diff options
Diffstat (limited to 'samples/bpf/bpf_load.c')
| -rw-r--r-- | samples/bpf/bpf_load.c | 114 |
1 files changed, 96 insertions, 18 deletions
diff --git a/samples/bpf/bpf_load.c b/samples/bpf/bpf_load.c index dcdce1270d38..0d449d8032d1 100644 --- a/samples/bpf/bpf_load.c +++ b/samples/bpf/bpf_load.c @@ -21,6 +21,7 @@ #include <sys/mman.h> #include <poll.h> #include <ctype.h> +#include <assert.h> #include "libbpf.h" #include "bpf_load.h" #include "perf-sys.h" @@ -37,15 +38,6 @@ int event_fd[MAX_PROGS]; int prog_cnt; int prog_array_fd = -1; -struct bpf_map_def { - unsigned int type; - unsigned int key_size; - unsigned int value_size; - unsigned int max_entries; - unsigned int map_flags; - unsigned int inner_map_idx; -}; - static int populate_prog_array(const char *event, int prog_fd) { int ind = atoi(event), err; @@ -193,11 +185,14 @@ static int load_and_attach(const char *event, struct bpf_insn *prog, int size) return 0; } -static int load_maps(struct bpf_map_def *maps, int len) +static int load_maps(struct bpf_map_def *maps, int len, + const char **map_names, fixup_map_cb fixup_map) { int i; for (i = 0; i < len / sizeof(struct bpf_map_def); i++) { + if (fixup_map) + fixup_map(&maps[i], map_names[i], i); if (maps[i].type == BPF_MAP_TYPE_ARRAY_OF_MAPS || maps[i].type == BPF_MAP_TYPE_HASH_OF_MAPS) { @@ -280,14 +275,64 @@ static int parse_relo_and_apply(Elf_Data *data, Elf_Data *symbols, return 0; } -int load_bpf_file(char *path) +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 get_sorted_map_names(Elf *elf, Elf_Data *symbols, int maps_shndx, + int strtabidx, char **map_names) +{ + GElf_Sym map_symbols[MAX_MAPS]; + int i, nr_maps = 0; + + for (i = 0; i < symbols->d_size / sizeof(GElf_Sym); i++) { + assert(nr_maps < MAX_MAPS); + if (!gelf_getsym(symbols, i, &map_symbols[nr_maps])) + continue; + if (map_symbols[nr_maps].st_shndx != maps_shndx) + continue; + nr_maps++; + } + + qsort(map_symbols, nr_maps, sizeof(GElf_Sym), cmp_symbols); + + for (i = 0; i < nr_maps; i++) { + char *map_name; + + map_name = elf_strptr(elf, strtabidx, map_symbols[i].st_name); + if (!map_name) { + printf("cannot get map symbol\n"); + return 1; + } + + map_names[i] = strdup(map_name); + if (!map_names[i]) { + printf("strdup(%s): %s(%d)\n", map_name, + strerror(errno), errno); + return 1; + } + } + + return 0; +} + +static int do_load_bpf_file(const char *path, fixup_map_cb fixup_map) { - int fd, i; + int fd, i, ret, maps_shndx = -1, strtabidx = -1; Elf *elf; GElf_Ehdr ehdr; GElf_Shdr shdr, shdr_prog; - Elf_Data *data, *data_prog, *symbols = NULL; - char *shname, *shname_prog; + Elf_Data *data, *data_prog, *data_maps = NULL, *symbols = NULL; + char *shname, *shname_prog, *map_names[MAX_MAPS] = { NULL }; /* reset global variables */ kern_version = 0; @@ -335,14 +380,33 @@ int load_bpf_file(char *path) } memcpy(&kern_version, data->d_buf, sizeof(int)); } else if (strcmp(shname, "maps") == 0) { - processed_sec[i] = true; - if (load_maps(data->d_buf, data->d_size)) - return 1; + maps_shndx = i; + data_maps = data; } 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) { + if (get_sorted_map_names(elf, symbols, maps_shndx, strtabidx, + map_names)) + goto done; + + if (load_maps(data_maps->d_buf, data_maps->d_size, + (const char **)map_names, fixup_map)) + goto done; + + processed_sec[maps_shndx] = true; + } + /* load programs that need map fixup (relocations) */ for (i = 1; i < ehdr.e_shnum; i++) { if (processed_sec[i]) @@ -399,8 +463,22 @@ int load_bpf_file(char *path) load_and_attach(shname, data->d_buf, data->d_size); } + ret = 0; +done: + for (i = 0; i < MAX_MAPS; i++) + free(map_names[i]); close(fd); - return 0; + 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); } void read_trace_pipe(void) |