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 <fcntl.h> 14 #include <linux/hw_breakpoint.h> 15 16 #include "tests.h" 17 #include "debug.h" 18 #include "event.h" 19 #include "parse-events.h" 20 #include "../perf-sys.h" 21 #include "cloexec.h" 22 23 /* 24 * PowerPC and S390 do not support creation of instruction breakpoints using the 25 * perf_event interface. 26 * 27 * Just disable the test for these architectures until these issues are 28 * resolved. 29 */ 30 #if defined(__powerpc__) || defined(__s390x__) 31 #define BP_ACCOUNT_IS_SUPPORTED 0 32 #else 33 #define BP_ACCOUNT_IS_SUPPORTED 1 34 #endif 35 36 static volatile long the_var; 37 38 static noinline int test_function(void) 39 { 40 return 0; 41 } 42 43 static int __event(bool is_x, void *addr, struct perf_event_attr *attr) 44 { 45 int fd; 46 47 memset(attr, 0, sizeof(struct perf_event_attr)); 48 attr->type = PERF_TYPE_BREAKPOINT; 49 attr->size = sizeof(struct perf_event_attr); 50 51 attr->config = 0; 52 attr->bp_type = is_x ? HW_BREAKPOINT_X : HW_BREAKPOINT_W; 53 attr->bp_addr = (unsigned long) addr; 54 attr->bp_len = is_x ? default_breakpoint_len() : sizeof(long); 55 56 attr->sample_period = 1; 57 attr->sample_type = PERF_SAMPLE_IP; 58 59 attr->exclude_kernel = 1; 60 attr->exclude_hv = 1; 61 62 fd = sys_perf_event_open(attr, -1, 0, -1, 63 perf_event_open_cloexec_flag()); 64 if (fd < 0) { 65 pr_debug("failed opening event %llx\n", attr->config); 66 return TEST_FAIL; 67 } 68 69 return fd; 70 } 71 72 static int wp_event(void *addr, struct perf_event_attr *attr) 73 { 74 return __event(false, addr, attr); 75 } 76 77 static int bp_event(void *addr, struct perf_event_attr *attr) 78 { 79 return __event(true, addr, attr); 80 } 81 82 static int bp_accounting(int wp_cnt, int share) 83 { 84 struct perf_event_attr attr, attr_mod, attr_new; 85 int i, fd[wp_cnt], fd_wp, ret; 86 87 for (i = 0; i < wp_cnt; i++) { 88 fd[i] = wp_event((void *)&the_var, &attr); 89 TEST_ASSERT_VAL("failed to create wp\n", fd[i] != -1); 90 pr_debug("wp %d created\n", i); 91 } 92 93 attr_mod = attr; 94 attr_mod.bp_type = HW_BREAKPOINT_X; 95 attr_mod.bp_addr = (unsigned long) test_function; 96 attr_mod.bp_len = default_breakpoint_len(); 97 98 ret = ioctl(fd[0], PERF_EVENT_IOC_MODIFY_ATTRIBUTES, &attr_mod); 99 TEST_ASSERT_VAL("failed to modify wp\n", ret == 0); 100 101 pr_debug("wp 0 modified to bp\n"); 102 103 if (!share) { 104 fd_wp = wp_event((void *)&the_var, &attr_new); 105 TEST_ASSERT_VAL("failed to create max wp\n", fd_wp != -1); 106 pr_debug("wp max created\n"); 107 close(fd_wp); 108 } 109 110 for (i = 0; i < wp_cnt; i++) 111 close(fd[i]); 112 113 return 0; 114 } 115 116 static int detect_cnt(bool is_x) 117 { 118 struct perf_event_attr attr; 119 void *addr = is_x ? (void *)test_function : (void *)&the_var; 120 int fd[100], cnt = 0, i; 121 122 while (1) { 123 if (cnt == 100) { 124 pr_debug("way too many debug registers, fix the test\n"); 125 return 0; 126 } 127 fd[cnt] = __event(is_x, addr, &attr); 128 129 if (fd[cnt] < 0) 130 break; 131 cnt++; 132 } 133 134 for (i = 0; i < cnt; i++) 135 close(fd[i]); 136 137 return cnt; 138 } 139 140 static int detect_ioctl(void) 141 { 142 struct perf_event_attr attr; 143 int fd, ret = 1; 144 145 fd = wp_event((void *) &the_var, &attr); 146 if (fd > 0) { 147 ret = ioctl(fd, PERF_EVENT_IOC_MODIFY_ATTRIBUTES, &attr); 148 close(fd); 149 } 150 151 return ret ? 0 : 1; 152 } 153 154 static int detect_share(int wp_cnt, int bp_cnt) 155 { 156 struct perf_event_attr attr; 157 int i, *fd = NULL, ret = -1; 158 159 if (wp_cnt + bp_cnt == 0) 160 return 0; 161 162 fd = malloc(sizeof(int) * (wp_cnt + bp_cnt)); 163 if (!fd) 164 return -1; 165 166 for (i = 0; i < wp_cnt; i++) { 167 fd[i] = wp_event((void *)&the_var, &attr); 168 if (fd[i] == -1) { 169 pr_err("failed to create wp\n"); 170 goto out; 171 } 172 } 173 174 for (; i < (bp_cnt + wp_cnt); i++) { 175 fd[i] = bp_event((void *)test_function, &attr); 176 if (fd[i] == -1) 177 break; 178 } 179 180 ret = i != (bp_cnt + wp_cnt); 181 182 out: 183 while (i--) 184 close(fd[i]); 185 186 free(fd); 187 return ret; 188 } 189 190 /* 191 * This test does following: 192 * - detects the number of watch/break-points, 193 * skip test if any is missing 194 * - detects PERF_EVENT_IOC_MODIFY_ATTRIBUTES ioctl, 195 * skip test if it's missing 196 * - detects if watchpoints and breakpoints share 197 * same slots 198 * - create all possible watchpoints on cpu 0 199 * - change one of it to breakpoint 200 * - in case wp and bp do not share slots, 201 * we create another watchpoint to ensure 202 * the slot accounting is correct 203 */ 204 static int test__bp_accounting(struct test_suite *test __maybe_unused, int subtest __maybe_unused) 205 { 206 int has_ioctl = detect_ioctl(); 207 int wp_cnt = detect_cnt(false); 208 int bp_cnt = detect_cnt(true); 209 int share = detect_share(wp_cnt, bp_cnt); 210 211 if (!BP_ACCOUNT_IS_SUPPORTED) { 212 pr_debug("Test not supported on this architecture"); 213 return TEST_SKIP; 214 } 215 216 pr_debug("watchpoints count %d, breakpoints count %d, has_ioctl %d, share %d\n", 217 wp_cnt, bp_cnt, has_ioctl, share); 218 219 if (!wp_cnt || !bp_cnt || !has_ioctl) 220 return TEST_SKIP; 221 222 return bp_accounting(wp_cnt, share); 223 } 224 225 DEFINE_SUITE("Breakpoint accounting", bp_accounting); 226