From patchwork Fri Oct 18 09:31:40 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthias Maennich X-Patchwork-Id: 11197883 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 410FF913 for ; Fri, 18 Oct 2019 09:32:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 201EB21852 for ; Fri, 18 Oct 2019 09:32:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Ua0IlvQY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2409757AbfJRJcE (ORCPT ); Fri, 18 Oct 2019 05:32:04 -0400 Received: from mail-wr1-f74.google.com ([209.85.221.74]:54706 "EHLO mail-wr1-f74.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2409753AbfJRJcD (ORCPT ); Fri, 18 Oct 2019 05:32:03 -0400 Received: by mail-wr1-f74.google.com with SMTP id e14so2312516wrm.21 for ; Fri, 18 Oct 2019 02:32:00 -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=VWGgVtR20by6j5rWakK1xLjIPHuT7TbYDPbUDce3jrs=; b=Ua0IlvQYhxOOW8wlwRn+1w0mDAE59j1sHlig/IMGI74mwajHhYIjQ9GKXDeOOyTgSZ ZGl7isYwxCBZtNDYo1vf+29g/OCYPgiD98wV9UE0KnFfyXsQoX6Zbt8Ak9nnFy+/X4AH CPZMiK3s2JYPYvDDU5WrDeu0S0G2hho5YKlZC9/vN9X50jfxqM+EmkZ9Erfzz1GjuVWg 59KXAHzuI2yp1hSPgTO6MZGoZjfN2N48kYPenYgZr1Thv0lsOfs372ZBQKuLTpc9NyDl wajPxgxdjn1brnWwhIHvTcQyQxzG6fYrKMqKr7i0VfHVi3NfZXaxG8Xi3IFY+uG3O6Qn ADIQ== 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=VWGgVtR20by6j5rWakK1xLjIPHuT7TbYDPbUDce3jrs=; b=Zn8HcZ3RUeW7bX56o4s27tDWOE5tX1fm/ynVham9GY2Tkh3su3gLe9IK7iOZKPlaxs rB5ZP+LjNfMybLU6lCSEcLSXMbSfTEOmAHOlz18EMsQEPciY+ks0XPaUYcHC3zQ+Xpzf GBkF+doky/fYxQ6R96K/MRlINUbNLakUUz/6surwqG6xR/NW1AsIJ0siGj0h5jrr8GBL 4ZXPA6MR7lZ/5ZRPQvU0j1j7Dtm3SoxEi91XIjayLYUNqTBpeRawjOu7bBbtfXC6tBGQ OLLcFsxSckwEYDZczVtTf2p7O3T5Tj68ofds/mRwhIhuUOmPOOZ6w13HdSykV1iD+ALt 0fog== X-Gm-Message-State: APjAAAWN7jVMfE/B6MLdujmRrwYXabFCkBKlMQD5FAVsXurfsKauMUQa qZL6qRYeeLOEWlQyxMHN7qZ426AT+dXZ8w== X-Google-Smtp-Source: APXvYqys3kM1GQPDID5IamEIJmq2t+9rGBLKuJ1Nxz6Q9/oGyOyyywzsfxCxcMrStAkX4m3Nn3FWNdhhUwceLA== X-Received: by 2002:adf:e2cc:: with SMTP id d12mr7076584wrj.345.1571391119582; Fri, 18 Oct 2019 02:31:59 -0700 (PDT) Date: Fri, 18 Oct 2019 10:31:40 +0100 In-Reply-To: <20191018093143.15997-1-maennich@google.com> Message-Id: <20191018093143.15997-2-maennich@google.com> Mime-Version: 1.0 References: <20191010151443.7399-1-maennich@google.com> <20191018093143.15997-1-maennich@google.com> X-Mailer: git-send-email 2.23.0.866.gb869b98d4c-goog Subject: [PATCH v2 1/4] modpost: delegate updating namespaces to separate function From: Matthias Maennich To: linux-kernel@vger.kernel.org Cc: kernel-team@android.com, maennich@google.com, Jessica Yu , Masahiro Yamada , Martijn Coenen , Lucas De Marchi , Shaun Ruffell , Greg Kroah-Hartman , Will Deacon , linux-kbuild@vger.kernel.org, linux-modules@vger.kernel.org Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org Let the function 'sym_update_namespace' take care of updating the namespace for a symbol. While this currently only replaces one single location where namespaces are updated, in a following patch, this function will get more call sites. The function signature is intentionally close to sym_update_crc and taking the name by char* seems like unnecessary work as the symbol has to be looked up again. In a later patch of this series, this concern will be addressed. This function ensures that symbol::namespace is either NULL or has a valid non-empty value. Previously, the empty string was considered 'no namespace' as well and this lead to confusion. Acked-by: Will Deacon Reviewed-by: Greg Kroah-Hartman Reviewed-by: Masahiro Yamada Signed-off-by: Matthias Maennich --- scripts/mod/modpost.