1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #include <stdlib.h> 3 4 #include <bpf/bpf.h> 5 #include <linux/err.h> 6 #include <internal/xyarray.h> 7 8 #include "util/debug.h" 9 #include "util/evsel.h" 10 11 #include "util/bpf-filter.h" 12 #include <util/bpf-filter-flex.h> 13 #include <util/bpf-filter-bison.h> 14 15 #include "bpf_skel/sample-filter.h" 16 #include "bpf_skel/sample_filter.skel.h" 17 18 #define FD(e, x, y) (*(int *)xyarray__entry(e->core.fd, x, y)) 19 20 #define __PERF_SAMPLE_TYPE(st, opt) { st, #st, opt } 21 #define PERF_SAMPLE_TYPE(_st, opt) __PERF_SAMPLE_TYPE(PERF_SAMPLE_##_st, opt) 22 23 static const struct perf_sample_info { 24 u64 type; 25 const char *name; 26 const char *option; 27 } sample_table[] = { 28 /* default sample flags */ 29 PERF_SAMPLE_TYPE(IP, NULL), 30 PERF_SAMPLE_TYPE(TID, NULL), 31 PERF_SAMPLE_TYPE(PERIOD, NULL), 32 /* flags mostly set by default, but still have options */ 33 PERF_SAMPLE_TYPE(ID, "--sample-identifier"), 34 PERF_SAMPLE_TYPE(CPU, "--sample-cpu"), 35 PERF_SAMPLE_TYPE(TIME, "-T"), 36 /* optional sample flags */ 37 PERF_SAMPLE_TYPE(ADDR, "-d"), 38 PERF_SAMPLE_TYPE(DATA_SRC, "-d"), 39 PERF_SAMPLE_TYPE(PHYS_ADDR, "--phys-data"), 40 PERF_SAMPLE_TYPE(WEIGHT, "-W"), 41 PERF_SAMPLE_TYPE(WEIGHT_STRUCT, "-W"), 42 PERF_SAMPLE_TYPE(TRANSACTION, "--transaction"), 43 PERF_SAMPLE_TYPE(CODE_PAGE_SIZE, "--code-page-size"), 44 PERF_SAMPLE_TYPE(DATA_PAGE_SIZE, "--data-page-size"), 45 }; 46 47 static const struct perf_sample_info *get_sample_info(u64 flags) 48 { 49 size_t i; 50 51 for (i = 0; i < ARRAY_SIZE(sample_table); i++) { 52 if (sample_table[i].type == flags) 53 return &sample_table[i]; 54 } 55 return NULL; 56 } 57 58 static int check_sample_flags(struct evsel *evsel, struct perf_bpf_filter_expr *expr) 59 { 60 const struct perf_sample_info *info; 61 62 if (evsel->core.attr.sample_type & expr->sample_flags) 63 return 0; 64 65 if (expr->op == PBF_OP_GROUP_BEGIN) { 66 struct perf_bpf_filter_expr *group; 67 68 list_for_each_entry(group, &expr->groups, list) { 69 if (check_sample_flags(evsel, group) < 0) 70 return -1; 71 } 72 return 0; 73 } 74 75 info = get_sample_info(expr->sample_flags); 76 if (info == NULL) { 77 pr_err("Error: %s event does not have sample flags %lx\n", 78 evsel__name(evsel), expr->sample_flags); 79 return -1; 80 } 81 82 pr_err("Error: %s event does not have %s\n", evsel__name(evsel), info->name); 83 if (info->option) 84 pr_err(" Hint: please add %s option to perf record\n", info->option); 85 return -1; 86 } 87 88 int perf_bpf_filter__prepare(struct evsel *evsel) 89 { 90 int i, x, y, fd; 91 struct sample_filter_bpf *skel; 92 struct bpf_program *prog; 93 struct bpf_link *link; 94 struct perf_bpf_filter_expr *expr; 95 96 skel = sample_filter_bpf__open_and_load(); 97 if (!skel) { 98 