+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0
-#include <stdio.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <libelf.h>
-#include <gelf.h>
-#include <errno.h>
-#include <unistd.h>
-#include <string.h>
-#include <stdbool.h>
-#include <stdlib.h>
-#include <linux/bpf.h>
-#include <linux/filter.h>
-#include <linux/perf_event.h>
-#include <linux/netlink.h>
-#include <linux/rtnetlink.h>
-#include <linux/types.h>
-#include <sys/socket.h>
-#include <sys/syscall.h>
-#include <sys/ioctl.h>
-#include <sys/mman.h>
-#include <poll.h>
-#include <ctype.h>
-#include <assert.h>
-#include <bpf/bpf.h>
-#include "bpf_load.h"
-#include "perf-sys.h"
-
-#define DEBUGFS "/sys/kernel/debug/tracing/"
-
-static char license[128];
-static int kern_version;
-static bool processed_sec[128];
-char bpf_log_buf[BPF_LOG_BUF_SIZE];
-int map_fd[MAX_MAPS];
-int prog_fd[MAX_PROGS];
-int event_fd[MAX_PROGS];
-int prog_cnt;
-int prog_array_fd = -1;
-
-struct bpf_map_data map_data[MAX_MAPS];
-int map_data_count;
-
-static int populate_prog_array(const char *event, int prog_fd)
-{
- int ind = atoi(event), err;
-
- err = bpf_map_update_elem(prog_array_fd, &ind, &prog_fd, BPF_ANY);
- if (err < 0) {
- printf("failed to store prog_fd in prog_array\n");
- return -1;
- }
- return 0;
-}
-
-static int write_kprobe_events(const char *val)
-{
- int fd, ret, flags;
-
- if (val == NULL)
- return -1;
- else if (val[0] == '\0')
- flags = O_WRONLY | O_TRUNC;
- else
- flags = O_WRONLY | O_APPEND;
-
- fd = open(DEBUGFS "kprobe_events", flags);
-
- ret = write(fd, val, strlen(val));
- close(fd);
-
- return ret;
-}
-
-static int load_and_attach(const char *event, struct bpf_insn *prog, int size)
-{
- bool is_socket = strncmp(event, "socket", 6) == 0;
- bool is_kprobe = strncmp(event, "kprobe/", 7) == 0;
- bool is_kretprobe = strncmp(event, "kretprobe/", 10) == 0;
- bool is_tracepoint = strncmp(event, "tracepoint/", 11) == 0;
- bool is_raw_tracepoint = strncmp(event, "raw_tracepoint/", 15) == 0;
- bool is_xdp = strncmp(event, "xdp", 3) == 0;
- bool is_perf_event = strncmp(event, "perf_event", 10) == 0;
- bool is_cgroup_skb = strncmp(event, "cgroup/skb", 10) == 0;
- bool is_cgroup_sk = strncmp(event, "cgroup/sock", 11) == 0;
- bool is_sockops = strncmp(event, "sockops", 7) == 0;
- bool is_sk_skb = strncmp(event, "sk_skb", 6) == 0;
- bool is_sk_msg = strncmp(event, "sk_msg", 6) == 0;
- size_t insns_cnt = size / sizeof(struct bpf_insn);
- enum bpf_prog_type prog_type;
- char buf[256];
- int fd, efd, err, id;
- struct perf_event_attr attr = {};
-
- attr.type = PERF_TYPE_TRACEPOINT;
- attr.sample_type = PERF_SAMPLE_RAW;
- attr.sample_period = 1;
- attr.wakeup_events = 1;
-
- if (is_socket) {
- prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
- } else if (is_kprobe || is_kretprobe) {
- prog_type = BPF_PROG_TYPE_KPROBE;
- } else if (is_tracepoint) {
- prog_type = BPF_PROG_TYPE_TRACEPOINT;
- } else if (is_raw_tracepoint) {
- prog_type = BPF_PROG_TYPE_RAW_TRACEPOINT;
- } else if (is_xdp) {
- prog_type = BPF_PROG_TYPE_XDP;
- } else if (is_perf_event) {
- prog_type = BPF_PROG_TYPE_PERF_EVENT;
- } else if (is_cgroup_skb) {
- prog_type = BPF_PROG_TYPE_CGROUP_SKB;
- } else if (is_cgroup_sk) {
- prog_type = BPF_PROG_TYPE_CGROUP_SOCK;
- } else if (is_sockops) {
- prog_type = BPF_PROG_TYPE_SOCK_OPS;
- } else if (is_sk_skb) {
- prog_type = BPF_PROG_TYPE_SK_SKB;
- } else if (is_sk_msg) {
- prog_type = BPF_PROG_TYPE_SK_MSG;
