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      1 /*
      2  * Originally done by Vince Weaver <vincent.weaver (at) maine.edu> for
      3  * perf_event_tests (git://github.com/deater/perf_event_tests)
      4  */
      5 
      6 /*
      7  * Powerpc needs __SANE_USERSPACE_TYPES__ before <linux/types.h> to select
      8  * 'int-ll64.h' and avoid compile warnings when printing __u64 with %llu.
      9  */
     10 #define __SANE_USERSPACE_TYPES__
     11 
     12 #include <stdlib.h>
     13 #include <stdio.h>
     14 #include <unistd.h>
     15 #include <string.h>
     16 #include <sys/ioctl.h>
     17 #include <time.h>
     18 #include <fcntl.h>
     19 #include <signal.h>
     20 #include <sys/mman.h>
     21 #include <linux/compiler.h>
     22 #include <linux/hw_breakpoint.h>
     23 
     24 #include "tests.h"
     25 #include "debug.h"
     26 #include "perf.h"
     27 
     28 static int overflows;
     29 
     30 __attribute__ ((noinline))
     31 static int test_function(void)
     32 {
     33 	return time(NULL);
     34 }
     35 
     36 static void sig_handler(int signum __maybe_unused,
     37 			siginfo_t *oh __maybe_unused,
     38 			void *uc __maybe_unused)
     39 {
     40 	overflows++;
     41 }
     42 
     43 static long long bp_count(int fd)
     44 {
     45 	long long count;
     46 	int ret;
     47 
     48 	ret = read(fd, &count, sizeof(long long));
     49 	if (ret != sizeof(long long)) {
     50 		pr_debug("failed to read: %d\n", ret);
     51 		return TEST_FAIL;
     52 	}
     53 
     54 	return count;
     55 }
     56 
     57 #define EXECUTIONS 10000
     58 #define THRESHOLD  100
     59 
     60 int test__bp_signal_overflow(void)
     61 {
     62 	struct perf_event_attr pe;
     63 	struct sigaction sa;
     64 	long long count;
     65 	int fd, i, fails = 0;
     66 
     67 	/* setup SIGIO signal handler */
     68 	memset(&sa, 0, sizeof(struct sigaction));
     69 	sa.sa_sigaction = (void *) sig_handler;
     70 	sa.sa_flags = SA_SIGINFO;
     71 
     72 	if (sigaction(SIGIO, &sa, NULL) < 0) {
     73 		pr_debug("failed setting up signal handler\n");
     74 		return TEST_FAIL;
     75 	}
     76 
     77 	memset(&pe, 0, sizeof(struct perf_event_attr));
     78 	pe.type = PERF_TYPE_BREAKPOINT;
     79 	pe.size = sizeof(struct perf_event_attr);
     80 
     81 	pe.config = 0;
     82 	pe.bp_type = HW_BREAKPOINT_X;
     83 	pe.bp_addr = (unsigned long) test_function;
     84 	pe.bp_len = sizeof(long);
     85 
     86 	pe.sample_period = THRESHOLD;
     87 	pe.sample_type = PERF_SAMPLE_IP;
     88 	pe.wakeup_events = 1;
     89 
     90 	pe.disabled = 1;
     91 	pe.exclude_kernel = 1;
     92 	pe.exclude_hv = 1;
     93 
     94 	fd = sys_perf_event_open(&pe, 0, -1, -1, 0);
     95 	if (fd < 0) {
     96 		pr_debug("failed opening event %llx\n", pe.config);
     97 		return TEST_FAIL;
     98 	}
     99 
    100 	fcntl(fd, F_SETFL, O_RDWR|O_NONBLOCK|O_ASYNC);
    101 	fcntl(fd, F_SETSIG, SIGIO);
    102 	fcntl(fd, F_SETOWN, getpid());
    103 
    104 	ioctl(fd, PERF_EVENT_IOC_RESET, 0);
    105 	ioctl(fd, PERF_EVENT_IOC_ENABLE, 0);
    106 
    107 	for (i = 0; i < EXECUTIONS; i++)
    108 		test_function();
    109 
    110 	ioctl(fd, PERF_EVENT_IOC_DISABLE, 0);
    111 
    112 	count = bp_count(fd);
    113 
    114 	close(fd);
    115 
    116 	pr_debug("count %lld, overflow %d\n",
    117 		 count, overflows);
    118 
    119 	if (count != EXECUTIONS) {
    120 		pr_debug("\tWrong number of executions %lld != %d\n",
    121 		count, EXECUTIONS);
    122 		fails++;
    123 	}
    124 
    125 	if (overflows != EXECUTIONS / THRESHOLD) {
    126 		pr_debug("\tWrong number of overflows %d != %d\n",
    127 		overflows, EXECUTIONS / THRESHOLD);
    128 		fails++;
    129 	}
    130 
    131 	return fails ? TEST_FAIL : TEST_OK;
    132 }
    133