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-rw-r--r--kernel/tools/lib/bpf/libbpf.c1125
1 files changed, 1125 insertions, 0 deletions
diff --git a/kernel/tools/lib/bpf/libbpf.c b/kernel/tools/lib/bpf/libbpf.c
new file mode 100644
index 000000000..e176bad19
--- /dev/null
+++ b/kernel/tools/lib/bpf/libbpf.c
@@ -0,0 +1,1125 @@
+/*
+ * Common eBPF ELF object loading operations.
+ *
+ * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
+ * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
+ * Copyright (C) 2015 Huawei Inc.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <inttypes.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <asm/unistd.h>
+#include <linux/kernel.h>
+#include <linux/bpf.h>
+#include <linux/list.h>
+#include <libelf.h>
+#include <gelf.h>
+
+#include "libbpf.h"
+#include "bpf.h"
+
+#define __printf(a, b) __attribute__((format(printf, a, b)))
+
+__printf(1, 2)
+static int __base_pr(const char *format, ...)
+{
+ va_list args;
+ int err;
+
+ va_start(args, format);
+ err = vfprintf(stderr, format, args);
+ va_end(args);
+ return err;
+}
+
+static __printf(1, 2) libbpf_print_fn_t __pr_warning = __base_pr;
+static __printf(1, 2) libbpf_print_fn_t __pr_info = __base_pr;
+static __printf(1, 2) libbpf_print_fn_t __pr_debug;
+
+#define __pr(func, fmt, ...) \
+do { \
+ if ((func)) \
+ (func)("libbpf: " fmt, ##__VA_ARGS__); \
+} while (0)
+
+#define pr_warning(fmt, ...) __pr(__pr_warning, fmt, ##__VA_ARGS__)
+#define pr_info(fmt, ...) __pr(__pr_info, fmt, ##__VA_ARGS__)
+#define pr_debug(fmt, ...) __pr(__pr_debug, fmt, ##__VA_ARGS__)
+
+void libbpf_set_print(libbpf_print_fn_t warn,
+ libbpf_print_fn_t info,
+ libbpf_print_fn_t debug)
+{
+ __pr_warning = warn;
+ __pr_info = info;
+ __pr_debug = debug;
+}
+
+#define STRERR_BUFSIZE 128
+
+#define ERRNO_OFFSET(e) ((e) - __LIBBPF_ERRNO__START)
+#define ERRCODE_OFFSET(c) ERRNO_OFFSET(LIBBPF_ERRNO__##c)
+#define NR_ERRNO (__LIBBPF_ERRNO__END - __LIBBPF_ERRNO__START)
+
+static const char *libbpf_strerror_table[NR_ERRNO] = {
+ [ERRCODE_OFFSET(LIBELF)] = "Something wrong in libelf",
+ [ERRCODE_OFFSET(FORMAT)] = "BPF object format invalid",
+ [ERRCODE_OFFSET(KVERSION)] = "'version' section incorrect or lost",
+ [ERRCODE_OFFSET(ENDIAN)] = "Endian missmatch",
+ [ERRCODE_OFFSET(INTERNAL)] = "Internal error in libbpf",
+ [ERRCODE_OFFSET(RELOC)] = "Relocation failed",
+ [ERRCODE_OFFSET(VERIFY)] = "Kernel verifier blocks program loading",
+ [ERRCODE_OFFSET(PROG2BIG)] = "Program too big",
+ [ERRCODE_OFFSET(KVER)] = "Incorrect kernel version",
+};
+
+int libbpf_strerror(int err, char *buf, size_t size)
+{
+ if (!buf || !size)
+ return -1;
+
+ err = err > 0 ? err : -err;
+
+ if (err < __LIBBPF_ERRNO__START) {
+ int ret;
+
+ ret = strerror_r(err, buf, size);
+ buf[size - 1] = '\0';
+ return ret;
+ }
+
+ if (err < __LIBBPF_ERRNO__END) {
+ const char *msg;
+
+ msg = libbpf_strerror_table[ERRNO_OFFSET(err)];
+ snprintf(buf, size, "%s", msg);
+ buf[size - 1] = '\0';
+ return 0;
+ }
+
+ snprintf(buf, size, "Unknown libbpf error %d", err);
+ buf[size - 1] = '\0';
+ return -1;
+}
+
+#define CHECK_ERR(action, err, out) do { \
+ err = action; \
+ if (err) \
+ goto out; \
+} while(0)
+
+
+/* Copied from tools/perf/util/util.h */
+#ifndef zfree
+# define zfree(ptr) ({ free(*ptr); *ptr = NULL; })
+#endif
+
+#ifndef zclose
+# define zclose(fd) ({ \
+ int ___err = 0; \
+ if ((fd) >= 0) \
+ ___err = close((fd)); \
+ fd = -1; \
+ ___err; })
+#endif
+
+#ifdef HAVE_LIBELF_MMAP_SUPPORT
+# define LIBBPF_ELF_C_READ_MMAP ELF_C_READ_MMAP
+#else
+# define LIBBPF_ELF_C_READ_MMAP ELF_C_READ
+#endif
+
+/*
+ * bpf_prog should be a better name but it has been used in
+ * linux/filter.h.