- } else {
- printf("Unknown event '%s'\n", event);
- return -1;
- }
-
- if (prog_cnt == MAX_PROGS)
- return -1;
-
- fd = bpf_load_program(prog_type, prog, insns_cnt, license, kern_version,
- bpf_log_buf, BPF_LOG_BUF_SIZE);
- if (fd < 0) {
- printf("bpf_load_program() err=%d\n%s", errno, bpf_log_buf);
- return -1;
- }
-
- prog_fd[prog_cnt++] = fd;
-
- if (is_xdp || is_perf_event || is_cgroup_skb || is_cgroup_sk)
- return 0;
-
- if (is_socket || is_sockops || is_sk_skb || is_sk_msg) {
- if (is_socket)
- event += 6;
- else
- event += 7;
- if (*event != '/')
- return 0;
- event++;
- if (!isdigit(*event)) {
- printf("invalid prog number\n");
- return -1;
- }
- return populate_prog_array(event, fd);
- }
-
- if (is_raw_tracepoint) {
- efd = bpf_raw_tracepoint_open(event + 15, fd);
- if (efd < 0) {
- printf("tracepoint %s %s\n", event + 15, strerror(errno));
- return -1;
- }
- event_fd[prog_cnt - 1] = efd;
- return 0;
- }
-
- if (is_kprobe || is_kretprobe) {
- bool need_normal_check = true;
- const char *event_prefix = "";
-
- if (is_kprobe)
- event += 7;
- else
- event += 10;
-
- if (*event == 0) {
- printf("event name cannot be empty\n");
- return -1;
- }
-
- if (isdigit(*event))
- return populate_prog_array(event, fd);
-
-#ifdef __x86_64__
- if (strncmp(event, "sys_", 4) == 0) {
- snprintf(buf, sizeof(buf), "%c:__x64_%s __x64_%s",
- is_kprobe ? 'p' : 'r', event, event);
- err = write_kprobe_events(buf);
- if (err >= 0) {
- need_normal_check = false;
- event_prefix = "__x64_";
- }
- }
-#endif
- if (need_normal_check) {
- snprintf(buf, sizeof(buf), "%c:%s %s",
- is_kprobe ? 'p' : 'r', event, event);
- err = write_kprobe_events(buf);
- if (err < 0) {
- printf("failed to create kprobe '%s' error '%s'\n",
- event, strerror(errno));
- return -1;
- }
- }
-
- strcpy(buf, DEBUGFS);
- strcat(buf, "events/kprobes/");
- strcat(buf, event_prefix);
- strcat(buf, event);
- strcat(buf, "/id");
- } else if (is_tracepoint) {
- event += 11;
-
- if (*event == 0) {
- printf("event name cannot be empty\n");
- return -1;
- }
- strcpy(buf, DEBUGFS);
- strcat(buf, "events/");
- strcat(buf, event);
- strcat(buf, "/id");
- }
-
- efd = open(buf, O_RDONLY, 0);
- if (efd < 0) {
- printf("failed to open event %s\n", event);
- return -1;
- }
-
- err = read(efd, buf, sizeof(buf));
- if (err < 0 || err >= sizeof(buf)) {
- printf("read from '%s' failed '%s'\n", event, strerror(errno));
- return -1;
- }
-
- close(efd);
-
- buf[err] = 0;
- id = atoi(buf);
- attr.config = id;
-
- efd = sys_perf_event_open(&attr, -1/*pid*/, 0/*cpu*/, -1/*group_fd*/, 0);
- if (efd < 0) {
- printf("event %d fd %d err %s\n", id, efd, strerror(errno));
- return -1;
- }
- event_fd[prog_cnt - 1] = efd;
- err = ioctl(efd, PERF_EVENT_IOC_ENABLE, 0);
- if (err < 0) {
- printf("ioctl PERF_EVENT_IOC_ENABLE failed err %s\n",
- strerror(errno));
- return -1;
- }
- err = ioctl(efd, PERF_EVENT_IOC_SET_BPF, fd);
- if (err < 0) {
- printf("ioctl PERF_EVENT_IOC_SET_BPF failed err %s\n",
- strerror(errno));
- return -1;
- }
-
- return 0;
-}
-
-static int load_maps(struct bpf_map_data *maps, int nr_maps,
- fixup_map_cb fixup_map)
-{
- int i, numa_node;
-
- for (i = 0; i < nr_maps; i++) {
- if (fixup_map) {
- fixup_map(&maps[i], i);
- /* Allow userspace to assign map FD prior to creation */
- if (maps[i].fd != -1) {
- map_fd[i] = maps[i].fd;
- continue;
- }
- }
-
- numa_node = maps[i].def.map_flags & BPF_F_NUMA_NODE ?
