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TP-Link_Archer-XR500v/BBA1.5_platform/apps/public/strace-4.16/affinity.c
2024-07-22 01:58:46 -03:00

123 lines
3.6 KiB
C

/*
* Copyright (c) 2002-2004 Roland McGrath <roland@redhat.com>
* Copyright (c) 2009-2016 Dmitry V. Levin <ldv@altlinux.org>
* All rights reserved.
*
* 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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 "defs.h"
#include <sched.h>
static unsigned int
get_cpuset_size(void)
{
static unsigned int cpuset_size;
if (!cpuset_size) {
/*
* If the cpuset size passed to sched_getaffinity is less
* than necessary to store the bitmask, the kernel does not
* look at the mask pointer and fails with EINVAL.
*
* If the cpuset size is large enough, the kernel fails with
* EFAULT on inaccessible mask pointers.
*
* This undocumented kernel feature can be used to probe
* the kernel and find out the minimal valid cpuset size
* without allocating any memory for the CPU affinity mask.
*/
cpuset_size = 128;
while (cpuset_size &&
sched_getaffinity(0, cpuset_size, NULL) == -1 &&
EINVAL == errno) {
cpuset_size <<= 1;
}
if (!cpuset_size)
cpuset_size = 128;
}
return cpuset_size;
}
static void
print_affinitylist(struct tcb *const tcp, const kernel_ulong_t addr,
const unsigned int len)
{
const unsigned int max_size = get_cpuset_size();
const unsigned int umove_size = len < max_size ? len : max_size;
const unsigned int size =
(umove_size + current_wordsize - 1) & -current_wordsize;
const unsigned int ncpu = size * 8;
void *cpu;
if (!verbose(tcp) || (exiting(tcp) && syserror(tcp)) ||
!addr || !len || !(cpu = calloc(size, 1))) {
printaddr(addr);
return;
}
if (!umoven_or_printaddr(tcp, addr, umove_size, cpu)) {
int i = 0;
const char *sep = "";
tprints("[");
for (;; i++) {
i = next_set_bit(cpu, i, ncpu);
if (i < 0)
break;
tprintf("%s%d", sep, i);
sep = ", ";
}
if (size < len)
tprintf("%s...", sep);
tprints("]");
}
free(cpu);
}
SYS_FUNC(sched_setaffinity)
{
const int pid = tcp->u_arg[0];
const unsigned int len = tcp->u_arg[1];
tprintf("%d, %u, ", pid, len);
print_affinitylist(tcp, tcp->u_arg[2], len);
return RVAL_DECODED;
}
SYS_FUNC(sched_getaffinity)
{
const int pid = tcp->u_arg[0];
const unsigned int len = tcp->u_arg[1];
if (entering(tcp)) {
tprintf("%d, %u, ", pid, len);
} else {
print_affinitylist(tcp, tcp->u_arg[2], tcp->u_rval);
}
return 0;
}