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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2022-08-02 10:06:12 -0700
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2022-08-02 10:06:12 -0700
commit8bb5e7f4dcd9b9ef22a3ea25c9066a8a968f12dd (patch)
tree0f1383880607a227142f9388a066959926233ff1 /tools/lib/bpf/libbpf.c
parent2a96271fb66c499e4a89d76a89d3d01170c10bef (diff)
parent7c744d00990ea999d27f306f6db5ccb61b1304b2 (diff)
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Merge branch 'next' into for-linus
Prepare input updates for 5.20 (or 6.0) merge window.
Diffstat (limited to 'tools/lib/bpf/libbpf.c')
-rw-r--r--tools/lib/bpf/libbpf.c2183
1 files changed, 1790 insertions, 393 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 7f10dd501a52..e89cc9c885b3 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -156,14 +156,6 @@ enum libbpf_strict_mode libbpf_mode = LIBBPF_STRICT_NONE;
int libbpf_set_strict_mode(enum libbpf_strict_mode mode)
{
- /* __LIBBPF_STRICT_LAST is the last power-of-2 value used + 1, so to
- * get all possible values we compensate last +1, and then (2*x - 1)
- * to get the bit mask
- */
- if (mode != LIBBPF_STRICT_ALL
- && (mode & ~((__LIBBPF_STRICT_LAST - 1) * 2 - 1)))
- return errno = EINVAL, -EINVAL;
-
libbpf_mode = mode;
return 0;
}
@@ -209,12 +201,6 @@ struct reloc_desc {
};
};
-struct bpf_sec_def;
-
-typedef int (*init_fn_t)(struct bpf_program *prog, long cookie);
-typedef int (*preload_fn_t)(struct bpf_program *prog, struct bpf_prog_load_opts *opts, long cookie);
-typedef struct bpf_link *(*attach_fn_t)(const struct bpf_program *prog, long cookie);
-
/* stored as sec_def->cookie for all libbpf-supported SEC()s */
enum sec_def_flags {
SEC_NONE = 0,
@@ -235,17 +221,22 @@ enum sec_def_flags {
SEC_SLEEPABLE = 8,
/* allow non-strict prefix matching */
SEC_SLOPPY_PFX = 16,
+ /* BPF program support non-linear XDP buffer */
+ SEC_XDP_FRAGS = 32,
+ /* deprecated sec definitions not supposed to be used */
+ SEC_DEPRECATED = 64,
};
struct bpf_sec_def {
- const char *sec;
+ char *sec;
enum bpf_prog_type prog_type;
enum bpf_attach_type expected_attach_type;
long cookie;
+ int handler_id;
- init_fn_t init_fn;
- preload_fn_t preload_fn;
- attach_fn_t attach_fn;
+ libbpf_prog_setup_fn_t prog_setup_fn;
+ libbpf_prog_prepare_load_fn_t prog_prepare_load_fn;
+ libbpf_prog_attach_fn_t prog_attach_fn;
};
/*
@@ -311,7 +302,7 @@ struct bpf_program {
void *priv;
bpf_program_clear_priv_t clear_priv;
- bool load;
+ bool autoload;
bool mark_btf_static;
enum bpf_prog_type type;
enum bpf_attach_type expected_attach_type;
@@ -366,6 +357,7 @@ enum libbpf_map_type {
};
struct bpf_map {
+ struct bpf_object *obj;
char *name;
/* real_name is defined for special internal maps (.rodata*,
* .data*, .bss, .kconfig) and preserves their original ELF section
@@ -395,7 +387,7 @@ struct bpf_map {
char *pin_path;
bool pinned;
bool reused;
- bool skipped;
+ bool autocreate;
__u64 map_extra;
};
@@ -492,6 +484,8 @@ struct elf_state {
int st_ops_shndx;
};
+struct usdt_manager;
+
struct bpf_object {
char name[BPF_OBJ_NAME_LEN];
char license[64];
@@ -554,6 +548,8 @@ struct bpf_object {
size_t fd_array_cap;
size_t fd_array_cnt;
+ struct usdt_manager *usdt_man;
+
char path[];
};
@@ -677,7 +673,18 @@ bpf_object__init_prog(struct bpf_object *obj, struct bpf_program *prog,
prog->insns_cnt = prog->sec_insn_cnt;
prog->type = BPF_PROG_TYPE_UNSPEC;
- prog->load = true;
+
+ /* libbpf's convention for SEC("?abc...") is that it's just like
+ * SEC("abc...") but the corresponding bpf_program starts out with
+ * autoload set to false.
