From 76cb841cb886eef6b3bee341a2266c76578724ad Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 6 May 2024 03:02:30 +0200 Subject: Adding upstream version 4.19.249. Signed-off-by: Daniel Baumann --- tools/testing/selftests/prctl/disable-tsc-test.c | 96 ++++++++++++++++++++++++ 1 file changed, 96 insertions(+) create mode 100644 tools/testing/selftests/prctl/disable-tsc-test.c (limited to 'tools/testing/selftests/prctl/disable-tsc-test.c') 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 000000000..f84d4ee11 --- /dev/null +++ b/tools/testing/selftests/prctl/disable-tsc-test.c @@ -0,0 +1,96 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Tests for prctl(PR_GET_TSC, ...) / prctl(PR_SET_TSC, ...) + * + * Basic test to test behaviour of PR_GET_TSC and PR_SET_TSC + */ + +#include +#include +#include +#include +#include + + +#include +#include + +/* 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); +} + -- cgit v1.2.3