From a5b35b64130afa26d91d771af474f947cc02a099 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Luk=C3=A1=C5=A1=20Zaoral?= Date: Mon, 29 Jan 2024 13:30:32 +0100 Subject: [PATCH] fix tail on kernels with 64k page size Resolves: RHEL-22866 --- coreutils-8.32-tail-64kpages.patch | 204 +++++++++++++++++++++++++++++ coreutils.spec | 8 +- 2 files changed, 211 insertions(+), 1 deletion(-) create mode 100644 coreutils-8.32-tail-64kpages.patch diff --git a/coreutils-8.32-tail-64kpages.patch b/coreutils-8.32-tail-64kpages.patch new file mode 100644 index 0000000..a4ae89d --- /dev/null +++ b/coreutils-8.32-tail-64kpages.patch @@ -0,0 +1,204 @@ +From 73d119f4f8052a9fb6cef13cd9e75d5a4e23311a Mon Sep 17 00:00:00 2001 +From: dann frazier +Date: Wed, 29 Nov 2023 18:32:34 -0700 +Subject: [PATCH] tail: fix tailing sysfs files where PAGE_SIZE > BUFSIZ + +* src/tail.c (file_lines): Ensure we use a buffer size >= PAGE_SIZE when +searching backwards to avoid seeking within a file, +which on sysfs files is accepted but also returns no data. +* tests/tail/tail-sysfs.sh: Add a new test. +* tests/local.mk: Reference the new test. +Fixes https://bugs.gnu.org/67490 + +Upstream-commit: 73d119f4f8052a9fb6cef13cd9e75d5a4e23311a +Cherry-picked-by: Lukáš Zaoral +--- + src/tail.c | 57 +++++++++++++++++++++++++++++----------- + tests/local.mk | 1 + + tests/tail-2/tail-sysfs.sh | 34 ++++++++++++++++++++++++ + 3 files changed, 77 insertions(+), 15 deletions(-) + create mode 100755 tests/tail/tail-sysfs.sh + +diff --git a/src/tail.c b/src/tail.c +index c45f3b65a..6979e0ba3 100644 +--- a/src/tail.c ++++ b/src/tail.c +@@ -208,6 +208,9 @@ static int nbpids = 0; + that is writing to all followed files. */ + static pid_t pid; + ++/* Used to determine the buffer size when scanning backwards in a file. */ ++static int page_size; ++ + /* True if we have ever read standard input. */ + static bool have_read_stdin; + +@@ -515,22 +518,40 @@ xlseek (int fd, off_t offset, int whence, char const *filename) + Return true if successful. */ + + static bool +-file_lines (const char *pretty_filename, int fd, uintmax_t n_lines, +- off_t start_pos, off_t end_pos, uintmax_t *read_pos) ++file_lines (const char *pretty_filename, int fd, struct stat const *sb, ++ uintmax_t n_lines, off_t start_pos, off_t end_pos, ++ uintmax_t *read_pos) + { +- char buffer[BUFSIZ]; ++ char *buffer; + size_t bytes_read; ++ blksize_t bufsize = BUFSIZ; + off_t pos = end_pos; ++ bool ok = true; + + if (n_lines == 0) + return true; + ++ /* Be careful with files with sizes that are a multiple of the page size, ++ as on /proc or /sys file systems these files accept seeking to within ++ the file, but then return no data when read. So use a buffer that's ++ at least PAGE_SIZE to avoid seeking within such files. ++ ++ We could also indirectly use a large enough buffer through io_blksize() ++ however this would be less efficient in the common case, as it would ++ generally pick a larger buffer size, resulting in reading more data ++ from the end of the file. */ ++ assert (S_ISREG (sb->st_mode)); ++ if (sb->st_size % page_size == 0) ++ bufsize = MAX (BUFSIZ, page_size); ++ ++ buffer = xmalloc (bufsize); ++ + /* Set 'bytes_read' to the size of the last, probably partial, buffer; +- 0 < 'bytes_read' <= 'BUFSIZ'. */ +- bytes_read = (pos - start_pos) % BUFSIZ; ++ 0 < 'bytes_read' <= 'bufsize'. */ ++ bytes_read = (pos - start_pos) % bufsize; + if (bytes_read == 0) +- bytes_read = BUFSIZ; +- /* Make 'pos' a multiple of 'BUFSIZ' (0 if the file is short), so that all ++ bytes_read = bufsize; ++ /* Make 'pos' a multiple of 'bufsize' (0 if the file is short), so that all + reads will be on block boundaries, which might increase efficiency. */ + pos -= bytes_read; + xlseek (fd, pos, SEEK_SET, pretty_filename); +@@ -538,7 +559,8 @@ file_lines (char const *pretty_filename, int fd, uintmax_t n_lines, + if (bytes_read == SAFE_READ_ERROR) + { + error (0, errno, _("error reading %s"), quoteaf (pretty_filename)); +- return false; ++ ok = false; ++ goto free_buffer; + } + *read_pos = pos + bytes_read; + +@@ -565,7 +587,7 @@ file_lines (char const *pretty_filename, int fd, uintmax_t n_lines, + xwrite_stdout (nl + 1, bytes_read - (n + 1)); + *read_pos += dump_remainder (false, pretty_filename, fd, + end_pos - (pos + bytes_read)); +- return true; ++ goto free_buffer; + } + } + +@@ -577,23 +599,26 @@ file_lines (char const *pretty_filename, int fd, uintmax_t n_lines, + xlseek (fd, start_pos, SEEK_SET, pretty_filename); + *read_pos = start_pos + dump_remainder (false, pretty_filename, fd, + end_pos); +- return true; ++ goto free_buffer; + } +- pos -= BUFSIZ; ++ pos -= bufsize; + xlseek (fd, pos, SEEK_SET, pretty_filename); + +- bytes_read = safe_read (fd, buffer, BUFSIZ); ++ bytes_read = safe_read (fd, buffer, bufsize); + if (bytes_read == SAFE_READ_ERROR) + { + error (0, errno, _("error reading %s"), quoteaf (pretty_filename)); +- return false; ++ ok = false; ++ goto free_buffer; + } + + *read_pos = pos + bytes_read; + } + while (bytes_read > 0); + +- return true; ++free_buffer: ++ free (buffer); ++ return ok; + } + + /* Print the last N_LINES lines from the end of the standard input, +@@ -1915,7 +1940,7 @@ tail_lines (char const *pretty_filename, int fd, uintmax_t n_lines, + { + *read_pos = end_pos; + if (end_pos != 0 +- && ! file_lines (pretty_filename, fd, n_lines, ++ && ! file_lines (pretty_filename, fd, &stats, n_lines, + start_pos, end_pos, read_pos)) + return false; + } +@@ -2337,6 +2362,8 @@ main (int argc, char **argv) + + atexit (close_stdout); + ++ page_size = getpagesize (); ++ + have_read_stdin = false; + + count_lines = true; +diff --git a/tests/local.mk b/tests/local.mk +index db4ee7ed8..bf03238c3 100644 +--- a/tests/local.mk ++++ b/tests/local.mk +@@ -257,6 +257,7 @@ all_tests = \ + tests/misc/seq-precision.sh \ + tests/misc/head.pl \ + tests/misc/head-elide-tail.pl \ ++ tests/tail-2/tail-sysfs.sh \ + tests/tail-2/tail-n0f.sh \ + tests/misc/ls-misc.pl \ + tests/misc/date.pl \ +diff --git a/tests/tail/tail-sysfs.sh b/tests/tail-2/tail-sysfs.sh +new file mode 100755 +index 000000000..00874b3dc +--- /dev/null ++++ b/tests/tail-2/tail-sysfs.sh +@@ -0,0 +1,34 @@ ++#!/bin/sh ++# sysfs files have weird properties that can be influenced by page size ++ ++# Copyright 2023 Free Software Foundation, Inc. ++ ++# This program is free software: you can redistribute it and/or modify ++# it under the terms of the GNU General Public License as published by ++# the Free Software Foundation, either version 3 of the License, or ++# (at your option) any later version. ++ ++# This program 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 General Public License for more details. ++ ++# You should have received a copy of the GNU General Public License ++# along with this program. If not, see . ++ ++. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src ++print_ver_ tail ++ ++file='/sys/kernel/profiling' ++ ++test -r "$file" || skip_ "No $file file" ++ ++cp -f "$file" exp || framework_failure_ ++ ++tail -n1 "$file" > out || fail=1 ++compare exp out || fail=1 ++ ++tail -c2 "$file" > out || fail=1 ++compare exp out || fail=1 ++ ++Exit $fail diff --git a/coreutils.spec b/coreutils.spec index a3693f5..b15ac63 100644 --- a/coreutils.spec +++ b/coreutils.spec @@ -1,7 +1,7 @@ Summary: A set of basic GNU tools commonly used in shell scripts Name: coreutils Version: 8.32 -Release: 34%{?dist} +Release: 35%{?dist} License: GPLv3+ Url: https://www.gnu.org/software/coreutils/ Source0: https://ftp.gnu.org/gnu/%{name}/%{name}-%{version}.tar.xz @@ -70,6 +70,9 @@ Patch18: coreutils-9.0-autofs-no-mount.patch # basic support for checking NFSv4 ACLs (#2137866) Patch19: coreutils-nfsv4-acls.patch +# fix tail on kernels with 64k pagesize +Patch20: coreutils-8.32-tail-64kpages.patch + # disable the test-lock gnulib test prone to deadlock Patch100: coreutils-8.26-test-lock.patch @@ -324,6 +327,9 @@ rm -f $RPM_BUILD_ROOT%{_infodir}/dir %license COPYING %changelog +* Mon Jan 29 2024 Lukáš Zaoral +- fix tail on kernels with 64k page sizes (RHEL-22866) + * Mon Jan 02 2023 Kamil Dudka - 8.32-34 - basic support for checking NFSv4 ACLs (#2137866)