+ */
+ if (sec_name[0] == '?') {
+ prog->autoload = false;
+ /* from now on forget there was ? in section name */
+ sec_name++;
+ } else {
+ prog->autoload = true;
+ }
prog->instances.fds = NULL;
prog->instances.nr = -1;
@@ -1227,10 +1234,8 @@ static void bpf_object__elf_finish(struct bpf_object *obj)
if (!obj->efile.elf)
return;
- if (obj->efile.elf) {
- elf_end(obj->efile.elf);
- obj->efile.elf = NULL;
- }
+ elf_end(obj->efile.elf);
+ obj->efile.elf = NULL;
obj->efile.symbols = NULL;
obj->efile.st_ops_data = NULL;
@@ -1378,22 +1383,20 @@ static bool bpf_map_type__is_map_in_map(enum bpf_map_type type)
static int find_elf_sec_sz(const struct bpf_object *obj, const char *name, __u32 *size)
{
- int ret = -ENOENT;
Elf_Data *data;
Elf_Scn *scn;
- *size = 0;
if (!name)
return -EINVAL;
scn = elf_sec_by_name(obj, name);
data = elf_sec_data(obj, scn);
if (data) {
- ret = 0; /* found it */
*size = data->d_size;
+ return 0; /* found it */
}
- return *size ? 0 : ret;
+ return -ENOENT;
}
static int find_elf_var_offset(const struct bpf_object *obj, const char *name, __u32 *off)
@@ -1408,8 +1411,11 @@ static int find_elf_var_offset(const struct bpf_object *obj, const char *name, _
for (si = 0; si < symbols->d_size / sizeof(Elf64_Sym); si++) {
Elf64_Sym *sym = elf_sym_by_idx(obj, si);
- if (ELF64_ST_BIND(sym->st_info) != STB_GLOBAL ||
- ELF64_ST_TYPE(sym->st_info) != STT_OBJECT)
+ if (ELF64_ST_TYPE(sym->st_info) != STT_OBJECT)
+ continue;
+
+ if (ELF64_ST_BIND(sym->st_info) != STB_GLOBAL &&
+ ELF64_ST_BIND(sym->st_info) != STB_WEAK)
continue;
sname = elf_sym_str(obj, sym->st_name);
@@ -1428,36 +1434,21 @@ static int find_elf_var_offset(const struct bpf_object *obj, const char *name, _
static struct bpf_map *bpf_object__add_map(struct bpf_object *obj)
{
- struct bpf_map *new_maps;
- size_t new_cap;
- int i;
-
- if (obj->nr_maps < obj->maps_cap)
- return &obj->maps[obj->nr_maps++];
-
- new_cap = max((size_t)4, obj->maps_cap * 3 / 2);
- new_maps = libbpf_reallocarray(obj->maps, new_cap, sizeof(*obj->maps));
- if (!new_maps) {
- pr_warn("alloc maps for object failed\n");
- return ERR_PTR(-ENOMEM);
- }
+ struct bpf_map *map;
+ int err;
- obj->maps_cap = new_cap;
- obj->maps = new_maps;
+ err = libbpf_ensure_mem((void **)&obj->maps, &obj->maps_cap,
+ sizeof(*obj->maps), obj->nr_maps + 1);
+ if (err)
+ return ERR_PTR(err);
- /* zero out new maps */
- memset(obj->maps + obj->nr_maps, 0,
- (obj->maps_cap - obj->nr_maps) * sizeof(*obj->maps));
- /*
- * fill all fd with -1 so won't close incorrect fd (fd=0 is stdin)
- * when failure (zclose won't close negative fd)).
- */
- for (i = obj->nr_maps; i < obj->maps_cap; i++) {
- obj->maps[i].fd = -1;
- obj->maps[i].inner_map_fd = -1;
- }
+ map = &obj->maps[obj->nr_maps++];
+ map->obj = obj;
+ map->fd = -1;
+ map->inner_map_fd = -1;
+ map->autocreate = true;
- return &obj->maps[obj->nr_maps++];
+ return map;
}
static size_t bpf_map_mmap_sz(const struct bpf_map *map)
@@ -1529,6 +1520,9 @@ static char *internal_map_name(struct bpf_object *obj, const char *real_name)
}
static int
+bpf_map_find_btf_info(struct bpf_object *obj, struct bpf_map *map);
+
+static int
bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
const char *real_name, int sec_idx, void *data, size_t data_sz)
{
@@ -1575,6 +1569,9 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
return err;
}
+ /* failures are fine because of maps like .rodata.str1.1 */
+ (void) bpf_map_find_btf_info(obj, map);
+
if (data)
memcpy(map->mmaped, data, data_sz);
@@ -1937,6 +1934,11 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict)
if (obj->efile.maps_shndx < 0)
return 0;
+ if (libbpf_mode & LIBBPF_STRICT_MAP_DEFINITIONS) {
+ pr_warn("legacy map definitions in SEC(\"maps\") are not supported\n");
