From patchwork Wed Oct 21 14:15:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adhemerval Zanella Netto X-Patchwork-Id: 40801 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 6A1143959E42; Wed, 21 Oct 2020 14:16:00 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 6A1143959E42 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1603289760; bh=KO0LyoRnRBc2eFz+9JJn5JV4QwtIr9orVAwnw4yX/uw=; h=To:Subject:Date:In-Reply-To:References:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc: From; b=vCRhQICBFUVscKzWwgdQvNLSaM1i/jhYof85J8VWyhGdTEIV41Bnt7pZ4sLYhVVnY 1mcR2eDUqSLXAZeduoB6NpRF6nXopdUaeN4rAZAZ1NOiVm6NmvjzB6aygIzSx+nWZ3 5vWTzvfzrOyUP0ljvEVl/dTEEUDyDJ3acLezUYyw= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from mail-qt1-x841.google.com (mail-qt1-x841.google.com [IPv6:2607:f8b0:4864:20::841]) by sourceware.org (Postfix) with ESMTPS id E237F3959CB6 for ; Wed, 21 Oct 2020 14:15:56 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org E237F3959CB6 Received: by mail-qt1-x841.google.com with SMTP id c15so2233687qtc.2 for ; Wed, 21 Oct 2020 07:15:56 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=KO0LyoRnRBc2eFz+9JJn5JV4QwtIr9orVAwnw4yX/uw=; b=KjwJfdOGnplKjRVJl4I4m2YboPCFib48znaX+PYkTtjbdJBc7YbbaoIbzoy8YtDg2G i9McI9NAu3l9llppYTUDIYJQMEm1n4HosUO22mYnSsaY3DC6eErL/DNIRmlk/KX5MHdO bTrjDC1qHtJ7qZADqFyGrr3mcTPpBQdMFxWjY6tIF+CKBdHQ6kowE5sGZW2Gxx86a4gL 1M++ZHxi86QFeGq8RxGr7V8celYTIUB5RCk8w41K1/Ewr1kAezjds+S6Rg852f6ThMSZ BkCHgF7GO3M4AYpZGQdwS6W13nkMXaVCKvMowrXNTDJuhSIDdxQ7HILzFFUs/ouSglSg 0N8A== X-Gm-Message-State: AOAM530mk6GMe4XsVPpV5+4VenVZqQqfN+4aV25jEOgaOhjXvaS9ShGY 4j4zYb5PnvXpn9axz3fnA37dNdrqFvuMHw== X-Google-Smtp-Source: ABdhPJwlC2hh+GAhYfgu0fbsWQKpntqq7sWEwR+rgtT4sFzOI/145lBtSfdeGdCSsO8QGmpExCHypg== X-Received: by 2002:ac8:1346:: with SMTP id f6mr3282504qtj.137.1603289755645; Wed, 21 Oct 2020 07:15:55 -0700 (PDT) Received: from localhost.localdomain ([177.194.48.209]) by smtp.googlemail.com with ESMTPSA id e17sm1187952qts.54.2020.10.21.07.15.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 21 Oct 2020 07:15:55 -0700 (PDT) To: libc-alpha@sourceware.org, Florian Weimer Subject: [PATCH v3 3/7] linux: Set internal DIR filepos as off64_t [BZ #23960, BZ #24050] Date: Wed, 21 Oct 2020 11:15:38 -0300 Message-Id: <20201021141542.2003377-4-adhemerval.zanella@linaro.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201021141542.2003377-1-adhemerval.zanella@linaro.org> References: <20201021141542.2003377-1-adhemerval.zanella@linaro.org> MIME-Version: 1.0 X-Spam-Status: No, score=-14.1 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, KAM_SHORT, 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 Cc: James Clarke , John Paul Adrian Glaubitz Errors-To: libc-alpha-bounces@sourceware.org Sender: "Libc-alpha" It allows to obtain the expected entry offset on telldir and set it correctly on seekdir on platforms where long int is smaller than off64_t. On such cases telldir will mantain an internal list that maps the DIR object off64_t offsets to the returned long int (the function return value). The seekdir will then set the correct offset from the internal list using the telldir as the list key. It also removes the overflow check on readdir and the returned value will be truncated by the non-LFS off_t size. As Joseph has noted in BZ #23960 comment #22, d_off is an opaque value and since telldir/seekdir works regardless of the returned dirent d_off value. Finally it removed the requirement to check for overflow values on telldir (BZ #24050). Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc-linux-gnu, and arm-linux-gnueabihf. --- dirent/Makefile | 2 +- dirent/tst-seekdir2.c | 158 ++++++++++++++++++++++++++++ sysdeps/unix/sysv/linux/closedir.c | 4 + sysdeps/unix/sysv/linux/dirstream.h | 6 +- sysdeps/unix/sysv/linux/opendir.c | 3 + sysdeps/unix/sysv/linux/readdir.c | 1 + sysdeps/unix/sysv/linux/rewinddir.c | 5 + sysdeps/unix/sysv/linux/seekdir.c | 36 ++++++- sysdeps/unix/sysv/linux/telldir.c | 47 ++++++++- sysdeps/unix/sysv/linux/telldir.h | 64 +++++++++++ 10 files changed, 317 insertions(+), 9 deletions(-) create mode 100644 dirent/tst-seekdir2.c create mode 100644 sysdeps/unix/sysv/linux/telldir.h diff --git a/dirent/Makefile b/dirent/Makefile index e917d5ceab..ba9755da64 100644 --- a/dirent/Makefile +++ b/dirent/Makefile @@ -31,7 +31,7 @@ routines := opendir closedir readdir readdir_r rewinddir \ scandir-cancel scandir-tail scandir64-tail tests := list tst-seekdir opendir-tst1 bug-readdir1 tst-fdopendir \ - tst-fdopendir2 tst-scandir tst-scandir64 + tst-fdopendir2 tst-scandir tst-scandir64 tst-seekdir2 CFLAGS-scandir.c += $(uses-callbacks) CFLAGS-scandir64.c += $(uses-callbacks) diff --git a/dirent/tst-seekdir2.c b/dirent/tst-seekdir2.c new file mode 100644 index 0000000000..3e01b361e5 --- /dev/null +++ b/dirent/tst-seekdir2.c @@ -0,0 +1,158 @@ +/* Check multiple telldir and seekdir. + Copyright (C) 2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#include +#include +#include +#include + +#include +#include +#include + +/* Some filesystems returns a arbitrary value for d_off direnty entry (ext4 + for instance, where the value is an internal hash key). The idea of + create a large number of file is to try trigger a overflow d_off value + in a entry to check if telldir/seekdir does work corretly in such + case. */ +static const char *dirname; +static const size_t nfiles = 10240; + +static void +do_prepare (int argc, char *argv[]) +{ + dirname = support_create_temp_directory ("tst-seekdir2-"); + + for (size_t i = 0; i < nfiles; i++) + { + int fd = create_temp_file_in_dir ("tempfile.", dirname, NULL); + TEST_VERIFY_EXIT (fd > 0); + close (fd); + } +} +#define PREPARE do_prepare + +/* Check for old non Large File Support (LFS). */ +static int +do_test_not_lfs (void) +{ + DIR *dirp = opendir (dirname); + TEST_VERIFY_EXIT (dirp != NULL); + + size_t dirp_count = 0; + for (struct dirent *dp = readdir (dirp); + dp != NULL; + dp = readdir (dirp)) + dirp_count++; + + /* The 2 extra files are '.' and '..'. */ + TEST_COMPARE (dirp_count, nfiles + 2); + + rewinddir (dirp); + + long *tdirp = xmalloc (dirp_count * sizeof (long)); + struct dirent **ddirp = xmalloc (dirp_count * sizeof (struct dirent *)); + + size_t i = 0; + do + { + tdirp[i] = telldir (dirp); + struct dirent *dp = readdir (dirp); + TEST_VERIFY_EXIT (dp != NULL); + ddirp[i] = xmalloc (dp->d_reclen); + memcpy (ddirp[i], dp, dp->d_reclen); + } while (++i < dirp_count); + + for (i = 0; i < dirp_count - 1; i++) + { + seekdir (dirp, tdirp[i]); + struct dirent *dp = readdir (dirp); + TEST_COMPARE (strcmp (dp->d_name, ddirp[i]->d_name), 0); + TEST_COMPARE (dp->d_ino, ddirp[i]->d_ino); + TEST_COMPARE (dp->d_off, ddirp[i]->d_off); + } + + closedir (dirp); + free (tdirp); + for (i = 0; i < dirp_count; i++) + free (ddirp[i]); + free (ddirp); + + return 0; +} + +/* Same as before but with LFS support. */ +static int +do_test_lfs (void) +{ + DIR *dirp = opendir (dirname); + TEST_VERIFY_EXIT (dirp != NULL); + + size_t dirp_count = 0; + for (struct dirent64 * dp = readdir64 (dirp); + dp != NULL; + dp = readdir64 (dirp)) + dirp_count++; + + /* The 2 extra files are '.' and '..'