#include <linux/limits.h>
#include <linux/perf_event.h>
#include <linux/ring_buffer.h>
+#include <linux/version.h>
#include <sys/epoll.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
bool loaded;
bool has_pseudo_calls;
+ bool relaxed_core_relocs;
/*
* Information when doing elf related work. Only valid if fd
*/
struct {
int fd;
- void *obj_buf;
+ const void *obj_buf;
size_t obj_buf_sz;
Elf *elf;
GElf_Ehdr ehdr;
return 0;
}
+static __u32 get_kernel_version(void)
+{
+ __u32 major, minor, patch;
+ struct utsname info;
+
+ uname(&info);
+ if (sscanf(info.release, "%u.%u.%u", &major, &minor, &patch) != 3)
+ return 0;
+ return KERNEL_VERSION(major, minor, patch);
+}
+
static struct bpf_object *bpf_object__new(const char *path,
- void *obj_buf,
- size_t obj_buf_sz)
+ const void *obj_buf,
+ size_t obj_buf_sz,
+ const char *obj_name)
{
struct bpf_object *obj;
char *end;
}
strcpy(obj->path, path);
- /* Using basename() GNU version which doesn't modify arg. */
- strncpy(obj->name, basename((void *)path), sizeof(obj->name) - 1);
- end = strchr(obj->name, '.');
- if (end)
- *end = 0;
+ if (obj_name) {
+ strncpy(obj->name, obj_name, sizeof(obj->name) - 1);
+ obj->name[sizeof(obj->name) - 1] = 0;
+ } else {
+ /* Using basename() GNU version which doesn't modify arg. */
+ strncpy(obj->name, basename((void *)path),
+ sizeof(obj->name) - 1);
+ end = strchr(obj->name, '.');
+ if (end)
+ *end = 0;
+ }
obj->efile.fd = -1;
/*
obj->efile.rodata_shndx = -1;
obj->efile.bss_shndx = -1;
+ obj->kern_version = get_kernel_version();
obj->loaded = false;
INIT_LIST_HEAD(&obj->list);
* obj_buf should have been validated by
* bpf_object__open_buffer().
*/
- obj->efile.elf = elf_memory(obj->efile.obj_buf,
+ obj->efile.elf = elf_memory((char *)obj->efile.obj_buf,
obj->efile.obj_buf_sz);
} else {
obj->efile.fd = open(obj->path, O_RDONLY);
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 compare_bpf_map(const void *_a, const void *_b)
{
const struct bpf_map *a = _a;
return 0;
}
-static int bpf_object__init_maps(struct bpf_object *obj, int flags)
+static int bpf_object__init_maps(struct bpf_object *obj, bool relaxed_maps)
{
- bool strict = !(flags & MAPS_RELAX_COMPAT);
+ bool strict = !relaxed_maps;
int err;
err = bpf_object__init_user_maps(obj, strict);
return 0;
}
-static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
+static int bpf_object__elf_collect(struct bpf_object *obj, bool relaxed_maps)
{
Elf *elf = obj->efile.elf;
GElf_Ehdr *ep = &obj->efile.ehdr;
if (err)
return err;
} else if (strcmp(name, "version") == 0) {
- err = bpf_object__init_kversion(obj,
- data->d_buf,
- data->d_size);
- if (err)
- return err;
+ /* skip, we don't need it anymore */
} else if (strcmp(name, "maps") == 0) {
obj->efile.maps_shndx = idx;
} else if (strcmp(name, MAPS_ELF_SEC) == 0) {
}
err = bpf_object__init_btf(obj, btf_data, btf_ext_data);
if (!err)
- err = bpf_object__init_maps(obj, flags);
+ err = bpf_object__init_maps(obj, relaxed_maps);
if (!err)
err = bpf_object__sanitize_and_load_btf(obj);
if (!err)
}
/*
- * Turn bpf_offset_reloc into a low- and high-level spec representation,
+ * Turn bpf_field_reloc into a low- and high-level spec representation,
* validating correctness along the way, as well as calculating resulting
* field offset (in bytes), specified by accessor string. Low-level spec
* captures every single level of nestedness, including traversing anonymous
/*
* Patch relocatable BPF instruction.
- * Expected insn->imm value is provided for validation, as well as the new
- * relocated value.
+ *
+ * Patched value is determined by relocation kind and target specification.
+ * For field existence relocation target spec will be NULL if field is not
+ * found.