+ return -EOPNOTSUPP;
+ }
+
if (!symbols)
return -EINVAL;
@@ -1999,6 +2001,8 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict)
return -LIBBPF_ERRNO__FORMAT;
}
+ pr_warn("map '%s' (legacy): legacy map definitions are deprecated, use BTF-defined maps instead\n", map_name);
+
if (ELF64_ST_BIND(sym->st_info) == STB_LOCAL) {
pr_warn("map '%s' (legacy): static maps are not supported\n", map_name);
return -ENOTSUP;
@@ -2050,6 +2054,9 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict)
}
memcpy(&map->def, def, sizeof(struct bpf_map_def));
}
+
+ /* btf info may not exist but fill it in if it does exist */
+ (void) bpf_map_find_btf_info(obj, map);
}
return 0;
}
@@ -2538,6 +2545,10 @@ static int bpf_object__init_user_btf_map(struct bpf_object *obj,
fill_map_from_def(map->inner_map, &inner_def);
}
+ err = bpf_map_find_btf_info(obj, map);
+ if (err)
+ return err;
+
return 0;
}
@@ -2740,6 +2751,9 @@ static int bpf_object__init_btf(struct bpf_object *obj,
btf__set_pointer_size(obj->btf, 8);
}
if (btf_ext_data) {
+ struct btf_ext_info *ext_segs[3];
+ int seg_num, sec_num;
+
if (!obj->btf) {
pr_debug("Ignore ELF section %s because its depending ELF section %s is not found.\n",
BTF_EXT_ELF_SEC, BTF_ELF_SEC);
@@ -2753,6 +2767,43 @@ static int bpf_object__init_btf(struct bpf_object *obj,
obj->btf_ext = NULL;
goto out;
}
+
+ /* setup .BTF.ext to ELF section mapping */
+ ext_segs[0] = &obj->btf_ext->func_info;
+ ext_segs[1] = &obj->btf_ext->line_info;
+ ext_segs[2] = &obj->btf_ext->core_relo_info;
+ for (seg_num = 0; seg_num < ARRAY_SIZE(ext_segs); seg_num++) {
+ struct btf_ext_info *seg = ext_segs[seg_num];
+ const struct btf_ext_info_sec *sec;
+ const char *sec_name;
+ Elf_Scn *scn;
+
+ if (seg->sec_cnt == 0)
+ continue;
+
+ seg->sec_idxs = calloc(seg->sec_cnt, sizeof(*seg->sec_idxs));
+ if (!seg->sec_idxs) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ sec_num = 0;
+ for_each_btf_ext_sec(seg, sec) {
+ /* preventively increment index to avoid doing
+ * this before every continue below
+ */
+ sec_num++;
+
+ sec_name = btf__name_by_offset(obj->btf, sec->sec_name_off);
+ if (str_is_empty(sec_name))
+ continue;
+ scn = elf_sec_by_name(obj, sec_name);
+ if (!scn)
+ continue;
+
+ seg->sec_idxs[sec_num - 1] = elf_ndxscn(scn);
+ }
+ }
}
out:
if (err && libbpf_needs_btf(obj)) {
@@ -2792,7 +2843,7 @@ static int btf_fixup_datasec(struct bpf_object *obj, struct btf *btf,
goto sort_vars;
ret = find_elf_sec_sz(obj, name, &size);
- if (ret || !size || (t->size && t->size != size)) {
+ if (ret || !size) {
pr_debug("Invalid size for section %s: %u bytes\n", name, size);
return -ENOENT;
}
@@ -2911,7 +2962,7 @@ static bool obj_needs_vmlinux_btf(const struct bpf_object *obj)
}
bpf_object__for_each_program(prog, obj) {
- if (!prog->load)
+ if (!prog->autoload)
continue;
if (prog_needs_vmlinux_btf(prog))
return true;
@@ -3836,7 +3887,14 @@ static bool prog_is_subprog(const struct bpf_object *obj,
* .text programs are subprograms (even if they are not called from
* other programs), because libbpf never explicitly supported mixing
* SEC()-designated BPF programs and .text entry-point BPF programs.
+ *
+ * In libbpf 1.0 strict mode, we always consider .text
+ * programs to be subprograms.
*/
+
+ if (libbpf_mode & LIBBPF_STRICT_SEC_NAME)
+ return prog->sec_idx == obj->efile.text_shndx;
+
return prog->sec_idx == obj->efile.text_shndx && obj->nr_programs > 1;
}
@@ -4181,6 +4239,9 @@ static int bpf_map_find_btf_info(struct bpf_object *obj, struct bpf_map *map)
__u32 key_type_id = 0, value_type_id = 0;
int ret;
+ if (!obj->btf)
+ return -ENOENT;
+
/* if it's BTF-defined map, we don't need to search for type IDs.
* For struct_ops map, it does not need btf_key_type_id and
* btf_value_type_id.
