8b4a118222
Building with -Os produces linknamespace and localplt failures for, among other functions, gnu_dev_major, gnu_dev_minor and gnu_dev_makedev. The issue is that those functions are not inlined when building with -Os. While one could force them to be inlined in that case, it seems more natural to fix this issue similarly to other namespace issues. Thus, this patch makes gnu_dev_* into weak aliases for hidden symbols __gnu_dev_*; __gnu_dev_* are then defined as inlines in the internal include/sys/sysmacros.h, and uses of gnu_dev_* (often via the macros major, minor and makedev) for which there are namespace issues are changed to use __gnu_dev_*; where there are no namespace issues, use of libc_hidden_proto serves to avoid unnecessary local PLT entry use. Tested for x86_64, (a) without -Os, to verify the testsuite continues to pass without problems and that the functions called under their new names continue to be inlined as expected in that case; (b) with -Os, to verify that the linknamespace and localplt failures in question go away (but because of other such failures present, neither of the relevant bugs can yet be closed). [BZ #15105] [BZ #19463] * include/sys/sysmacros.h [!_ISOMAC] (__SYSMACROS_NEED_IMPLEMENTATION): Define macro. [!_SYS_SYSMACROS_H_WRAPPER && !_ISOMAC] (_SYS_SYSMACROS_H_WRAPPER): Likewise. [!_SYS_SYSMACROS_H_WRAPPER && !_ISOMAC] (gnu_dev_major): Use libc_hidden_proto. [!_SYS_SYSMACROS_H_WRAPPER && !_ISOMAC] (gnu_dev_minor): Likewise. [!_SYS_SYSMACROS_H_WRAPPER && !_ISOMAC] (gnu_dev_makedev): Likewise. [!_SYS_SYSMACROS_H_WRAPPER && !_ISOMAC] (__SYSMACROS_DECL_TEMPL): Undefine and redefine to add use __gnu_dev_ prefix. [!_SYS_SYSMACROS_H_WRAPPER && !_ISOMAC] (__SYSMACROS_IMPL_TEMPL): Likewise. [!_SYS_SYSMACROS_H_WRAPPER && !_ISOMAC] (__gnu_dev_major): Declare and define as hidden inline function. [!_SYS_SYSMACROS_H_WRAPPER && !_ISOMAC] (__gnu_dev_minor): Likewise. [!_SYS_SYSMACROS_H_WRAPPER && !_ISOMAC] (__gnu_dev_makedev): Likewise. * misc/makedev.c (OUT_OF_LINE_IMPL_TEMPL): Use __gnu_dev_ prefix. (gnu_dev_major): Use weak_alias and libc_hidden_weak. (gnu_dev_minor): Likewise. (gnu_dev_makedev): Likewise. * csu/check_fds.c (check_one_fd): Use __gnu_dev_makedev instead of makedev. * posix/wordexp.c (exec_comm_child): Likewise. * sysdeps/mach/hurd/xmknodat.c (__xmknodat): Use __gnu_dev_minor instead of minor and __gnu_dev_major instead of major. * sysdeps/unix/sysv/linux/device-nrs.h (DEV_TTY_P): Use __gnu_dev_major instead of major. * sysdeps/unix/sysv/linux/pathconf.c (distinguish_extX): Use __gnu_dev_major instead of gnu_dev_major and __gnu_dev_minor instead of gnu_dev_minor. * sysdeps/unix/sysv/linux/ptsname.c (MASTER_P): Likewise. (SLAVE_P): Likewise. (__ptsname_internal): Use __gnu_dev_minor instead of minor. * sysdeps/unix/sysv/linux/ttyname.h (is_pty): Use __gnu_dev_major instead of major.
98 lines
3.2 KiB
C
98 lines
3.2 KiB
C
/* Copyright (C) 2000-2018 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
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <paths.h>
|
|
#include <unistd.h>
|
|
#include <sys/stat.h>
|
|
#include <sys/sysmacros.h>
|
|
|
|
/* Try to get a machine dependent instruction which will make the
|
|
program crash. This is used in case everything else fails. */
|
|
#include <abort-instr.h>
|
|
#ifndef ABORT_INSTRUCTION
|
|
/* No such instruction is available. */
|
|
# define ABORT_INSTRUCTION
|
|
#endif
|
|
|
|
#include <device-nrs.h>
|
|
#include <not-cancel.h>
|
|
|
|
|
|
/* Should other OSes (e.g., Hurd) have different versions which can
|
|
be written in a better way? */
|
|
static void
|
|
check_one_fd (int fd, int mode)
|
|
{
|
|
/* Note that fcntl() with this parameter is not a cancellation point. */
|
|
if (__builtin_expect (__libc_fcntl (fd, F_GETFD), 0) == -1
|
|
&& errno == EBADF)
|
|
{
|
|
const char *name;
|
|
dev_t dev;
|
|
|
|
/* For writable descriptors we use /dev/full. */
|
|
if ((mode & O_ACCMODE) == O_WRONLY)
|
|
{
|
|
name = _PATH_DEV "full";
|
|
dev = __gnu_dev_makedev (DEV_FULL_MAJOR, DEV_FULL_MINOR);
|
|
}
|
|
else
|
|
{
|
|
name = _PATH_DEVNULL;
|
|
dev = __gnu_dev_makedev (DEV_NULL_MAJOR, DEV_NULL_MINOR);
|
|
}
|
|
|
|
/* Something is wrong with this descriptor, it's probably not
|
|
opened. Open /dev/null so that the SUID program we are
|
|
about to start does not accidentally use this descriptor. */
|
|
int nullfd = __open_nocancel (name, mode, 0);
|
|
|
|
/* We are very paranoid here. With all means we try to ensure
|
|
that we are actually opening the /dev/null device and nothing
|
|
else.
|
|
|
|
Note that the following code assumes that STDIN_FILENO,
|
|
STDOUT_FILENO, STDERR_FILENO are the three lowest file
|
|
decsriptor numbers, in this order. */
|
|
struct stat64 st;
|
|
if (__builtin_expect (nullfd != fd, 0)
|
|
|| __builtin_expect (__fxstat64 (_STAT_VER, fd, &st), 0) != 0
|
|
|| __builtin_expect (S_ISCHR (st.st_mode), 1) == 0
|
|
|| st.st_rdev != dev)
|
|
/* We cannot even give an error message here since it would
|
|
run into the same problems. */
|
|
while (1)
|
|
/* Try for ever and ever. */
|
|
ABORT_INSTRUCTION;
|
|
}
|
|
}
|
|
|
|
|
|
void
|
|
__libc_check_standard_fds (void)
|
|
{
|
|
/* Check all three standard file descriptors. The O_NOFOLLOW flag
|
|
is really paranoid but some people actually are. If /dev/null
|
|
should happen to be a symlink to somewhere else and not the
|
|
device commonly known as "/dev/null" we bail out. */
|
|
check_one_fd (STDIN_FILENO, O_WRONLY | O_NOFOLLOW);
|
|
check_one_fd (STDOUT_FILENO, O_RDONLY | O_NOFOLLOW);
|
|
check_one_fd (STDERR_FILENO, O_RDONLY | O_NOFOLLOW);
|
|
}
|