+ * Expected insn->imm value is determined using relocation kind and local
+ * spec, and is checked before patching instruction. If actual insn->imm value
+ * is wrong, bail out with error.
*
* Currently three kinds of BPF instructions are supported:
* 1. rX = <imm> (assignment with immediate operand);
* 2. rX += <imm> (arithmetic operations with immediate operand);
- * 3. *(rX) = <imm> (indirect memory assignment with immediate operand).
- *
- * If actual insn->imm value is wrong, bail out.
*/
-static int bpf_core_reloc_insn(struct bpf_program *prog, int insn_off,
- __u32 orig_off, __u32 new_off)
+static int bpf_core_reloc_insn(struct bpf_program *prog,
+ const struct bpf_field_reloc *relo,
+ const struct bpf_core_spec *local_spec,
+ const struct bpf_core_spec *targ_spec)
{
+ __u32 orig_val, new_val;
struct bpf_insn *insn;
int insn_idx;
__u8 class;
- if (insn_off % sizeof(struct bpf_insn))
+ if (relo->insn_off % sizeof(struct bpf_insn))
return -EINVAL;
- insn_idx = insn_off / sizeof(struct bpf_insn);
+ insn_idx = relo->insn_off / sizeof(struct bpf_insn);
+
+ switch (relo->kind) {
+ case BPF_FIELD_BYTE_OFFSET:
+ orig_val = local_spec->offset;
+ if (targ_spec) {
+ new_val = targ_spec->offset;
+ } else {
+ pr_warning("prog '%s': patching insn #%d w/ failed reloc, imm %d -> %d\n",
+ bpf_program__title(prog, false), insn_idx,
+ orig_val, -1);
+ new_val = (__u32)-1;
+ }
+ break;
+ case BPF_FIELD_EXISTS:
+ orig_val = 1; /* can't generate EXISTS relo w/o local field */
+ new_val = targ_spec ? 1 : 0;
+ break;
+ default:
+ pr_warning("prog '%s': unknown relo %d at insn #%d'\n",
+ bpf_program__title(prog, false),
+ relo->kind, insn_idx);
+ return -EINVAL;
+ }
insn = &prog->insns[insn_idx];
class = BPF_CLASS(insn->code);
if (class == BPF_ALU || class == BPF_ALU64) {
if (BPF_SRC(insn->code) != BPF_K)
return -EINVAL;
- if (insn->imm != orig_off)
+ if (insn->imm != orig_val)
return -EINVAL;
- insn->imm = new_off;
+ insn->imm = new_val;
pr_debug("prog '%s': patched insn #%d (ALU/ALU64) imm %d -> %d\n",
bpf_program__title(prog, false),
- insn_idx, orig_off, new_off);
+ insn_idx, orig_val, new_val);
} else {
pr_warning("prog '%s': trying to relocate unrecognized insn #%d, code:%x, src:%x, dst:%x, off:%x, imm:%x\n",
bpf_program__title(prog, false),
insn->off, insn->imm);
return -EINVAL;
}
+
return 0;
}
* types should be compatible (see bpf_core_fields_are_compat for details).
* 3. It is supported and expected that there might be multiple flavors
* matching the spec. As long as all the specs resolve to the same set of
- * offsets across all candidates, there is not error. If there is any
+ * offsets across all candidates, there is no error. If there is any
* ambiguity, CO-RE relocation will fail. This is necessary to accomodate
* imprefection of BTF deduplication, which can cause slight duplication of
* the same BTF type, if some directly or indirectly referenced (by
* CPU-wise compared to prebuilding a map from all local type names to
* a list of candidate type names. It's also sped up by caching resolved
* list of matching candidates per each local "root" type ID, that has at
- * least one bpf_offset_reloc associated with it. This list is shared
+ * least one bpf_field_reloc associated with it. This list is shared
* between multiple relocations for the same type ID and is updated as some
* of the candidates are pruned due to structural incompatibility.
*/
-static int bpf_core_reloc_offset(struct bpf_program *prog,
- const struct bpf_offset_reloc *relo,
+static int bpf_core_reloc_field(struct bpf_program *prog,
+ const struct bpf_field_reloc *relo,
int relo_idx,
const struct btf *local_btf,
const struct btf *targ_btf,
cand_ids->data[j++] = cand_spec.spec[0].type_id;
}
- cand_ids->len = j;
- if (cand_ids->len == 0) {
+ /*
+ * For BPF_FIELD_EXISTS relo or when relaxed CO-RE reloc mode is
+ * requested, it's expected that we might not find any candidates.