@@ -4190,9 +4251,13 @@ static int bpf_map_find_btf_info(struct bpf_object *obj, struct bpf_map *map)
return 0;
if (!bpf_map__is_internal(map)) {
+ pr_warn("Use of BPF_ANNOTATE_KV_PAIR is deprecated, use BTF-defined maps in .maps section instead\n");
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
ret = btf__get_map_kv_tids(obj->btf, map->name, def->key_size,
def->value_size, &key_type_id,
&value_type_id);
+#pragma GCC diagnostic pop
} else {
/*
* LLVM annotates global data differently in BTF, that is,
@@ -4245,6 +4310,20 @@ static int bpf_get_map_info_from_fdinfo(int fd, struct bpf_map_info *info)
return 0;
}
+bool bpf_map__autocreate(const struct bpf_map *map)
+{
+ return map->autocreate;
+}
+
+int bpf_map__set_autocreate(struct bpf_map *map, bool autocreate)
+{
+ if (map->obj->loaded)
+ return libbpf_err(-EBUSY);
+
+ map->autocreate = autocreate;
+ return 0;
+}
+
int bpf_map__reuse_fd(struct bpf_map *map, int fd)
{
struct bpf_map_info info = {};
@@ -4564,7 +4643,7 @@ static int probe_kern_probe_read_kernel(void)
};
int fd, insn_cnt = ARRAY_SIZE(insns);
- fd = bpf_prog_load(BPF_PROG_TYPE_KPROBE, NULL, "GPL", insns, insn_cnt, NULL);
+ fd = bpf_prog_load(BPF_PROG_TYPE_TRACEPOINT, NULL, "GPL", insns, insn_cnt, NULL);
return probe_fd(fd);
}
@@ -4655,6 +4734,18 @@ static int probe_perf_link(void)
return link_fd < 0 && err == -EBADF;
}
+static int probe_kern_bpf_cookie(void)
+{
+ struct bpf_insn insns[] = {
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_get_attach_cookie),
+ BPF_EXIT_INSN(),
+ };
+ int ret, insn_cnt = ARRAY_SIZE(insns);
+
+ ret = bpf_prog_load(BPF_PROG_TYPE_KPROBE, NULL, "GPL", insns, insn_cnt, NULL);
+ return probe_fd(ret);
+}
+
enum kern_feature_result {
FEAT_UNKNOWN = 0,
FEAT_SUPPORTED = 1,
@@ -4717,6 +4808,9 @@ static struct kern_feature_desc {
[FEAT_MEMCG_ACCOUNT] = {
"memcg-based memory accounting", probe_memcg_account,
},
+ [FEAT_BPF_COOKIE] = {
+ "BPF cookie support", probe_kern_bpf_cookie,
+ },
};
bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id)
@@ -4800,8 +4894,8 @@ bpf_object__reuse_map(struct bpf_map *map)
}
err = bpf_map__reuse_fd(map, pin_fd);
+ close(pin_fd);
if (err) {
- close(pin_fd);
return err;
}
map->pinned = true;
@@ -4849,12 +4943,47 @@ bpf_object__populate_internal_map(struct bpf_object *obj, struct bpf_map *map)
static void bpf_map__destroy(struct bpf_map *map);
+static bool is_pow_of_2(size_t x)
+{
+ return x && (x & (x - 1));
+}
+
+static size_t adjust_ringbuf_sz(size_t sz)
+{
+ __u32 page_sz = sysconf(_SC_PAGE_SIZE);
+ __u32 mul;
+
+ /* if user forgot to set any size, make sure they see error */
+ if (sz == 0)
+ return 0;
+ /* Kernel expects BPF_MAP_TYPE_RINGBUF's max_entries to be
+ * a power-of-2 multiple of kernel's page size. If user diligently
+ * satisified these conditions, pass the size through.
+ */
+ if ((sz % page_sz) == 0 && is_pow_of_2(sz / page_sz))
+ return sz;
+
+ /* Otherwise find closest (page_sz * power_of_2) product bigger than
+ * user-set size to satisfy both user size request and kernel
+ * requirements and substitute correct max_entries for map creation.