+ */
+struct bpf_program {
+ /* Index in elf obj file, for relocation use. */
+ int idx;
+ char *section_name;
+ struct bpf_insn *insns;
+ size_t insns_cnt;
+
+ struct {
+ int insn_idx;
+ int map_idx;
+ } *reloc_desc;
+ int nr_reloc;
+
+ int fd;
+
+ struct bpf_object *obj;
+ void *priv;
+ bpf_program_clear_priv_t clear_priv;
+};
+
+static LIST_HEAD(bpf_objects_list);
+
+struct bpf_object {
+ char license[64];
+ u32 kern_version;
+ void *maps_buf;
+ size_t maps_buf_sz;
+
+ struct bpf_program *programs;
+ size_t nr_programs;
+ int *map_fds;
+ /*
+ * This field is required because maps_buf will be freed and
+ * maps_buf_sz will be set to 0 after loaded.
+ */
+ size_t nr_map_fds;
+ bool loaded;
+
+ /*
+ * Information when doing elf related work. Only valid if fd
+ * is valid.
+ */
+ struct {
+ int fd;
+ void *obj_buf;
+ size_t obj_buf_sz;
+ Elf *elf;
+ GElf_Ehdr ehdr;
+ Elf_Data *symbols;
+ struct {
+ GElf_Shdr shdr;
+ Elf_Data *data;
+ } *reloc;
+ int nr_reloc;
+ } efile;
+ /*
+ * All loaded bpf_object is linked in a list, which is
+ * hidden to caller. bpf_objects__<func> handlers deal with
+ * all objects.
+ */
+ struct list_head list;
+ char path[];
+};
+#define obj_elf_valid(o) ((o)->efile.elf)
+
+static void bpf_program__unload(struct bpf_program *prog)
+{
+ if (!prog)
+ return;
+
+ zclose(prog->fd);
+}
+
+static void bpf_program__exit(struct bpf_program *prog)
+{
+ if (!prog)
+ return;
+
+ if (prog->clear_priv)
+ prog->clear_priv(prog, prog->priv);
+
+ prog->priv = NULL;
+ prog->clear_priv = NULL;
+
+ bpf_program__unload(prog);
+ zfree(&prog->section_name);
+ zfree(&prog->insns);
+ zfree(&prog->reloc_desc);
+
+ prog->nr_reloc = 0;
+ prog->insns_cnt = 0;
+ prog->idx = -1;
+}
+
+static int
+bpf_program__init(void *data, size_t size, char *name, int idx,
+ struct bpf_program *prog)
+{
+ if (size < sizeof(struct bpf_insn)) {
+ pr_warning("corrupted section '%s'\n", name);
+ return -EINVAL;
+ }
+
+ bzero(prog, sizeof(*prog));
+
+ prog->section_name = strdup(name);
+ if (!prog->section_name) {
+ pr_warning("failed to alloc name for prog %s\n",
+ name);
+ goto errout;
+ }
+
+ prog->insns = malloc(size);
+ if (!prog->insns) {
+ pr_warning("failed to alloc insns for %s\n", name);
+ goto errout;
+ }
+ prog->insns_cnt = size / sizeof(struct bpf_insn);
+ memcpy(prog->insns, data,
+ prog->insns_cnt * sizeof(struct bpf_insn));
+ prog->idx = idx;
+ prog->fd = -1;
+
+ return 0;
+errout:
+ bpf_program__exit(prog);
+ return -ENOMEM;
+}
+
+static int
+bpf_object__add_program(struct bpf_object *obj, void *data, size_t size,
+ char *name, int idx)
+{
+ struct bpf_program prog, *progs;
+ int nr_progs, err;
+
+ err = bpf_program__init(data, size, name, idx, &prog);
+ if (err)
+ return err;
+
+ progs = obj->programs;
+ nr_progs = obj->nr_programs;
+
+ progs = realloc(progs, sizeof(progs[0]) * (nr_progs + 1));
+ if (!progs) {
+ /*
+ * In this case the original obj->programs
+ * is still valid, so don't need special treat for
+ * bpf_close_object().