+ * In this case, if field wasn't found in any candidate, the list of
+ * candidates shouldn't change at all, we'll just handle relocating
+ * appropriately, depending on relo's kind.
+ */
+ if (j > 0)
+ cand_ids->len = j;
+
+ if (j == 0 && !prog->obj->relaxed_core_relocs &&
+ relo->kind != BPF_FIELD_EXISTS) {
pr_warning("prog '%s': relo #%d: no matching targets found for [%d] %s + %s\n",
prog_name, relo_idx, local_id, local_name, spec_str);
return -ESRCH;
}
- err = bpf_core_reloc_insn(prog, relo->insn_off,
- local_spec.offset, targ_spec.offset);
+ /* bpf_core_reloc_insn should know how to handle missing targ_spec */
+ err = bpf_core_reloc_insn(prog, relo, &local_spec,
+ j ? &targ_spec : NULL);
if (err) {
pr_warning("prog '%s': relo #%d: failed to patch insn at offset %d: %d\n",
prog_name, relo_idx, relo->insn_off, err);
}
static int
-bpf_core_reloc_offsets(struct bpf_object *obj, const char *targ_btf_path)
+bpf_core_reloc_fields(struct bpf_object *obj, const char *targ_btf_path)
{
const struct btf_ext_info_sec *sec;
- const struct bpf_offset_reloc *rec;
+ const struct bpf_field_reloc *rec;
const struct btf_ext_info *seg;
struct hashmap_entry *entry;
struct hashmap *cand_cache = NULL;
goto out;
}
- seg = &obj->btf_ext->offset_reloc_info;
+ seg = &obj->btf_ext->field_reloc_info;
for_each_btf_ext_sec(seg, sec) {
sec_name = btf__name_by_offset(obj->btf, sec->sec_name_off);
if (str_is_empty(sec_name)) {
sec_name, sec->num_info);
for_each_btf_ext_rec(seg, sec, i, rec) {
- err = bpf_core_reloc_offset(prog, rec, i, obj->btf,
- targ_btf, cand_cache);
+ err = bpf_core_reloc_field(prog, rec, i, obj->btf,
+ targ_btf, cand_cache);
if (err) {
pr_warning("prog '%s': relo #%d: failed to relocate: %d\n",
sec_name, i, err);
{
int err = 0;
- if (obj->btf_ext->offset_reloc_info.len)
- err = bpf_core_reloc_offsets(obj, targ_btf_path);
+ if (obj->btf_ext->field_reloc_info.len)
+ err = bpf_core_reloc_fields(obj, targ_btf_path);
return err;
}
return 0;
}
-static bool bpf_prog_type__needs_kver(enum bpf_prog_type type)
-{
- switch (type) {
- case BPF_PROG_TYPE_SOCKET_FILTER:
- case BPF_PROG_TYPE_SCHED_CLS:
- case BPF_PROG_TYPE_SCHED_ACT:
- case BPF_PROG_TYPE_XDP:
- case BPF_PROG_TYPE_CGROUP_SKB:
- case BPF_PROG_TYPE_CGROUP_SOCK:
- case BPF_PROG_TYPE_LWT_IN:
- case BPF_PROG_TYPE_LWT_OUT:
- case BPF_PROG_TYPE_LWT_XMIT:
- case BPF_PROG_TYPE_LWT_SEG6LOCAL:
- case BPF_PROG_TYPE_SOCK_OPS:
- case BPF_PROG_TYPE_SK_SKB:
- case BPF_PROG_TYPE_CGROUP_DEVICE:
- case BPF_PROG_TYPE_SK_MSG:
- case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
- case BPF_PROG_TYPE_LIRC_MODE2:
- case BPF_PROG_TYPE_SK_REUSEPORT:
- case BPF_PROG_TYPE_FLOW_DISSECTOR:
- case BPF_PROG_TYPE_UNSPEC:
- case BPF_PROG_TYPE_TRACEPOINT:
- case BPF_PROG_TYPE_RAW_TRACEPOINT:
- case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
- case BPF_PROG_TYPE_PERF_EVENT:
- case BPF_PROG_TYPE_CGROUP_SYSCTL:
- case BPF_PROG_TYPE_CGROUP_SOCKOPT:
- return false;
- case BPF_PROG_TYPE_KPROBE:
- default:
- return true;
- }
-}
-
-static int bpf_object__validate(struct bpf_object *obj, bool needs_kver)
-{
- if (needs_kver && 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,
- bool needs_kver, int flags)
+__bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz,