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 4d2cdb4d71e3..dbfa3997136b 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -362,6 +362,25 @@ static char *sym_extract_namespace(const char **symname) return namespace; } +static void sym_update_namespace(const char *symname, const char *namespace) +{ + struct symbol *s = find_symbol(symname); + + /* + * That symbol should have been created earlier and thus this is + * actually an assertion. + */ + if (!s) { + merror("Could not update namespace(%s) for symbol %s\n", + namespace, symname); + return; + } + + free(s->namespace); + s->namespace = + namespace && namespace[0] ? NOFAIL(strdup(namespace)) : NULL; +} + /** * Add an exported symbol - it may have already been added without a * CRC, in this case just update the CRC @@ -383,8 +402,7 @@ static struct symbol *sym_add_exported(const char *name, const char *namespace, s->module = mod; } } - free(s->namespace); - s->namespace = namespace ? strdup(namespace) : NULL; + sym_update_namespace(name, namespace); s->preloaded = 0; s->vmlinux = is_vmlinux(mod->name); s->kernel = 0; @@ -2196,7 +2214,7 @@ static int check_exports(struct module *mod) else basename = mod->name; - if (exp->namespace && exp->namespace[0]) { + if (exp->namespace) { add_namespace(&mod->required_namespaces, exp->namespace); From patchwork Fri Oct 18 09:31:41 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthias Maennich X-Patchwork-Id: 11197871 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 E8C78913 for ; Fri, 18 Oct 2019 09:32:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C6F0921852 for ; Fri, 18 Oct 2019 09:32:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Hp4pTQtB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2409767AbfJRJcF (ORCPT ); Fri, 18 Oct 2019 05:32:05 -0400 Received: from mail-ua1-f74.google.com ([209.85.222.74]:38062 "EHLO mail-ua1-f74.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2409765AbfJRJcF (ORCPT ); Fri, 18 Oct 2019 05:32:05 -0400 Received: by mail-ua1-f74.google.com with SMTP id 46so693116uar.5 for ; Fri, 18 Oct 2019 02:32:03 -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=EbDe35gaiTVD4DdjxfTK6/lBi6D37axpnOTT3faN+u8=; b=Hp4pTQtB9H4RzTPhCrvqp4ZAYKpXP3AD+MX8LyGiDmbLYtie3H71Obdi2ZdPk48O/9 IzeOd8HzVA4+00CRvw1BKb+mEycLjYcfYT332AX/eM0g0+XWru9uSvTAg9qSk941PoBM jXlrd9JWLr4741yiIyNqAPJleZLYvOJ0VkiNTOWL6Lrkm70aCX5m2NeQhVWWY2YTiBLB QDfv9miNQSAuoU2jJSHcnv/10QlUf0PZCLoNrwTIfUQJOb0wpebDe4utZhurY7lcrgXI Qlt+/Ef2izmFl5KH2zJqpcTxDf07SNQgsLeqpZ7AZ1QMb7ZnD04agTHs/5oJxFY1Z3D8 u1gA== 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=EbDe35gaiTVD4DdjxfTK6/lBi6D37axpnOTT3faN+u8=; b=uVNgrU94RyW5ybONHJT6yQWApxrVFpKJJRDr+MxFXCZ8YZOv5Ve6UtmHbQy6EbjmPx moJ+K2rHeBjHeMI/STQX/dWt00W2BYelLX5SJ1jbkB/bc3v6Tl+RlCVE2HbH8OJAYCJ4 Cg/k34t3yrU69nFA1+rNb+sxCsVqBdeS+EnalYLQshi/grk43SlVUhR6g0MyrpMQQ5V/ c1dudRX8s7gSXQ4uZErvKW9qHEojUeR7Tgx6SfVsVzlekCscSfJMjYMnHY8libQX4DeA A5yWGCda6Vi1yKhM2d+lb3k/RO0GIY99lF5vZHkgazQJyx4ZyekD18FDyyUGVUVp57wU dBrA== X-Gm-Message-State: APjAAAUfI9qt24P4FWKGsOqs9YwcypjyKajXp8x2NDocNtLrHd+R6Kwz hKxMytu6Pe4Aza/wMUhDNJ9yM54AawX5fw== X-Google-Smtp-Source: APXvYqwm3JAaNGrRLhYAGqlufSc7y18VjyaCGOOtM/NFeuOAcMJCuEDGObXhxBPuIsiRjCfS+atlYIa8HihUPg== X-Received: by 2002:a05:6122:2bb:: with SMTP id 27mr4754455vkq.66.1571391122450; Fri, 18 Oct 2019 02:32:02 -0700 (PDT) Date: Fri, 18 Oct 2019 10:31:41 +0100 In-Reply-To: <20191018093143.15997-1-maennich@google.com> Message-Id: <20191018093143.15997-3-maennich@google.com> Mime-Version: 1.0 References: <20191010151443.7399-1-maennich@google.com> <20191018093143.15997-1-maennich@google.com> X-Mailer: git-send-email 2.23.0.866.gb869b98d4c-goog Subject: [PATCH v2 2/4] modpost: make updating the symbol namespace explicit From: Matthias Maennich To: linux-kernel@vger.kernel.org Cc: kernel-team@android.com, maennich@google.com, Jessica Yu , Masahiro Yamada , Martijn Coenen , Lucas De Marchi , Shaun Ruffell , Greg Kroah-Hartman , Will Deacon , linux-kbuild@vger.kernel.org, linux-modules@vger.kernel.org Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org Setting the symbol namespace of a symbol within sym_add_exported feels displaced and lead to issues in the current implementation of symbol namespaces. This patch makes updating the namespace an explicit call to decouple it from adding a symbol to the export list. Acked-by: Will Deacon Reviewed-by: Greg Kroah-Hartman Reviewed-by: Masahiro Yamada Signed-off-by: Matthias Maennich --- scripts/mod/modpost.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index dbfa3997136b..95b1eac656aa 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -385,8 +385,8 @@ static void sym_update_namespace(const char *symname, const char *namespace) * 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, const char *namespace, - struct module *mod, enum export export) +static struct symbol *sym_add_exported(const char *name, struct module *mod, + enum export export) { struct symbol *s = find_symbol(name); @@ -402,7 +402,6 @@ static struct symbol *sym_add_exported(const char *name, const char *namespace, s->module = mod; } } - sym_update_namespace(name, namespace); s->preloaded = 0; s->vmlinux = is_vmlinux(mod->name); s->kernel = 0; @@ -764,7 +763,8 @@ static void handle_modversions(struct module *mod, struct elf_info *info, if (strstarts(symname, "__ksymtab_")) { name = symname + strlen("__ksymtab_"); namespace = sym_extract_namespace(&name); - sym_add_exported(name, namespace, mod, export); + sym_add_exported(name, mod, export); + sym_update_namespace(name, namespace); free(namespace); } if (strcmp(symname, "init_module") == 0) @@ -2472,12 +2472,12 @@ static void read_dump(const char *fname, unsigned int kernel) mod = new_module(modname); mod->skip = 1; } - s = sym_add_exported(symname, namespace, mod, - export_no(export)); + s = sym_add_exported(symname, mod, export_no(export)); s->kernel = kernel; s->preloaded = 1; s->is_static = 0; sym_update_crc(symname, mod, crc, export_no(export)); + sym_update_namespace(symname, namespace); } release_file(file, size); return; From patchwork Fri Oct 18 09:31:42 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthias Maennich X-Patchwork-Id: 11197873 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 CD198913 for ; Fri, 18 Oct 2019 09:32:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A469821852 for ; Fri, 18 Oct 2019 09:32:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="UuMXbS1V" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2409779AbfJRJcH (ORCPT ); Fri, 18 Oct 2019 05:32:07 -0400 Received: from mail-vk1-f201.google.com ([209.85.221.201]:44217 "EHLO mail-vk1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2409764AbfJRJcH (ORCPT ); Fri, 18 Oct 2019 05:32:07 -0400 Received: by mail-vk1-f201.google.com with SMTP id b204so2134780vkb.11 for ; Fri, 18 Oct 2019 02:32:06 -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=w96IBFa+LbhPv1tMNCO5lO3g8Rc4+dCAyv83kBM1KbQ=; b=UuMXbS1VDXSrzg400/ZlVcUiZJtpa/YrjX2duCZgzlqBt37ATXDNGUA5Lomr2S98Zo gb89rsts8JNDeagiZNGwvA4LAFHapDI3AgZZAmjI9iKlB6pyzsvupyZySFMKdsIS/NPn QUflCT1aK2m7QD1JrVHDnJu5vafPXa78Qpt3/l9vgnkMPBXRGxIjOpJGiUV7JuUvGyiL 1AwhI97fb6ohGuPxupLhHuFdjSYojeD1VNYTT5qZ/MJoy8TBwDXPWhS4UGC9lqjgq7Qa XVNJBhA9udIzTffkcorFGOIqcVKYHZwE4RWpMf9l8oEfVW8wczIZ0outmdoG9aU8++NR HduA== 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=w96IBFa+LbhPv1tMNCO5lO3g8Rc4+dCAyv83kBM1KbQ=; b=PD/hIObyyQDNNfX0D09NAF0H1skDgO7CUZKDCGCBhbWY6v8s4vYzt6VA8uvSH1qhR/ vDwzls1EmwON/Ai4JAMCD7qr/15YRmPDfi4E8Vy3YYNdbu3oUjkdvgMLMbb4dKq8hf+e pUjbzJHFJjrKKEw/Y05OywEX1nft39BKbd1NB1+9a9UoQW+Rcg7g+nWMhZVf3MEMVFqk FU55Z9j9YvnWiTs7kvWX93Y1GrEd6z8Dd4nEAFAgr/lpVlxMyEvpnphJ599aoKYjrxvo s3GSezSYbrflvDsAbTkJNM3aBB+D/gWnSaV4wUZkOh8GE16kwODT+ikjEsCAYGqMI6/s 315w== X-Gm-Message-State: APjAAAUU8J46d3hoHUKi24c/PkahlTYWcBh1B7jQyOLZoESOkOE7ivV4 jBImhf/LKN2i9mfi6Qgsm3Y85IPkJrF1SA== X-Google-Smtp-Source: APXvYqx0I59HdbOYdXZ8mLY4td8zpIb3GxCjwY5MOrKW1sOkSQ0BwBPKSyMC8VAXMcnGQ4CsxgRvSBIki69F7A== X-Received: by 2002:a67:c50d:: with SMTP id e13mr4853730vsk.88.1571391125373; Fri, 18 Oct 2019 02:32:05 -0700 (PDT) Date: Fri, 18 Oct 2019 10:31:42 +0100 In-Reply-To: <20191018093143.15997-1-maennich@google.com> Message-Id: <20191018093143.15997-4-maennich@google.com> Mime-Version: 1.0 References: <20191010151443.7399-1-maennich@google.com> <20191018093143.15997-1-maennich@google.com> X-Mailer: git-send-email 2.23.0.866.gb869b98d4c-goog Subject: [PATCH v2 3/4] symbol namespaces: revert to previous __ksymtab name scheme From: Matthias Maennich To: linux-kernel@vger.kernel.org Cc: kernel-team@android.com, maennich@google.com, Jessica Yu , Masahiro Yamada , Martijn Coenen , Lucas De Marchi , Shaun Ruffell , Greg Kroah-Hartman , Will Deacon , linux-kbuild@vger.kernel.org, linux-modules@vger.kernel.org, Stefan Wahren Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org The introduction of Symbol Namespaces changed the naming schema of the __ksymtab entries from __kysmtab__symbol to __ksymtab_NAMESPACE.symbol. That caused some breakages in tools that depend on the name layout in either the binaries(vmlinux,*.ko) or in System.map. E.g. kmod's depmod would not be able to read System.map without a patch to support symbol namespaces. A warning reported by depmod for namespaced symbols would look like depmod: WARNING: [...]/uas.ko needs unknown symbol usb_stor_adjust_quirks In order to address this issue, revert to the original naming scheme and rather read the __kstrtabns_ entries and their corresponding values from __ksymtab_strings to update the namespace values for symbols. After having read all symbols and handled them in handle_modversions(), the symbols are created. In a second pass, read the __kstrtabns_ entries and update the namespaces accordingly. Reported-by: Stefan Wahren Suggested-by: Masahiro Yamada Fixes: 8651ec01daed ("module: add support for symbol namespaces.") Acked-by: Will Deacon Reviewed-by: Greg Kroah-Hartman Reviewed-by: Masahiro Yamada Signed-off-by: Matthias Maennich --- include/linux/export.h | 14 +++++--------- scripts/mod/modpost.c | 33 ++++++++++++++++++--------------- scripts/mod/modpost.h | 1 + 3 files changed, 24 insertions(+), 24 deletions(-) diff --git a/include/linux/export.h b/include/linux/export.h index 621158ecd2e2..941d075f03d6 100644 --- a/include/linux/export.h +++ b/include/linux/export.h @@ -18,8 +18,6 @@ extern struct module __this_module; #define THIS_MODULE ((struct module *)0) #endif -#define NS_SEPARATOR "." - #ifdef CONFIG_MODVERSIONS /* Mark the CRC weak since genksyms apparently decides not to * generate a checksums for some symbols */ @@ -48,11 +46,11 @@ extern struct module __this_module; * absolute relocations that require runtime processing on relocatable * kernels. */ -#define __KSYMTAB_ENTRY_NS(sym, sec, ns) \ +#define __KSYMTAB_ENTRY_NS(sym, sec) \ __ADDRESSABLE(sym) \ asm(" .section \"___ksymtab" sec "+" #sym "\", \"a\" \n" \ " .balign 4 \n" \ - "__ksymtab_" #ns NS_SEPARATOR #sym ": \n" \ + "__ksymtab_" #sym ": \n" \ " .long " #sym "- . \n" \ " .long __kstrtab_" #sym "- . \n" \ " .long __kstrtabns_" #sym "- . \n" \ @@ -74,16 +72,14 @@ struct kernel_symbol { int namespace_offset; }; #else -#define __KSYMTAB_ENTRY_NS(sym, sec, ns) \ - static const struct kernel_symbol __ksymtab_##sym##__##ns \ - asm("__ksymtab_" #ns NS_SEPARATOR #sym) \ +#define __KSYMTAB_ENTRY_NS(sym, sec) \ + static const struct kernel_symbol __ksymtab_##sym \ __attribute__((section("___ksymtab" sec "+" #sym), used)) \ __aligned(sizeof(void *)) \ = { (unsigned long)&sym, __kstrtab_##sym, __kstrtabns_##sym } #define __KSYMTAB_ENTRY(sym, sec) \ static const struct kernel_symbol __ksymtab_##sym \ - asm("__ksymtab_" #sym) \ __attribute__((section("___ksymtab" sec "+" #sym), used)) \ __aligned(sizeof(void *)) \ = { (unsigned long)&sym, __kstrtab_##sym, NULL } @@ -115,7 +111,7 @@ struct kernel_symbol { static const char __kstrtabns_##sym[] \ __attribute__((section("__ksymtab_strings"), used, aligned(1))) \ = #ns; \ - __KSYMTAB_ENTRY_NS(sym, sec, ns) + __KSYMTAB_ENTRY_NS(sym, sec) #define ___EXPORT_SYMBOL(sym, sec) \ ___export_symbol_common(sym, sec); \ diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 95b1eac656aa..0bf7eab80d9f 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -348,18 +348,11 @@ static enum export export_from_sec(struct elf_info *elf, unsigned int sec) return export_unknown; } -static char *sym_extract_namespace(const char **symname) +static const char *namespace_from_kstrtabns(struct elf_info *info, + Elf_Sym *kstrtabns) { - char *namespace = NULL; - char *ns_separator; - - ns_separator = strchr(*symname, '.'); - if (ns_separator) { - namespace = NOFAIL(strndup(*symname, ns_separator - *symname)); - *symname = ns_separator + 1; - } - - return namespace; + char *value = info->ksymtab_strings + kstrtabns->st_value; + return value[0] ? value : NULL; } static void sym_update_namespace(const char *symname, const char *namespace) @@ -600,6 +593,10 @@ static int parse_elf(struct elf_info *info, const char *filename) info->export_unused_gpl_sec = i; else if (strcmp(secname, "__ksymtab_gpl_future") == 0) info->export_gpl_future_sec = i; + else if (strcmp(secname, "__ksymtab_strings") == 0) + info->ksymtab_strings = (void *)hdr + + sechdrs[i].sh_offset - + sechdrs[i].sh_addr; if (sechdrs[i].sh_type == SHT_SYMTAB) { unsigned int sh_link_idx; @@ -689,7 +686,6 @@ static void handle_modversions(struct module *mod, struct elf_info *info, enum export export; bool is_crc = false; const char *name; - char *namespace; if ((!is_vmlinux(mod->name) || mod->is_dot_o) && strstarts(symname, "__ksymtab")) @@ -762,10 +758,7 @@ static void handle_modversions(struct module *mod, struct elf_info *info, /* All exported symbols */ if (strstarts(symname, "__ksymtab_")) { name = symname + strlen("__ksymtab_"); - namespace = sym_extract_namespace(&name); sym_add_exported(name, mod, export); - sym_update_namespace(name, namespace); - free(namespace); } if (strcmp(symname, "init_module") == 0) mod->has_init = 1; @@ -2061,6 +2054,16 @@ static void read_symbols(const char *modname) handle_moddevtable(mod, &info, sym, symname); } + /* Apply symbol namespaces from __kstrtabns_ entries. */ + for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { + symname = remove_dot(info.strtab + sym->st_name); + + if (strstarts(symname, "__kstrtabns_")) + sym_update_namespace(symname + strlen("__kstrtabns_"), + namespace_from_kstrtabns(&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); diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h index 92a926d375d2..ad271bc6c313 100644 --- a/scripts/mod/modpost.h +++ b/scripts/mod/modpost.h @@ -143,6 +143,7 @@ struct elf_info { Elf_Section export_gpl_sec; Elf_Section export_unused_gpl_sec; Elf_Section export_gpl_future_sec; + char *ksymtab_strings; char *strtab; char *modinfo; unsigned int modinfo_len; From patchwork Fri Oct 18 09:31:43 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthias Maennich X-Patchwork-Id: 11197877 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 6E260913 for ; Fri, 18 Oct 2019 09:32:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3B4B9222C9 for ; Fri, 18 Oct 2019 09:32:19 +0000 (UTC) Authentication-Results: mail.kernel.org; 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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=EOYWaebnqr4bdUqKvgBWQLBw0XpiuWDYFAjzzlBAHXY=; b=D93MN3fFNTABKTGlF0/6IrTtkWYOPYBp+InCjmJf8QoFGLUB8/tlPeiWG5kIH+nffV JYSRorRqXcTZCnje99w3tvVinkvF44SiqhNkLitXVduSiGb5EHkCBMZ4s3o7+ok9Qm1W jt8DPp/r5ZPPvA9oRsk6WtrYH4eYS2lyjIMRz7wu57oD3LD9i4X5U3DkTz9rt/yhH3B8 wP4oiHtF0sDyRLVNjdbRii7adKFK7ahvIYW9IrFz9RiTpkrzIN6pTbtanwt0iekYZEdS YoCdNf7YZy/lDinS8ZFLO4d/hR07SBf/rY40gsHKHTJxwFi9c2tQauj6c6rXyJXDvH2Z 7fMg== X-Gm-Message-State: APjAAAVqd0bGlXUEBdvzBNumjXck1MvYyAVFZ2YU77o4SPkncj/xfJp6 b2V48eSnbqL7vR9nL3ecwtLtx3YLMYlz2A== X-Google-Smtp-Source: APXvYqzV1MEOz6axUddoEVlXVgpVxUdOImVrI2s3/ru+G9PNxije8sd8fJb3N8JtJ6Z6C2Ks4dOOxo6KZfdllw== X-Received: by 2002:adf:ed02:: with SMTP id a2mr6764291wro.11.1571391127786; Fri, 18 Oct 2019 02:32:07 -0700 (PDT) Date: Fri, 18 Oct 2019 10:31:43 +0100 In-Reply-To: <20191018093143.15997-1-maennich@google.com> Message-Id: <20191018093143.15997-5-maennich@google.com> Mime-Version: 1.0 References: <20191010151443.7399-1-maennich@google.com> <20191018093143.15997-1-maennich@google.com> X-Mailer: git-send-email 2.23.0.866.gb869b98d4c-goog Subject: [PATCH v2 4/4] export: avoid code duplication in include/linux/export.h From: Matthias Maennich To: linux-kernel@vger.kernel.org Cc: kernel-team@android.com, maennich@google.com, Jessica Yu , Masahiro Yamada , Martijn Coenen , Lucas De Marchi , Shaun Ruffell , Greg Kroah-Hartman , Will Deacon , linux-kbuild@vger.kernel.org, linux-modules@vger.kernel.org Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org From: Masahiro Yamada include/linux/export.h has lots of code duplication between EXPORT_SYMBOL and EXPORT_SYMBOL_NS. To improve the maintainability and readability, unify the implementation. When the symbol has no namespace, pass the empty string "" to the 'ns' parameter. The drawback of this change is, it grows the code size. When the symbol has no namespace, sym->namespace was previously NULL, but it is now an empty string "". So, it increases 1 byte for every no namespace EXPORT_SYMBOL. A typical kernel