+ */
+ pr_warning("failed to alloc a new program '%s'\n",
+ name);
+ bpf_program__exit(&prog);
+ return -ENOMEM;
+ }
+
+ pr_debug("found program %s\n", prog.section_name);
+ obj->programs = progs;
+ obj->nr_programs = nr_progs + 1;
+ prog.obj = obj;
+ progs[nr_progs] = prog;
+ return 0;
+}
+
+static struct bpf_object *bpf_object__new(const char *path,
+ void *obj_buf,
+ size_t obj_buf_sz)
+{
+ struct bpf_object *obj;
+
+ obj = calloc(1, sizeof(struct bpf_object) + strlen(path) + 1);
+ if (!obj) {
+ pr_warning("alloc memory failed for %s\n", path);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ strcpy(obj->path, path);
+ obj->efile.fd = -1;
+
+ /*
+ * Caller of this function should also calls
+ * bpf_object__elf_finish() after data collection to return
+ * obj_buf to user. If not, we should duplicate the buffer to
+ * avoid user freeing them before elf finish.
+ */
+ obj->efile.obj_buf = obj_buf;
+ obj->efile.obj_buf_sz = obj_buf_sz;
+
+ obj->loaded = false;
+
+ INIT_LIST_HEAD(&obj->list);
+ list_add(&obj->list, &bpf_objects_list);
+ return obj;
+}
+
+static void bpf_object__elf_finish(struct bpf_object *obj)
+{
+ if (!obj_elf_valid(obj))
+ return;
+
+ if (obj->efile.elf) {
+ elf_end(obj->efile.elf);
+ obj->efile.elf = NULL;
+ }
+ obj->efile.symbols = NULL;
+
+ zfree(&obj->efile.reloc);
+ obj->efile.nr_reloc = 0;
+ zclose(obj->efile.fd);
+ obj->efile.obj_buf = NULL;
+ obj->efile.obj_buf_sz = 0;
+}
+
+static int bpf_object__elf_init(struct bpf_object *obj)
+{
+ int err = 0;
+ GElf_Ehdr *ep;
+
+ if (obj_elf_valid(obj)) {
+ pr_warning("elf init: internal error\n");
+ return -LIBBPF_ERRNO__LIBELF;
+ }
+
+ if (obj->efile.obj_buf_sz > 0) {
+ /*
+ * obj_buf should have been validated by
+ * bpf_object__open_buffer().
+ */
+ obj->efile.elf = elf_memory(obj->efile.obj_buf,
+ obj->efile.obj_buf_sz);
+ } else {
+ obj->efile.fd = open(obj->path, O_RDONLY);
+ if (obj->efile.fd < 0) {
+ pr_warning("failed to open %s: %s\n", obj->path,
+ strerror(errno));
+ return -errno;
+ }
+
+ obj->efile.elf = elf_begin(obj->efile.fd,
+ LIBBPF_ELF_C_READ_MMAP,
+ NULL);
+ }
+
+ if (!obj->efile.elf) {
+ pr_warning("failed to open %s as ELF file\n",
+ obj->path);
+ err = -LIBBPF_ERRNO__LIBELF;
+ goto errout;
+ }
+
+ if (!gelf_getehdr(obj->efile.elf, &obj->efile.ehdr)) {
+ pr_warning("failed to get EHDR from %s\n",
+ obj->path);
+ err = -LIBBPF_ERRNO__FORMAT;
+ goto errout;
+ }
+ ep = &obj->efile.ehdr;
+
+ if ((ep->e_type != ET_REL) || (ep->e_machine != 0)) {
+ pr_warning("%s is not an eBPF object file\n",
+ obj->path);
+ err = -LIBBPF_ERRNO__FORMAT;
+ goto errout;
+ }
+
+ return 0;
+errout:
+ bpf_object__elf_finish(obj);
+ return err;
+}
+
+static int
+bpf_object__check_endianness(struct bpf_object *obj)
+{
+ static unsigned int const endian = 1;
+
+ switch (obj->efile.ehdr.e_ident[EI_DATA]) {
+ case ELFDATA2LSB:
+ /* We are big endian, BPF obj is little endian. */
+ if (*(unsigned char const *)&endian != 1)
+ goto mismatch;
+ break;
+
+ case ELFDATA2MSB:
+ /* We are little endian, BPF obj is big endian. */
