From patchwork Tue Jun 25 06:15:05 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 11014775 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E9A13112C for ; Tue, 25 Jun 2019 06:15:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D93E326E56 for ; Tue, 25 Jun 2019 06:15:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CDE0D28658; Tue, 25 Jun 2019 06:15:35 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E1C9A26E73 for ; Tue, 25 Jun 2019 06:15:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729149AbfFYGPe (ORCPT ); Tue, 25 Jun 2019 02:15:34 -0400 Received: from conuserg-12.nifty.com ([210.131.2.79]:49502 "EHLO conuserg-12.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726495AbfFYGPe (ORCPT ); Tue, 25 Jun 2019 02:15:34 -0400 Received: from pug.e01.socionext.com (p14092-ipngnfx01kyoto.kyoto.ocn.ne.jp [153.142.97.92]) (authenticated) by conuserg-12.nifty.com with ESMTP id x5P6FPWt021421; Tue, 25 Jun 2019 15:15:25 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-12.nifty.com x5P6FPWt021421 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1561443325; bh=niTmtVxWpZ2hyzHyFc7bG1KkBiNgtu3U3WVbxtL8umU=; h=From:To:Cc:Subject:Date:From; b=CkNE3X5pjbVxOxivrGRh6Bbb2pepJUSuvOsS8cdeF/9ww/ZoNbK1mv6u4CulgC2uv jjCj9/Gmr0A1XTlomrFpJtrrkSTdnkxDXv3QJ5tNVwzEVss6NRaNxkwHJ5RMwKVuS+ DhXnRbNFBG2TRBr8TqN3DuwvV/8rajTWf3+7L6y7f4C3nybP1JuUA+dT9RpPJI5Sin oWqwJLc8+vcqnBaRSjVW0frG1+m34U/UJ/aVsvFeBGAqXUlEx/XrVk3Vf+oP5pl1Ap lBI6tRGd8YbQOugX3G5MVVgfbkdUthNSSyrmGSOwpiP1nvwJVOEZTjHo8KklbwQK1o OjxAwpccESVaw== X-Nifty-SrcIP: [153.142.97.92] From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: Masahiro Yamada , Michal Marek , linux-kernel@vger.kernel.org Subject: [PATCH] fixdep: check return code of printf() and putchar() Date: Tue, 25 Jun 2019 15:15:05 +0900 Message-Id: <20190625061505.30107-1-yamada.masahiro@socionext.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When there is not enough space on your storage device, the build will fail with 'No space left on device' error message. The reason is obvious from the message, so you will free up some disk space, then you will resume the build. However, sometimes you may still see a mysterious error message: unterminated call to function 'wildcard': missing ')'. If you run out of the disk space, fixdep may end up with generating incomplete .*.cmd files. For example, if the disk shortage occurs while fixdep is running print_dep(), the .*.cmd might be truncated like this: $(wildcard include/config/ When you run 'make' next time, this broken .*.cmd will be included, then GNU Make will terminate parsing since it is a wrong syntax. Once this happens, you need to run 'make clean' or delete the broken .*.cmd file manually. Even if you do not see any error message, the .*.cmd files after any error could be potentially incomplete, and unreliable. You may miss the re-compilation due to missing header dependency. If printf() cannot output the string for disk shortage or whatever reason, it returns a negative return code, but currently fixdep does not check it at all. Consequently, fixdep *successfully* generates a broken .*.cmd file. Make never notices that since fixdep exits with 0, which means success. Given the intended usage of fixdep, it must respect the return code of not only malloc(), but also printf() and putchar(). This seems a long-standing issue since the introduction of fixdep. In old days, Kbuild tried to provide an extra safety by letting fixdep output to a temporary file and renaming it after everything is done: scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\ rm -f $(depfile); \ mv -f $(dot-target).tmp $(dot-target).cmd) It did not avoid the current issue; fixdep created a truncated tmp file reporting success, so the broken tmp would be renamed to a .*.cmd file. By propagating the error code to the build system, this problem should be solved because: [1] Since commit 9c2af1c7377a ("kbuild: add .DELETE_ON_ERROR special target"), Make will delete the target automatically on any failure in the recipe. [2] Since commit 392885ee82d3 ("kbuild: let fixdep directly write to .*.cmd files"), .*.cmd file is included only when the corresponding target already exists. Signed-off-by: Masahiro Yamada --- scripts/basic/fixdep.c | 47 +++++++++++++++++++++++++++++++++--------- 1 file changed, 37 insertions(+), 10 deletions(-) diff --git a/scripts/basic/fixdep.c b/scripts/basic/fixdep.c index facbd603adf6..fea1d58bda68 100644 --- a/scripts/basic/fixdep.c +++ b/scripts/basic/fixdep.c @@ -99,6 +99,7 @@ #include #include #include +#include #include #include #include @@ -109,6 +110,32 @@ static void usage(void) exit(1); } +/* + * In the intended usage of this program, the stdout is redirected to .*.cmd + * The return code of printf() and putchar() must be checked to catch any error + * like "No space left on device". + */ +static void xprintf(const char *format, ...) +{ + va_list ap; + int ret; + + va_start(ap, format); + ret = vprintf(format, ap); + if (ret < 0) + exit(1); + va_end(ap); +} + +static void xputchar(int c) +{ + int ret; + + ret = putchar(c); + if (ret == EOF) + exit(1); +} + /* * Print out a dependency path from a symbol name */ @@ -116,7 +143,7 @@ static void print_dep(const char *m, int slen, const char *dir) { int c, prev_c = '/', i; - printf(" $(wildcard %s/", dir); + xprintf(" $(wildcard %s/", dir); for (i = 0; i < slen; i++) { c = m[i]; if (c == '_') @@ -124,10 +151,10 @@ static void print_dep(const char *m, int slen, const char *dir) else c = tolower(c); if (c != '/' || prev_c != '/') - putchar(c); + xputchar(c); prev_c = c; } - printf(".h) \\\n"); + xprintf(".h) \\\n"); } struct item { @@ -324,13 +351,13 @@ static void parse_dep_file(char *m, const char *target) */ if (!saw_any_target) { saw_any_target = 1; - printf("source_%s := %s\n\n", - target, m); - printf("deps_%s := \\\n", target); + xprintf("source_%s := %s\n\n", + target, m); + xprintf("deps_%s := \\\n", target); } is_first_dep = 0; } else { - printf(" %s \\\n", m); + xprintf(" %s \\\n", m); } buf = read_file(m); @@ -353,8 +380,8 @@ static void parse_dep_file(char *m, const char *target) exit(1); } - printf("\n%s: $(deps_%s)\n\n", target, target); - printf("$(deps_%s):\n", target); + xprintf("\n%s: $(deps_%s)\n\n", target, target); + xprintf("$(deps_%s):\n", target); } int main(int argc, char *argv[]) @@ -369,7 +396,7 @@ int main(int argc, char *argv[]) target = argv[2]; cmdline = argv[3]; - printf("cmd_%s := %s\n\n", target, cmdline); + xprintf("cmd_%s := %s\n\n", target, cmdline); buf = read_file(depfile); parse_dep_file(buf, target);