pr_err("Failed to load perf sample-filter BPF skeleton\n"); 99 return -1; 100 } 101 102 i = 0; 103 fd = bpf_map__fd(skel->maps.filters); 104 list_for_each_entry(expr, &evsel->bpf_filters, list) { 105 struct perf_bpf_filter_entry entry = { 106 .op = expr->op, 107 .part = expr->part, 108 .flags = expr->sample_flags, 109 .value = expr->val, 110 }; 111 112 if (check_sample_flags(evsel, expr) < 0) 113 return -1; 114 115 bpf_map_update_elem(fd, &i, &entry, BPF_ANY); 116 i++; 117 118 if (expr->op == PBF_OP_GROUP_BEGIN) { 119 struct perf_bpf_filter_expr *group; 120 121 list_for_each_entry(group, &expr->groups, list) { 122 struct perf_bpf_filter_entry group_entry = { 123 .op = group->op, 124 .part = group->part, 125 .flags = group->sample_flags, 126 .value = group->val, 127 }; 128 bpf_map_update_elem(fd, &i, &group_entry, BPF_ANY); 129 i++; 130 } 131 132 memset(&entry, 0, sizeof(entry)); 133 entry.op = PBF_OP_GROUP_END; 134 bpf_map_update_elem(fd, &i, &entry, BPF_ANY); 135 i++; 136 } 137 } 138 139 if (i > MAX_FILTERS) { 140 pr_err("Too many filters: %d (max = %d)\n", i, MAX_FILTERS); 141 return -1; 142 } 143 prog = skel->progs.perf_sample_filter; 144 for (x = 0; x < xyarray__max_x(evsel->core.fd); x++) { 145 for (y = 0; y < xyarray__max_y(evsel->core.fd); y++) { 146 link = bpf_program__attach_perf_event(prog, FD(evsel, x, y)); 147 if (IS_ERR(link)) { 148 pr_err("Failed to attach perf sample-filter program\n"); 149 return PTR_ERR(link); 150 } 151 } 152 } 153 evsel->bpf_skel = skel; 154 return 0; 155 } 156 157 int perf_bpf_filter__destroy(struct evsel *evsel) 158 { 159 struct perf_bpf_filter_expr *expr, *tmp; 160 161 list_for_each_entry_safe(expr, tmp, &evsel->bpf_filters, list) { 162 list_del(&expr->list); 163 free(expr); 164 } 165 sample_filter_bpf__destroy(evsel->bpf_skel); 166 return 0; 167 } 168 169 u64 perf_bpf_filter__lost_count(struct evsel *evsel) 170 { 171 struct sample_filter_bpf *skel = evsel->bpf_skel; 172 173 return skel ? skel->bss->dropped : 0; 174 } 175 176 struct perf_bpf_filter_expr *perf_bpf_filter_expr__new(unsigned long sample_flags, int part, 177 enum perf_bpf_filter_op op, 178 unsigned long val) 179 { 180 struct perf_bpf_filter_expr *expr; 181 182 expr = malloc(sizeof(*expr)); 183 if (expr != NULL) { 184 expr->sample_flags = sample_flags; 185 expr->part = part; 186 expr->op = op; 187 expr->val = val; 188 INIT_LIST_HEAD(&expr->groups); 189 } 190 return expr; 191 } 192 193 int perf_bpf_filter__parse(struct list_head *expr_head, const char *str) 194 { 195 YY_BUFFER_STATE buffer; 196 int ret; 197 198 buffer = perf_bpf_filter__scan_string(str); 199 200 ret = perf_bpf_filter_parse(expr_head); 201 202 perf_bpf_filter__flush_buffer(buffer); 203 perf_bpf_filter__delete_buffer(buffer); 204 perf_bpf_filter_lex_destroy(); 205 206 return ret; 207 } 208