+ if (*(unsigned char const *)&endian != 0)
+ goto mismatch;
+ break;
+ default:
+ return -LIBBPF_ERRNO__ENDIAN;
+ }
+
+ return 0;
+
+mismatch:
+ pr_warning("Error: endianness mismatch.\n");
+ return -LIBBPF_ERRNO__ENDIAN;
+}
+
+static int
+bpf_object__init_license(struct bpf_object *obj,
+ void *data, size_t size)
+{
+ memcpy(obj->license, data,
+ min(size, sizeof(obj->license) - 1));
+ pr_debug("license of %s is %s\n", obj->path, obj->license);
+ return 0;
+}
+
+static int
+bpf_object__init_kversion(struct bpf_object *obj,
+ void *data, size_t size)
+{
+ u32 kver;
+
+ if (size != sizeof(kver)) {
+ pr_warning("invalid kver section in %s\n", obj->path);
+ return -LIBBPF_ERRNO__FORMAT;
+ }
+ memcpy(&kver, data, sizeof(kver));
+ obj->kern_version = kver;
+ pr_debug("kernel version of %s is %x\n", obj->path,
+ obj->kern_version);
+ return 0;
+}
+
+static int
+bpf_object__init_maps(struct bpf_object *obj, void *data,
+ size_t size)
+{
+ if (size == 0) {
+ pr_debug("%s doesn't need map definition\n",
+ obj->path);
+ return 0;
+ }
+
+ obj->maps_buf = malloc(size);
+ if (!obj->maps_buf) {
+ pr_warning("malloc maps failed: %s\n", obj->path);
+ return -ENOMEM;
+ }
+
+ obj->maps_buf_sz = size;
+ memcpy(obj->maps_buf, data, size);
+ pr_debug("maps in %s: %ld bytes\n", obj->path, (long)size);
+ return 0;
+}
+
+static int bpf_object__elf_collect(struct bpf_object *obj)
+{
+ Elf *elf = obj->efile.elf;
+ GElf_Ehdr *ep = &obj->efile.ehdr;
+ Elf_Scn *scn = NULL;
+ int idx = 0, err = 0;
+
+ /* Elf is corrupted/truncated, avoid calling elf_strptr. */
+ if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL)) {
+ pr_warning("failed to get e_shstrndx from %s\n",
+ obj->path);
+ return -LIBBPF_ERRNO__FORMAT;
+ }
+
+ while ((scn = elf_nextscn(elf, scn)) != NULL) {
+ char *name;
+ GElf_Shdr sh;
+ Elf_Data *data;
+
+ idx++;
+ if (gelf_getshdr(scn, &sh) != &sh) {
+ pr_warning("failed to get section header from %s\n",
+ obj->path);
+ err = -LIBBPF_ERRNO__FORMAT;
+ goto out;
+ }
+
+ name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name);
+ if (!name) {
+ pr_warning("failed to get section name from %s\n",
+ obj->path);
+ err = -LIBBPF_ERRNO__FORMAT;
+ goto out;
+ }
+
+ data = elf_getdata(scn, 0);
+ if (!data) {
+ pr_warning("failed to get section data from %s(%s)\n",
+ name, obj->path);
+ err = -LIBBPF_ERRNO__FORMAT;
+ goto out;
+ }
+ pr_debug("section %s, size %ld, link %d, flags %lx, type=%d\n",
+ name, (unsigned long)data->d_size,
+ (int)sh.sh_link, (unsigned long)sh.sh_flags,
+ (int)sh.sh_type);
+
+ if (strcmp(name, "license") == 0)
+ err = bpf_object__init_license(obj,
+ data->d_buf,
+ data->d_size);
+ else if (strcmp(name, "version") == 0)
+ err = bpf_object__init_kversion(obj,
+ data->d_buf,
+ data->d_size);
+ else if (strcmp(name, "maps") == 0)
+ err = bpf_object__init_maps(obj, data->d_buf,
+ data->d_size);
+ else if (sh.sh_type == SHT_SYMTAB) {
+ if (obj->efile.symbols) {
+ pr_warning("bpf: multiple SYMTAB in %s\n",
+ obj->path);
+ err = -LIBBPF_ERRNO__FORMAT;
+ } else
