From patchwork Sat Jun 14 09:57:56 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matteo Croce X-Patchwork-Id: 114484 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 4B02C38C37E3 for ; Sat, 14 Jun 2025 10:01:01 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 4B02C38C37E3 Authentication-Results: sourceware.org; dkim=pass (2048-bit key, unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20230601 header.b=DnwWC7W8 X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from mail-ej1-x62b.google.com (mail-ej1-x62b.google.com [IPv6:2a00:1450:4864:20::62b]) by sourceware.org (Postfix) with ESMTPS id C797038CAC92 for ; Sat, 14 Jun 2025 09:58:01 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org C797038CAC92 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org C797038CAC92 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=2a00:1450:4864:20::62b ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1749895082; cv=none; b=bfGdN0Q1EQeuoBffbVJV8YT3DdJhWbVoVmesYFJSZKTlYySeiMKrj9hRONiHNbFDaqbki0ihClLmjTU/jvvBLugN6da7wKeUYcwRNdujVEWIDzVjDe39qvqjTU0Lgovz92KDpPXr+8mgT9tFCi/VnMFnxG2o6TZ3K4K7G+lPowo= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1749895082; c=relaxed/simple; bh=CjqQEQCUdKWNwsQy8rs6u0t8AYzD8piBfOmTC4qj3P0=; h=DKIM-Signature:From:To:Subject:Date:Message-ID:MIME-Version; b=tQuEH+C2Cm0Esbi1wh6GUm1m203xLrk+SDrwhBtXO4Uc1REZi018AdSHzkIWScsTAkt5FB+UZA/8mKUDn6uBkA6vmznyLYQtzCqGQwP0GWsJNsJyFAlTfpwex/4hdjxGUwr6WMYa8/zYhSlzyhQOshKjaPoEnoZIhoyH/cZjy14= ARC-Authentication-Results: i=1; server2.sourceware.org DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org C797038CAC92 Received: by mail-ej1-x62b.google.com with SMTP id a640c23a62f3a-ad891bb0957so485709066b.3 for ; Sat, 14 Jun 2025 02:58:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1749895080; x=1750499880; darn=sourceware.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=2d5meJwx+1YbFVRNG+OIw7SkgP4O+G4u8zMsIpBTwg4=; b=DnwWC7W8sQRyG0vTIwanSIaOS7gssNIsrpBeOi1TFZjD7aW86Tl0TGUVkQTJKI110M nlENoQBiGGANivtOJOa0XGsFXrmGNKiUG6Agkh8clz1fUN16gbzW7G5f54p4RwebciCz A9Bks+yCcpsTtRRahXVIqe0pqrULAxbZyzkioPoQz1cUsIQV0kHTW+rHrsUmi3OCD7q3 Hg/VCxfJZ3Y8dfGNDihxsFbEv7x4ObszboL+PI4JujbXefGt68Bb7TWhPSLIZCTlan1V IdY/5uShBjNsF0aIdaY6WDD18XyLKhdS6jr4mN3IrX+awwfU91gXRsKrZIt1NyWv/x2a hC+Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1749895080; x=1750499880; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=2d5meJwx+1YbFVRNG+OIw7SkgP4O+G4u8zMsIpBTwg4=; b=C9uvj6Y0RxuVu8z3QFZZs8Gx/tedz1kbC0TlsqEkhXYcsWdnQo4n4i0xUfLfx3Vck8 LIMbbxqlLs2ZpHHrO8NE4RHshNkACaKj176Lsr/6nwaWJTfQ11tGQBktEW164yqBpgGc TdVIVi2VGgSlRMIHEDXawaqCGUd4erjmbb8KJlws+4FgSGGMUMpuorhfPhJtmLPybFcU 4n8kKdsouk2NcUfGutovn6ON+DvyGwVXaCxdagUL5jyJ01K/78ZDKEV8QZ5rR7AoU7et JdBi9Eu/CP9sLWf4jmUjXZoFlzjEXIzfQS82ZkbHMUWdcaa5S4VnEB5dWQirl3YgxViE lGtA== X-Gm-Message-State: AOJu0YxLtnEvgXRTwCKeVO4NM/NzRDOk9Ig0rl9BOm3jUJQoc7NNLpqK lEmSxQUwUzIuxRf8W6MBAinPBUowfG13cmVha2eS6l+Aiq8SaefT9ohoEVKC7VDl4fw= X-Gm-Gg: ASbGncsnWo0tA9VDCkJbU1PZJiQlNNS6fEFlNvo8e4OuI1hroYGsKClIeyTcgF14Phg dEoQg49prwoYJ0z2AJ2I0umoq+Gjwgg20qBn7z4MKUT+hVjz0G8qvGKA6qeE0H+ZJ8giF1SWyID EhZQgnNdGFVOWnf1dbpn++uJNl5GI2TFpmd4j+aqzTXpYlZ+YE7UIy+Wo02z2lBw1U5UZnd4pxr VuHqqdCnFIPpFKE4Mmj9S48KwOtETfns+H5/DlJ5hlrpT36ywQ9snmu0Kr5DwCRpvIsYkhyFRUr qTRTkK+it8VqH0bw41YlD8gtGZ3BZB7z8PoXf2OIcanmYriR+uRgftgUn5HajipKA81njM/PVyX efk92D+HJ2LZe X-Google-Smtp-Source: AGHT+IFhi7OBVE3gF3kW/z16876McontibF4LBIiuICTDby6zE2NbE8PLNJYRScm96+3uECFLGoo5g== X-Received: by 2002:a17:906:4fca:b0:ad8:a50c:f6cb with SMTP id a640c23a62f3a-adfad373b51mr199813366b.26.1749895080168; Sat, 14 Jun 2025 02:58:00 -0700 (PDT) Received: from fedorarm.. ([147.229.117.1]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-adec897ab9fsm274453466b.152.2025.06.14.02.57.