+ */
+ for (mul = 1; mul <= UINT_MAX / page_sz; mul <<= 1) {
+ if (mul * page_sz > sz)
+ return mul * page_sz;
+ }
+
+ /* if it's impossible to satisfy the conditions (i.e., user size is
+ * very close to UINT_MAX but is not a power-of-2 multiple of
+ * page_size) then just return original size and let kernel reject it
+ */
+ return sz;
+}
+
static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, bool is_inner)
{
LIBBPF_OPTS(bpf_map_create_opts, create_attr);
struct bpf_map_def *def = &map->def;
const char *map_name = NULL;
- __u32 max_entries;
int err = 0;
if (kernel_supports(obj, FEAT_PROG_NAME))
@@ -4864,25 +4993,10 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b
create_attr.numa_node = map->numa_node;
create_attr.map_extra = map->map_extra;
- if (def->type == BPF_MAP_TYPE_PERF_EVENT_ARRAY && !def->max_entries) {
- int nr_cpus;
-
- nr_cpus = libbpf_num_possible_cpus();
- if (nr_cpus < 0) {
- pr_warn("map '%s': failed to determine number of system CPUs: %d\n",
- map->name, nr_cpus);
- return nr_cpus;
- }
- pr_debug("map '%s': setting size to %d\n", map->name, nr_cpus);
- max_entries = nr_cpus;
- } else {
- max_entries = def->max_entries;
- }
-
if (bpf_map__is_struct_ops(map))
create_attr.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
- if (obj->btf && btf__fd(obj->btf) >= 0 && !bpf_map_find_btf_info(obj, map)) {
+ if (obj->btf && btf__fd(obj->btf) >= 0) {
create_attr.btf_fd = btf__fd(obj->btf);
create_attr.btf_key_type_id = map->btf_key_type_id;
create_attr.btf_value_type_id = map->btf_value_type_id;
@@ -4903,6 +5017,9 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b
}
switch (def->type) {
+ case BPF_MAP_TYPE_RINGBUF:
+ map->def.max_entries = adjust_ringbuf_sz(map->def.max_entries);
+ /* fallthrough */
case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
case BPF_MAP_TYPE_CGROUP_ARRAY:
case BPF_MAP_TYPE_STACK_TRACE:
@@ -4916,7 +5033,6 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b
case BPF_MAP_TYPE_SOCKHASH:
case BPF_MAP_TYPE_QUEUE:
case BPF_MAP_TYPE_STACK:
- case BPF_MAP_TYPE_RINGBUF:
create_attr.btf_fd = 0;
create_attr.btf_key_type_id = 0;
create_attr.btf_value_type_id = 0;
@@ -4928,7 +5044,7 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b
if (obj->gen_loader) {
bpf_gen__map_create(obj->gen_loader, def->type, map_name,
- def->key_size, def->value_size, max_entries,
+ def->key_size, def->value_size, def->max_entries,
&create_attr, is_inner ? -1 : map - obj->maps);
/* Pretend to have valid FD to pass various fd >= 0 checks.
* This fd == 0 will not be used with any syscall and will be reset to -1 eventually.
@@ -4937,7 +5053,7 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b
} else {
map->fd = bpf_map_create(def->type, map_name,
def->key_size, def->value_size,
- max_entries, &create_attr);
+ def->max_entries, &create_attr);
}
if (map->fd < 0 && (create_attr.btf_key_type_id ||
create_attr.btf_value_type_id)) {
@@ -4954,7 +5070,7 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b
map->btf_value_type_id = 0;
map->fd = bpf_map_create(def->type, map_name,
def->key_size, def->value_size,
- max_entries, &create_attr);
+ def->max_entries, &create_attr);
}
err = map->fd < 0 ? -errno : 0;
@@ -5058,6 +5174,24 @@ static int bpf_object_init_prog_arrays(struct bpf_object *obj)
return 0;
}
+static int map_set_def_max_entries(struct bpf_map *map)
+{
+ if (map->def.type == BPF_MAP_TYPE_PERF_EVENT_ARRAY && !map->def.max_entries) {
+ int nr_cpus;
+
+ nr_cpus = libbpf_num_possible_cpus();
+ if (nr_cpus < 0) {
+ pr_warn("map '%s': failed to determine number of system CPUs: %d\n",
+ map->name, nr_cpus);
+ return nr_cpus;
+ }
+ pr_debug("map '%s': setting size to %d\n", map->name, nr_cpus);
+ map->def.max_entries = nr_cpus;
+ }
+
+ return 0;
+}
+
static int
bpf_object__create_maps(struct bpf_object *obj)
{
@@ -5084,12 +5218,18 @@ bpf_object__create_maps(struct bpf_object *obj)
* bpf_object loading will succeed just fine even on old
* kernels.
*/
- if (bpf_map__is_internal(map) &&
- !kernel_supports(obj, FEAT_GLOBAL_DATA)) {
- map->skipped = true;
+ if (bpf_map__is_internal(map) && !kernel_supports(obj, FEAT_GLOBAL_DATA))
+ map->autocreate = false;
+
+ if (!map->autocreate) {
+ pr_debug("map '%s': skipped auto-creating...\n", map->name);
continue;
}
+ err = map_set_def_max_entries(map);
+ if (err)
+ goto err_out;
+
retried = false;
retry:
if (map->pin_path) {
@@ -5185,18 +5325,21 @@ size_t bpf_core_essential_name_len(const char *name)
return n;
}
-static void bpf_core_free_cands(struct bpf_core_cand_list *cands)
+void bpf_core_free_cands(struct bpf_core_cand_list *cands)
{
+ if (!cands)
+ return;
+
free(cands->cands);
free(cands);
}
-static int bpf_core_add_cands(struct bpf_core_cand *local_cand,
- size_t local_essent_len,
- const struct btf *targ_btf,
- const char *targ_btf_name,
- int targ_start_id,
- struct bpf_core_cand_list *cands)
+int bpf_core_add_cands(struct bpf_core_cand *local_cand,