+ obj->efile.symbols = data;
+ } else if ((sh.sh_type == SHT_PROGBITS) &&
+ (sh.sh_flags & SHF_EXECINSTR) &&
+ (data->d_size > 0)) {
+ err = bpf_object__add_program(obj, data->d_buf,
+ data->d_size, name, idx);
+ if (err) {
+ char errmsg[STRERR_BUFSIZE];
+
+ strerror_r(-err, errmsg, sizeof(errmsg));
+ pr_warning("failed to alloc program %s (%s): %s",
+ name, obj->path, errmsg);
+ }
+ } else if (sh.sh_type == SHT_REL) {
+ void *reloc = obj->efile.reloc;
+ int nr_reloc = obj->efile.nr_reloc + 1;
+
+ reloc = realloc(reloc,
+ sizeof(*obj->efile.reloc) * nr_reloc);
+ if (!reloc) {
+ pr_warning("realloc failed\n");
+ err = -ENOMEM;
+ } else {
+ int n = nr_reloc - 1;
+
+ obj->efile.reloc = reloc;
+ obj->efile.nr_reloc = nr_reloc;
+
+ obj->efile.reloc[n].shdr = sh;
+ obj->efile.reloc[n].data = data;
+ }
+ }
+ if (err)
+ goto out;
+ }
+out:
+ return err;
+}
+
+static struct bpf_program *
+bpf_object__find_prog_by_idx(struct bpf_object *obj, int idx)
+{
+ struct bpf_program *prog;
+ size_t i;
+
+ for (i = 0; i < obj->nr_programs; i++) {
+ prog = &obj->programs[i];
+ if (prog->idx == idx)
+ return prog;
+ }
+ return NULL;
+}
+
+static int
+bpf_program__collect_reloc(struct bpf_program *prog,
+ size_t nr_maps, GElf_Shdr *shdr,
+ Elf_Data *data, Elf_Data *symbols)
+{
+ int i, nrels;
+
+ pr_debug("collecting relocating info for: '%s'\n",
+ prog->section_name);
+ nrels = shdr->sh_size / shdr->sh_entsize;
+
+ prog->reloc_desc = malloc(sizeof(*prog->reloc_desc) * nrels);
+ if (!prog->reloc_desc) {
+ pr_warning("failed to alloc memory in relocation\n");
+ return -ENOMEM;
+ }
+ prog->nr_reloc = nrels;
+
+ for (i = 0; i < nrels; i++) {
+ GElf_Sym sym;
+ GElf_Rel rel;
+ unsigned int insn_idx;
+ struct bpf_insn *insns = prog->insns;
+ size_t map_idx;
+
+ if (!gelf_getrel(data, i, &rel)) {
+ pr_warning("relocation: failed to get %d reloc\n", i);
+ return -LIBBPF_ERRNO__FORMAT;
+ }
+
+ insn_idx = rel.r_offset / sizeof(struct bpf_insn);
+ pr_debug("relocation: insn_idx=%u\n", insn_idx);
+
+ if (!gelf_getsym(symbols,
+ GELF_R_SYM(rel.r_info),
+ &sym)) {
+ pr_warning("relocation: symbol %"PRIx64" not found\n",
+ GELF_R_SYM(rel.r_info));
+ return -LIBBPF_ERRNO__FORMAT;
+ }
+
+ if (insns[insn_idx].code != (BPF_LD | BPF_IMM | BPF_DW)) {
+ pr_warning("bpf: relocation: invalid relo for insns[%d].code 0x%x\n",
+ insn_idx, insns[insn_idx].code);
+ return -LIBBPF_ERRNO__RELOC;
+ }
+
+ map_idx = sym.st_value / sizeof(struct bpf_map_def);
+ if (map_idx >= nr_maps) {
+ pr_warning("bpf relocation: map_idx %d large than %d\n",
+ (int)map_idx, (int)nr_maps - 1);
+ return -LIBBPF_ERRNO__RELOC;
+ }
+
+ prog->reloc_desc[i].insn_idx = insn_idx;
+ prog->reloc_desc[i].map_idx = map_idx;
+ }
+ return 0;
+}
+
+static int
+bpf_object__create_maps(struct bpf_object *obj)
+{
+ unsigned int i;
+ size_t nr_maps;
+ int *pfd;
+
+ nr_maps = obj->maps_buf_sz / sizeof(struct bpf_map_def);
+ if (!obj->maps_buf || !nr_maps) {
+ pr_debug("don't need create maps for %s\n",
+ obj->path);
+ return 0;
+ }
+
+ obj->map_fds = malloc(sizeof(int) * nr_maps);