- maps[i].def.numa_node : -1;
-
- if (maps[i].def.type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
- maps[i].def.type == BPF_MAP_TYPE_HASH_OF_MAPS) {
- int inner_map_fd = map_fd[maps[i].def.inner_map_idx];
-
- map_fd[i] = bpf_create_map_in_map_node(maps[i].def.type,
- maps[i].name,
- maps[i].def.key_size,
- inner_map_fd,
- maps[i].def.max_entries,
- maps[i].def.map_flags,
- numa_node);
- } else {
- map_fd[i] = bpf_create_map_node(maps[i].def.type,
- maps[i].name,
- maps[i].def.key_size,
- maps[i].def.value_size,
- maps[i].def.max_entries,
- maps[i].def.map_flags,
- numa_node);
- }
- if (map_fd[i] < 0) {
- printf("failed to create map %d (%s): %d %s\n",
- i, maps[i].name, errno, strerror(errno));
- return 1;
- }
- maps[i].fd = map_fd[i];
-
- if (maps[i].def.type == BPF_MAP_TYPE_PROG_ARRAY)
- prog_array_fd = map_fd[i];
- }
- return 0;
-}
-
-static int get_sec(Elf *elf, int i, GElf_Ehdr *ehdr, char **shname,
- GElf_Shdr *shdr, Elf_Data **data)
-{
- Elf_Scn *scn;
-
- scn = elf_getscn(elf, i);
- if (!scn)
- return 1;
-
- if (gelf_getshdr(scn, shdr) != shdr)
- return 2;
-
- *shname = elf_strptr(elf, ehdr->e_shstrndx, shdr->sh_name);
- if (!*shname || !shdr->sh_size)
- return 3;
-
- *data = elf_getdata(scn, 0);
- if (!*data || elf_getdata(scn, *data) != NULL)
- return 4;
-
- return 0;
-}
-
-static int parse_relo_and_apply(Elf_Data *data, Elf_Data *symbols,
- GElf_Shdr *shdr, struct bpf_insn *insn,
- struct bpf_map_data *maps, int nr_maps)
-{
- int i, nrels;
-
- nrels = shdr->sh_size / shdr->sh_entsize;
-
- for (i = 0; i < nrels; i++) {
- GElf_Sym sym;
- GElf_Rel rel;
- unsigned int insn_idx;
- bool match = false;
- int j, map_idx;
-
- gelf_getrel(data, i, &rel);
-
- insn_idx = rel.r_offset / sizeof(struct bpf_insn);
-
- gelf_getsym(symbols, GELF_R_SYM(rel.r_info), &sym);
-
- if (insn[insn_idx].code != (BPF_LD | BPF_IMM | BPF_DW)) {
- printf("invalid relo for insn[%d].code 0x%x\n",
- insn_idx, insn[insn_idx].code);
- return 1;
- }
- insn[insn_idx].src_reg = BPF_PSEUDO_MAP_FD;
-
- /* Match FD relocation against recorded map_data[] offset */
- for (map_idx = 0; map_idx < nr_maps; map_idx++) {
- if (maps[map_idx].elf_offset == sym.st_value) {
- match = true;
- break;
- }
- }
- if (match) {
- insn[insn_idx].imm = maps[map_idx].fd;
- } else {
- printf("invalid relo for insn[%d] no map_data match\n",
- insn_idx);
- return 1;
- }
- }
-
- return 0;
-}
-
-static int cmp_symbols(const void *l, const void *r)
-{
- const GElf_Sym *lsym = (const GElf_Sym *)l;
- const GElf_Sym *rsym = (const GElf_Sym *)r;
-
- if (lsym->st_value < rsym->st_value)
- return -1;
- else if (lsym->st_value > rsym->st_value)
- return 1;
- else
- return 0;
-}
-
-static int load_elf_maps_section(struct bpf_map_data *maps, int maps_shndx,
- Elf *elf, Elf_Data *symbols, int strtabidx)
-{
- int map_sz_elf, map_sz_copy;
- bool validate_zero = false;
- Elf_Data *data_maps;
- int i, nr_maps;
- GElf_Sym *sym;
- Elf_Scn *scn;
- int copy_sz;
-
- if (maps_shndx < 0)
- return -EINVAL;
- if (!symbols)
- return -EINVAL;
-
- /* Get data for maps section via elf index */
- scn = elf_getscn(elf, maps_shndx);
- if (scn)
- data_maps = elf_getdata(scn, NULL);
- if (!scn || !data_maps) {
