root/tools/perf/tests/bp_signal_overflow.c

DEFINITIONS

1. test_function
2. sig_handler
3. bp_count
4. test__bp_signal_overflow

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Originally done by Vince Weaver <vincent.weaver@maine.edu> for
   4  * perf_event_tests (git://github.com/deater/perf_event_tests)
   5  */
   6 
   7 /*
   8  * Powerpc needs __SANE_USERSPACE_TYPES__ before <linux/types.h> to select
   9  * 'int-ll64.h' and avoid compile warnings when printing __u64 with %llu.
  10  */
  11 #define __SANE_USERSPACE_TYPES__
  12 
  13 #include <stdlib.h>
  14 #include <stdio.h>
  15 #include <unistd.h>
  16 #include <string.h>
  17 #include <sys/ioctl.h>
  18 #include <time.h>
  19 #include <fcntl.h>
  20 #include <signal.h>
  21 #include <sys/mman.h>
  22 #include <linux/compiler.h>
  23 #include <linux/hw_breakpoint.h>
  24 
  25 #include "tests.h"
  26 #include "debug.h"
  27 #include "event.h"
  28 #include "../perf-sys.h"
  29 #include "cloexec.h"
  30 
  31 static int overflows;
  32 
  33 static noinline int test_function(void)
  34 {
  35         return time(NULL);
  36 }
  37 
  38 static void sig_handler(int signum __maybe_unused,
  39                         siginfo_t *oh __maybe_unused,
  40                         void *uc __maybe_unused)
  41 {
  42         overflows++;
  43 }
  44 
  45 static long long bp_count(int fd)
  46 {
  47         long long count;
  48         int ret;
  49 
  50         ret = read(fd, &count, sizeof(long long));
  51         if (ret != sizeof(long long)) {
  52                 pr_debug("failed to read: %d\n", ret);
  53                 return TEST_FAIL;
  54         }
  55 
  56         return count;
  57 }
  58 
  59 #define EXECUTIONS 10000
  60 #define THRESHOLD  100
  61 
  62 int test__bp_signal_overflow(struct test *test __maybe_unused, int subtest __maybe_unused)
  63 {
  64         struct perf_event_attr pe;
  65         struct sigaction sa;
  66         long long count;
  67         int fd, i, fails = 0;
  68 
  69         /* setup SIGIO signal handler */
  70         memset(&sa, 0, sizeof(struct sigaction));
  71         sa.sa_sigaction = (void *) sig_handler;
  72         sa.sa_flags = SA_SIGINFO;
  73 
  74         if (sigaction(SIGIO, &sa, NULL) < 0) {
  75                 pr_debug("failed setting up signal handler\n");
  76                 return TEST_FAIL;
  77         }
  78 
  79         memset(&pe, 0, sizeof(struct perf_event_attr));
  80         pe.type = PERF_TYPE_BREAKPOINT;
  81         pe.size = sizeof(struct perf_event_attr);
  82 
  83         pe.config = 0;
  84         pe.bp_type = HW_BREAKPOINT_X;
  85         pe.bp_addr = (unsigned long) test_function;
  86         pe.bp_len = sizeof(long);
  87 
  88         pe.sample_period = THRESHOLD;
  89         pe.sample_type = PERF_SAMPLE_IP;
  90         pe.wakeup_events = 1;
  91 
  92         pe.disabled = 1;
  93         pe.exclude_kernel = 1;
  94         pe.exclude_hv = 1;
  95 
  96         fd = sys_perf_event_open(&pe, 0, -1, -1,
  97                                  perf_event_open_cloexec_flag());
  98         if (fd < 0) {
  99                 pr_debug("failed opening event %llx\n", pe.config);
 100                 return TEST_FAIL;
 101         }
 102 
 103         fcntl(fd, F_SETFL, O_RDWR|O_NONBLOCK|O_ASYNC);
 104         fcntl(fd, F_SETSIG, SIGIO);
 105         fcntl(fd, F_SETOWN, getpid());
 106 
 107         ioctl(fd, PERF_EVENT_IOC_RESET, 0);
 108         ioctl(fd, PERF_EVENT_IOC_ENABLE, 0);
 109 
 110         for (i = 0; i < EXECUTIONS; i++)
 111                 test_function();
 112 
 113         ioctl(fd, PERF_EVENT_IOC_DISABLE, 0);
 114 
 115         count = bp_count(fd);
 116 
 117         close(fd);
 118 
 119         pr_debug("count %lld, overflow %d\n",
 120                  count, overflows);
 121 
 122         if (count != EXECUTIONS) {
 123                 pr_debug("\tWrong number of executions %lld != %d\n",
 124                 count, EXECUTIONS);
 125                 fails++;
 126         }
 127 
 128         if (overflows != EXECUTIONS / THRESHOLD) {
 129                 pr_debug("\tWrong number of overflows %d != %d\n",
 130                 overflows, EXECUTIONS / THRESHOLD);
 131                 fails++;
 132         }
 133 
 134         return fails ? TEST_FAIL : TEST_OK;
 135 }