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 info = get_sample_info(expr->sample_flags); 66 if (info == NULL) { 67 pr_err("Error: %s event does not have sample flags %lx\n", 68 evsel__name(evsel), expr->sample_flags); 69 return -1; 70 } 71 72 pr_err("Error: %s event does not have %s\n", evsel__name(evsel), info->name); 73 if (info->option) 74 pr_err(" Hint: please add %s option to perf record\n", info->option); 75 return -1; 76 } 77 78 int perf_bpf_filter__prepare(struct evsel *evsel) 79 { 80 int i, x, y, fd; 81 struct sample_filter_bpf *skel; 82 struct bpf_program *prog; 83 struct bpf_link *link; 84 struct perf_bpf_filter_expr *expr; 85 86 skel = sample_filter_bpf__open_and_load(); 87 if (!skel) { 88 pr_err("Failed to load perf sample-filter BPF skeleton\n"); 89 return -1; 90 } 91 92 i = 0; 93 fd = bpf_map__fd(skel->maps.filters); 94 list_for_each_entry(expr, &evsel->bpf_filters, list) { 95 struct perf_bpf_filter_entry entry = { 96 .op = expr->op, 97 .part = expr->part, 98 .flags = expr->sample_flags, 99 .value = expr->val, 100 }; 101 102 if (check_sample_flags(evsel, expr) < 0) 103 return -1; 104 105 bpf_map_update_elem(fd, &i, &entry, BPF_ANY); 106 i++; 107 108 if (expr->op == PBF_OP_GROUP_BEGIN) { 109 struct perf_bpf_filter_expr *group; 110 111 list_for_each_entry(group, &expr->groups, list) { 112 struct perf_bpf_filter_entry group_entry = { 113 .op = group->op, 114 .part = group->part, 115 .flags = group->sample_flags, 116 .value = group->val, 117 }; 118 bpf_map_update_elem(fd, &i, &group_entry, BPF_ANY); 119 i++; 120 } 121 122 memset(&entry, 0, sizeof(entry)); 123 entry.op = PBF_OP_GROUP_END; 124 bpf_map_update_elem(fd, &i, &entry, BPF_ANY); 125 i++; 126 } 127 } 128 129 if (i > MAX_FILTERS) { 130 pr_err("Too many filters: %d (max = %d)\n", i, MAX_FILTERS); 131 return -1; 132 } 133 prog = skel->progs.perf_sample_filter; 134 for (x = 0; x < xyarray__max_x(evsel->core.fd); x++) { 135 for (y = 0; y < xyarray__max_y(evsel->core.fd); y++) { 136 link = bpf_program__attach_perf_event(prog, FD(evsel, x, y)); 137 if (IS_ERR(link)) { 138 pr_err("Failed to attach perf sample-filter program\n"); 139 return PTR_ERR(link); 140 } 141 } 142 } 143 evsel->bpf_skel = skel; 144 return 0; 145 } 146 147 int perf_bpf_filter__destroy(struct evsel *evsel) 148 { 149 struct perf_bpf_filter_expr *expr, *tmp; 150 151 list_for_each_entry_safe(expr, tmp, &evsel->bpf_filters, list) { 152 list_del(&expr->list); 153 free(expr); 154 } 155 sample_filter_bpf__destroy(evsel->bpf_skel); 156 return 0; 157 } 158 159 u64 perf_bpf_filter__lost_count(struct evsel *evsel) 160 { 161 struct sample_filter_bpf *skel = evsel->bpf_skel; 162 163 return skel ? skel->bss->dropped : 0; 164 } 165 166 struct perf_bpf_filter_expr *perf_bpf_filter_expr__new(unsigned long sample_flags, int part, 167 enum perf_bpf_filter_op op, 168 unsigned long val) 169 { 170 struct perf_bpf_filter_expr *expr; 171 172 expr = malloc(sizeof(*expr)); 173 if (expr != NULL) { 174 expr->sample_flags = sample_flags; 175 expr->part = part; 176 expr->op = op; 177 expr->val = val; 178 INIT_LIST_HEAD(&expr->groups); 179 } 180 return expr; 181 } 182 183 int perf_bpf_filter__parse(struct list_head *expr_head, const char *str) 184 { 185 YY_BUFFER_STATE buffer; 186 int ret; 187 188 buffer = perf_bpf_filter__scan_string(str); 189 190 ret = perf_bpf_filter_parse(expr_head); 191 192 perf_bpf_filter__flush_buffer(buffer); 193 perf_bpf_filter__delete_buffer(buffer); 194 perf_bpf_filter_lex_destroy(); 195 196 return ret; 197 } 198