. */ + TEST_COMPARE (dirp_count, nfiles + 2); + + rewinddir (dirp); + + long *tdirp = xmalloc (dirp_count * sizeof (long)); + struct dirent64 **ddirp = xmalloc (dirp_count * sizeof (struct dirent64 *)); + + size_t i = 0; + do + { + tdirp[i] = telldir (dirp); + struct dirent64 *dp = readdir64 (dirp); + TEST_VERIFY_EXIT (dp != NULL); + ddirp[i] = xmalloc (dp->d_reclen); + memcpy (ddirp[i], dp, dp->d_reclen); + } while (++i < dirp_count); + + for (i = 0; i < dirp_count - 1; i++) + { + seekdir (dirp, tdirp[i]); + struct dirent64 *dp = readdir64 (dirp); + TEST_COMPARE (strcmp (dp->d_name, ddirp[i]->d_name), 0); + TEST_COMPARE (dp->d_ino, ddirp[i]->d_ino); + TEST_COMPARE (dp->d_off, ddirp[i]->d_off); + } + + closedir (dirp); + free (tdirp); + for (i = 0; i < dirp_count; i++) + free (ddirp[i]); + free (ddirp); + + return 0; +} + +static int +do_test (void) +{ + do_test_not_lfs (); + do_test_lfs (); + + return 0; +} + +#include diff --git a/sysdeps/unix/sysv/linux/closedir.c b/sysdeps/unix/sysv/linux/closedir.c index d67b590d5f..3436780519 100644 --- a/sysdeps/unix/sysv/linux/closedir.c +++ b/sysdeps/unix/sysv/linux/closedir.c @@ -43,6 +43,10 @@ __closedir (DIR *dirp) fd = dirp->fd; +#ifndef __LP64__ + dirstream_loc_clear (&dirp->locs); +#endif + #if IS_IN (libc) __libc_lock_fini (dirp->lock); #endif diff --git a/sysdeps/unix/sysv/linux/dirstream.h b/sysdeps/unix/sysv/linux/dirstream.h index da9315d353..369d0a697c 100644 --- a/sysdeps/unix/sysv/linux/dirstream.h +++ b/sysdeps/unix/sysv/linux/dirstream.h @@ -21,6 +21,7 @@ #include #include +#include /* Directory stream type. @@ -37,7 +38,7 @@ struct __dirstream size_t size; /* Total valid data in the block. */ size_t offset; /* Current offset into the block. */ - off_t filepos; /* Position of next entry to read. */ + off64_t filepos; /* Position of next entry to read. */ int errcode; /* Delayed error code. */ @@ -45,6 +46,9 @@ struct __dirstream char *tbuffer; /* Translation buffer for non-LFS calls. */ size_t tbuffer_size; /* Size of translation buffer. */ #endif +#ifndef __LP64__ + struct dirstream_loc_t locs; /* off64_t to long int map for telldir. */ +#endif /* Directory block. We must make sure that this block starts at an address that is aligned adequately enough to store diff --git a/sysdeps/unix/sysv/linux/opendir.c b/sysdeps/unix/sysv/linux/opendir.c index 329575e809..28fd55341e 100644 --- a/sysdeps/unix/sysv/linux/opendir.c +++ b/sysdeps/unix/sysv/linux/opendir.c @@ -149,6 +149,9 @@ __alloc_dir (int fd, bool close_fd, int flags, const struct stat64 *statp) dirp->offset = 0; dirp->filepos = 0; dirp->errcode = 0; +#ifndef __LP64__ + dirstream_loc_init (&dirp->locs); +#endif return dirp; } diff --git a/sysdeps/unix/sysv/linux/readdir.c b/sysdeps/unix/sysv/linux/readdir.c index 9af4561a8c..656672c706 100644 --- a/sysdeps/unix/sysv/linux/readdir.c +++ b/sysdeps/unix/sysv/linux/readdir.c @@ -17,6 +17,7 @@ . */ #include +#include #if !_DIRENT_MATCHES_DIRENT64 #include diff --git a/sysdeps/unix/sysv/linux/rewinddir.c b/sysdeps/unix/sysv/linux/rewinddir.c index 860bfda004..8db0d0be4a 100644 --- a/sysdeps/unix/sysv/linux/rewinddir.c +++ b/sysdeps/unix/sysv/linux/rewinddir.c @@ -33,6 +33,11 @@ __rewinddir (DIR *dirp) dirp->offset = 0; dirp->size = 0; dirp->errcode = 0; + +#ifndef __LP64__ + dirstream_loc_clear (&dirp->locs); +#endif + #if IS_IN (libc) __libc_lock_unlock (dirp->lock); #endif diff --git a/sysdeps/unix/sysv/linux/seekdir.c b/sysdeps/unix/sysv/linux/seekdir.c index 3c30520928..5f39ef9eef 100644 --- a/sysdeps/unix/sysv/linux/seekdir.c +++ b/sysdeps/unix/sysv/linux/seekdir.c @@ -22,14 +22,40 @@ #include /* Seek to position POS in DIRP. */ -/* XXX should be __seekdir ? */ void seekdir (DIR *dirp, long int pos) { + off64_t