+ if (!obj->map_fds) {
+ pr_warning("realloc perf_bpf_map_fds failed\n");
+ return -ENOMEM;
+ }
+ obj->nr_map_fds = nr_maps;
+
+ /* fill all fd with -1 */
+ memset(obj->map_fds, -1, sizeof(int) * nr_maps);
+
+ pfd = obj->map_fds;
+ for (i = 0; i < nr_maps; i++) {
+ struct bpf_map_def def;
+
+ def = *(struct bpf_map_def *)(obj->maps_buf +
+ i * sizeof(struct bpf_map_def));
+
+ *pfd = bpf_create_map(def.type,
+ def.key_size,
+ def.value_size,
+ def.max_entries);
+ if (*pfd < 0) {
+ size_t j;
+ int err = *pfd;
+
+ pr_warning("failed to create map: %s\n",
+ strerror(errno));
+ for (j = 0; j < i; j++)
+ zclose(obj->map_fds[j]);
+ obj->nr_map_fds = 0;
+ zfree(&obj->map_fds);
+ return err;
+ }
+ pr_debug("create map: fd=%d\n", *pfd);
+ pfd++;
+ }
+
+ zfree(&obj->maps_buf);
+ obj->maps_buf_sz = 0;
+ return 0;
+}
+
+static int
+bpf_program__relocate(struct bpf_program *prog, int *map_fds)
+{
+ int i;
+
+ if (!prog || !prog->reloc_desc)
+ return 0;
+
+ for (i = 0; i < prog->nr_reloc; i++) {
+ int insn_idx, map_idx;
+ struct bpf_insn *insns = prog->insns;
+
+ insn_idx = prog->reloc_desc[i].insn_idx;
+ map_idx = prog->reloc_desc[i].map_idx;
+
+ if (insn_idx >= (int)prog->insns_cnt) {
+ pr_warning("relocation out of range: '%s'\n",
+ prog->section_name);
+ return -LIBBPF_ERRNO__RELOC;
+ }
+ insns[insn_idx].src_reg = BPF_PSEUDO_MAP_FD;
+ insns[insn_idx].imm = map_fds[map_idx];
+ }
+
+ zfree(&prog->reloc_desc);
+ prog->nr_reloc = 0;
+ return 0;
+}
+
+
+static int
+bpf_object__relocate(struct bpf_object *obj)
+{
+ struct bpf_program *prog;
+ size_t i;
+ int err;
+
+ for (i = 0; i < obj->nr_programs; i++) {
+ prog = &obj->programs[i];
+
+ err = bpf_program__relocate(prog, obj->map_fds);
+ if (err) {
+ pr_warning("failed to relocate '%s'\n",
+ prog->section_name);
+ return err;
+ }
+ }
+ return 0;
+}
+
+static int bpf_object__collect_reloc(struct bpf_object *obj)
+{
+ int i, err;
+
+ if (!obj_elf_valid(obj)) {
+ pr_warning("Internal error: elf object is closed\n");
+ return -LIBBPF_ERRNO__INTERNAL;
+ }
+
+ for (i = 0; i < obj->efile.nr_reloc; i++) {
+ GElf_Shdr *shdr = &obj->efile.reloc[i].shdr;
+ Elf_Data *data = obj->efile.reloc[i].data;
+ int idx = shdr->sh_info;
+ struct bpf_program *prog;
+ size_t nr_maps = obj->maps_buf_sz /
+ sizeof(struct bpf_map_def);
+
+ if (shdr->sh_type != SHT_REL) {
+ pr_warning("internal error at %d\n", __LINE__);
+ return -LIBBPF_ERRNO__INTERNAL;
+ }
+
+ prog = bpf_object__find_prog_by_idx(obj, idx);
+ if (!prog) {
+ pr_warning("relocation failed: no %d section\n",
+ idx);
+ return -LIBBPF_ERRNO__RELOC;
+ }
+
+ err = bpf_program__collect_reloc(prog, nr_maps,
+ shdr, data,
+ obj->efile.symbols);
+ if (err)
+ return err;
+ }
+ return 0;
+}
+
+static int
+load_program(struct bpf_insn *insns, int insns_cnt,
+ char *license, u32 kern_version, int *pfd)
+{
+ int ret;
+ char *log_buf;
+
+ if (!insns || !insns_cnt)
+ return -EINVAL;
+
+ log_buf = malloc(BPF_LOG_BUF_SIZE);
+ if (!log_buf)
+ pr_warning("Alloc log buffer for bpf loader error, continue without log\n");
