~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/tools/testing/selftests/bpf/trace_helpers.c

Version: ~ [ linux-4.20-rc6 ] ~ [ linux-4.19.8 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.87 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.144 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.166 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.128 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.61 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.39.4 ] ~ [ linux-2.6.38.8 ] ~ [ linux-2.6.37.6 ] ~ [ linux-2.6.36.4 ] ~ [ linux-2.6.35.14 ] ~ [ linux-2.6.34.15 ] ~ [ linux-2.6.33.20 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.31.14 ] ~ [ linux-2.6.30.10 ] ~ [ linux-2.6.29.6 ] ~ [ linux-2.6.28.10 ] ~ [ linux-2.6.27.62 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 // SPDX-License-Identifier: GPL-2.0
  2 #include <stdio.h>
  3 #include <stdlib.h>
  4 #include <string.h>
  5 #include <assert.h>
  6 #include <errno.h>
  7 #include <poll.h>
  8 #include <unistd.h>
  9 #include <linux/perf_event.h>
 10 #include <sys/mman.h>
 11 #include "trace_helpers.h"
 12 
 13 #define MAX_SYMS 300000
 14 static struct ksym syms[MAX_SYMS];
 15 static int sym_cnt;
 16 
 17 static int ksym_cmp(const void *p1, const void *p2)
 18 {
 19         return ((struct ksym *)p1)->addr - ((struct ksym *)p2)->addr;
 20 }
 21 
 22 int load_kallsyms(void)
 23 {
 24         FILE *f = fopen("/proc/kallsyms", "r");
 25         char func[256], buf[256];
 26         char symbol;
 27         void *addr;
 28         int i = 0;
 29 
 30         if (!f)
 31                 return -ENOENT;
 32 
 33         while (!feof(f)) {
 34                 if (!fgets(buf, sizeof(buf), f))
 35                         break;
 36                 if (sscanf(buf, "%p %c %s", &addr, &symbol, func) != 3)
 37                         break;
 38                 if (!addr)
 39                         continue;
 40                 syms[i].addr = (long) addr;
 41                 syms[i].name = strdup(func);
 42                 i++;
 43         }
 44         fclose(f);
 45         sym_cnt = i;
 46         qsort(syms, sym_cnt, sizeof(struct ksym), ksym_cmp);
 47         return 0;
 48 }
 49 
 50 struct ksym *ksym_search(long key)
 51 {
 52         int start = 0, end = sym_cnt;
 53         int result;
 54 
 55         while (start < end) {
 56                 size_t mid = start + (end - start) / 2;
 57 
 58                 result = key - syms[mid].addr;
 59                 if (result < 0)
 60                         end = mid;
 61                 else if (result > 0)
 62                         start = mid + 1;
 63                 else
 64                         return &syms[mid];
 65         }
 66 
 67         if (start >= 1 && syms[start - 1].addr < key &&
 68             key < syms[start].addr)
 69                 /* valid ksym */
 70                 return &syms[start - 1];
 71 
 72         /* out of range. return _stext */
 73         return &syms[0];
 74 }
 75 
 76 long ksym_get_addr(const char *name)
 77 {
 78         int i;
 79 
 80         for (i = 0; i < sym_cnt; i++) {
 81                 if (strcmp(syms[i].name, name) == 0)
 82                         return syms[i].addr;
 83         }
 84 
 85         return 0;
 86 }
 87 
 88 static int page_size;
 89 static int page_cnt = 8;
 90 static struct perf_event_mmap_page *header;
 91 
 92 int perf_event_mmap_header(int fd, struct perf_event_mmap_page **header)
 93 {
 94         void *base;
 95         int mmap_size;
 96 
 97         page_size = getpagesize();
 98         mmap_size = page_size * (page_cnt + 1);
 99 
100         base = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
101         if (base == MAP_FAILED) {
102                 printf("mmap err\n");
103                 return -1;
104         }
105 
106         *header = base;
107         return 0;
108 }
109 
110 int perf_event_mmap(int fd)
111 {
112         return perf_event_mmap_header(fd, &header);
113 }
114 
115 static int perf_event_poll(int fd)
116 {
117         struct pollfd pfd = { .fd = fd, .events = POLLIN };
118 
119         return poll(&pfd, 1, 1000);
120 }
121 
122 struct perf_event_sample {
123         struct perf_event_header header;
124         __u32 size;
125         char data[];
126 };
127 
128 static enum bpf_perf_event_ret
129 bpf_perf_event_print(struct perf_event_header *hdr, void *private_data)
130 {
131         struct perf_event_sample *e = (struct perf_event_sample *)hdr;
132         perf_event_print_fn fn = private_data;
133         int ret;
134 
135         if (e->header.type == PERF_RECORD_SAMPLE) {
136                 ret = fn(e->data, e->size);
137                 if (ret != LIBBPF_PERF_EVENT_CONT)
138                         return ret;
139         } else if (e->header.type == PERF_RECORD_LOST) {
140                 struct {
141                         struct perf_event_header header;
142                         __u64 id;
143                         __u64 lost;
144                 } *lost = (void *) e;
145                 printf("lost %lld events\n", lost->lost);
146         } else {
147                 printf("unknown event type=%d size=%d\n",
148                        e->header.type, e->header.size);
149         }
150 
151         return LIBBPF_PERF_EVENT_CONT;
152 }
153 
154 int perf_event_poller(int fd, perf_event_print_fn output_fn)
155 {
156         enum bpf_perf_event_ret ret;
157         void *buf = NULL;
158         size_t len = 0;
159 
160         for (;;) {
161                 perf_event_poll(fd);
162                 ret = bpf_perf_event_read_simple(header, page_cnt * page_size,
163                                                  page_size, &buf, &len,
164                                                  bpf_perf_event_print,
165                                                  output_fn);
166                 if (ret != LIBBPF_PERF_EVENT_CONT)
167                         break;
168         }
169         free(buf);
170 
171         return ret;
172 }
173 
174 int perf_event_poller_multi(int *fds, struct perf_event_mmap_page **headers,
175                             int num_fds, perf_event_print_fn output_fn)
176 {
177         enum bpf_perf_event_ret ret;
178         struct pollfd *pfds;
179         void *buf = NULL;
180         size_t len = 0;
181         int i;
182 
183         pfds = calloc(num_fds, sizeof(*pfds));
184         if (!pfds)
185                 return LIBBPF_PERF_EVENT_ERROR;
186 
187         for (i = 0; i < num_fds; i++) {
188                 pfds[i].fd = fds[i];
189                 pfds[i].events = POLLIN;
190         }
191 
192         for (;;) {
193                 poll(pfds, num_fds, 1000);
194                 for (i = 0; i < num_fds; i++) {
195                         if (!pfds[i].revents)
196                                 continue;
197 
198                         ret = bpf_perf_event_read_simple(headers[i],
199                                                          page_cnt * page_size,
200                                                          page_size, &buf, &len,
201                                                          bpf_perf_event_print,
202                                                          output_fn);
203                         if (ret != LIBBPF_PERF_EVENT_CONT)
204                                 break;
205                 }
206         }
207         free(buf);
208         free(pfds);
209 
210         return ret;
211 }
212 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp