cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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proc-uptime-002.c (2111B)

      1/*
      2 * Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com>
      3 *
      4 * Permission to use, copy, modify, and distribute this software for any
      5 * purpose with or without fee is hereby granted, provided that the above
      6 * copyright notice and this permission notice appear in all copies.
      7 *
      8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
      9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
     10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
     11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
     12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
     13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
     14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
     15 */
     16// Test that values in /proc/uptime increment monotonically
     17// while shifting across CPUs.
     18#undef NDEBUG
     19#include <assert.h>
     20#include <unistd.h>
     21#include <sys/syscall.h>
     22#include <stdlib.h>
     23#include <string.h>
     24
     25#include <stdint.h>
     26#include <sys/types.h>
     27#include <sys/stat.h>
     28#include <fcntl.h>
     29
     30#include "proc-uptime.h"
     31
     32static inline int sys_sched_getaffinity(pid_t pid, unsigned int len, unsigned long *m)
     33{
     34	return syscall(SYS_sched_getaffinity, pid, len, m);
     35}
     36
     37static inline int sys_sched_setaffinity(pid_t pid, unsigned int len, unsigned long *m)
     38{
     39	return syscall(SYS_sched_setaffinity, pid, len, m);
     40}
     41
     42int main(void)
     43{
     44	unsigned int len;
     45	unsigned long *m;
     46	unsigned int cpu;
     47	uint64_t u0, u1, i0, i1;
     48	int fd;
     49
     50	/* find out "nr_cpu_ids" */
     51	m = NULL;
     52	len = 0;
     53	do {
     54		len += sizeof(unsigned long);
     55		free(m);
     56		m = malloc(len);
     57	} while (sys_sched_getaffinity(0, len, m) == -EINVAL);
     58
     59	fd = open("/proc/uptime", O_RDONLY);
     60	assert(fd >= 0);
     61
     62	proc_uptime(fd, &u0, &i0);
     63	for (cpu = 0; cpu < len * 8; cpu++) {
     64		memset(m, 0, len);
     65		m[cpu / (8 * sizeof(unsigned long))] |= 1UL << (cpu % (8 * sizeof(unsigned long)));
     66
     67		/* CPU might not exist, ignore error */
     68		sys_sched_setaffinity(0, len, m);
     69
     70		proc_uptime(fd, &u1, &i1);
     71		assert(u1 >= u0);
     72		assert(i1 >= i0);
     73		u0 = u1;
     74		i0 = i1;
     75	}
     76
     77	return 0;
     78}