+
+ ret = bpf_load_program(BPF_PROG_TYPE_KPROBE, insns,
+ insns_cnt, license, kern_version,
+ log_buf, BPF_LOG_BUF_SIZE);
+
+ if (ret >= 0) {
+ *pfd = ret;
+ ret = 0;
+ goto out;
+ }
+
+ ret = -LIBBPF_ERRNO__LOAD;
+ pr_warning("load bpf program failed: %s\n", strerror(errno));
+
+ if (log_buf && log_buf[0] != '\0') {
+ ret = -LIBBPF_ERRNO__VERIFY;
+ pr_warning("-- BEGIN DUMP LOG ---\n");
+ pr_warning("\n%s\n", log_buf);
+ pr_warning("-- END LOG --\n");
+ } else {
+ if (insns_cnt >= BPF_MAXINSNS) {
+ pr_warning("Program too large (%d insns), at most %d insns\n",
+ insns_cnt, BPF_MAXINSNS);
+ ret = -LIBBPF_ERRNO__PROG2BIG;
+ } else if (log_buf) {
+ pr_warning("log buffer is empty\n");
+ ret = -LIBBPF_ERRNO__KVER;
+ }
+ }
+
+out:
+ free(log_buf);
+ return ret;
+}
+
+static int
+bpf_program__load(struct bpf_program *prog,
+ char *license, u32 kern_version)
+{
+ int err, fd;
+
+ err = load_program(prog->insns, prog->insns_cnt,
+ license, kern_version, &fd);
+ if (!err)
+ prog->fd = fd;
+
+ if (err)
+ pr_warning("failed to load program '%s'\n",
+ prog->section_name);
+ zfree(&prog->insns);
+ prog->insns_cnt = 0;
+ return err;
+}
+
+static int
+bpf_object__load_progs(struct bpf_object *obj)
+{
+ size_t i;
+ int err;
+
+ for (i = 0; i < obj->nr_programs; i++) {
+ err = bpf_program__load(&obj->programs[i],
+ obj->license,
+ obj->kern_version);
+ if (err)
+ return err;
+ }
+ return 0;
+}
+
+static int bpf_object__validate(struct bpf_object *obj)
+{
+ if (obj->kern_version == 0) {
+ pr_warning("%s doesn't provide kernel version\n",
+ obj->path);
+ return -LIBBPF_ERRNO__KVERSION;
+ }
+ return 0;
+}
+
+static struct bpf_object *
+__bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz)
+{
+ struct bpf_object *obj;
+ int err;
+
+ if (elf_version(EV_CURRENT) == EV_NONE) {
+ pr_warning("failed to init libelf for %s\n", path);
+ return ERR_PTR(-LIBBPF_ERRNO__LIBELF);
+ }
+
+ obj = bpf_object__new(path, obj_buf, obj_buf_sz);
+ if (IS_ERR(obj))
+ return obj;
+
+ CHECK_ERR(bpf_object__elf_init(obj), err, out);
+ CHECK_ERR(bpf_object__check_endianness(obj), err, out);
+ CHECK_ERR(bpf_object__elf_collect(obj), err, out);
+ CHECK_ERR(bpf_object__collect_reloc(obj), err, out);
+ CHECK_ERR(bpf_object__validate(obj), err, out);
+
+ bpf_object__elf_finish(obj);
+ return obj;
+out:
+ bpf_object__close(obj);
+ return ERR_PTR(err);
+}
+
+struct bpf_object *bpf_object__open(const char *path)
+{
+ /* param validation */
+ if (!path)
+ return NULL;
+
+ pr_debug("loading %s\n", path);
+
+ return __bpf_object__open(path, NULL, 0);
+}
+
+struct bpf_object *bpf_object__open_buffer(void *obj_buf,
+ size_t obj_buf_sz,
+ const char *name)
+{
+ char tmp_name[64];
+
+ /* param validation */
+ if (!obj_buf || obj_buf_sz <= 0)
+ return NULL;
+
+ if (!name) {
+ snprintf(tmp_name, sizeof(tmp_name), "%lx-%lx",
+ (unsigned long)obj_buf,
+ (unsigned long)obj_buf_sz);
+ tmp_name[sizeof(tmp_name) - 1] = '\0';
+ name = tmp_name;
+ }
+ pr_debug("loading object '%s' from buffer\n",
+ name);
+
+ return __bpf_object__open(name, obj_buf, obj_buf_sz);