- printf("Failed to get Elf_Data from maps section %d\n",
- maps_shndx);
- return -EINVAL;
- }
-
- /* For each map get corrosponding symbol table entry */
- sym = calloc(MAX_MAPS+1, sizeof(GElf_Sym));
- for (i = 0, nr_maps = 0; i < symbols->d_size / sizeof(GElf_Sym); i++) {
- assert(nr_maps < MAX_MAPS+1);
- if (!gelf_getsym(symbols, i, &sym[nr_maps]))
- continue;
- if (sym[nr_maps].st_shndx != maps_shndx)
- continue;
- /* Only increment iif maps section */
- nr_maps++;
- }
-
- /* Align to map_fd[] order, via sort on offset in sym.st_value */
- qsort(sym, nr_maps, sizeof(GElf_Sym), cmp_symbols);
-
- /* Keeping compatible with ELF maps section changes
- * ------------------------------------------------
- * The program size of struct bpf_load_map_def is known by loader
- * code, but struct stored in ELF file can be different.
- *
- * Unfortunately sym[i].st_size is zero. To calculate the
- * struct size stored in the ELF file, assume all struct have
- * the same size, and simply divide with number of map
- * symbols.
- */
- map_sz_elf = data_maps->d_size / nr_maps;
- map_sz_copy = sizeof(struct bpf_load_map_def);
- if (map_sz_elf < map_sz_copy) {
- /*
- * Backward compat, loading older ELF file with
- * smaller struct, keeping remaining bytes zero.
- */
- map_sz_copy = map_sz_elf;
- } else if (map_sz_elf > map_sz_copy) {
- /*
- * Forward compat, loading newer ELF file with larger
- * struct with unknown features. Assume zero means
- * feature not used. Thus, validate rest of struct
- * data is zero.
- */
- validate_zero = true;
- }
-
- /* Memcpy relevant part of ELF maps data to loader maps */
- for (i = 0; i < nr_maps; i++) {
- struct bpf_load_map_def *def;
- unsigned char *addr, *end;
- const char *map_name;
- size_t offset;
-
- map_name = elf_strptr(elf, strtabidx, sym[i].st_name);
- maps[i].name = strdup(map_name);
- if (!maps[i].name) {
- printf("strdup(%s): %s(%d)\n", map_name,
- strerror(errno), errno);
- free(sym);
- return -errno;
- }
-
- /* Symbol value is offset into ELF maps section data area */
- offset = sym[i].st_value;
- def = (struct bpf_load_map_def *)(data_maps->d_buf + offset);
- maps[i].elf_offset = offset;
- memset(&maps[i].def, 0, sizeof(struct bpf_load_map_def));
- memcpy(&maps[i].def, def, map_sz_copy);
-
- /* Verify no newer features were requested */
- if (validate_zero) {
- addr = (unsigned char *) def + map_sz_copy;
- end = (unsigned char *) def + map_sz_elf;
- for (; addr < end; addr++) {
- if (*addr != 0) {
- free(sym);
- return -EFBIG;
- }
- }
- }
- }
-
- free(sym);
- return nr_maps;
-}
-
-static int do_load_bpf_file(const char *path, fixup_map_cb fixup_map)
-{
- int fd, i, ret, maps_shndx = -1, strtabidx = -1;
- Elf *elf;
- GElf_Ehdr ehdr;
- GElf_Shdr shdr, shdr_prog;
- Elf_Data *data, *data_prog, *data_maps = NULL, *symbols = NULL;
- char *shname, *shname_prog;
- int nr_maps = 0;
-
- /* reset global variables */
- kern_version = 0;
- memset(license, 0, sizeof(license));
- memset(processed_sec, 0, sizeof(processed_sec));
-
- if (elf_version(EV_CURRENT) == EV_NONE)
- return 1;
-
- fd = open(path, O_RDONLY, 0);
- if (fd < 0)
- return 1;
-
- elf = elf_begin(fd, ELF_C_READ, NULL);
-
- if (!elf)
- return 1;
-
- if (gelf_getehdr(elf, &ehdr) != &ehdr)