filepos; + __libc_lock_lock (dirp->lock); - (void) __lseek (dirp->fd, pos, SEEK_SET); - dirp->size = 0; - dirp->offset = 0; - dirp->filepos = pos; + +#ifndef __LP64__ + union dirstream_packed dsp; + + dsp.l = pos; + + if (dsp.p.is_packed == 1) + filepos = dsp.p.info; + else + { + size_t index = dsp.p.info; + + if (index >= dirstream_loc_size (&dirp->locs)) + return; + struct dirstream_loc *loc = dirstream_loc_at (&dirp->locs, index); + filepos = loc->filepos; + } +#else + filepos = pos; +#endif + + if (dirp->filepos != filepos) + { + __lseek64 (dirp->fd, filepos, SEEK_SET); + dirp->filepos = filepos; + dirp->offset = 0; + dirp->size = 0; + } + __libc_lock_unlock (dirp->lock); } diff --git a/sysdeps/unix/sysv/linux/telldir.c b/sysdeps/unix/sysv/linux/telldir.c index 57d435ed21..bb33626fa4 100644 --- a/sysdeps/unix/sysv/linux/telldir.c +++ b/sysdeps/unix/sysv/linux/telldir.c @@ -18,16 +18,59 @@ #include #include +#include /* Return the current position of DIRP. */ long int telldir (DIR *dirp) { - long int ret; +#ifndef __LP64__ + /* If the directory position fits in the packet structure returns it. + Otherwise, check if the position is already been recorded in the + dynamic array. If not, add the new record. */ + + union dirstream_packed dsp; + size_t i; __libc_lock_lock (dirp->lock); - ret = dirp->filepos; + + if (dirp->filepos < (1U << 31)) + { + dsp.p.is_packed = 1; + dsp.p.info = dirp->filepos; + goto out; + } + + dsp.l = -1; + + for (i = 0; i < dirstream_loc_size (&dirp->locs); i++) + { + struct dirstream_loc *loc = dirstream_loc_at (&dirp->locs, i); + if (loc->filepos == dirp->filepos) + break; + } + if (i == dirstream_loc_size (&dirp->locs)) + { + dirstream_loc_add (&dirp->locs, + (struct dirstream_loc) { dirp->filepos }); + if (dirstream_loc_has_failed (&dirp->locs)) + goto out; + } + + dsp.p.is_packed = 0; + /* This assignment might overflow, however most likely ENOMEM would happen + long before. */ + dsp.p.info = i; + +out: __libc_lock_unlock (dirp->lock); + return dsp.l; +#else + long int ret; + __libc_lock_lock (dirp->lock); + ret = dirp->filepos; + __libc_lock_unlock (dirp->lock); return ret; +#endif } diff --git a/sysdeps/unix/sysv/linux/telldir.h b/sysdeps/unix/sysv/linux/telldir.h new file mode 100644 index 0000000000..7c45886341 --- /dev/null +++ b/sysdeps/unix/sysv/linux/telldir.h @@ -0,0 +1,64 @@ +/* Linux internal telldir definitions. + Copyright (C) 2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#ifndef _TELLDIR_H +#define _TELLDIR_H 1 + +#ifndef __LP64__ + +/* On platforms where long int is smaller than off64_t this is how the + returned value is encoded and returned by 'telldir'. If the directory + offset can be enconded in 31 bits it is returned in the 'info' member + with 'is_packed' set to 1. + + Otherwise, the 'info' member describes an index in a dynamic array at + 'DIR' structure. */ + +union dirstream_packed +{ + long int l; + struct + { + unsigned long is_packed:1; + unsigned long info:31; + } p; +}; + +_Static_assert (sizeof (long int) == sizeof (union dirstream_packed), + "sizeof (long int) != sizeof (union dirstream_packed)"); + +/* telldir will mantain a list of offsets that describe the obtained diretory + position if it can fit this information in the returned 'dirstream_packed' + struct. */ + +struct dirstream_loc +{ + off64_t filepos; +}; + +# define DYNARRAY_STRUCT dirstream_loc_t +# define DYNARRAY_ELEMENT struct dirstream_loc +# define DYNARRAY_PREFIX dirstream_loc_ +# include +#else + +_Static_assert (sizeof (long int) == sizeof (off64_t), + "sizeof (long int) != sizeof (off64_t)"); +#endif /* __LP64__ */ + +#endif /* _TELLDIR_H */