B635641611; Fri, 13 May 2022 04:42:10 -0700 (PDT) Received: from grover.sesame (133-32-177-133.west.xps.vectant.ne.jp [133.32.177.133]) (authenticated) by conuserg-07.nifty.com with ESMTP id 24DBeEwg008349; Fri, 13 May 2022 20:40:21 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-07.nifty.com 24DBeEwg008349 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1652442022; bh=tcr+72ZYpbdDhhd7b5O3qNkSWb92WQKtLNqtDxevyAs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OV1zKueC95HJzEs4YNsULTic+nna5e5ypNTY7m3NhIVfc2INdeDR+cF7c9HiKtmfO Qsxy9MeGttwP5DhD5nIjIGS6Jw3zwcorHMHHWVYJXiFYZuUK3k5q/BUSOsEBIqbT8G tGuZMPTt2WpKvva0OBHxCxS11/aJcwiPnkgM61RQAg73E0WcoRQSJTRSOy/3bOCVla QW2I/PD7vcNam1TYdRNs1sgpGDPvpJh0OJcetNEO9K2wXgxHC3AHv76hixXjfu06ul 6TB+psG90p2nRGU0R3CISH6Aixz7/sUjannthx6dJi3gpikM00BAsIF10kg0SIQGSy Dmy2tZFi5CnoQ== X-Nifty-SrcIP: [133.32.177.133] From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nathan Chancellor , Nick Desaulniers , Nicolas Schier , Peter Zijlstra , linux-modules@vger.kernel.org, llvm@lists.linux.dev, Ard Biesheuvel , Sami Tolvanen , Masahiro Yamada Subject: [PATCH v6 07/10] kbuild: make built-in.a rule robust against too long argument error Date: Fri, 13 May 2022 20:39:27 +0900 Message-Id: <20220513113930.10488-8-masahiroy@kernel.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220513113930.10488-1-masahiroy@kernel.org> References: <20220513113930.10488-1-masahiroy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org Kbuild runs at the top of objtree instead of changing the working directory to subdirectories. I think this design is nice overall but some commands have a scalability issue. The build command of built-in.a is one of them whose length scales with: O(D * N) Here, D is the length of the directory path (i.e. $(obj)/ prefix), N is the number of objects in the Makefile, O() is the big O notation. The deeper directory the Makefile directory is located, the more easily it will hit the too long argument error. We can make it better. Trim the $(obj)/ by Make's builtin function, and restore it by a shell command (sed). With this, the command length scales with: O(D + N) In-tree modules still have some room to the limit (ARG_MAX=2097152), but this is more future-proof for big modules in a deep directory. For example, you can build i915 as builtin (CONFIG_DRM_I915=y) and compare drivers/gpu/drm/i915/.built-in.a.cmd with/without this commit. Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier Tested-by: Nathan Chancellor --- (no changes since v2) Changes in v2: - New patch scripts/Makefile.build | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/scripts/Makefile.build b/scripts/Makefile.build index c2a173b3fd60..8f1a355df7aa 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -374,7 +374,10 @@ $(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ; # quiet_cmd_ar_builtin = AR $@ - cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs) + cmd_ar_builtin = rm -f $@; \ + echo $(patsubst $(obj)/%,%,$(real-prereqs)) | \ + sed -E 's:([^ ]+):$(obj)/\1:g' | \ + xargs $(AR) cDPrST $@ $(obj)/built-in.a: $(real-obj-y) FORCE $(call if_changed,ar_builtin) From patchwork Fri May 13 11:39:28 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 12848704 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 309AEC433EF for ; Fri, 13 May 2022 11:43:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1379997AbiEMLnR (ORCPT ); Fri, 13 May 2022 07:43:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41390 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1379963AbiEMLnL (ORCPT ); Fri, 13 May 2022 07:43:11 -0400 Received: from conuserg-07.nifty.com (conuserg-07.nifty.com [210.131.2.74]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A7CDFD8081; Fri, 13 May 2022 04:42:32 -0700 (PDT) Received: from grover.sesame (133-32-177-133.west.xps.vectant.ne.jp [133.32.177.133]) (authenticated) by conuserg-07.nifty.com with ESMTP id 24DBeEwh008349; Fri, 13 May 2022 20:40:22 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-07.nifty.com 24DBeEwh008349 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1652442023; bh=OcOEuS6jEbLubdZRYm9mI6nzM08ugGxo0tuefY4hIgE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bp9jvRuF56C6r43GNXjG6BX+TvZHLTbdTLlR34dCXZg/oW32238SNreYsd6ecrnG6 PWr/NUZR0Fj64xkX3yxzCkcDwm8BUtpOQer8MUJE0kfUxAXrmqhHXhUVBDO1eaFvmZ Zd2DgWMNXGj/fTUiZ/fP4rrMZ0P/EShz6FzQ0fejjM7Fk5Mk+4x3zIAjw7LvNr3l8P 6RqksiC0umDQhSOQrTIO45Q7vzc3cdAd1y7uI/ao5m/kB6w/+AoM6bRZyfIpfL/JKy BLmQpIaa0h1Ej7NhYPC3vBgHWU9i3BlD07Dxm/NP3Kvu3JsIm6e+nmrjotY7EuCyv8 GgKFtSPjQ+KrA== X-Nifty-SrcIP: [133.32.177.133] From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nathan Chancellor , Nick Desaulniers , Nicolas Schier , Peter Zijlstra , linux-modules@vger.kernel.org, llvm@lists.linux.dev, Ard Biesheuvel , Sami Tolvanen , Masahiro Yamada Subject: [PATCH v6 08/10] kbuild: make *.mod rule robust against too long argument error Date: Fri, 13 May 2022 20:39:28 +0900 Message-Id: <20220513113930.10488-9-masahiroy@kernel.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220513113930.10488-1-masahiroy@kernel.org> References: <20220513113930.10488-1-masahiroy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org Like built-in.a, the command length of the *.mod rule scales with the depth of the directory times the number of objects in the Makefile. Add $(obj)/ by the shell command (awk) instead of by Make's builtin function. In-tree modules still have some room to the limit (ARG_MAX=2097152), but this is more future-proof for big modules in a deep directory. For example, you can build i915 as a module (CONFIG_DRM_I915=m) and compare drivers/gpu/drm/i915/.i915.mod.cmd with/without this commit. The issue is more critical for external modules because the M= path can be very long as Jeff Johnson reported before [1]. [1] https://lore.kernel.org/linux-kbuild/4c02050c4e95e4cb8cc04282695f8404@codeaurora.org/ Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier Tested-by: Nathan Chancellor --- (no changes since v2) Changes in v2: - New patch scripts/Makefile.build | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 8f1a355df7aa..f546b5f1f33f 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -270,8 +270,8 @@ $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE $(call if_changed_rule,cc_o_c) $(call cmd,force_checksrc) -cmd_mod = echo $(addprefix $(obj)/, $(call real-search, $*.o, .o, -objs -y -m)) | \ - $(AWK) -v RS='( |\n)' '!x[$$0]++' > $@ +cmd_mod = echo $(call real-search, $*.o, .o, -objs -y -m) | \ + $(AWK) -v RS='( |\n)' '!x[$$0]++ { print("$(obj)/"$$0) }' > $@ $(obj)/%.mod: FORCE $(call if_changed,mod) From patchwork Fri May 13 11:39:29 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 12848705 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 490C9C433EF for ; Fri, 13 May 2022 11:43:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1380116AbiEMLnp (ORCPT ); Fri, 13 May 2022 07:43:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43632 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345668AbiEMLnR (ORCPT ); Fri, 13 May 2022 07:43:17 -0400 Received: from conuserg-07.nifty.com (conuserg-07.nifty.com [210.131.2.74]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 67B3DF68BC; Fri, 13 May 2022 04:42:42 -0700 (PDT) Received: from grover.sesame (133-32-177-133.west.xps.vectant.ne.jp [133.32.177.133]) (authenticated) by conuserg-07.nifty.com with ESMTP id 24DBeEwi008349; Fri, 13 May 2022 20:40:23 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-07.nifty.com 24DBeEwi008349 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1652442024; bh=tWubGKl01wW+DNljh3UjfGXWoQ6mtZdfdLtoxs2fSmI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KbXwfWVjakJu02uXsXnx36SE59nU4vsPwBw/CfSyj5v6M6t4/Avd9B2x0smijLCSx 84p7T8j5EDL1A32qvR5whd8+tM+uwi51xgKXoiNknaj1cBr4UTe20kKDqcvKNKtfME MLvJL+kquJpKTvaZ5n9XEZ7EIcebLJtol8doAnt4gWg90Q8a3Pwua4/AXSFzv4B2eC O/okFmfD/nPHQdfI/bYqR/TAMoMwkAPeM6XWPZp1oznKpH3JJ0X2KufoD4QRDR2eve 1ugmGWoj29n2dhL8UFsDvfj0SXRfxhTU7XedZtQR92eVpNm4agtvLFTE45qetVL/XX 1iCu2QxxAwhZg== X-Nifty-SrcIP: [133.32.177.133] From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nathan Chancellor , Nick Desaulniers , Nicolas Schier , Peter Zijlstra , linux-modules@vger.kernel.org, llvm@lists.linux.dev, Ard Biesheuvel , Sami Tolvanen , Masahiro Yamada , Kees Cook Subject: [PATCH v6 09/10] kbuild: add cmd_and_savecmd macro Date: Fri, 13 May 2022 20:39:29 +0900 Message-Id: <20220513113930.10488-10-masahiroy@kernel.