+ size_t local_essent_len,
+ const struct btf *targ_btf,
+ const char *targ_btf_name,
+ int targ_start_id,
+ struct bpf_core_cand_list *cands)
{
struct bpf_core_cand *new_cands, *cand;
const struct btf_type *t, *local_t;
@@ -5523,11 +5666,28 @@ static int record_relo_core(struct bpf_program *prog,
return 0;
}
-static int bpf_core_apply_relo(struct bpf_program *prog,
- const struct bpf_core_relo *relo,
- int relo_idx,
- const struct btf *local_btf,
- struct hashmap *cand_cache)
+static const struct bpf_core_relo *find_relo_core(struct bpf_program *prog, int insn_idx)
+{
+ struct reloc_desc *relo;
+ int i;
+
+ for (i = 0; i < prog->nr_reloc; i++) {
+ relo = &prog->reloc_desc[i];
+ if (relo->type != RELO_CORE || relo->insn_idx != insn_idx)
+ continue;
+
+ return relo->core_relo;
+ }
+
+ return NULL;
+}
+
+static int bpf_core_resolve_relo(struct bpf_program *prog,
+ const struct bpf_core_relo *relo,
+ int relo_idx,
+ const struct btf *local_btf,
+ struct hashmap *cand_cache,
+ struct bpf_core_relo_res *targ_res)
{
struct bpf_core_spec specs_scratch[3] = {};
const void *type_key = u32_as_hash_key(relo->type_id);
@@ -5536,20 +5696,7 @@ static int bpf_core_apply_relo(struct bpf_program *prog,
const struct btf_type *local_type;
const char *local_name;
__u32 local_id = relo->type_id;
- struct bpf_insn *insn;
- int insn_idx, err;
-
- if (relo->insn_off % BPF_INSN_SZ)
- return -EINVAL;
- insn_idx = relo->insn_off / BPF_INSN_SZ;
- /* adjust insn_idx from section frame of reference to the local
- * program's frame of reference; (sub-)program code is not yet
- * relocated, so it's enough to just subtract in-section offset
- */
- insn_idx = insn_idx - prog->sec_insn_off;
- if (insn_idx >= prog->insns_cnt)
- return -EINVAL;
- insn = &prog->insns[insn_idx];
+ int err;
local_type = btf__type_by_id(local_btf, local_id);
if (!local_type)
@@ -5559,15 +5706,6 @@ static int bpf_core_apply_relo(struct bpf_program *prog,
if (!local_name)
return -EINVAL;
- if (prog->obj->gen_loader) {
- const char *spec_str = btf__name_by_offset(local_btf, relo->access_str_off);
-
- pr_debug("record_relo_core: prog %td insn[%d] %s %s %s final insn_idx %d\n",
- prog - prog->obj->programs, relo->insn_off / 8,
- btf_kind_str(local_type), local_name, spec_str, insn_idx);
- return record_relo_core(prog, relo, insn_idx);
- }
-
if (relo->kind != BPF_CORE_TYPE_ID_LOCAL &&
!hashmap__find(cand_cache, type_key, (void **)&cands)) {
cands = bpf_core_find_cands(prog->obj, local_btf, local_id);
@@ -5584,21 +5722,23 @@ static int bpf_core_apply_relo(struct bpf_program *prog,
}
}
- return bpf_core_apply_relo_insn(prog_name, insn, insn_idx, relo,
- relo_idx, local_btf, cands, specs_scratch);
+ return bpf_core_calc_relo_insn(prog_name, relo, relo_idx, local_btf, cands, specs_scratch,
+ targ_res);
}
static int
bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path)
{
const struct btf_ext_info_sec *sec;
+ struct bpf_core_relo_res targ_res;
const struct bpf_core_relo *rec;
const struct btf_ext_info *seg;
struct hashmap_entry *entry;
struct hashmap *cand_cache = NULL;
struct bpf_program *prog;
+ struct bpf_insn *insn;
const char *sec_name;
- int i, err = 0, insn_idx, sec_idx;
+ int i, err = 0, insn_idx, sec_idx, sec_num;
if (obj->btf_ext->core_relo_info.len == 0)
return 0;
@@ -5619,54 +5759,75 @@ bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path)
}
seg = &obj->btf_ext->core_relo_info;
+ sec_num = 0;
for_each_btf_ext_sec(seg, sec) {
+ sec_idx = seg->sec_idxs[sec_num];
+ sec_num++;
+
sec_name = btf__name_by_offset(obj->btf, sec->sec_name_off);
if (str_is_empty(sec_name)) {
err = -EINVAL;
goto out;
}
- /* bpf_object's ELF is gone by now so it's not easy to find
- * section index by section name, but we can find *any*
- * bpf_program within desired section name and use it's
- * prog->sec_idx to do a proper search by section index and
- * instruction offset
- */
- prog = NULL;
- for (i = 0; i < obj->nr_programs; i++) {
- prog = &obj->programs[i];
- if (strcmp(prog->sec_name, sec_name) == 0)
- break;
- }
- if (!prog) {
- pr_warn("sec '%s': failed to find a BPF program\n", sec_name);
- return -ENOENT;
- }
- sec_idx = prog->sec_idx;
- pr_debug("sec '%s': found %d CO-RE relocations\n",
- sec_name, sec->num_info);
+ pr_debug("sec '%s': found %d CO-RE relocations\n", sec_name, sec->num_info);
for_each_btf_ext_rec(seg, sec, i, rec) {
+ if (rec->insn_off % BPF_INSN_SZ)
+ return -EINVAL;
insn_idx = rec->insn_off / BPF_INSN_SZ;
prog = find_prog_by_sec_insn(obj, sec_idx, insn_idx);
if (!prog) {
- pr_warn("sec '%s': failed to find program at insn #%d for CO-RE offset relocation #%d\n",
- sec_name, insn_idx, i);
- err = -EINVAL;
- goto out;
+ /* When __weak subprog is "overridden" by another instance
+ * of the subprog from a different object file, linker still
+ * appends all the .BTF.ext info that used to belong to that
+ * eliminated subprogram.
