1 /* 2 * Inspired by breakpoint overflow test done by 3 * Vince Weaver <vincent.weaver@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 #include "cloexec.h" 29 30 static int fd1; 31 static int fd2; 32 static int overflows; 33 34 __attribute__ ((noinline)) 35 static int test_function(void) 36 { 37 return time(NULL); 38 } 39 40 static void sig_handler(int signum __maybe_unused, 41 siginfo_t *oh __maybe_unused, 42 void *uc __maybe_unused) 43 { 44 overflows++; 45 46 if (overflows > 10) { 47 /* 48 * This should be executed only once during 49 * this test, if we are here for the 10th 50 * time, consider this the recursive issue. 51 * 52 * We can get out of here by disable events, 53 * so no new SIGIO is delivered. 54 */ 55 ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0); 56 ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0); 57 } 58 } 59 60 static int bp_event(void *fn, int setup_signal) 61 { 62 struct perf_event_attr pe; 63 int fd; 64 65 memset(&pe, 0, sizeof(struct perf_event_attr)); 66 pe.type = PERF_TYPE_BREAKPOINT; 67 pe.size = sizeof(struct perf_event_attr); 68 69 pe.config = 0; 70 pe.bp_type = HW_BREAKPOINT_X; 71 pe.bp_addr = (unsigned long) fn; 72 pe.bp_len = sizeof(long); 73 74 pe.sample_period = 1; 75 pe.sample_type = PERF_SAMPLE_IP; 76 pe.wakeup_events = 1; 77 78 pe.disabled = 1; 79 pe.exclude_kernel = 1; 80 pe.exclude_hv = 1; 81 82 fd = sys_perf_event_open(&pe, 0, -1, -1, 83 perf_event_open_cloexec_flag()); 84 if (fd < 0) { 85 pr_debug("failed opening event %llx\n", pe.config); 86 return TEST_FAIL; 87 } 88 89 if (setup_signal) { 90 fcntl(fd, F_SETFL, O_RDWR|O_NONBLOCK|O_ASYNC); 91 fcntl(fd, F_SETSIG, SIGIO); 92 fcntl(fd, F_SETOWN, getpid()); 93 } 94 95 ioctl(fd, PERF_EVENT_IOC_RESET, 0); 96 97 return fd; 98 } 99 100 static long long bp_count(int fd) 101 { 102 long long count; 103 int ret; 104 105 ret = read(fd, &count, sizeof(long long)); 106 if (ret != sizeof(long long)) { 107 pr_debug("failed to read: %d\n", ret); 108 return TEST_FAIL; 109 } 110 111 return count; 112 } 113 114 int test__bp_signal(void) 115 { 116 struct sigaction sa; 117 long long count1, count2; 118 119 /* setup SIGIO signal handler */ 120 memset(&sa, 0, sizeof(struct sigaction)); 121 sa.sa_sigaction = (void *) sig_handler; 122 sa.sa_flags = SA_SIGINFO; 123 124 if (sigaction(SIGIO, &sa, NULL) < 0) { 125 pr_debug("failed setting up signal handler\n"); 126 return TEST_FAIL; 127 } 128 129 /* 130 * We create following events: 131 * 132 * fd1 - breakpoint event on test_function with SIGIO 133 * signal configured. We should get signal 134 * notification each time the breakpoint is hit 135 * 136 * fd2 - breakpoint event on sig_handler without SIGIO 137 * configured. 138 * 139 * Following processing should happen: 140 * - execute test_function 141 * - fd1 event breakpoint hit -> count1 == 1 142 * - SIGIO is delivered -> overflows == 1 143 * - fd2 event breakpoint hit -> count2 == 1 144 * 145 * The test case check following error conditions: 146 * - we get stuck in signal handler because of debug 147 * exception being triggered receursively due to 148 * the wrong RF EFLAG management 149 * 150 * - we never trigger the sig_handler breakpoint due 151 * to the rong RF EFLAG management 152 * 153 */ 154 155 fd1 = bp_event(test_function, 1); 156 fd2 = bp_event(sig_handler, 0); 157 158 ioctl(fd1, PERF_EVENT_IOC_ENABLE, 0); 159 ioctl(fd2, PERF_EVENT_IOC_ENABLE, 0); 160 161 /* 162 * Kick off the test by trigering 'fd1' 163 * breakpoint. 164 */ 165 test_function(); 166 167 ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0); 168 ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0); 169 170 count1 = bp_count(fd1); 171 count2 = bp_count(fd2); 172 173 close(fd1); 174 close(fd2); 175 176 pr_debug("count1 %lld, count2 %lld, overflow %d\n", 177 count1, count2, overflows); 178 179 if (count1 != 1) { 180 if (count1 == 11) 181 pr_debug("failed: RF EFLAG recursion issue detected\n"); 182 else 183 pr_debug("failed: wrong count for bp1%lld\n", count1); 184 } 185 186 if (overflows != 1) 187 pr_debug("failed: wrong overflow hit\n"); 188 189 if (count2 != 1) 190 pr_debug("failed: wrong count for bp2\n"); 191 192 return count1 == 1 && overflows == 1 && count2 == 1 ? 193 TEST_OK : TEST_FAIL; 194 } 195