projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| f1326973 EB |
1 | /* |
| 2 | * Tests for prctl(PR_GET_TSC, ...) / prctl(PR_SET_TSC, ...) | |
| 3 | * | |
| 4 | * Basic test to test behaviour of PR_GET_TSC and PR_SET_TSC | |
| 5 | */ | |
| 6 | ||
| 7 | #include <stdio.h> | |
| 8 | #include <stdlib.h> | |
| 9 | #include <unistd.h> | |
| 10 | #include <signal.h> | |
| 11 | #include <inttypes.h> | |
| 12 | ||
| 13 | ||
| 14 | #include <sys/prctl.h> | |
| 15 | #include <linux/prctl.h> | |
| 16 | ||
| 17 | /* Get/set the process' ability to use the timestamp counter instruction */ | |
| 18 | #ifndef PR_GET_TSC | |
| 19 | #define PR_GET_TSC 25 | |
| 20 | #define PR_SET_TSC 26 | |
| 21 | # define PR_TSC_ENABLE 1 /* allow the use of the timestamp counter */ | |
| 22 | # define PR_TSC_SIGSEGV 2 /* throw a SIGSEGV instead of reading the TSC */ | |
| 23 | #endif | |
| 24 | ||
| 25 | const char *tsc_names[] = | |
| 26 | { | |
| 27 | [0] = "[not set]", | |
| 28 | [PR_TSC_ENABLE] = "PR_TSC_ENABLE", | |
| 29 | [PR_TSC_SIGSEGV] = "PR_TSC_SIGSEGV", | |
| 30 | }; | |
| 31 | ||
| 0421fc83 PF |
32 | static uint64_t rdtsc(void) |
| 33 | { | |
| f1326973 EB |
34 | uint32_t lo, hi; |
| 35 | /* We cannot use "=A", since this would use %rax on x86_64 */ | |
| 36 | __asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi)); | |
| 37 | return (uint64_t)hi << 32 | lo; | |
| 38 | } | |
| 39 | ||
| 0421fc83 | 40 | static void sigsegv_cb(int sig) |
| f1326973 EB |
41 | { |
| 42 | int tsc_val = 0; | |
| 43 | ||
| 44 | printf("[ SIG_SEGV ]\n"); | |
| 45 | printf("prctl(PR_GET_TSC, &tsc_val); "); | |
| 46 | fflush(stdout); | |
| 47 | ||
| 48 | if ( prctl(PR_GET_TSC, &tsc_val) == -1) | |
| 49 | perror("prctl"); | |
| 50 | ||
| 51 | printf("tsc_val == %s\n", tsc_names[tsc_val]); | |
| 52 | printf("prctl(PR_SET_TSC, PR_TSC_ENABLE)\n"); | |
| 53 | fflush(stdout); | |
| 54 | if ( prctl(PR_SET_TSC, PR_TSC_ENABLE) == -1) | |
| 55 | perror("prctl"); | |
| 56 | ||
| 57 | printf("rdtsc() == "); | |
| 58 | } | |
| 59 | ||
| f0cd147e | 60 | int main(void) |
| f1326973 EB |
61 | { |
| 62 | int tsc_val = 0; | |
| 63 | ||
| 64 | signal(SIGSEGV, sigsegv_cb); | |
| 65 | ||
| 66 | printf("rdtsc() == %llu\n", (unsigned long long)rdtsc()); | |
| 67 | printf("prctl(PR_GET_TSC, &tsc_val); "); | |
| 68 | fflush(stdout); | |
| 69 | ||
| 70 | if ( prctl(PR_GET_TSC, &tsc_val) == -1) | |
| 71 | perror("prctl"); | |
| 72 | ||
| 73 | printf("tsc_val == %s\n", tsc_names[tsc_val]); | |
| 74 | printf("rdtsc() == %llu\n", (unsigned long long)rdtsc()); | |
| 75 | printf("prctl(PR_SET_TSC, PR_TSC_ENABLE)\n"); | |
| 76 | fflush(stdout); | |
| 77 | ||
| 78 | if ( prctl(PR_SET_TSC, PR_TSC_ENABLE) == -1) | |
| 79 | perror("prctl"); | |
| 80 | ||
| 81 | printf("rdtsc() == %llu\n", (unsigned long long)rdtsc()); | |
| 82 | printf("prctl(PR_SET_TSC, PR_TSC_SIGSEGV)\n"); | |
| 83 | fflush(stdout); | |
| 84 | ||
| 85 | if ( prctl(PR_SET_TSC, PR_TSC_SIGSEGV) == -1) | |
| 86 | perror("prctl"); | |
| 87 | ||
| 88 | printf("rdtsc() == "); | |
| 89 | fflush(stdout); | |
| 90 | printf("%llu\n", (unsigned long long)rdtsc()); | |
| 91 | fflush(stdout); | |
| 92 | ||
| 93 | exit(EXIT_SUCCESS); | |
| 94 | } | |
| 95 |