glibc/sysdeps/unix/sysv/linux/prlimit.c
Joseph Myers 695d7d138e Assume prlimit64 is available.
This patch makes sysdeps/unix/sysv/linux code assume the prlimit64
syscall is always available, given the minimum of a 3.2 kernel.

__ASSUME_PRLIMIT64, which in fact was no longer used, is removed.
Code conditional on __NR_prlimit64 being defined is made
unconditional.  Fallback code for the case where prlimit64 produces an
ENOSYS error is removed, substantially simplifying some functions.

Tested for x86_64 and x86.

	* sysdeps/unix/sysv/linux/kernel-features.h (__ASSUME_PRLIMIT64):
	Remove macro.
	* sysdeps/unix/sysv/linux/getrlimit64.c (__getrlimit64): Assume
	prlimit64 is always available and does not give an ENOSYS error.
	* sysdeps/unix/sysv/linux/prlimit.c [__NR_prlimit64]: Make code
	unconditional.
	[!__NR_prlimit64]: Remove conditional code.
	* sysdeps/unix/sysv/linux/setrlimit.c (__setrlimit): Assume
	prlimit64 is always available and does not give an ENOSYS error.
	* sysdeps/unix/sysv/linux/setrlimit64.c (__setrlimit64): Likewise.
2017-05-09 14:05:09 +00:00

75 lines
2.6 KiB
C

/* Copyright (C) 2010-2017 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 <sys/resource.h>
#include <sys/syscall.h>
int
prlimit (__pid_t pid, enum __rlimit_resource resource,
const struct rlimit *new_rlimit, struct rlimit *old_rlimit)
{
struct rlimit64 new_rlimit64_mem;
struct rlimit64 *new_rlimit64 = NULL;
struct rlimit64 old_rlimit64_mem;
struct rlimit64 *old_rlimit64 = (old_rlimit != NULL
? &old_rlimit64_mem : NULL);
if (new_rlimit != NULL)
{
if (new_rlimit->rlim_cur == RLIM_INFINITY)
new_rlimit64_mem.rlim_cur = RLIM64_INFINITY;
else
new_rlimit64_mem.rlim_cur = new_rlimit->rlim_cur;
if (new_rlimit->rlim_max == RLIM_INFINITY)
new_rlimit64_mem.rlim_max = RLIM64_INFINITY;
else
new_rlimit64_mem.rlim_max = new_rlimit->rlim_max;
new_rlimit64 = &new_rlimit64_mem;
}
int res = INLINE_SYSCALL (prlimit64, 4, pid, resource, new_rlimit64,
old_rlimit64);
if (res == 0 && old_rlimit != NULL)
{
/* The prlimit64 syscall is ill-designed for 32-bit machines.
We have to provide a 32-bit variant since otherwise the LFS
system would not work. But what shall we do if the syscall
succeeds but the old values do not fit into a rlimit
structure? We cannot return an error because the operation
itself worked. Best is perhaps to return RLIM_INFINITY. */
old_rlimit->rlim_cur = old_rlimit64_mem.rlim_cur;
if (old_rlimit->rlim_cur != old_rlimit64_mem.rlim_cur)
{
if (new_rlimit == NULL)
return INLINE_SYSCALL_ERROR_RETURN_VALUE (EOVERFLOW);
old_rlimit->rlim_cur = RLIM_INFINITY;
}
old_rlimit->rlim_max = old_rlimit64_mem.rlim_max;
if (old_rlimit->rlim_max != old_rlimit64_mem.rlim_max)
{
if (new_rlimit == NULL)
return INLINE_SYSCALL_ERROR_RETURN_VALUE (EOVERFLOW);
old_rlimit->rlim_max = RLIM_INFINITY;
}
}
return res;
}