generic, x86: add tests for prctl PR_GET_TSC and PR_SET_TSC
This patch adds three tests that test whether the PR_GET_TSC and PR_SET_TSC commands have the desirable effect. The tests check whether the control register is updated correctly at context switches and try to discover bugs while enabling/disabling the timestamp counter. Signed-off-by: Erik Bosman <ejbosman@cs.vu.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Родитель
529e25f646
Коммит
f132697326
|
@ -0,0 +1,96 @@
|
|||
/*
|
||||
* Tests for prctl(PR_GET_TSC, ...) / prctl(PR_SET_TSC, ...)
|
||||
*
|
||||
* Tests if the control register is updated correctly
|
||||
* at context switches
|
||||
*
|
||||
* Warning: this test will cause a very high load for a few seconds
|
||||
*
|
||||
*/
|
||||
|
||||
#include <stdio.h>
|
||||
#include <stdlib.h>
|
||||
#include <unistd.h>
|
||||
#include <signal.h>
|
||||
#include <inttypes.h>
|
||||
#include <wait.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
|
||||
|
||||
uint64_t rdtsc() {
|
||||
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;
|
||||
}
|
||||
|
||||
void sigsegv_expect(int sig)
|
||||
{
|
||||
/* */
|
||||
}
|
||||
|
||||
void segvtask(void)
|
||||
{
|
||||
if (prctl(PR_SET_TSC, PR_TSC_SIGSEGV) < 0)
|
||||
{
|
||||
perror("prctl");
|
||||
exit(0);
|
||||
}
|
||||
signal(SIGSEGV, sigsegv_expect);
|
||||
alarm(10);
|
||||
rdtsc();
|
||||
fprintf(stderr, "FATAL ERROR, rdtsc() succeeded while disabled\n");
|
||||
exit(0);
|
||||
}
|
||||
|
||||
|
||||
void sigsegv_fail(int sig)
|
||||
{
|
||||
fprintf(stderr, "FATAL ERROR, rdtsc() failed while enabled\n");
|
||||
exit(0);
|
||||
}
|
||||
|
||||
void rdtsctask(void)
|
||||
{
|
||||
if (prctl(PR_SET_TSC, PR_TSC_ENABLE) < 0)
|
||||
{
|
||||
perror("prctl");
|
||||
exit(0);
|
||||
}
|
||||
signal(SIGSEGV, sigsegv_fail);
|
||||
alarm(10);
|
||||
for(;;) rdtsc();
|
||||
}
|
||||
|
||||
|
||||
int main(int argc, char **argv)
|
||||
{
|
||||
int n_tasks = 100, i;
|
||||
|
||||
fprintf(stderr, "[No further output means we're allright]\n");
|
||||
|
||||
for (i=0; i<n_tasks; i++)
|
||||
if (fork() == 0)
|
||||
{
|
||||
if (i & 1)
|
||||
segvtask();
|
||||
else
|
||||
rdtsctask();
|
||||
}
|
||||
|
||||
for (i=0; i<n_tasks; i++)
|
||||
wait(NULL);
|
||||
|
||||
exit(0);
|
||||
}
|
||||
|
|
@ -0,0 +1,95 @@
|
|||
/*
|
||||
* Tests for prctl(PR_GET_TSC, ...) / prctl(PR_SET_TSC, ...)
|
||||
*
|
||||
* Tests if the control register is updated correctly
|
||||
* when set with prctl()
|
||||
*
|
||||
* Warning: this test will cause a very high load for a few seconds
|
||||
*
|
||||
*/
|
||||
|
||||
#include <stdio.h>
|
||||
#include <stdlib.h>
|
||||
#include <unistd.h>
|
||||
#include <signal.h>
|
||||
#include <inttypes.h>
|
||||
#include <wait.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
|
||||
|
||||
/* snippet from wikipedia :-) */
|
||||
|
||||
uint64_t rdtsc() {
|
||||
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;
|
||||
}
|
||||
|
||||
int should_segv = 0;
|
||||
|
||||
void sigsegv_cb(int sig)
|
||||
{
|
||||
if (!should_segv)
|
||||
{
|
||||
fprintf(stderr, "FATAL ERROR, rdtsc() failed while enabled\n");
|
||||
exit(0);
|
||||
}
|
||||
if (prctl(PR_SET_TSC, PR_TSC_ENABLE) < 0)
|
||||
{
|
||||
perror("prctl");
|
||||
exit(0);
|
||||
}
|
||||
should_segv = 0;
|
||||
|
||||
rdtsc();
|
||||
}
|
||||
|
||||
void task(void)
|
||||
{
|
||||
signal(SIGSEGV, sigsegv_cb);
|
||||
alarm(10);
|
||||
for(;;)
|
||||
{
|
||||
rdtsc();
|
||||
if (should_segv)
|
||||
{
|
||||
fprintf(stderr, "FATAL ERROR, rdtsc() succeeded while disabled\n");
|
||||
exit(0);
|
||||
}
|
||||
if (prctl(PR_SET_TSC, PR_TSC_SIGSEGV) < 0)
|
||||
{
|
||||
perror("prctl");
|
||||
exit(0);
|
||||
}
|
||||
should_segv = 1;
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
int main(int argc, char **argv)
|
||||
{
|
||||
int n_tasks = 100, i;
|
||||
|
||||
fprintf(stderr, "[No further output means we're allright]\n");
|
||||
|
||||
for (i=0; i<n_tasks; i++)
|
||||
if (fork() == 0)
|
||||
task();
|
||||
|
||||
for (i=0; i<n_tasks; i++)
|
||||
wait(NULL);
|
||||
|
||||
exit(0);
|
||||
}
|
||||
|
|
@ -0,0 +1,94 @@
|
|||
/*
|
||||
* 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",
|
||||
};
|
||||
|
||||
uint64_t rdtsc() {
|
||||
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;
|
||||
}
|
||||
|
||||
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() == ");
|
||||
}
|
||||
|
||||
int main(int argc, char **argv)
|
||||
{
|
||||
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);
|
||||
}
|
||||
|
Загрузка…
Ссылка в новой задаче