From bb1e8b0ca99b5cbedfae3e6245528a87d95ff3e2 Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Wed, 10 Aug 2022 14:24:47 -0300 Subject: linux: Fix sys/mount.h usage with kernel headers Now that kernel exports linux/mount.h and includes it on linux/fs.h, its definitions might clash with glibc exports sys/mount.h. To avoid the need to rearrange the Linux header to be always after glibc one, the glibc sys/mount.h is changed to: 1. Undefine the macros also used as enum constants. This covers prior inclusion of (for instance MS_RDONLY). 2. Include based on the usual __has_include check (needs to use __has_include ("linux/mount.h") to paper over GCC bugs. 3. Define enum fsconfig_command only if FSOPEN_CLOEXEC is not defined. (FSOPEN_CLOEXEC should be a very close proxy.) 4. Define struct mount_attr if MOUNT_ATTR_SIZE_VER0 is not defined. (Added in the same commit on the Linux side.) This patch also adds some tests to check if including linux/fs.h and linux/mount.h after and before sys/mount.h does work. Checked on x86_64-linux-gnu. Reviewed-by: Florian Weimer (cherry picked from commit 774058d72942249f71d74e7f2b639f77184160a6) --- sysdeps/unix/sysv/linux/tst-mount-compile.py | 66 ++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) create mode 100755 sysdeps/unix/sysv/linux/tst-mount-compile.py (limited to 'sysdeps/unix/sysv/linux/tst-mount-compile.py') diff --git a/sysdeps/unix/sysv/linux/tst-mount-compile.py b/sysdeps/unix/sysv/linux/tst-mount-compile.py new file mode 100755 index 0000000000..0ec74d4e0b --- /dev/null +++ b/sysdeps/unix/sysv/linux/tst-mount-compile.py @@ -0,0 +1,66 @@ +#!/usr/bin/python3 +# Check if glibc provided sys/mount.h can be used along related kernel +# headers. +# Copyright (C) 2022 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 +# . + +import argparse +import sys + +import glibcextract + + +def main(): + """The main entry point.""" + parser = argparse.ArgumentParser( + description='Check if glibc provided sys/mount.h can be ' + ' used along related kernel headers.') + parser.add_argument('--cc', metavar='CC', + help='C compiler (including options) to use') + args = parser.parse_args() + + if glibcextract.compile_c_snippet( + '#include ', + args.cc).returncode != 0: + sys.exit (77) + + def check(testname, snippet): + # Add -Werror to catch macro redefinitions and _ISOMAC to avoid + # internal glibc definitions. + r = glibcextract.compile_c_snippet(snippet, args.cc, + '-Werror -D_ISOMAC') + if r.returncode != 0: + print('error: test {}:\n{}'.format(testname, r.output.decode())) + return r.returncode + + status = max( + check("sys/mount.h + linux/mount.h", + "#include \n" + "#include "), + check("sys/mount.h + linux/fs.h", + "#include \n" + "#include "), + check("linux/mount.h + sys/mount.h", + "#include \n" + "#include "), + check("linux/fs.h + sys/mount.h", + "#include \n" + "#include ")) + sys.exit(status) + +if __name__ == '__main__': + main() -- cgit v1.2.3-70-g09d2