+ * This is similar to what x86-64 linker does for relocations.
+ * So just ignore such relocations just like we ignore
+ * subprog instructions when discovering subprograms.
+ */
+ pr_debug("sec '%s': skipping CO-RE relocation #%d for insn #%d belonging to eliminated weak subprogram\n",
+ sec_name, i, insn_idx);
+ continue;
}
/* no need to apply CO-RE relocation if the program is
* not going to be loaded
*/
- if (!prog->load)
+ if (!prog->autoload)
+ continue;
+
+ /* adjust insn_idx from section frame of reference to the local
+ * program's frame of reference; (sub-)program code is not yet
+ * relocated, so it's enough to just subtract in-section offset
+ */
+ insn_idx = insn_idx - prog->sec_insn_off;
+ if (insn_idx >= prog->insns_cnt)
+ return -EINVAL;
+ insn = &prog->insns[insn_idx];
+
+ err = record_relo_core(prog, rec, insn_idx);
+ if (err) {
+ pr_warn("prog '%s': relo #%d: failed to record relocation: %d\n",
+ prog->name, i, err);
+ goto out;
+ }
+
+ if (prog->obj->gen_loader)
continue;
- err = bpf_core_apply_relo(prog, rec, i, obj->btf, cand_cache);
+ err = bpf_core_resolve_relo(prog, rec, i, obj->btf, cand_cache, &targ_res);
if (err) {
pr_warn("prog '%s': relo #%d: failed to relocate: %d\n",
prog->name, i, err);
goto out;
}
+
+ err = bpf_core_patch_insn(prog->name, insn, insn_idx, rec, i, &targ_res);
+ if (err) {
+ pr_warn("prog '%s': relo #%d: failed to patch insn #%u: %d\n",
+ prog->name, i, insn_idx, err);
+ goto out;
+ }
}
}
@@ -5684,6 +5845,36 @@ out:
return err;
}
+/* base map load ldimm64 special constant, used also for log fixup logic */
+#define MAP_LDIMM64_POISON_BASE 2001000000
+#define MAP_LDIMM64_POISON_PFX "200100"
+
+static void poison_map_ldimm64(struct bpf_program *prog, int relo_idx,
+ int insn_idx, struct bpf_insn *insn,
+ int map_idx, const struct bpf_map *map)
+{
+ int i;
+
+ pr_debug("prog '%s': relo #%d: poisoning insn #%d that loads map #%d '%s'\n",
+ prog->name, relo_idx, insn_idx, map_idx, map->name);
+
+ /* we turn single ldimm64 into two identical invalid calls */
+ for (i = 0; i < 2; i++) {
+ insn->code = BPF_JMP | BPF_CALL;
+ insn->dst_reg = 0;
+ insn->src_reg = 0;
+ insn->off = 0;
+ /* if this instruction is reachable (not a dead code),
+ * verifier will complain with something like:
+ * invalid func unknown#2001000123
+ * where lower 123 is map index into obj->maps[] array
+ */
+ insn->imm = MAP_LDIMM64_POISON_BASE + map_idx;
+
+ insn++;
+ }
+}
+
/* Relocate data references within program code:
* - map references;
* - global variable references;
@@ -5697,33 +5888,35 @@ bpf_object__relocate_data(struct bpf_object *obj, struct bpf_program *prog)
for (i = 0; i < prog->nr_reloc; i++) {
struct reloc_desc *relo = &prog->reloc_desc[i];
struct bpf_insn *insn = &prog->insns[relo->insn_idx];
+ const struct bpf_map *map;
struct extern_desc *ext;
switch (relo->type) {
case RELO_LD64:
+ map = &obj->maps[relo->map_idx];
if (obj->gen_loader) {
insn[0].src_reg = BPF_PSEUDO_MAP_IDX;
insn[0].imm = relo->map_idx;
- } else {
+ } else if (map->autocreate) {
insn[0].src_reg = BPF_PSEUDO_MAP_FD;
- insn[0].imm = obj->maps[relo->map_idx].fd;
+ insn[0].imm = map->fd;
+ } else {
+ poison_map_ldimm64(prog, i, relo->insn_idx, insn,
+ relo->map_idx, map);
}
break;
case RELO_DATA:
+ map = &obj->maps[relo->map_idx];
insn[1].imm = insn[0].imm + relo->sym_off;
if (obj->gen_loader) {
insn[0].src_reg = BPF_PSEUDO_MAP_IDX_VALUE;
insn[0].imm = relo->map_idx;
- } else {
- const struct bpf_map *map = &obj->maps[relo->map_idx];
