glibc/sysdeps/unix/sysv/linux/ttyname.h
Joseph Myers 8b4a118222 Fix -Os gnu_dev_* linknamespace, localplt issues (bug 15105, bug 19463).
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.
2018-02-07 14:57:31 +00:00

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1.5 KiB
C

/* Copyright (C) 2016-2018 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; see the file COPYING.LIB. If
not, see <http://www.gnu.org/licenses/>. */
#include <unistd.h>
#include <stdbool.h>
#include <sys/sysmacros.h>
#include <sys/types.h>
#include <sys/stat.h>
/* Return true if this is a UNIX98 pty device, as defined in
linux/Documentation/devices.txt (on linux < 4.10) or
linux/Documentation/admin-guide/devices.txt (on linux >= 4.10). */
static inline bool
is_pty (struct stat64 *sb)
{
#ifdef _STATBUF_ST_RDEV
int m = __gnu_dev_major (sb->st_rdev);
return (136 <= m && m <= 143);
#else
return false;
#endif
}
static inline bool
is_mytty (const struct stat64 *mytty, const struct stat64 *maybe)
{
return (maybe->st_ino == mytty->st_ino
&& maybe->st_dev == mytty->st_dev
#ifdef _STATBUF_ST_RDEV
&& S_ISCHR (maybe->st_mode)
&& maybe->st_rdev == mytty->st_rdev
#endif
);
}