From patchwork Tue Jan 5 18:58:12 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adhemerval Zanella Netto X-Patchwork-Id: 41641 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 90667393BC34; Tue, 5 Jan 2021 18:58:31 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 90667393BC34 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1609873111; bh=qBwfT61Ck2CSE40N1pXmE1sAX8vTlxIVFOw7OwRdEec=; h=To:Subject:Date:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:From; b=t9/O9mCmli5iqWzvi0ww9mpE8F/uQlw9NaM6EYKLvlE3x+iy8i2o9S45A/H28MnCu VyY8t58VnTauSZjFHisJ8XwAPAhBT9IVfE+WMkoWj4GqA/uN5KNDJxIggk7TJj7wYB WbmKHiJmQV/AZNgw1KgOP07TpegGeBGw8ByaHz6c= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from mail-qk1-x730.google.com (mail-qk1-x730.google.com [IPv6:2607:f8b0:4864:20::730]) by sourceware.org (Postfix) with ESMTPS id CDE7C393BC39 for ; Tue, 5 Jan 2021 18:58:26 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org CDE7C393BC39 Received: by mail-qk1-x730.google.com with SMTP id 19so287124qkm.8 for ; Tue, 05 Jan 2021 10:58:26 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:mime-version :content-transfer-encoding; bh=qBwfT61Ck2CSE40N1pXmE1sAX8vTlxIVFOw7OwRdEec=; b=QjvH7+jqOrv4h2EBAN8YcOgcyL27qT6xsMut8aX8joRNax036+Z3qqdW90eKKk2u3E dWGXKx0GxZgobyOoK2X4T3z+03txMbRNWTDH64Wx45ITVqPISjkgoGDywBBRLIYRLfXC cZAiKysp/y1TylzDFzrZgIsguYUrQNtahZlgWjKzSkFmrJJsqbVJRSOreapkMbIN0Tvu xyTiR7dV8on9MoY4ephA8rl/I+kNF3XplIbqu/VmLMjUbQveuZGqKP45llI9oJ0/gUp1 4jt1xrLo/NdrLOXCeHPu3UNC4Dhspgs3K0/lA92Ob+fS4bfBgb3IbfQlDhloM4xssfeF OIOg== X-Gm-Message-State: AOAM532794syrF2334dBjjITBFuxXlkCfvarCrtlgrIhjD7etjCJg9D8 Vnv32pklG4Ai1snJqCc08KCtviexS7ufCA== X-Google-Smtp-Source: ABdhPJzIc8b/P1MTUMg3RVpjJjf6zrrIjCU2HN4wJ7XvRGTLqcds6ylfgBDkOWQo2DnBuhG84Ty8dQ== X-Received: by 2002:a05:620a:22ee:: with SMTP id p14mr886611qki.343.1609873105894; Tue, 05 Jan 2021 10:58:25 -0800 (PST) Received: from localhost.localdomain ([177.194.48.209]) by smtp.googlemail.com with ESMTPSA id t68sm67792qkd.35.2021.01.05.10.58.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 05 Jan 2021 10:58:25 -0800 (PST) To: libc-alpha@sourceware.org, Paul Eggert , bug-gnulib@gnu.org Subject: [PATCH 0/8] Remove alloca usage from glob Date: Tue, 5 Jan 2021 15:58:12 -0300 Message-Id: <20210105185820.3796657-1-adhemerval.zanella@linaro.org> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Spam-Status: No, score=-7.7 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Adhemerval Zanella via Libc-alpha From: Adhemerval Zanella Netto Reply-To: Adhemerval Zanella Errors-To: libc-alpha-bounces@sourceware.org Sender: "Libc-alpha" This is a respin on an old patchset [1] which is no longer on patchwork. The main change is just a rebase against master since glibc version is now on sync with gnulib. I am sending it also to gnulib to get feedback from the project, specifically for the part not specific for the system support by glibc and extra requirements. The idea of removing the alloca allows a slight better code generation, simplifies the boilerplate code to avoid the unbounded alloca usage, and it plays better with security compiler mitigation tools (such as the ones for stack clash). On x86_64 with gcc 9.2.1 build glob for shared object, the total stack usage went from: glob.c:261:1:next_brace_sub 8 static glob.c:1205:1:prefix_array 96 static glob.c:1185:1:collated_compare 8 static glob.c:250:1:is_dir.isra.0 160 static glob.c:1259:1:glob_in_dir 864 dynamic glob.c:297:1:__glob 1360 dynamic to glob.c:231:1:next_brace_sub 8 static dynarray-skeleton.c:203:1:globnames_array_free 32 static glob.c:1131:1:prefix_array 96 static glob.c:1111:1:collated_compare 8 static dynarray-skeleton.c:275:1:globnames_array_add__ 48 static dynarray-skeleton.c:373:1:char_array_resize.part.0 48 static char_array-skeleton.c:274:1:char_array_replace_str_pos 48 static char_array-skeleton.c:204:1:char_array_crop 32 static char_array-skeleton.c:240:1:char_array_append_str 48 static char_array-skeleton.c:118:1:char_array_set_str_size 32 static char_array-skeleton.c:161:1:char_array_init_str 32 static glob.c:220:1:is_dir.isra.0 160 static glob.c:1200:1:glob_in_dir 1088 static glob.c:267:1:__glob 1824 static (it was obtained with -fstack-usage gcc option). It is a slight increase and due GNU extension where glob might be called recursivelly internally the total stack usage might be still slight larger than current implementation. But I still think it is a worth tradeoff. [1] https://sourceware.org/pipermail/libc-alpha/2018-February/091326.html Adhemerval Zanella (8): malloc: Add specialized dynarray for C strings posix: Use char_array for internal glob dirname posix: Remove alloca usage for GLOB_BRACE on glob posix: Remove alloca usage on glob dirname posix: Use dynarray for globname in glob posix: Remove alloca usage on glob user_name posix: Use char_array for home_dir in glob posix: Remove all alloca usage in glob malloc/Makefile | 4 +- malloc/Versions | 7 + malloc/char_array-impl.c | 57 +++ malloc/char_array-skeleton.c | 288 +++++++++++++ malloc/char_array.h | 53 +++ malloc/dynarray.h | 9 + malloc/dynarray_overflow_failure.c | 31 ++ malloc/malloc-internal.h | 14 + malloc/tst-char_array.c | 112 ++++++ posix/glob.c | 622 +++++++++++------------------ 10 files changed, 817 insertions(+), 380 deletions(-) create mode 100644 malloc/char_array-impl.c create mode 100644 malloc/char_array-skeleton.c create mode 100644 malloc/char_array.h create mode 100644 malloc/dynarray_overflow_failure.c create mode 100644 malloc/tst-char_array.c