freebsd-nq/lib/libc/gen/sched_setaffinity.c
Konstantin Belousov d9cacbf4b0 sched_get/setaffinity(): try to be more compatible with Linux
in handling the cpuset sizes different from sizeof(cpuset_t).

For both cases, cpuset size shorter than sizeof(cpuset_t) results
in EINVAL on Linux.

For sched_getaffinity(), be more permissive and accept cpuset size
larger than our cpuset_t, by clipping the syscall argument and zeroing
the rest of the output buffer.  For sched_setaffinity(), we should allow
shorter cpusets than current ABI size, again zeroing the rest of the bits.

With this change, python os.sched_get/setaffinity functions work.

Reported by:	se
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2022-01-03 04:31:40 +02:00

48 lines
1.8 KiB
C

/*-
* Copyright (c) 2021 The FreeBSD Foundation
*
* This software were developed by Konstantin Belousov <kib@FreeBSD.org>
* under sponsorship from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <errno.h>
#include <sched.h>
#include <string.h>
int
sched_setaffinity(pid_t pid, size_t cpusetsz, const cpuset_t *cpuset)
{
cpuset_t c;
if (cpusetsz > sizeof(cpuset_t)) {
errno = EINVAL;
return (-1);
} else {
memset(&c, 0, sizeof(c));
memcpy(&c, cpuset, cpusetsz);
}
return (cpuset_setaffinity(CPU_LEVEL_WHICH, CPU_WHICH_PID,
pid == 0 ? -1 : pid, sizeof(cpuset_t), &c));
}