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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-14 15:17:12 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-14 15:17:12 -0700 |
| commit | 5d89d9f502f9c33ed0270d716f238429861e1942 (patch) | |
| tree | 6a353640e6836ca465f2dcf00323a7f8a793ae59 /tools/testing/selftests/prctl/disable-tsc-test.c | |
| parent | 50cff89837a43a7c62ac080de9742a298d6418b3 (diff) | |
| parent | fecf861e765b2f9ce1a0487c3940afaed80ef7a8 (diff) | |
| download | linux-5d89d9f502f9c33ed0270d716f238429861e1942.tar.bz2 | |
Merge tag 'linux-kselftest-4.9-rc1-update' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
Pull kselftest updates from Shuah Khan:
"This update consists of:
- Fixes and improvements to existing tests
- Moving code from Documentation to selftests, samples, and tools:
* Moves dnotify_test, prctl, ptp, vDSO, ia64, watchdog, and
networking tests from Documentation to selftests.
* Moves mic/mpssd, misc-devices/mei, timers, watchdog, auxdisplay,
and blackfin examples from Documentation to samples.
* Moves accounting, laptops/dslm, and pcmcia/crc32hash tools from
Documentation to tools.
* Deletes BUILD_DOCSRC and its dependencies"
* tag 'linux-kselftest-4.9-rc1-update' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (21 commits)
selftests/futex: Check ANSI terminal color support
Doc: update 00-INDEX files to reflect the runnable code move
samples: move blackfin gptimers-example from Documentation
tools: move pcmcia crc32hash tool from Documentation
tools: move laptops dslm tool from Documentation
tools: move accounting tool from Documentation
samples: move auxdisplay example code from Documentation
samples: move watchdog example code from Documentation
samples: move timers example code from Documentation
samples: move misc-devices/mei example code from Documentation
samples: move mic/mpssd example code from Documentation
selftests: Move networking/timestamping from Documentation
selftests: move watchdog tests from Documentation/watchdog
selftests: move ia64 tests from Documentation/ia64
selftests: move vDSO tests from Documentation/vDSO
selftests: move ptp tests from Documentation/ptp
selftests: move prctl tests from Documentation/prctl
selftests: move dnotify_test from Documentation/filesystems
selftests/timers: Add missing error code assignment before test
selftests/zram: replace ZRAM_LZ4_COMPRESS
...
Diffstat (limited to 'tools/testing/selftests/prctl/disable-tsc-test.c')
| -rw-r--r-- | tools/testing/selftests/prctl/disable-tsc-test.c | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/tools/testing/selftests/prctl/disable-tsc-test.c b/tools/testing/selftests/prctl/disable-tsc-test.c new file mode 100644 index 000000000000..8d494f7bebdb --- /dev/null +++ b/tools/testing/selftests/prctl/disable-tsc-test.c @@ -0,0 +1,95 @@ +/* + * 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; +} + +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() == "); +} + +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); +} + |