1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Powerpc needs __SANE_USERSPACE_TYPES__ before <linux/types.h> to select 4 * 'int-ll64.h' and avoid compile warnings when printing __u64 with %llu. 5 */ 6 #define __SANE_USERSPACE_TYPES__ 7 8 #include <stdlib.h> 9 #include <stdio.h> 10 #include <unistd.h> 11 #include <string.h> 12 #include <sys/ioctl.h> 13 #include <time.h> 14 #include <fcntl.h> 15 #include <signal.h> 16 #include <sys/mman.h> 17 #include <linux/compiler.h> 18 #include <linux/hw_breakpoint.h> 19 20 #include "tests.h" 21 #include "debug.h" 22 #include "perf.h" 23 #include "cloexec.h" 24 25 volatile long the_var; 26 27 static noinline int test_function(void) 28 { 29 return 0; 30 } 31 32 static int __event(bool is_x, void *addr, struct perf_event_attr *attr) 33 { 34 int fd; 35 36 memset(attr, 0, sizeof(struct perf_event_attr)); 37 attr->type = PERF_TYPE_BREAKPOINT; 38 attr->size = sizeof(struct perf_event_attr); 39 40 attr->config = 0; 41 attr->bp_type = is_x ? HW_BREAKPOINT_X : HW_BREAKPOINT_W; 42 attr->bp_addr = (unsigned long) addr; 43 attr->bp_len = sizeof(long); 44 45 attr->sample_period = 1; 46 attr->sample_type = PERF_SAMPLE_IP; 47 48 attr->exclude_kernel = 1; 49 attr->exclude_hv = 1; 50 51 fd = sys_perf_event_open(attr, -1, 0, -1, 52 perf_event_open_cloexec_flag()); 53 if (fd < 0) { 54 pr_debug("failed opening event %llx\n", attr->config); 55 return TEST_FAIL; 56 } 57 58 return fd; 59 } 60 61 static int wp_event(void *addr, struct perf_event_attr *attr) 62 { 63 return __event(false, addr, attr); 64 } 65 66 static int bp_event(void *addr, struct perf_event_attr *attr) 67 { 68 return __event(true, addr, attr); 69 } 70 71 static int bp_accounting(int wp_cnt, int share) 72 { 73 struct perf_event_attr attr, attr_mod, attr_new; 74 int i, fd[wp_cnt], fd_wp, ret; 75 76 for (i = 0; i < wp_cnt; i++) { 77 fd[i] = wp_event((void *)&the_var, &attr); 78 TEST_ASSERT_VAL("failed to create wp\n", fd[i] != -1); 79 pr_debug("wp %d created\n", i); 80 } 81 82 attr_mod = attr; 83 attr_mod.bp_type = HW_BREAKPOINT_X; 84 attr_mod.bp_addr = (unsigned long) test_function; 85 86 ret = ioctl(fd[0], PERF_EVENT_IOC_MODIFY_ATTRIBUTES, &attr_mod); 87 TEST_ASSERT_VAL("failed to modify wp\n", ret == 0); 88 89 pr_debug("wp 0 modified to bp\n"); 90 91 if (!share) { 92 fd_wp = wp_event((void *)&the_var, &attr_new); 93 TEST_ASSERT_VAL("failed to create max wp\n", fd_wp != -1); 94 pr_debug("wp max created\n"); 95 } 96 97 for (i = 0; i < wp_cnt; i++) 98 close(fd[i]); 99 100 return 0; 101 } 102 103 static int detect_cnt(bool is_x) 104 { 105 struct perf_event_attr attr; 106 void *addr = is_x ? (void *)test_function : (void *)&the_var; 107 int fd[100], cnt = 0, i; 108 109 while (1) { 110 if (cnt == 100) { 111 pr_debug("way too many debug registers, fix the test\n"); 112 return 0; 113 } 114 fd[cnt] = __event(is_x, addr, &attr); 115 116 if (fd[cnt] < 0) 117 break; 118 cnt++; 119 } 120 121 for (i = 0; i < cnt; i++) 122 close(fd[i]); 123 124 return cnt; 125 } 126 127 static int detect_ioctl(void) 128 { 129 struct perf_event_attr attr; 130 int fd, ret = 1; 131 132 fd = wp_event((void *) &the_var, &attr); 133 if (fd > 0) { 134 ret = ioctl(fd, PERF_EVENT_IOC_MODIFY_ATTRIBUTES, &attr); 135 close(fd); 136 } 137 138 return ret ? 0 : 1; 139 } 140 141 static int detect_share(int wp_cnt, int bp_cnt) 142 { 143 struct perf_event_attr attr; 144 int i, fd[wp_cnt + bp_cnt], ret; 145 146 for (i = 0; i < wp_cnt; i++) { 147 fd[i] = wp_event((void *)&the_var, &attr); 148 TEST_ASSERT_VAL("failed to create wp\n", fd[i] != -1); 149 } 150 151 for (; i < (bp_cnt + wp_cnt); i++) { 152 fd[i] = bp_event((void *)test_function, &attr); 153 if (fd[i] == -1) 154 break; 155 } 156 157 ret = i != (bp_cnt + wp_cnt); 158 159 while (i--) 160 close(fd[i]); 161 162 return ret; 163 } 164 165 /* 166 * This test does following: 167 * - detects the number of watch/break-points, 168 * skip test if any is missing 169 * - detects PERF_EVENT_IOC_MODIFY_ATTRIBUTES ioctl, 170 * skip test if it's missing 171 * - detects if watchpoints and breakpoints share 172 * same slots 173 * - create all possible watchpoints on cpu 0 174 * - change one of it to breakpoint 175 * - in case wp and bp do not share slots, 176 * we create another watchpoint to ensure 177 * the slot accounting is correct 178 */ 179 int test__bp_accounting(struct test *test __maybe_unused, int subtest __maybe_unused) 180 { 181 int has_ioctl = detect_ioctl(); 182 int wp_cnt = detect_cnt(false); 183 int bp_cnt = detect_cnt(true); 184 int share = detect_share(wp_cnt, bp_cnt); 185 186 pr_debug("watchpoints count %d, breakpoints count %d, has_ioctl %d, share %d\n", 187 wp_cnt, bp_cnt, has_ioctl, share); 188 189 if (!wp_cnt || !bp_cnt || !has_ioctl) 190 return TEST_SKIP; 191 192 return bp_accounting(wp_cnt, share); 193 } 194