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