configuration has 10K exported symbols, so it increases 10KB in rough estimation. I did not come up with a good idea to refactor it without increasing the code size. I am not sure how big a deal it is, but at least include/linux/export.h looks nicer. Reviewed-by: Greg Kroah-Hartman Signed-off-by: Masahiro Yamada [maennich: rebase on top of 3 fixes for the namespace feature] Signed-off-by: Matthias Maennich --- include/linux/export.h | 91 +++++++++++++----------------------------- kernel/module.c | 2 +- 2 files changed, 29 insertions(+), 64 deletions(-) diff --git a/include/linux/export.h b/include/linux/export.h index 941d075f03d6..201262793369 100644 --- a/include/linux/export.h +++ b/include/linux/export.h @@ -46,7 +46,7 @@ extern struct module __this_module; * absolute relocations that require runtime processing on relocatable * kernels. */ -#define __KSYMTAB_ENTRY_NS(sym, sec) \ +#define __KSYMTAB_ENTRY(sym, sec) \ __ADDRESSABLE(sym) \ asm(" .section \"___ksymtab" sec "+" #sym "\", \"a\" \n" \ " .balign 4 \n" \ @@ -56,33 +56,17 @@ extern struct module __this_module; " .long __kstrtabns_" #sym "- . \n" \ " .previous \n") -#define __KSYMTAB_ENTRY(sym, sec) \ - __ADDRESSABLE(sym) \ - asm(" .section \"___ksymtab" sec "+" #sym "\", \"a\" \n" \ - " .balign 4 \n" \ - "__ksymtab_" #sym ": \n" \ - " .long " #sym "- . \n" \ - " .long __kstrtab_" #sym "- . \n" \ - " .long 0 \n" \ - " .previous \n") - struct kernel_symbol { int value_offset; int name_offset; int namespace_offset; }; #else -#define __KSYMTAB_ENTRY_NS(sym, sec) \ - static const struct kernel_symbol __ksymtab_##sym \ - __attribute__((section("___ksymtab" sec "+" #sym), used)) \ - __aligned(sizeof(void *)) \ - = { (unsigned long)&sym, __kstrtab_##sym, __kstrtabns_##sym } - #define __KSYMTAB_ENTRY(sym, sec) \ static const struct kernel_symbol __ksymtab_##sym \ __attribute__((section("___ksymtab" sec "+" #sym), used)) \ __aligned(sizeof(void *)) \ - = { (unsigned long)&sym, __kstrtab_##sym, NULL } + = { (unsigned long)&sym, __kstrtab_##sym, __kstrtabns_##sym } struct kernel_symbol { unsigned long value; @@ -93,28 +77,20 @@ struct kernel_symbol { #ifdef __GENKSYMS__ -#define ___EXPORT_SYMBOL(sym,sec) __GENKSYMS_EXPORT_SYMBOL(sym) -#define ___EXPORT_SYMBOL_NS(sym,sec,ns) __GENKSYMS_EXPORT_SYMBOL(sym) +#define ___EXPORT_SYMBOL(sym, sec, ns) __GENKSYMS_EXPORT_SYMBOL(sym) #else -#define ___export_symbol_common(sym, sec) \ +/* For every exported symbol, place a struct in the __ksymtab section */ +#define ___EXPORT_SYMBOL(sym, sec, ns) \ extern typeof(sym) sym; \ __CRC_SYMBOL(sym, sec); \ static const char __kstrtab_##sym[] \ __attribute__((section("__ksymtab_strings"), used, aligned(1))) \ - = #sym \ - -/* For every exported symbol, place a struct in the __ksymtab section */ -#define ___EXPORT_SYMBOL_NS(sym, sec, ns) \ - ___export_symbol_common(sym, sec); \ + = #sym; \ static const char __kstrtabns_##sym[] \ __attribute__((section("__ksymtab_strings"), used, aligned(1))) \ - = #ns; \ - __KSYMTAB_ENTRY_NS(sym, sec) - -#define ___EXPORT_SYMBOL(sym, sec) \ - ___export_symbol_common(sym, sec); \ + = ns; \ __KSYMTAB_ENTRY(sym, sec) #endif @@ -126,8 +102,7 @@ struct kernel_symbol { * be reused in other execution contexts such as the UEFI stub or the * decompressor. */ -#define __EXPORT_SYMBOL_NS(sym, sec, ns) -#define __EXPORT_SYMBOL(sym, sec) +#define __EXPORT_SYMBOL(sym, sec, ns) #elif defined(CONFIG_TRIM_UNUSED_KSYMS) @@ -143,48 +118,38 @@ struct kernel_symbol { #define __ksym_marker(sym) \ static int __ksym_marker_##sym[0] __section(".discard.ksym") __used -#define __EXPORT_SYMBOL(sym, sec) \ - __ksym_marker(sym); \ - __cond_export_sym(sym, sec, __is_defined(__KSYM_##sym)) -#define __cond_export_sym(sym, sec, conf) \ - ___cond_export_sym(sym, sec, conf) -#define ___cond_export_sym(sym, sec, enabled) \ - __cond_export_sym_##enabled(sym, sec) -#define __cond_export_sym_1(sym, sec) ___EXPORT_SYMBOL(sym, sec) -#define __cond_export_sym_0(sym, sec) /* nothing */ - -#define __EXPORT_SYMBOL_NS(sym, sec, ns) \ +#define __EXPORT_SYMBOL(sym, sec, ns) \ __ksym_marker(sym); \ - __cond_export_ns_sym(sym, sec, ns, __is_defined(__KSYM_##sym)) -#define __cond_export_ns_sym(sym, sec, ns, conf) \ - ___cond_export_ns_sym(sym, sec, ns, conf) -#define ___cond_export_ns_sym(sym, sec, ns, enabled) \ - __cond_export_ns_sym_##enabled(sym, sec, ns) -#define __cond_export_ns_sym_1(sym, sec, ns) ___EXPORT_SYMBOL_NS(sym, sec, ns) -#define __cond_export_ns_sym_0(sym, sec, ns) /* nothing */ + __cond_export_sym(sym, sec, ns, __is_defined(__KSYM_##sym)) +#define __cond_export_sym(sym, sec, ns, conf) \ + ___cond_export_sym(sym, sec, ns, conf) +#define ___cond_export_sym(sym, sec, ns, enabled) \ + __cond_export_sym_##enabled(sym, sec, ns) +#define __cond_export_sym_1(sym, sec, ns) ___EXPORT_SYMBOL(sym, sec, ns) +#define __cond_export_sym_0(sym, sec, ns) /* nothing */ #else -#define __EXPORT_SYMBOL_NS(sym,sec,ns) ___EXPORT_SYMBOL_NS(sym,sec,ns) -#define __EXPORT_SYMBOL(sym,sec) ___EXPORT_SYMBOL(sym,sec) +#define __EXPORT_SYMBOL(sym, sec, ns) ___EXPORT_SYMBOL(sym, sec, ns) #endif /* CONFIG_MODULES */ #ifdef DEFAULT_SYMBOL_NAMESPACE -#undef __EXPORT_SYMBOL -#define __EXPORT_SYMBOL(sym, sec) \ - __EXPORT_SYMBOL_NS(sym, sec, DEFAULT_SYMBOL_NAMESPACE) +#include +#define _EXPORT_SYMBOL(sym, sec) __EXPORT_SYMBOL(sym, sec, __stringify(DEFAULT_SYMBOL_NAMESPACE)) +#else +#define _EXPORT_SYMBOL(sym, sec) __EXPORT_SYMBOL(sym, sec, "") #endif -#define EXPORT_SYMBOL(sym) __EXPORT_SYMBOL(sym, "") -#define EXPORT_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_gpl") -#define EXPORT_SYMBOL_GPL_FUTURE(sym) __EXPORT_SYMBOL(sym, "_gpl_future") -#define EXPORT_SYMBOL_NS(sym, ns) __EXPORT_SYMBOL_NS(sym, "", ns) -#define EXPORT_SYMBOL_NS_GPL(sym, ns) __EXPORT_SYMBOL_NS(sym, "_gpl", ns) +#define EXPORT_SYMBOL(sym) _EXPORT_SYMBOL(sym, "") +#define EXPORT_SYMBOL_GPL(sym) _EXPORT_SYMBOL(sym, "_gpl") +#define EXPORT_SYMBOL_GPL_FUTURE(sym) _EXPORT_SYMBOL(sym, "_gpl_future") +#define EXPORT_SYMBOL_NS(sym, ns) __EXPORT_SYMBOL(sym, "", #ns) +#define EXPORT_SYMBOL_NS_GPL(sym, ns) __EXPORT_SYMBOL(sym, "_gpl", #ns) #ifdef CONFIG_UNUSED_SYMBOLS -#define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused") -#define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl") +#define EXPORT_UNUSED_SYMBOL(sym) _EXPORT_SYMBOL(sym, "_unused") +#define EXPORT_UNUSED_SYMBOL_GPL(sym) _EXPORT_SYMBOL(sym, "_unused_gpl") #else #define EXPORT_UNUSED_SYMBOL(sym) #define EXPORT_UNUSED_SYMBOL_GPL(sym) diff --git a/kernel/module.c b/kernel/module.c index ff2d7359a418..26c13173da3d 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1400,7 +1400,7 @@ static int verify_namespace_is_imported(const struct load_info *info, char *imported_namespace; namespace = kernel_symbol_namespace(sym); - if (namespace) { + if (namespace && namespace[0]) { imported_namespace = get_modinfo(info, "import_ns"); while (imported_namespace) { if (strcmp(namespace, imported_namespace) == 0)