+ struct bpf_object_open_opts *opts)
{
struct bpf_object *obj;
+ const char *obj_name;
+ char tmp_name[64];
+ bool relaxed_maps;
int err;
if (elf_version(EV_CURRENT) == EV_NONE) {
- pr_warning("failed to init libelf for %s\n", path);
+ pr_warning("failed to init libelf for %s\n",
+ path ? : "(mem buf)");
return ERR_PTR(-LIBBPF_ERRNO__LIBELF);
}
- obj = bpf_object__new(path, obj_buf, obj_buf_sz);
+ if (!OPTS_VALID(opts, bpf_object_open_opts))
+ return ERR_PTR(-EINVAL);
+
+ obj_name = OPTS_GET(opts, object_name, path);
+ if (obj_buf) {
+ if (!obj_name) {
+ snprintf(tmp_name, sizeof(tmp_name), "%lx-%lx",
+ (unsigned long)obj_buf,
+ (unsigned long)obj_buf_sz);
+ obj_name = tmp_name;
+ }
+ path = obj_name;
+ pr_debug("loading object '%s' from buffer\n", obj_name);
+ }
+
+ obj = bpf_object__new(path, obj_buf, obj_buf_sz, obj_name);
if (IS_ERR(obj))
return obj;
+ obj->relaxed_core_relocs = OPTS_GET(opts, relaxed_core_relocs, false);
+ relaxed_maps = OPTS_GET(opts, relaxed_maps, false);
+
CHECK_ERR(bpf_object__elf_init(obj), err, out);
CHECK_ERR(bpf_object__check_endianness(obj), err, out);
CHECK_ERR(bpf_object__probe_caps(obj), err, out);
- CHECK_ERR(bpf_object__elf_collect(obj, flags), err, out);
+ CHECK_ERR(bpf_object__elf_collect(obj, relaxed_maps), err, out);
CHECK_ERR(bpf_object__collect_reloc(obj), err, out);
- CHECK_ERR(bpf_object__validate(obj, needs_kver), err, out);
bpf_object__elf_finish(obj);
return obj;
return ERR_PTR(err);
}
-struct bpf_object *__bpf_object__open_xattr(struct bpf_object_open_attr *attr,
- int flags)
+static struct bpf_object *
+__bpf_object__open_xattr(struct bpf_object_open_attr *attr, int flags)
{
+ LIBBPF_OPTS(bpf_object_open_opts, opts,
+ .relaxed_maps = flags & MAPS_RELAX_COMPAT,
+ );
+
/* param validation */
if (!attr->file)
return NULL;
pr_debug("loading %s\n", attr->file);
-
- return __bpf_object__open(attr->file, NULL, 0,
- bpf_prog_type__needs_kver(attr->prog_type),
- flags);
+ return __bpf_object__open(attr->file, NULL, 0, &opts);
}
struct bpf_object *bpf_object__open_xattr(struct bpf_object_open_attr *attr)
return bpf_object__open_xattr(&attr);
}
-struct bpf_object *bpf_object__open_buffer(void *obj_buf,
- size_t obj_buf_sz,
- const char *name)
+struct bpf_object *
+bpf_object__open_file(const char *path, struct bpf_object_open_opts *opts)
{
- char tmp_name[64];
+ if (!path)
+ return ERR_PTR(-EINVAL);
- /* param validation */
- if (!obj_buf || obj_buf_sz <= 0)
- return NULL;
+ pr_debug("loading %s\n", path);
- if (!name) {
- snprintf(tmp_name, sizeof(tmp_name), "%lx-%lx",
- (unsigned long)obj_buf,
- (unsigned long)obj_buf_sz);
- name = tmp_name;
- }
- pr_debug("loading object '%s' from buffer\n", name);
+ return __bpf_object__open(path, NULL, 0, opts);
+}
+
+struct bpf_object *
+bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz,
+ struct bpf_object_open_opts *opts)
+{
+ if (!obj_buf || obj_buf_sz == 0)
+ return ERR_PTR(-EINVAL);
- return __bpf_object__open(name, obj_buf, obj_buf_sz, true, true);
+ return __bpf_object__open(NULL, obj_buf, obj_buf_sz, opts);
+}
+
+struct bpf_object *
+bpf_object__open_buffer(const void *obj_buf, size_t obj_buf_sz,
+ const char *name)
+{
+ LIBBPF_OPTS(bpf_object_open_opts, opts,
+ .object_name = name,
