diff options
Diffstat (limited to 'kernel/tools/perf/tests/bp_signal.c')
| -rw-r--r-- | kernel/tools/perf/tests/bp_signal.c | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/kernel/tools/perf/tests/bp_signal.c b/kernel/tools/perf/tests/bp_signal.c new file mode 100644 index 000000000..a02b035fd --- /dev/null +++ b/kernel/tools/perf/tests/bp_signal.c @@ -0,0 +1,194 @@ +/* + * Inspired by breakpoint overflow test done by + * Vince Weaver <vincent.weaver@maine.edu> for perf_event_tests + * (git://github.com/deater/perf_event_tests) + */ + +/* + * Powerpc needs __SANE_USERSPACE_TYPES__ before <linux/types.h> to select + * 'int-ll64.h' and avoid compile warnings when printing __u64 with %llu. + */ +#define __SANE_USERSPACE_TYPES__ + +#include <stdlib.h> +#include <stdio.h> +#include <unistd.h> +#include <string.h> +#include <sys/ioctl.h> +#include <time.h> +#include <fcntl.h> +#include <signal.h> +#include <sys/mman.h> +#include <linux/compiler.h> +#include <linux/hw_breakpoint.h> + +#include "tests.h" +#include "debug.h" +#include "perf.h" +#include "cloexec.h" + +static int fd1; +static int fd2; +static int overflows; + +__attribute__ ((noinline)) +static int test_function(void) +{ + return time(NULL); +} + +static void sig_handler(int signum __maybe_unused, + siginfo_t *oh __maybe_unused, + void *uc __maybe_unused) +{ + overflows++; + + if (overflows > 10) { + /* + * This should be executed only once during + * this test, if we are here for the 10th + * time, consider this the recursive issue. + * + * We can get out of here by disable events, + * so no new SIGIO is delivered. + */ + ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0); + ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0); + } +} + +static int bp_event(void *fn, int setup_signal) +{ + struct perf_event_attr pe; + int fd; + + memset(&pe, 0, sizeof(struct perf_event_attr)); + pe.type = PERF_TYPE_BREAKPOINT; + pe.size = sizeof(struct perf_event_attr); + + pe.config = 0; + pe.bp_type = HW_BREAKPOINT_X; + pe.bp_addr = (unsigned long) fn; + pe.bp_len = sizeof(long); + + pe.sample_period = 1; + pe.sample_type = PERF_SAMPLE_IP; + pe.wakeup_events = 1; + + pe.disabled = 1; + pe.exclude_kernel = 1; + pe.exclude_hv = 1; + + fd = sys_perf_event_open(&pe, 0, -1, -1, + perf_event_open_cloexec_flag()); + if (fd < 0) { + pr_debug("failed opening event %llx\n", pe.config); + return TEST_FAIL; + } + + if (setup_signal) { + fcntl(fd, F_SETFL, O_RDWR|O_NONBLOCK|O_ASYNC); + fcntl(fd, F_SETSIG, SIGIO); + fcntl(fd, F_SETOWN, getpid()); + } + + ioctl(fd, PERF_EVENT_IOC_RESET, 0); + + return fd; +} + +static long long bp_count(int fd) +{ + long long count; + int ret; + + ret = read(fd, &count, sizeof(long long)); + if (ret != sizeof(long long)) { + pr_debug("failed to read: %d\n", ret); + return TEST_FAIL; + } + + return count; +} + +int test__bp_signal(void) +{ + struct sigaction sa; + long long count1, count2; + + /* setup SIGIO signal handler */ + memset(&sa, 0, sizeof(struct sigaction)); + sa.sa_sigaction = (void *) sig_handler; + sa.sa_flags = SA_SIGINFO; + + if (sigaction(SIGIO, &sa, NULL) < 0) { + pr_debug("failed setting up signal handler\n"); + return TEST_FAIL; + } + + /* + * We create following events: + * + * fd1 - breakpoint event on test_function with SIGIO + * signal configured. We should get signal + * notification each time the breakpoint is hit + * + * fd2 - breakpoint event on sig_handler without SIGIO + * configured. + * + * Following processing should happen: + * - execute test_function + * - fd1 event breakpoint hit -> count1 == 1 + * - SIGIO is delivered -> overflows == 1 + * - fd2 event breakpoint hit -> count2 == 1 + * + * The test case check following error conditions: + * - we get stuck in signal handler because of debug + * exception being triggered receursively due to + * the wrong RF EFLAG management + * + * - we never trigger the sig_handler breakpoint due + * to the rong RF EFLAG management + * + */ + + fd1 = bp_event(test_function, 1); + fd2 = bp_event(sig_handler, 0); + + ioctl(fd1, PERF_EVENT_IOC_ENABLE, 0); + ioctl(fd2, PERF_EVENT_IOC_ENABLE, 0); + + /* + * Kick off the test by trigering 'fd1' + * breakpoint. + */ + test_function(); + + ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0); + ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0); + + count1 = bp_count(fd1); + count2 = bp_count(fd2); + + close(fd1); + close(fd2); + + pr_debug("count1 %lld, count2 %lld, overflow %d\n", + count1, count2, overflows); + + if (count1 != 1) { + if (count1 == 11) + pr_debug("failed: RF EFLAG recursion issue detected\n"); + else + pr_debug("failed: wrong count for bp1%lld\n", count1); + } + + if (overflows != 1) + pr_debug("failed: wrong overflow hit\n"); + + if (count2 != 1) + pr_debug("failed: wrong count for bp2\n"); + + return count1 == 1 && overflows == 1 && count2 == 1 ? + TEST_OK : TEST_FAIL; +} |