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220513113930.10488-1-masahiroy@kernel.org> References: <20220513113930.10488-1-masahiroy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org Separate out the command execution part of if_changed, as we did for if_changed_dep. This allows us to reuse it in if_changed_rule. define rule_foo $(call cmd_and_savecmd,foo) $(call cmd,bar) endef Signed-off-by: Masahiro Yamada Reviewed-by: Kees Cook Tested-by: Nathan Chancellor --- (no changes since v4) Changes in v4: - New. Resent of my previous submission. https://lore.kernel.org/all/20210831074004.3195284-10-masahiroy@kernel.org/ scripts/Kbuild.include | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index 455a0a6ce12d..ece44b735061 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -142,9 +142,11 @@ check-FORCE = $(if $(filter FORCE, $^),,$(warning FORCE prerequisite is missing) if-changed-cond = $(newer-prereqs)$(cmd-check)$(check-FORCE) # Execute command if command has changed or prerequisite(s) are updated. -if_changed = $(if $(if-changed-cond), \ +if_changed = $(if $(if-changed-cond),$(cmd_and_savecmd),@:) + +cmd_and_savecmd = \ $(cmd); \ - printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:) + printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd # Execute the command and also postprocess generated .d dependencies file. if_changed_dep = $(if $(if-changed-cond),$(cmd_and_fixdep),@:) From patchwork Fri May 13 11:39:30 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 12848706 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 1452FC433F5 for ; Fri, 13 May 2022 11:44:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1380032AbiEMLoM (ORCPT ); Fri, 13 May 2022 07:44:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41198 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1380033AbiEMLnV (ORCPT ); Fri, 13 May 2022 07:43:21 -0400 Received: from conuserg-07.nifty.com (conuserg-07.nifty.com [210.131.2.74]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DF8D3101161; Fri, 13 May 2022 04:42:44 -0700 (PDT) Received: from grover.sesame (133-32-177-133.west.xps.vectant.ne.jp [133.32.177.133]) (authenticated) by conuserg-07.nifty.com with ESMTP id 24DBeEwj008349; Fri, 13 May 2022 20:40:24 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-07.nifty.com 24DBeEwj008349 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1652442025; bh=Bi6sLfbdKmIO2edbwjx7czMHPSd9O/aqQ3lYRuHiOMI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hdUTS2mg2rDpdAJcbEQpj2OfKf33I0W4Yq5MEfcwF+1CtKl+75/KpXnDJmtO7abjQ RalunWSjbIoNDQnrNfI+hyKQWJtRvhtCkSglRaoWbw8rZ3h43spsOO9UcygVE+pdf9 gHnsela+702mUaKYbhwf8D47e4VnC4mHHVG3kUUKcVZ/vb/zrrO+MHawDh/EIbq6s0 kqwxx6ckuggBKwsz37MGkSro6qw02t47kTEF16n9+/0/wt1x/HVOadDkYiAHm/t5za aXxTc0Bv/Q+idke1jb+Jv4VedpCMtdI9JdzSOq1ElCijT79ZbtpBUVagrLEeAtE5y2 +ucnspf/63/OA== X-Nifty-SrcIP: [133.32.177.133] From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nathan Chancellor , Nick Desaulniers , Nicolas Schier , Peter Zijlstra , linux-modules@vger.kernel.org, llvm@lists.linux.dev, Ard Biesheuvel , Sami Tolvanen , Masahiro Yamada , Kees Cook , Josh Poimboeuf Subject: [PATCH v6 10/10] kbuild: rebuild multi-object modules when objtool is updated Date: Fri, 13 May 2022 20:39:30 +0900 Message-Id: <20220513113930.10488-11-masahiroy@kernel.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220513113930.10488-1-masahiroy@kernel.org> References: <20220513113930.10488-1-masahiroy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org When CONFIG_LTO_CLANG or CONFIG_X86_KERNEL_IBT is enabled, objtool for multi-object modules is postponed until the objects are linked together. Make sure to re-run objtool and re-link multi-object modules when objtool is updated. Signed-off-by: Masahiro Yamada Reviewed-by: Kees Cook Acked-by: Josh Poimboeuf Tested-by: Nathan Chancellor --- (no changes since v4) Changes in v4: - New Resent of my previous submission https://lore.kernel.org/linux-kbuild/20210831074004.3195284-11-masahiroy@kernel.org/ scripts/Makefile.build | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/scripts/Makefile.build b/scripts/Makefile.build index f546b5f1f33f..4e6902e099e8 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -404,13 +404,18 @@ $(obj)/modules.order: $(obj-m) FORCE $(obj)/lib.a: $(lib-y) FORCE $(call if_changed,ar) -quiet_cmd_link_multi-m = LD [M] $@ - cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ @$(patsubst %.o,%.mod,$@) $(cmd_objtool) +quiet_cmd_ld_multi_m = LD [M] $@ + cmd_ld_multi_m = $(LD) $(ld_flags) -r -o $@ @$(patsubst %.o,%.mod,$@) $(cmd_objtool) + +define rule_ld_multi_m + $(call cmd_and_savecmd,ld_multi_m) + $(call cmd,gen_objtooldep) +endef $(multi-obj-m): objtool-enabled := $(delay-objtool) $(multi-obj-m): part-of-module := y $(multi-obj-m): %.o: %.mod FORCE - $(call if_changed,link_multi-m) + $(call if_changed_rule,ld_multi_m) $(call multi_depend, $(multi-obj-m), .o, -objs -y -m) targets := $(filter-out $(PHONY), $(targets))