glibc/sysdeps/unix/sysv/linux/bits/local_lim.h
Florian Weimer aaacde11f2 Reduce <limits.h> pollution due to dynamic PTHREAD_STACK_MIN
<limits.h> used to be a header file with no declarations.
GCC's libgomp includes it in a #pragma GCC visibility hidden block.
Including <unistd.h> from <limits.h> (indirectly) declares everything
in <unistd.h> with hidden visibility, resulting in linker failures.

This commit avoids C declarations in assembler mode and only declares
__sysconf in <limits.h> (and not the entire contents of <unistd.h>).
The __sysconf symbol is already part of the ABI.  PTHREAD_STACK_MIN
is no longer defined for __USE_DYNAMIC_STACK_SIZE && __ASSEMBLER__
because there is no possible definition.

Additionally, PTHREAD_STACK_MIN is now defined by <pthread.h> for
__USE_MISC because this is what developers expect based on the macro
name.  It also helps to avoid libgomp linker failures in GCC because
libgomp includes <pthread.h> before its visibility hacks.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-07-12 18:43:32 +02:00

100 lines
3.1 KiB
C

/* Minimum guaranteed maximum values for system limits. Linux version.
Copyright (C) 1993-2021 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 <https://www.gnu.org/licenses/>. */
/* The kernel header pollutes the namespace with the NR_OPEN symbol
and defines LINK_MAX although filesystems have different maxima. A
similar thing is true for OPEN_MAX: the limit can be changed at
runtime and therefore the macro must not be defined. Remove this
after including the header if necessary. */
#ifndef NR_OPEN
# define __undef_NR_OPEN
#endif
#ifndef LINK_MAX
# define __undef_LINK_MAX
#endif
#ifndef OPEN_MAX
# define __undef_OPEN_MAX
#endif
#ifndef ARG_MAX
# define __undef_ARG_MAX
#endif
/* The kernel sources contain a file with all the needed information. */
#include <linux/limits.h>
/* Have to remove NR_OPEN? */
#ifdef __undef_NR_OPEN
# undef NR_OPEN
# undef __undef_NR_OPEN
#endif
/* Have to remove LINK_MAX? */
#ifdef __undef_LINK_MAX
# undef LINK_MAX
# undef __undef_LINK_MAX
#endif
/* Have to remove OPEN_MAX? */
#ifdef __undef_OPEN_MAX
# undef OPEN_MAX
# undef __undef_OPEN_MAX
#endif
/* Have to remove ARG_MAX? */
#ifdef __undef_ARG_MAX
# undef ARG_MAX
# undef __undef_ARG_MAX
#endif
/* The number of data keys per process. */
#define _POSIX_THREAD_KEYS_MAX 128
/* This is the value this implementation supports. */
#define PTHREAD_KEYS_MAX 1024
/* Controlling the iterations of destructors for thread-specific data. */
#define _POSIX_THREAD_DESTRUCTOR_ITERATIONS 4
/* Number of iterations this implementation does. */
#define PTHREAD_DESTRUCTOR_ITERATIONS _POSIX_THREAD_DESTRUCTOR_ITERATIONS
/* The number of threads per process. */
#define _POSIX_THREAD_THREADS_MAX 64
/* We have no predefined limit on the number of threads. */
#undef PTHREAD_THREADS_MAX
/* Maximum amount by which a process can descrease its asynchronous I/O
priority level. */
#define AIO_PRIO_DELTA_MAX 20
/* Arrange for the definition of PTHREAD_STACK_MIN. */
#include <bits/pthread_stack_min-dynamic.h>
/* Maximum number of timer expiration overruns. */
#define DELAYTIMER_MAX 2147483647
/* Maximum tty name length. */
#define TTY_NAME_MAX 32
/* Maximum login name length. This is arbitrary. */
#define LOGIN_NAME_MAX 256
/* Maximum host name length. */
#define HOST_NAME_MAX 64
/* Maximum message queue priority level. */
#define MQ_PRIO_MAX 32768
/* Maximum value the semaphore can have. */
#define SEM_VALUE_MAX (2147483647)