/* * Copyright (c) 2002-2004 Roland McGrath * Copyright (c) 2009-2018 Dmitry V. Levin * All rights reserved. * * SPDX-License-Identifier: LGPL-2.1-or-later */ #include "defs.h" #include 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; }