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 14 Jun 2025 02:57:59 -0700 (PDT) From: Matteo Croce To: libc-alpha@sourceware.org Cc: Matteo Croce Subject: [PATCH] fstat: add test and documentation for an edge case. Date: Sat, 14 Jun 2025 11:57:56 +0200 Message-ID: <20250614095756.202225-1-technoboy85@gmail.com> X-Mailer: git-send-email 2.49.0 MIME-Version: 1.0 X-Spam-Status: No, score=-12.6 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_ENVFROM_END_DIGIT, FREEMAIL_FROM, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.30 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: libc-alpha-bounces~patchwork=sourceware.org@sourceware.org From: Matteo Croce The fstatat behaviour when the target is a dangling symlink is different if flags contains AT_SYMLINK_NOFOLLOW or not. Add a test for this and document it. --- io/_linkname | 1 + io/tst-stat.c | 17 +++++++++++++++-- manual/filesys.texi | 5 +++-- 3 files changed, 19 insertions(+), 4 deletions(-) create mode 120000 io/_linkname diff --git a/io/_linkname b/io/_linkname new file mode 120000 index 0000000000..1084818f23 --- /dev/null +++ b/io/_linkname @@ -0,0 +1 @@ +_target \ No newline at end of file diff --git a/io/tst-stat.c b/io/tst-stat.c index 61bdbfb638..31e3b22579 100644 --- a/io/tst-stat.c +++ b/io/tst-stat.c @@ -62,6 +62,17 @@ fstatat_check (int fd, const char *path, struct stat *st) TEST_COMPARE (fstatat (fd, path, st, 0), 0); } +static void +fstatat_link (struct stat *st) +{ + symlink("_target", "_linkname"); + + TEST_COMPARE (fstatat (AT_FDCWD, "_linkname", st, 0), -1); + TEST_COMPARE (errno, ENOENT); + + TEST_COMPARE (fstatat (AT_FDCWD, "_linkname", st, AT_SYMLINK_NOFOLLOW), 0); +} + typedef void (*test_t)(int, const char *path, struct stat *); static int @@ -81,13 +92,13 @@ do_test (void) printf ("warning: timestamp with nanoseconds not supported\n"); struct statx stx; + struct stat st; TEST_COMPARE (statx (fd, path, 0, STATX_BASIC_STATS, &stx), 0); - test_t tests[] = { stat_check, lstat_check, fstat_check, fstatat_check }; + test_t tests[] = { stat_check, lstat_check, fstat_check, fstatat_check}; for (int i = 0; i < array_length (tests); i++) { - struct stat st; tests[i](fd, path, &st); TEST_COMPARE (stx.stx_dev_major, major (st.st_dev)); @@ -111,6 +122,8 @@ do_test (void) } } + fstatat_link(&st); + return 0; } diff --git a/manual/filesys.texi b/manual/filesys.texi index d0ced84bf6..e3721c3d23 100644 --- a/manual/filesys.texi +++ b/manual/filesys.texi @@ -2397,8 +2397,9 @@ The descriptor @var{filedes} is not associated with a directory, and @var{filename} is a relative file name. @item ENOENT -The file named by @var{filename} does not exist, or @var{filename} is an -empty string and @var{flags} does not contain @code{AT_EMPTY_PATH}. +The file named by @var{filename} does not exist, it's a dangling symlink +and @var{flags} does not contain @code{AT_SYMLINK_NOFOLLOW}, or @var{filename} +is an empty string and @var{flags} does not contain @code{AT_EMPTY_PATH}. @end table When the sources are compiled with @code{_FILE_OFFSET_BITS == 64} this