+ /* wrong default, but backwards-compatible */
+ .relaxed_maps = true,
+ );
+
+ /* returning NULL is wrong, but backwards-compatible */
+ if (!obj_buf || obj_buf_sz == 0)
+ return NULL;
+
+ return bpf_object__open_mem(obj_buf, obj_buf_sz, &opts);
}
int bpf_object__unload(struct bpf_object *obj)
const char *bpf_object__name(const struct bpf_object *obj)
{
- return obj ? obj->path : ERR_PTR(-EINVAL);
+ return obj ? obj->name : ERR_PTR(-EINVAL);
}
unsigned int bpf_object__kversion(const struct bpf_object *obj)
prog->expected_attach_type = type;
}
-#define BPF_PROG_SEC_IMPL(string, ptype, eatype, is_attachable, atype) \
- { string, sizeof(string) - 1, ptype, eatype, is_attachable, atype }
+#define BPF_PROG_SEC_IMPL(string, ptype, eatype, is_attachable, btf, atype) \
+ { string, sizeof(string) - 1, ptype, eatype, is_attachable, btf, atype }
/* Programs that can NOT be attached. */
-#define BPF_PROG_SEC(string, ptype) BPF_PROG_SEC_IMPL(string, ptype, 0, 0, 0)
+#define BPF_PROG_SEC(string, ptype) BPF_PROG_SEC_IMPL(string, ptype, 0, 0, 0, 0)
/* Programs that can be attached. */
#define BPF_APROG_SEC(string, ptype, atype) \
- BPF_PROG_SEC_IMPL(string, ptype, 0, 1, atype)
+ BPF_PROG_SEC_IMPL(string, ptype, 0, 1, 0, atype)
/* Programs that must specify expected attach type at load time. */
#define BPF_EAPROG_SEC(string, ptype, eatype) \
- BPF_PROG_SEC_IMPL(string, ptype, eatype, 1, eatype)
+ BPF_PROG_SEC_IMPL(string, ptype, eatype, 1, 0, eatype)
+
+/* Programs that use BTF to identify attach point */
+#define BPF_PROG_BTF(string, ptype) BPF_PROG_SEC_IMPL(string, ptype, 0, 0, 1, 0)
/* Programs that can be attached but attach type can't be identified by section
* name. Kept for backward compatibility.
size_t len;
enum bpf_prog_type prog_type;
enum bpf_attach_type expected_attach_type;
- int is_attachable;
+ bool is_attachable;
+ bool is_attach_btf;
enum bpf_attach_type attach_type;
} section_names[] = {
BPF_PROG_SEC("socket", BPF_PROG_TYPE_SOCKET_FILTER),
BPF_PROG_SEC("action", BPF_PROG_TYPE_SCHED_ACT),
BPF_PROG_SEC("tracepoint/", BPF_PROG_TYPE_TRACEPOINT),
BPF_PROG_SEC("raw_tracepoint/", BPF_PROG_TYPE_RAW_TRACEPOINT),
+ BPF_PROG_BTF("tp_btf/", BPF_PROG_TYPE_RAW_TRACEPOINT),
BPF_PROG_SEC("xdp", BPF_PROG_TYPE_XDP),
BPF_PROG_SEC("perf_event", BPF_PROG_TYPE_PERF_EVENT),
BPF_PROG_SEC("lwt_in", BPF_PROG_TYPE_LWT_IN),
continue;
*prog_type = section_names[i].prog_type;
*expected_attach_type = section_names[i].expected_attach_type;
+ if (section_names[i].is_attach_btf) {
+ struct btf *btf = bpf_core_find_kernel_btf();
+ char raw_tp_btf_name[128] = "btf_trace_";
+ char *dst = raw_tp_btf_name + sizeof("btf_trace_") - 1;
+ int ret;
+
+ if (IS_ERR(btf)) {
+ pr_warning("vmlinux BTF is not found\n");
+ return -EINVAL;
+ }
+ /* prepend "btf_trace_" prefix per kernel convention */
+ strncat(dst, name + section_names[i].len,
+ sizeof(raw_tp_btf_name) - (dst - raw_tp_btf_name));
+ ret = btf__find_by_name(btf, raw_tp_btf_name);
+ btf__free(btf);
+ if (ret <= 0) {
+ pr_warning("%s is not found in vmlinux BTF\n", dst);
+ return -EINVAL;
+ }
+ *expected_attach_type = ret;
+ }
return 0;
}
pr_warning("failed to guess program type based on ELF section name '%s'\n", name);
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