-
- if (map->skipped) {
- pr_warn("prog '%s': relo #%d: kernel doesn't support global data\n",
- prog->name, i);
- return -ENOTSUP;
- }
+ } else if (map->autocreate) {
insn[0].src_reg = BPF_PSEUDO_MAP_VALUE;
- insn[0].imm = obj->maps[relo->map_idx].fd;
+ insn[0].imm = map->fd;
+ } else {
+ poison_map_ldimm64(prog, i, relo->insn_idx, insn,
+ relo->map_idx, map);
}
break;
case RELO_EXTERN_VAR:
@@ -5793,14 +5986,13 @@ static int adjust_prog_btf_ext_info(const struct bpf_object *obj,
void *rec, *rec_end, *new_prog_info;
const struct btf_ext_info_sec *sec;
size_t old_sz, new_sz;
- const char *sec_name;
- int i, off_adj;
+ int i, sec_num, sec_idx, off_adj;
+ sec_num = 0;
for_each_btf_ext_sec(ext_info, sec) {
- sec_name = btf__name_by_offset(obj->btf, sec->sec_name_off);
- if (!sec_name)
- return -EINVAL;
- if (strcmp(sec_name, prog->sec_name) != 0)
+ sec_idx = ext_info->sec_idxs[sec_num];
+ sec_num++;
+ if (prog->sec_idx != sec_idx)
continue;
for_each_btf_ext_rec(ext_info, sec, i, rec) {
@@ -6195,7 +6387,6 @@ bpf_object__relocate_calls(struct bpf_object *obj, struct bpf_program *prog)
if (err)
return err;
-
return 0;
}
@@ -6256,8 +6447,7 @@ bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path)
err);
return err;
}
- if (obj->gen_loader)
- bpf_object__sort_relos(obj);
+ bpf_object__sort_relos(obj);
}
/* Before relocating calls pre-process relocations and mark
@@ -6293,7 +6483,7 @@ bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path)
*/
if (prog_is_subprog(obj, prog))
continue;
- if (!prog->load)
+ if (!prog->autoload)
continue;
err = bpf_object__relocate_calls(obj, prog);
@@ -6308,7 +6498,7 @@ bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path)
prog = &obj->programs[i];
if (prog_is_subprog(obj, prog))
continue;
- if (!prog->load)
+ if (!prog->autoload)
continue;
err = bpf_object__relocate_data(obj, prog);
if (err) {
@@ -6317,8 +6507,7 @@ bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path)
return err;
}
}
- if (!obj->gen_loader)
- bpf_object__free_relocs(obj);
+
return 0;
}
@@ -6549,9 +6738,9 @@ static int bpf_object__sanitize_prog(struct bpf_object *obj, struct bpf_program
static int libbpf_find_attach_btf_id(struct bpf_program *prog, const char *attach_name,
int *btf_obj_fd, int *btf_type_id);
-/* this is called as prog->sec_def->preload_fn for libbpf-supported sec_defs */
-static int libbpf_preload_prog(struct bpf_program *prog,
- struct bpf_prog_load_opts *opts, long cookie)
+/* this is called as prog->sec_def->prog_prepare_load_fn for libbpf-supported sec_defs */
+static int libbpf_prepare_prog_load(struct bpf_program *prog,
+ struct bpf_prog_load_opts *opts, long cookie)
{
enum sec_def_flags def = cookie;
@@ -6562,13 +6751,35 @@ static int libbpf_preload_prog(struct bpf_program *prog,
if (def & SEC_SLEEPABLE)
opts->prog_flags |= BPF_F_SLEEPABLE;
- if ((prog->type == BPF_PROG_TYPE_TRACING ||
- prog->type == BPF_PROG_TYPE_LSM ||
- prog->type == BPF_PROG_TYPE_EXT) && !prog->attach_btf_id) {
+ if (prog->type == BPF_PROG_TYPE_XDP && (def & SEC_XDP_FRAGS))
+ opts->prog_flags |= BPF_F_XDP_HAS_FRAGS;
+
+ if (def & SEC_DEPRECATED) {
+ pr_warn("SEC(\"%s\") is deprecated, please see https://github.com/libbpf/libbpf/wiki/Libbpf-1.0-migration-guide#bpf-program-sec-annotation-deprecations for details\n",
+ prog->sec_name);
+ }
+
+ if ((def & SEC_ATTACH_BTF) && !prog->attach_btf_id) {
int btf_obj_fd = 0, btf_type_id = 0, err;
const char *attach_name;
- attach_name = str