diff options
Diffstat (limited to 'kernel/tools/lib/bpf')
| -rw-r--r-- | kernel/tools/lib/bpf/.gitignore | 2 | ||||
| -rw-r--r-- | kernel/tools/lib/bpf/Build | 1 | ||||
| -rw-r--r-- | kernel/tools/lib/bpf/Makefile | 198 | ||||
| -rw-r--r-- | kernel/tools/lib/bpf/bpf.c | 85 | ||||
| -rw-r--r-- | kernel/tools/lib/bpf/bpf.h | 23 | ||||
| -rw-r--r-- | kernel/tools/lib/bpf/libbpf.c | 1125 | ||||
| -rw-r--r-- | kernel/tools/lib/bpf/libbpf.h | 104 |
7 files changed, 1538 insertions, 0 deletions
diff --git a/kernel/tools/lib/bpf/.gitignore b/kernel/tools/lib/bpf/.gitignore new file mode 100644 index 000000000..f81e549dd --- /dev/null +++ b/kernel/tools/lib/bpf/.gitignore @@ -0,0 +1,2 @@ +libbpf_version.h +FEATURE-DUMP.libbpf diff --git a/kernel/tools/lib/bpf/Build b/kernel/tools/lib/bpf/Build new file mode 100644 index 000000000..d87497563 --- /dev/null +++ b/kernel/tools/lib/bpf/Build @@ -0,0 +1 @@ +libbpf-y := libbpf.o bpf.o diff --git a/kernel/tools/lib/bpf/Makefile b/kernel/tools/lib/bpf/Makefile new file mode 100644 index 000000000..a3caaf3ea --- /dev/null +++ b/kernel/tools/lib/bpf/Makefile @@ -0,0 +1,198 @@ +# Most of this file is copied from tools/lib/traceevent/Makefile + +BPF_VERSION = 0 +BPF_PATCHLEVEL = 0 +BPF_EXTRAVERSION = 1 + +MAKEFLAGS += --no-print-directory + + +# Makefiles suck: This macro sets a default value of $(2) for the +# variable named by $(1), unless the variable has been set by +# environment or command line. This is necessary for CC and AR +# because make sets default values, so the simpler ?= approach +# won't work as expected. +define allow-override + $(if $(or $(findstring environment,$(origin $(1))),\ + $(findstring command line,$(origin $(1)))),,\ + $(eval $(1) = $(2))) +endef + +# Allow setting CC and AR, or setting CROSS_COMPILE as a prefix. +$(call allow-override,CC,$(CROSS_COMPILE)gcc) +$(call allow-override,AR,$(CROSS_COMPILE)ar) + +INSTALL = install + +# Use DESTDIR for installing into a different root directory. +# This is useful for building a package. The program will be +# installed in this directory as if it was the root directory. +# Then the build tool can move it later. +DESTDIR ?= +DESTDIR_SQ = '$(subst ','\'',$(DESTDIR))' + +LP64 := $(shell echo __LP64__ | ${CC} ${CFLAGS} -E -x c - | tail -n 1) +ifeq ($(LP64), 1) + libdir_relative = lib64 +else + libdir_relative = lib +endif + +prefix ?= /usr/local +libdir = $(prefix)/$(libdir_relative) +man_dir = $(prefix)/share/man +man_dir_SQ = '$(subst ','\'',$(man_dir))' + +export man_dir man_dir_SQ INSTALL +export DESTDIR DESTDIR_SQ + +include ../../scripts/Makefile.include + +# copy a bit from Linux kbuild + +ifeq ("$(origin V)", "command line") + VERBOSE = $(V) +endif +ifndef VERBOSE + VERBOSE = 0 +endif + +ifeq ($(srctree),) +srctree := $(patsubst %/,%,$(dir $(shell pwd))) +srctree := $(patsubst %/,%,$(dir $(srctree))) +srctree := $(patsubst %/,%,$(dir $(srctree))) +#$(info Determined 'srctree' to be $(srctree)) +endif + +FEATURE_USER = .libbpf +FEATURE_TESTS = libelf libelf-getphdrnum libelf-mmap bpf +FEATURE_DISPLAY = libelf bpf + +INCLUDES = -I. -I$(srctree)/tools/include -I$(srctree)/arch/$(ARCH)/include/uapi -I$(srctree)/include/uapi +FEATURE_CHECK_CFLAGS-bpf = $(INCLUDES) + +include $(srctree)/tools/build/Makefile.feature + +export prefix libdir src obj + +# Shell quotes +libdir_SQ = $(subst ','\'',$(libdir)) +libdir_relative_SQ = $(subst ','\'',$(libdir_relative)) +plugin_dir_SQ = $(subst ','\'',$(plugin_dir)) + +LIB_FILE = libbpf.a libbpf.so + +VERSION = $(BPF_VERSION) +PATCHLEVEL = $(BPF_PATCHLEVEL) +EXTRAVERSION = $(BPF_EXTRAVERSION) + +OBJ = $@ +N = + +LIBBPF_VERSION = $(BPF_VERSION).$(BPF_PATCHLEVEL).$(BPF_EXTRAVERSION) + +# Set compile option CFLAGS +ifdef EXTRA_CFLAGS + CFLAGS := $(EXTRA_CFLAGS) +else + CFLAGS := -g -Wall +endif + +ifeq ($(feature-libelf-mmap), 1) + override CFLAGS += -DHAVE_LIBELF_MMAP_SUPPORT +endif + +ifeq ($(feature-libelf-getphdrnum), 1) + override CFLAGS += -DHAVE_ELF_GETPHDRNUM_SUPPORT +endif + +# Append required CFLAGS +override CFLAGS += $(EXTRA_WARNINGS) +override CFLAGS += -Werror -Wall +override CFLAGS += -fPIC +override CFLAGS += $(INCLUDES) + +ifeq ($(VERBOSE),1) + Q = +else + Q = @ +endif + +# Disable command line variables (CFLAGS) overide from top +# level Makefile (perf), otherwise build Makefile will get +# the same command line setup. +MAKEOVERRIDES= + +all: + +export srctree OUTPUT CC LD CFLAGS V +include $(srctree)/tools/build/Makefile.include + +BPF_IN := $(OUTPUT)libbpf-in.o +LIB_FILE := $(addprefix $(OUTPUT),$(LIB_FILE)) + +CMD_TARGETS = $(LIB_FILE) + +TARGETS = $(CMD_TARGETS) + +all: fixdep $(VERSION_FILES) all_cmd + +all_cmd: $(CMD_TARGETS) + +$(BPF_IN): force elfdep bpfdep + $(Q)$(MAKE) $(build)=libbpf + +$(OUTPUT)libbpf.so: $(BPF_IN) + $(QUIET_LINK)$(CC) --shared $^ -o $@ + +$(OUTPUT)libbpf.a: $(BPF_IN) + $(QUIET_LINK)$(RM) $@; $(AR) rcs $@ $^ + +define update_dir + (echo $1 > $@.tmp; \ + if [ -r $@ ] && cmp -s $@ $@.tmp; then \ + rm -f $@.tmp; \ + else \ + echo ' UPDATE $@'; \ + mv -f $@.tmp $@; \ + fi); +endef + +define do_install + if [ ! -d '$(DESTDIR_SQ)$2' ]; then \ + $(INSTALL) -d -m 755 '$(DESTDIR_SQ)$2'; \ + fi; \ + $(INSTALL) $1 '$(DESTDIR_SQ)$2' +endef + +install_lib: all_cmd + $(call QUIET_INSTALL, $(LIB_FILE)) \ + $(call do_install,$(LIB_FILE),$(libdir_SQ)) + +install: install_lib + +### Cleaning rules + +config-clean: + $(call QUIET_CLEAN, config) + $(Q)$(MAKE) -C $(srctree)/tools/build/feature/ clean >/dev/null + +clean: + $(call QUIET_CLEAN, libbpf) $(RM) *.o *~ $(TARGETS) *.a *.so $(VERSION_FILES) .*.d \ + $(RM) LIBBPF-CFLAGS + $(call QUIET_CLEAN, core-gen) $(RM) $(OUTPUT)FEATURE-DUMP.libbpf + + + +PHONY += force elfdep bpfdep +force: + +elfdep: + @if [ "$(feature-libelf)" != "1" ]; then echo "No libelf found"; exit -1 ; fi + +bpfdep: + @if [ "$(feature-bpf)" != "1" ]; then echo "BPF API too old"; exit -1 ; fi + +# Declare the contents of the .PHONY variable as phony. We keep that +# information in a variable so we can use it in if_changed and friends. +.PHONY: $(PHONY) diff --git a/kernel/tools/lib/bpf/bpf.c b/kernel/tools/lib/bpf/bpf.c new file mode 100644 index 000000000..a6331050a --- /dev/null +++ b/kernel/tools/lib/bpf/bpf.c @@ -0,0 +1,85 @@ +/* + * common eBPF ELF 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 <memory.h> +#include <unistd.h> +#include <asm/unistd.h> +#include <linux/bpf.h> +#include "bpf.h" + +/* + * When building perf, unistd.h is override. Define __NR_bpf is + * required to be defined. + */ +#ifndef __NR_bpf +# if defined(__i386__) +# define __NR_bpf 357 +# elif defined(__x86_64__) +# define __NR_bpf 321 +# elif defined(__aarch64__) +# define __NR_bpf 280 +# else +# error __NR_bpf not defined. libbpf does not support your arch. +# endif +#endif + +static __u64 ptr_to_u64(void *ptr) +{ + return (__u64) (unsigned long) ptr; +} + +static int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr, + unsigned int size) +{ + return syscall(__NR_bpf, cmd, attr, size); +} + +int bpf_create_map(enum bpf_map_type map_type, int key_size, + int value_size, int max_entries) +{ + union bpf_attr attr; + + memset(&attr, '\0', sizeof(attr)); + + attr.map_type = map_type; + attr.key_size = key_size; + attr.value_size = value_size; + attr.max_entries = max_entries; + + return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); +} + +int bpf_load_program(enum bpf_prog_type type, struct bpf_insn *insns, + size_t insns_cnt, char *license, + u32 kern_version, char *log_buf, size_t log_buf_sz) +{ + int fd; + union bpf_attr attr; + + bzero(&attr, sizeof(attr)); + attr.prog_type = type; + attr.insn_cnt = (__u32)insns_cnt; + attr.insns = ptr_to_u64(insns); + attr.license = ptr_to_u64(license); + attr.log_buf = ptr_to_u64(NULL); + attr.log_size = 0; + attr.log_level = 0; + attr.kern_version = kern_version; + + fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); + if (fd >= 0 || !log_buf || !log_buf_sz) + return fd; + + /* Try again with log */ + attr.log_buf = ptr_to_u64(log_buf); + attr.log_size = log_buf_sz; + attr.log_level = 1; + log_buf[0] = 0; + return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); +} diff --git a/kernel/tools/lib/bpf/bpf.h b/kernel/tools/lib/bpf/bpf.h new file mode 100644 index 000000000..854b7361b --- /dev/null +++ b/kernel/tools/lib/bpf/bpf.h @@ -0,0 +1,23 @@ +/* + * common eBPF ELF operations. + * + * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org> + * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com> + * Copyright (C) 2015 Huawei Inc. + */ +#ifndef __BPF_BPF_H +#define __BPF_BPF_H + +#include <linux/bpf.h> + +int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size, + int max_entries); + +/* Recommend log buffer size */ +#define BPF_LOG_BUF_SIZE 65536 +int bpf_load_program(enum bpf_prog_type type, struct bpf_insn *insns, + size_t insns_cnt, char *license, + u32 kern_version, char *log_buf, + size_t log_buf_sz); + +#endif 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; +} diff --git a/kernel/tools/lib/bpf/libbpf.h b/kernel/tools/lib/bpf/libbpf.h new file mode 100644 index 000000000..c9a9aef28 --- /dev/null +++ b/kernel/tools/lib/bpf/libbpf.h @@ -0,0 +1,104 @@ +/* + * 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. + */ +#ifndef __BPF_LIBBPF_H +#define __BPF_LIBBPF_H + +#include <stdio.h> +#include <stdbool.h> +#include <linux/err.h> + +enum libbpf_errno { + __LIBBPF_ERRNO__START = 4000, + + /* Something wrong in libelf */ + LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START, + LIBBPF_ERRNO__FORMAT, /* BPF object format invalid */ + LIBBPF_ERRNO__KVERSION, /* Incorrect or no 'version' section */ + LIBBPF_ERRNO__ENDIAN, /* Endian missmatch */ + LIBBPF_ERRNO__INTERNAL, /* Internal error in libbpf */ + LIBBPF_ERRNO__RELOC, /* Relocation failed */ + LIBBPF_ERRNO__LOAD, /* Load program failure for unknown reason */ + LIBBPF_ERRNO__VERIFY, /* Kernel verifier blocks program loading */ + LIBBPF_ERRNO__PROG2BIG, /* Program too big */ + LIBBPF_ERRNO__KVER, /* Incorrect kernel version */ + __LIBBPF_ERRNO__END, +}; + +int libbpf_strerror(int err, char *buf, size_t size); + +/* + * In include/linux/compiler-gcc.h, __printf is defined. However + * it should be better if libbpf.h doesn't depend on Linux header file. + * So instead of __printf, here we use gcc attribute directly. + */ +typedef int (*libbpf_print_fn_t)(const char *, ...) + __attribute__((format(printf, 1, 2))); + +void libbpf_set_print(libbpf_print_fn_t warn, + libbpf_print_fn_t info, + libbpf_print_fn_t debug); + +/* Hide internal to user */ +struct bpf_object; + +struct bpf_object *bpf_object__open(const char *path); +struct bpf_object *bpf_object__open_buffer(void *obj_buf, + size_t obj_buf_sz, + const char *name); +void bpf_object__close(struct bpf_object *object); + +/* Load/unload object into/from kernel */ +int bpf_object__load(struct bpf_object *obj); +int bpf_object__unload(struct bpf_object *obj); +const char *bpf_object__get_name(struct bpf_object *obj); +unsigned int bpf_object__get_kversion(struct bpf_object *obj); + +struct bpf_object *bpf_object__next(struct bpf_object *prev); +#define bpf_object__for_each_safe(pos, tmp) \ + for ((pos) = bpf_object__next(NULL), \ + (tmp) = bpf_object__next(pos); \ + (pos) != NULL; \ + (pos) = (tmp), (tmp) = bpf_object__next(tmp)) + +/* Accessors of bpf_program. */ +struct bpf_program; +struct bpf_program *bpf_program__next(struct bpf_program *prog, + struct bpf_object *obj); + +#define bpf_object__for_each_program(pos, obj) \ + for ((pos) = bpf_program__next(NULL, (obj)); \ + (pos) != NULL; \ + (pos) = bpf_program__next((pos), (obj))) + +typedef void (*bpf_program_clear_priv_t)(struct bpf_program *, + void *); + +int bpf_program__set_private(struct bpf_program *prog, void *priv, + bpf_program_clear_priv_t clear_priv); + +int bpf_program__get_private(struct bpf_program *prog, + void **ppriv); + +const char *bpf_program__title(struct bpf_program *prog, bool needs_copy); + +int bpf_program__fd(struct bpf_program *prog); + +/* + * We don't need __attribute__((packed)) now since it is + * unnecessary for 'bpf_map_def' because they are all aligned. + * In addition, using it will trigger -Wpacked warning message, + * and will be treated as an error due to -Werror. + */ +struct bpf_map_def { + unsigned int type; + unsigned int key_size; + unsigned int value_size; + unsigned int max_entries; +}; + +#endif |