- return 1;
-
- /* clear all kprobes */
- i = write_kprobe_events("");
-
- /* scan over all elf sections to get license and map info */
- for (i = 1; i < ehdr.e_shnum; i++) {
-
- if (get_sec(elf, i, &ehdr, &shname, &shdr, &data))
- continue;
-
- if (0) /* helpful for llvm debugging */
- printf("section %d:%s data %p size %zd link %d flags %d\n",
- i, shname, data->d_buf, data->d_size,
- shdr.sh_link, (int) shdr.sh_flags);
-
- if (strcmp(shname, "license") == 0) {
- processed_sec[i] = true;
- memcpy(license, data->d_buf, data->d_size);
- } else if (strcmp(shname, "version") == 0) {
- processed_sec[i] = true;
- if (data->d_size != sizeof(int)) {
- printf("invalid size of version section %zd\n",
- data->d_size);
- return 1;
- }
- memcpy(&kern_version, data->d_buf, sizeof(int));
- } else if (strcmp(shname, "maps") == 0) {
- int j;
-
- maps_shndx = i;
- data_maps = data;
- for (j = 0; j < MAX_MAPS; j++)
- map_data[j].fd = -1;
- } else if (shdr.sh_type == SHT_SYMTAB) {
- strtabidx = shdr.sh_link;
- symbols = data;
- }
- }
-
- ret = 1;
-
- if (!symbols) {
- printf("missing SHT_SYMTAB section\n");
- goto done;
- }
-
- if (data_maps) {
- nr_maps = load_elf_maps_section(map_data, maps_shndx,
- elf, symbols, strtabidx);
- if (nr_maps < 0) {
- printf("Error: Failed loading ELF maps (errno:%d):%s\n",
- nr_maps, strerror(-nr_maps));
- goto done;
- }
- if (load_maps(map_data, nr_maps, fixup_map))
- goto done;
- map_data_count = nr_maps;
-
- processed_sec[maps_shndx] = true;
- }
-
- /* process all relo sections, and rewrite bpf insns for maps */
- for (i = 1; i < ehdr.e_shnum; i++) {
- if (processed_sec[i])
- continue;
-
- if (get_sec(elf, i, &ehdr, &shname, &shdr, &data))
- continue;
-
- if (shdr.sh_type == SHT_REL) {
- struct bpf_insn *insns;
-
- /* locate prog sec that need map fixup (relocations) */
- if (get_sec(elf, shdr.sh_info, &ehdr, &shname_prog,
- &shdr_prog, &data_prog))
- continue;
-
- if (shdr_prog.sh_type != SHT_PROGBITS ||
- !(shdr_prog.sh_flags & SHF_EXECINSTR))
- continue;
-
- insns = (struct bpf_insn *) data_prog->d_buf;
- processed_sec[i] = true; /* relo section */
-
- if (parse_relo_and_apply(data, symbols, &shdr, insns,
- map_data, nr_maps))
- continue;
- }
- }
-
- /* load programs */
- for (i = 1; i < ehdr.e_shnum; i++) {
-
- if (processed_sec[i])
- continue;
-
- if (get_sec(elf, i, &ehdr, &shname, &shdr, &data))
- continue;
-
- if (memcmp(shname, "kprobe/", 7) == 0 ||
- memcmp(shname, "kretprobe/", 10) == 0 ||
- memcmp(shname, "tracepoint/", 11) == 0 ||
- memcmp(shname, "raw_tracepoint/", 15) == 0 ||
- memcmp(shname, "xdp", 3) == 0 ||
- memcmp(shname, "perf_event", 10) == 0 ||
- memcmp(shname, "socket", 6) == 0 ||
- memcmp(shname, "cgroup/", 7) == 0 ||
- memcmp(shname, "sockops", 7) == 0 ||
- memcmp(shname, "sk_skb", 6) == 0 ||
- memcmp(shname, "sk_msg", 6) == 0) {
- ret = load_and_attach(shname, data->d_buf,
- data->d_size);
- if (ret != 0)
- goto done;
- }
- }
-
-done:
- close(fd);
- return ret;
-}
-
-int load_bpf_file(char *path)
-{
- return do_load_bpf_file(path, NULL);
-}
-
-int load_bpf_file_fixup_map(const char *path, fixup_map_cb fixup_map)
-{
- return do_load_bpf_file(path, fixup_map);
-}
projects / platform / kernel / linux-rpi.git / commitdiff