From patchwork Wed Aug 21 11:49:19 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthias Maennich X-Patchwork-Id: 11106451 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 E829F13B1 for ; Wed, 21 Aug 2019 11:54:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BD2D2233A0 for ; Wed, 21 Aug 2019 11:54:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ojkYQTn7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727719AbfHULy0 (ORCPT ); Wed, 21 Aug 2019 07:54:26 -0400 Received: from mail-qt1-f201.google.com ([209.85.160.201]:48445 "EHLO mail-qt1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727780AbfHULyX (ORCPT ); Wed, 21 Aug 2019 07:54:23 -0400 Received: by mail-qt1-f201.google.com with SMTP id k13so2304575qtp.15 for ; Wed, 21 Aug 2019 04:54:22 -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=heDLmLkB+fjtN8h+C63fhpjDHtJz/7QA8MMNDS5S1pM=; b=ojkYQTn7kxOMpKGiU1LXaZcBAh0rU/eF71k1f17Igp1OIvvgNof7Tn31NH65R/URrw fRv9IkhwJBt+3XXwUIC9ymI006954wlgsLxS9umplXd0q+sFthQ1Nv8LoeAQeZMuq05J QzdAa4PmPt2wTI/Uvan0unZFtIR4RFmsuCcXF5wexWaOPffGbpZ96fTu8o/29BkKCKJW HVRIA77ilK7P71mpQjERlN0iG70wUHeHMr8VIqRzAYKd7gm2/xR2SBsm1AAx+N+ZHKiH 5RTUlLTmUZ1LtFf6NoJKZxy80d8shUg7trmNnzHY4l+5/GR4AIrtyioP6dhaosHBNI45 XFwg== 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=heDLmLkB+fjtN8h+C63fhpjDHtJz/7QA8MMNDS5S1pM=; b=p6lmzJSUeiyHc1IkPVbSqr+u23CZtJNGC/6xtZGxcjA4zqtTU+pK26xIfZK/fGxRO2 KFNCY57BuLUzYFBJqmcwplejyAfZmeAGvz/vsz2ITbpme0q69pUbhPDGM7FpDg9HcHRM 7dNyPdd3fUze/eP1OP98huj3gi8T9j6iGqBIm7UqDsJIamgWuOK+iDshxppaH0bSxtqv +UR0dA9VFUiTwDByHp7Uf/eKrgxoUhrxZkmWuaPluKtkG5SL+iypgaAFVFnoygpDNkE3 33m0GZ7xWlhSBeQU6PI8uLqyVNrprUv/05z38gXCd0vsohzOaSLBFcuVOFVGxFxn0o8q 6s0g== X-Gm-Message-State: APjAAAVx+BuoXlmcfkhg0XuP+vODjoICT4NigArJlb4N4tI1FbCvwptx KMhIi0cEvuZLMqQOJjej83hIY+A5q/GVjw== X-Google-Smtp-Source: APXvYqwPHOWtUtji1xGPAEPAvJ6nM7pYnXD0DZLcUYhTqLkWP+9jxzS4XN45hcQG5zfjxGrAEh3CgHKiuYvhlw== X-Received: by 2002:ac8:2955:: with SMTP id z21mr30871117qtz.204.1566388461804; Wed, 21 Aug 2019 04:54:21 -0700 (PDT) Date: Wed, 21 Aug 2019 12:49:19 +0100 In-Reply-To: <20190821114955.12788-1-maennich@google.com> Message-Id: <20190821114955.12788-5-maennich@google.com> Mime-Version: 1.0 References: <20190813121733.52480-1-maennich@google.com> <20190821114955.12788-1-maennich@google.com> X-Mailer: git-send-email 2.23.0.rc1.153.gdeed80330f-goog Subject: [PATCH v3 04/11] 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, geert@linux-m68k.org, gregkh@linuxfoundation.org, hpa@zytor.com, jeyu@kernel.org, joel@joelfernandes.org, kstewart@linuxfoundation.org, linux-arch@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-modules@vger.kernel.org, linux-scsi@vger.kernel.org, linux-usb@vger.kernel.org, lucas.de.marchi@gmail.com, maco@android.com, maco@google.com, michal.lkml@markovi.net, mingo@redhat.com, oneukum@suse.com, pombredanne@nexb.com, sam@ravnborg.org, sspatil@google.com, stern@rowland.harvard.edu, tglx@linutronix.de, usb-storage@lists.one-eyed-alien.net, x86@kernel.org, yamada.masahiro@socionext.com Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@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 --- scripts/mod/modpost.c | 91 +++++++++++++++++++++++++++++++++++++------ scripts/mod/modpost.h | 7 ++++ 2 files changed, 87 insertions(+), 11 deletions(-) diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index f277e116e0eb..538bb24ffee3 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; @@ -312,6 +344,22 @@ 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 @@ -319,16 +367,18 @@ static enum export export_from_sec(struct elf_info *elf, unsigned int sec) static struct symbol *sym_add_exported(const char *name, struct module *mod, enum export export) { - struct symbol *s = find_symbol(name); + const char *symbol_name = name; + const char *namespace = sym_extract_namespace(&symbol_name); + struct symbol *s = find_symbol(symbol_name); if (!s) { - s = new_symbol(name, mod, export); + s = new_symbol(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, symbol_name, s->module->name, + is_vmlinux(s->module->name) ? "" : ".ko"); } else { /* In case Module.symvers was out of date */ s->module = mod; @@ -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); @@ -2395,16 +2459,21 @@ 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%s%s\t%s\t%s\n", + symbol->crc, symbol->name, + namespace ? "." : "", + 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 {