+}
+
+int bpf_object__unload(struct bpf_object *obj)
+{
+ size_t i;
+
+ if (!obj)
+ return -EINVAL;
+
+ for (i = 0; i < obj->nr_map_fds; i++)
+ zclose(obj->map_fds[i]);
+ zfree(&obj->map_fds);
+ obj->nr_map_fds = 0;
+
+ for (i = 0; i < obj->nr_programs; i++)
+ bpf_program__unload(&obj->programs[i]);
+
+ return 0;
+}
+
+int bpf_object__load(struct bpf_object *obj)
+{
+ int err;
+
+ if (!obj)
+ return -EINVAL;
+
+ if (obj->loaded) {
+ pr_warning("object should not be loaded twice\n");
+ return -EINVAL;
+ }
+
+ obj->loaded = true;
+
+ CHECK_ERR(bpf_object__create_maps(obj), err, out);
+ CHECK_ERR(bpf_object__relocate(obj), err, out);
+ CHECK_ERR(bpf_object__load_progs(obj), err, out);
+
+ return 0;
+out:
+ bpf_object__unload(obj);
+ pr_warning("failed to load object '%s'\n", obj->path);
+ return err;
+}
+
+void bpf_object__close(struct bpf_object *obj)
+{
+ size_t i;
+
+ if (!obj)
+ return;
+
+ bpf_object__elf_finish(obj);
+ bpf_object__unload(obj);
+
+ zfree(&obj->maps_buf);
+
+ if (obj->programs && obj->nr_programs) {
+ for (i = 0; i < obj->nr_programs; i++)
+ bpf_program__exit(&obj->programs[i]);
+ }
+ zfree(&obj->programs);
+
+ list_del(&obj->list);
+ free(obj);
+}
+
+struct bpf_object *
+bpf_object__next(struct bpf_object *prev)
+{
+ struct bpf_object *next;
+
+ if (!prev)
+ next = list_first_entry(&bpf_objects_list,
+ struct bpf_object,
+ list);
+ else
+ next = list_next_entry(prev, list);
+
+ /* Empty list is noticed here so don't need checking on entry. */
+ if (&next->list == &bpf_objects_list)
+ return NULL;
+
+ return next;
+}
+
+const char *
+bpf_object__get_name(struct bpf_object *obj)
+{
+ if (!obj)
+ return ERR_PTR(-EINVAL);
+ return obj->path;
+}
+
+unsigned int
+bpf_object__get_kversion(struct bpf_object *obj)
+{
+ if (!obj)
+ return 0;
+ return obj->kern_version;
+}
+
+struct bpf_program *
+bpf_program__next(struct bpf_program *prev, struct bpf_object *obj)
+{
+ size_t idx;
+
+ if (!obj->programs)
+ return NULL;
+ /* First handler */
+ if (prev == NULL)
+ return &obj->programs[0];
+
+ if (prev->obj != obj) {
+ pr_warning("error: program handler doesn't match object\n");
+ return NULL;
+ }
+
+ idx = (prev - obj->programs) + 1;
+ if (idx >= obj->nr_programs)
+ return NULL;
+ return &obj->programs[idx];
+}
+
+int bpf_program__set_private(struct bpf_program *prog,
+ void *priv,
+ bpf_program_clear_priv_t clear_priv)
+{
+ if (prog->priv && prog->clear_priv)
+ prog->clear_priv(prog, prog->priv);
+
+ prog->priv = priv;
+ prog->clear_priv = clear_priv;
+ return 0;
+}
+
+int bpf_program__get_private(struct bpf_program *prog, void **ppriv)
+{
+ *ppriv = prog->priv;
+ return 0;
+}
+
+const char *bpf_program__title(struct bpf_program *prog, bool needs_copy)
+{
+ const char *title;
+
+ title = prog->section_name;
+ if (needs_copy) {
+ title = strdup(title);
+ if (!title) {
+ pr_warning("failed to strdup program title\n");
+ return ERR_PTR(-ENOMEM);
+ }
+ }
+
+ return title;
+}
+
+int bpf_program__fd(struct bpf_program *prog)
+{
+ return prog->fd;
+}