Release 4.10 tools/testing/selftests/prctl/disable-tsc-test.c
/*
* Tests for prctl(PR_GET_TSC, ...) / prctl(PR_SET_TSC, ...)
*
* Basic test to test behaviour of PR_GET_TSC and PR_SET_TSC
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <inttypes.h>
#include <sys/prctl.h>
#include <linux/prctl.h>
/* Get/set the process' ability to use the timestamp counter instruction */
#ifndef PR_GET_TSC
#define PR_GET_TSC 25
#define PR_SET_TSC 26
# define PR_TSC_ENABLE 1
/* allow the use of the timestamp counter */
# define PR_TSC_SIGSEGV 2
/* throw a SIGSEGV instead of reading the TSC */
#endif
const char *tsc_names[] =
{
[0] = "[not set]",
[PR_TSC_ENABLE] = "PR_TSC_ENABLE",
[PR_TSC_SIGSEGV] = "PR_TSC_SIGSEGV",
};
static uint64_t rdtsc(void)
{
uint32_t lo, hi;
/* We cannot use "=A", since this would use %rax on x86_64 */
__asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi));
return (uint64_t)hi << 32 | lo;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| erik bosman | erik bosman | 23 | 85.19% | 1 | 50.00% |
| peter foley | peter foley | 4 | 14.81% | 1 | 50.00% |
| Total | 27 | 100.00% | 2 | 100.00% |
static void sigsegv_cb(int sig)
{
int tsc_val = 0;
printf("[ SIG_SEGV ]\n");
printf("prctl(PR_GET_TSC, &tsc_val); ");
fflush(stdout);
if ( prctl(PR_GET_TSC, &tsc_val) == -1)
perror("prctl");
printf("tsc_val == %s\n", tsc_names[tsc_val]);
printf("prctl(PR_SET_TSC, PR_TSC_ENABLE)\n");
fflush(stdout);
if ( prctl(PR_SET_TSC, PR_TSC_ENABLE) == -1)
perror("prctl");
printf("rdtsc() == ");
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| erik bosman | erik bosman | 88 | 98.88% | 1 | 50.00% |
| peter foley | peter foley | 1 | 1.12% | 1 | 50.00% |
| Total | 89 | 100.00% | 2 | 100.00% |
int main(void)
{
int tsc_val = 0;
signal(SIGSEGV, sigsegv_cb);
printf("rdtsc() == %llu\n", (unsigned long long)rdtsc());
printf("prctl(PR_GET_TSC, &tsc_val); ");
fflush(stdout);
if ( prctl(PR_GET_TSC, &tsc_val) == -1)
perror("prctl");
printf("tsc_val == %s\n", tsc_names[tsc_val]);
printf("rdtsc() == %llu\n", (unsigned long long)rdtsc());
printf("prctl(PR_SET_TSC, PR_TSC_ENABLE)\n");
fflush(stdout);
if ( prctl(PR_SET_TSC, PR_TSC_ENABLE) == -1)
perror("prctl");
printf("rdtsc() == %llu\n", (unsigned long long)rdtsc());
printf("prctl(PR_SET_TSC, PR_TSC_SIGSEGV)\n");
fflush(stdout);
if ( prctl(PR_SET_TSC, PR_TSC_SIGSEGV) == -1)
perror("prctl");
printf("rdtsc() == ");
fflush(stdout);
printf("%llu\n", (unsigned long long)rdtsc());
fflush(stdout);
exit(EXIT_SUCCESS);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| erik bosman | erik bosman | 182 | 99.45% | 1 | 50.00% |
| mahesh khanwalkar | mahesh khanwalkar | 1 | 0.55% | 1 | 50.00% |
| Total | 183 | 100.00% | 2 | 100.00% |
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| erik bosman | erik bosman | 365 | 98.38% | 1 | 33.33% |
| peter foley | peter foley | 5 | 1.35% | 1 | 33.33% |
| mahesh khanwalkar | mahesh khanwalkar | 1 | 0.27% | 1 | 33.33% |
| Total | 371 | 100.00% | 3 | 100.00% |
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.