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