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