1 /* 2 * Inspired by breakpoint overflow test done by 3 * Vince Weaver <vincent.weaver (at) maine.edu> for perf_event_tests 4 * (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 "perf.h" 28 29 static int fd1; 30 static int fd2; 31 static int overflows; 32 33 __attribute__ ((noinline)) 34 static int test_function(void) 35 { 36 return time(NULL); 37 } 38 39 static void sig_handler(int signum __maybe_unused, 40 siginfo_t *oh __maybe_unused, 41 void *uc __maybe_unused) 42 { 43 overflows++; 44 45 if (overflows > 10) { 46 /* 47 * This should be executed only once during 48 * this test, if we are here for the 10th 49 * time, consider this the recursive issue. 50 * 51 * We can get out of here by disable events, 52 * so no new SIGIO is delivered. 53 */ 54 ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0); 55 ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0); 56 } 57 } 58 59 static int bp_event(void *fn, int setup_signal) 60 { 61 struct perf_event_attr pe; 62 int fd; 63 64 memset(&pe, 0, sizeof(struct perf_event_attr)); 65 pe.type = PERF_TYPE_BREAKPOINT; 66 pe.size = sizeof(struct perf_event_attr); 67 68 pe.config = 0; 69 pe.bp_type = HW_BREAKPOINT_X; 70 pe.bp_addr = (unsigned long) fn; 71 pe.bp_len = sizeof(long); 72 73 pe.sample_period = 1; 74 pe.sample_type = PERF_SAMPLE_IP; 75 pe.wakeup_events = 1; 76 77 pe.disabled = 1; 78 pe.exclude_kernel = 1; 79 pe.exclude_hv = 1; 80 81 fd = sys_perf_event_open(&pe, 0, -1, -1, 0); 82 if (fd < 0) { 83 pr_debug("failed opening event %llx\n", pe.config); 84 return TEST_FAIL; 85 } 86 87 if (setup_signal) { 88 fcntl(fd, F_SETFL, O_RDWR|O_NONBLOCK|O_ASYNC); 89 fcntl(fd, F_SETSIG, SIGIO); 90 fcntl(fd, F_SETOWN, getpid()); 91 } 92 93 ioctl(fd, PERF_EVENT_IOC_RESET, 0); 94 95 return fd; 96 } 97 98 static long long bp_count(int fd) 99 { 100 long long count; 101 int ret; 102 103 ret = read(fd, &count, sizeof(long long)); 104 if (ret != sizeof(long long)) { 105 pr_debug("failed to read: %d\n", ret); 106 return TEST_FAIL; 107 } 108 109 return count; 110 } 111 112 int test__bp_signal(void) 113 { 114 struct sigaction sa; 115 long long count1, count2; 116 117 /* setup SIGIO signal handler */ 118 memset(&sa, 0, sizeof(struct sigaction)); 119 sa.sa_sigaction = (void *) sig_handler; 120 sa.sa_flags = SA_SIGINFO; 121 122 if (sigaction(SIGIO, &sa, NULL) < 0) { 123 pr_debug("failed setting up signal handler\n"); 124 return TEST_FAIL; 125 } 126 127 /* 128 * We create following events: 129 * 130 * fd1 - breakpoint event on test_function with SIGIO 131 * signal configured. We should get signal 132 * notification each time the breakpoint is hit 133 * 134 * fd2 - breakpoint event on sig_handler without SIGIO 135 * configured. 136 * 137 * Following processing should happen: 138 * - execute test_function 139 * - fd1 event breakpoint hit -> count1 == 1 140 * - SIGIO is delivered -> overflows == 1 141 * - fd2 event breakpoint hit -> count2 == 1 142 * 143 * The test case check following error conditions: 144 * - we get stuck in signal handler because of debug 145 * exception being triggered receursively due to 146 * the wrong RF EFLAG management 147 * 148 * - we never trigger the sig_handler breakpoint due 149 * to the rong RF EFLAG management 150 * 151 */ 152 153 fd1 = bp_event(test_function, 1); 154 fd2 = bp_event(sig_handler, 0); 155 156 ioctl(fd1, PERF_EVENT_IOC_ENABLE, 0); 157 ioctl(fd2, PERF_EVENT_IOC_ENABLE, 0); 158 159 /* 160 * Kick off the test by trigering 'fd1' 161 * breakpoint. 162 */ 163 test_function(); 164 165 ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0); 166 ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0); 167 168 count1 = bp_count(fd1); 169 count2 = bp_count(fd2); 170 171 close(fd1); 172 close(fd2); 173 174 pr_debug("count1 %lld, count2 %lld, overflow %d\n", 175 count1, count2, overflows); 176 177 if (count1 != 1) { 178 if (count1 == 11) 179 pr_debug("failed: RF EFLAG recursion issue detected\n"); 180 else 181 pr_debug("failed: wrong count for bp1%lld\n", count1); 182 } 183 184 if (overflows != 1) 185 pr_debug("failed: wrong overflow hit\n"); 186 187 if (count2 != 1) 188 pr_debug("failed: wrong count for bp2\n"); 189 190 return count1 == 1 && overflows == 1 && count2 == 1 ? 191 TEST_OK : TEST_FAIL; 192 } 193
