From patchwork Tue Sep 3 15:06:30 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Matthias_M=C3=A4nnich?= X-Patchwork-Id: 11128219 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 570A71813 for ; Tue, 3 Sep 2019 15:08:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2E80F2377D for ; Tue, 3 Sep 2019 15:08:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="DjpPoCow" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729812AbfICPIX (ORCPT ); Tue, 3 Sep 2019 11:08:23 -0400 Received: from mail-yw1-f74.google.com ([209.85.161.74]:47439 "EHLO mail-yw1-f74.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729806AbfICPHg (ORCPT ); Tue, 3 Sep 2019 11:07:36 -0400 Received: by mail-yw1-f74.google.com with SMTP id p205so7535136ywc.14 for ; Tue, 03 Sep 2019 08:07:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=TomRv8WBRCsnjt12ZHD1+VdCr+4pjb/fkJlpjNFFLG4=; b=DjpPoCowYoYMtqq6HChqsAFuCxySsXs6nnis1S6OjRSfR5h5o60lx6prLWk2IFp2SB ZL/iH4uSQoA87fOY1SCt0JtauSbUEx9o01Cw6SePQ2YK4+oEDisY472VSZN5nIZvfvbz tVMjf1T/FJN/3X6ktlKarr3AKfRelcnCr8tDvp87Ha9hBen3ifVU1gQR5ccBVcsgUIZK gC4SqEWp++ijD8pUY4RQdXZx+pdOYK4onjRmTH0sTgRBTOvy06mKNBGZBSsvkFC5UZTV I436Nils03M3qCKFxh2B+xkDNq4uJfvNaH29KloUvqo8TVZgUK3gCEWzNe47LlkGywPr /3lw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=TomRv8WBRCsnjt12ZHD1+VdCr+4pjb/fkJlpjNFFLG4=; b=gdrqobA94f6j1ALvVzc1htVH/IaCByE8sP1G9IYnp12H024VKHv3bEalCU0WHdjmer YZPLeXWCbXM2czBObqUCHbLig+aWP5uOjS/J2axqr3U686g9WB9MeAiSz0QnDciNqKWf v6CbKZMp2yiyjNTQDcE4W1cjrNpwgKm60ZEWYRxjYafEdmYI2uUe+2QB7D9l5tZVqdMz LieTYJXJSFgC4Tnh0SLs9r8c0GPF/g7KcmZX88/tbaEvmx8rk37EDdDRQ0Vwtk3vbZFi PZng7Aw18hekTTwDi5tl5mOmmKsKFUADCfcIJpVBuxLaEyoSQxja7pGkpagTgGvM5A3K b3ag== X-Gm-Message-State: APjAAAXHz45JbCB7pUaOubPGbq+0dSPEXESikdz6kW1glbv+qcDqniMy i7JObT6wsAjCMGxeL0YoeliIprLzlIOiXQ== X-Google-Smtp-Source: APXvYqxEBrg7gJojzVUw3GwcZ9otAyXaBVd2jFNcrR6p4Ed9JS8wISKsWDTTwpk0FQ8t1mXJbWEJPSJ83QnbiA== X-Received: by 2002:a25:2e4e:: with SMTP id b14mr24713314ybn.242.1567523255286; Tue, 03 Sep 2019 08:07:35 -0700 (PDT) Date: Tue, 3 Sep 2019 16:06:30 +0100 In-Reply-To: <20190903150638.242049-1-maennich@google.com> Message-Id: <20190903150638.242049-5-maennich@google.com> Mime-Version: 1.0 References: <20180716122125.175792-1-maco@android.com> <20190903150638.242049-1-maennich@google.com> X-Mailer: git-send-email 2.23.0.187.g17f5b7556c-goog Subject: [PATCH v4 04/12] modpost: add support for symbol namespaces From: Matthias Maennich To: linux-kernel@vger.kernel.org Cc: kernel-team@android.com, maennich@google.com, arnd@arndb.de, gregkh@linuxfoundation.org, jeyu@kernel.org, joel@joelfernandes.org, lucas.de.marchi@gmail.com, maco@android.com, sspatil@google.com, will@kernel.org, yamada.masahiro@socionext.com, linux-kbuild@vger.kernel.org, linux-modules@vger.kernel.org, linux-usb@vger.kernel.org, usb-storage@lists.one-eyed-alien.net, linux-watchdog@vger.kernel.org Sender: linux-watchdog-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org Add support for symbols that are exported into namespaces. For that, extract any namespace suffix from the symbol name. In addition, emit a warning whenever a module refers to an exported symbol without explicitly importing the namespace that it is defined in. This patch consistently adds the namespace suffix to symbol names exported into Module.symvers. Example warning emitted by modpost in case of the above violation: WARNING: module ums-usbat uses symbol usb_stor_resume from namespace USB_STORAGE, but does not import it. Co-developed-by: Martijn Coenen Signed-off-by: Martijn Coenen Reviewed-by: Joel Fernandes (Google) Reviewed-by: Greg Kroah-Hartman Signed-off-by: Matthias Maennich --- Documentation/kbuild/modules.rst | 7 ++- scripts/export_report.pl | 2 +- scripts/mod/modpost.c | 104 ++++++++++++++++++++++++++----- scripts/mod/modpost.h | 7 +++ 4 files changed, 101 insertions(+), 19 deletions(-) diff --git a/Documentation/kbuild/modules.rst b/Documentation/kbuild/modules.rst index 24e763482650..d2ae799237fd 100644 --- a/Documentation/kbuild/modules.rst +++ b/Documentation/kbuild/modules.rst @@ -470,9 +470,12 @@ build. The syntax of the Module.symvers file is:: - + - 0x2d036834 scsi_remove_host drivers/scsi/scsi_mod + 0xe1cc2a05 usb_stor_suspend USB_STORAGE drivers/usb/storage/usb-storage EXPORT_SYMBOL_GPL + + The fields are separated by tabs and values may be empty (e.g. + if no namespace is defined for an exported symbol). For a kernel build without CONFIG_MODVERSIONS enabled, the CRC would read 0x00000000. diff --git a/scripts/export_report.pl b/scripts/export_report.pl index 7d3030d03a25..548330e8c4e7 100755 --- a/scripts/export_report.pl +++ b/scripts/export_report.pl @@ -94,7 +94,7 @@ if (defined $opt{'o'}) { # while ( <$module_symvers> ) { chomp; - my (undef, $symbol, $module, $gpl) = split; + my (undef, $symbol, $namespace, $module, $gpl) = split('\t'); $SYMBOL { $symbol } = [ $module , "0" , $symbol, $gpl]; } close($module_symvers); diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index f277e116e0eb..c2d49afaea1c 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -164,6 +164,7 @@ struct symbol { struct module *module; unsigned int crc; int crc_valid; + const char *namespace; unsigned int weak:1; unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */ unsigned int kernel:1; /* 1 if symbol is from kernel @@ -233,6 +234,37 @@ static struct symbol *find_symbol(const char *name) return NULL; } +static bool contains_namespace(struct namespace_list *list, + const char *namespace) +{ + struct namespace_list *ns_entry; + + for (ns_entry = list; ns_entry != NULL; ns_entry = ns_entry->next) + if (strcmp(ns_entry->namespace, namespace) == 0) + return true; + + return false; +} + +static void add_namespace(struct namespace_list **list, const char *namespace) +{ + struct namespace_list *ns_entry; + + if (!contains_namespace(*list, namespace)) { + ns_entry = NOFAIL(malloc(sizeof(struct namespace_list) + + strlen(namespace) + 1)); + strcpy(ns_entry->namespace, namespace); + ns_entry->next = *list; + *list = ns_entry; + } +} + +static bool module_imports_namespace(struct module *module, + const char *namespace) +{ + return contains_namespace(module->imported_namespaces, namespace); +} + static const struct { const char *str; enum export export; @@ -312,23 +344,39 @@ static enum export export_from_sec(struct elf_info *elf, unsigned int sec) return export_unknown; } +static const char *sym_extract_namespace(const char **symname) +{ + size_t n; + char *dupsymname; + + n = strcspn(*symname, "."); + if (n < strlen(*symname) - 1) { + dupsymname = NOFAIL(strdup(*symname)); + dupsymname[n] = '\0'; + *symname = dupsymname; + return dupsymname + n + 1; + } + + return NULL; +} + /** * Add an exported symbol - it may have already been added without a * CRC, in this case just update the CRC **/ -static struct symbol *sym_add_exported(const char *name, struct module *mod, - enum export export) +static struct symbol *sym_add_exported(const char *name, const char *namespace, + struct module *mod, enum export export) { struct symbol *s = find_symbol(name); if (!s) { s = new_symbol(name, mod, export); + s->namespace = namespace; } else { if (!s->preloaded) { - warn("%s: '%s' exported twice. Previous export " - "was in %s%s\n", mod->name, name, - s->module->name, - is_vmlinux(s->module->name) ?"":".ko"); + warn("%s: '%s' exported twice. Previous export was in %s%s\n", + mod->name, name, s->module->name, + is_vmlinux(s->module->name) ? "" : ".ko"); } else { /* In case Module.symvers was out of date */ s->module = mod; @@ -620,6 +668,7 @@ static void handle_modversions(struct module *mod, struct elf_info *info, unsigned int crc; enum export export; bool is_crc = false; + const char *name, *namespace; if ((!is_vmlinux(mod->name) || mod->is_dot_o) && strstarts(symname, "__ksymtab")) @@ -691,8 +740,9 @@ static void handle_modversions(struct module *mod, struct elf_info *info, default: /* All exported symbols */ if (strstarts(symname, "__ksymtab_")) { - sym_add_exported(symname + strlen("__ksymtab_"), mod, - export); + name = symname + strlen("__ksymtab_"); + namespace = sym_extract_namespace(&name); + sym_add_exported(name, namespace, mod, export); } if (strcmp(symname, "init_module") == 0) mod->has_init = 1; @@ -1943,6 +1993,7 @@ static void read_symbols(const char *modname) const char *symname; char *version; char *license; + char *namespace; struct module *mod; struct elf_info info = { }; Elf_Sym *sym; @@ -1974,6 +2025,12 @@ static void read_symbols(const char *modname) license = get_next_modinfo(&info, "license", license); } + namespace = get_modinfo(&info, "import_ns"); + while (namespace) { + add_namespace(&mod->imported_namespaces, namespace); + namespace = get_next_modinfo(&info, "import_ns", namespace); + } + for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { symname = remove_dot(info.strtab + sym->st_name); @@ -2118,6 +2175,13 @@ static int check_exports(struct module *mod) basename++; else basename = mod->name; + + if (exp->namespace && + !module_imports_namespace(mod, exp->namespace)) { + warn("module %s uses symbol %s from namespace %s, but does not import it.\n", + basename, exp->name, exp->namespace); + } + if (!mod->gpl_compatible) check_for_gpl_usage(exp->export, basename, exp->name); check_for_unused(exp->export, basename, exp->name); @@ -2341,7 +2405,7 @@ static void read_dump(const char *fname, unsigned int kernel) return; while ((line = get_next_line(&pos, file, size))) { - char *symname, *modname, *d, *export, *end; + char *symname, *namespace, *modname, *d, *export, *end; unsigned int crc; struct module *mod; struct symbol *s; @@ -2349,7 +2413,10 @@ static void read_dump(const char *fname, unsigned int kernel) if (!(symname = strchr(line, '\t'))) goto fail; *symname++ = '\0'; - if (!(modname = strchr(symname, '\t'))) + if (!(namespace = strchr(symname, '\t'))) + goto fail; + *namespace++ = '\0'; + if (!(modname = strchr(namespace, '\t'))) goto fail; *modname++ = '\0'; if ((export = strchr(modname, '\t')) != NULL) @@ -2366,7 +2433,8 @@ static void read_dump(const char *fname, unsigned int kernel) mod = new_module(modname); mod->skip = 1; } - s = sym_add_exported(symname, mod, export_no(export)); + s = sym_add_exported(symname, namespace, mod, + export_no(export)); s->kernel = kernel; s->preloaded = 1; sym_update_crc(symname, mod, crc, export_no(export)); @@ -2395,16 +2463,20 @@ static void write_dump(const char *fname) { struct buffer buf = { }; struct symbol *symbol; + const char *namespace; int n; for (n = 0; n < SYMBOL_HASH_SIZE ; n++) { symbol = symbolhash[n]; while (symbol) { - if (dump_sym(symbol)) - buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n", - symbol->crc, symbol->name, - symbol->module->name, - export_str(symbol->export)); + if (dump_sym(symbol)) { + namespace = symbol->namespace; + buf_printf(&buf, "0x%08x\t%s\t%s\t%s\t%s\n", + symbol->crc, symbol->name, + namespace ? namespace : "", + symbol->module->name, + export_str(symbol->export)); + } symbol = symbol->next; } } diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h index 8453d6ac2f77..9626bf3e7424 100644 --- a/scripts/mod/modpost.h +++ b/scripts/mod/modpost.h @@ -109,6 +109,11 @@ buf_printf(struct buffer *buf, const char *fmt, ...); void buf_write(struct buffer *buf, const char *s, int len); +struct namespace_list { + struct namespace_list *next; + char namespace[0]; +}; + struct module { struct module *next; const char *name; @@ -121,6 +126,8 @@ struct module { struct buffer dev_table_buf; char srcversion[25]; int is_dot_o; + // Actual imported namespaces + struct namespace_list *imported_namespaces; }; struct elf_info {