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-rw-r--r--tools/lib/bpf/bpf_helpers.h1
-rw-r--r--tools/lib/bpf/libbpf.c281
-rw-r--r--tools/testing/selftests/bpf/prog_tests/btf_map_in_map.c49
-rw-r--r--tools/testing/selftests/bpf/progs/test_btf_map_in_map.c76
4 files changed, 384 insertions, 23 deletions
diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
index 60aad054eea1..da00b87aa199 100644
--- a/tools/lib/bpf/bpf_helpers.h
+++ b/tools/lib/bpf/bpf_helpers.h
@@ -12,6 +12,7 @@
#define __uint(name, val) int (*name)[val]
#define __type(name, val) typeof(val) *name
+#define __array(name, val) typeof(val) *name[]
/* Helper macro to print out debug messages */
#define bpf_printk(fmt, ...) \
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 9c845cf4cfcf..445ee903f9cd 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -310,6 +310,7 @@ struct bpf_map {
int map_ifindex;
int inner_map_fd;
struct bpf_map_def def;
+ __u32 btf_var_idx;
__u32 btf_key_type_id;
__u32 btf_value_type_id;
__u32 btf_vmlinux_value_type_id;
@@ -318,6 +319,9 @@ struct bpf_map {
enum libbpf_map_type libbpf_type;
void *mmaped;
struct bpf_struct_ops *st_ops;
+ struct bpf_map *inner_map;
+ void **init_slots;
+ int init_slots_sz;
char *pin_path;
bool pinned;
bool reused;
@@ -389,6 +393,7 @@ struct bpf_object {
int nr_reloc_sects;
int maps_shndx;
int btf_maps_shndx;
+ __u32 btf_maps_sec_btf_id;
int text_shndx;
int symbols_shndx;
int data_shndx;
@@ -1918,7 +1923,7 @@ static int build_map_pin_path(struct bpf_map *map, const char *path)
static int parse_btf_map_def(struct bpf_object *obj,
struct bpf_map *map,
const struct btf_type *def,
- bool strict,
+ bool strict, bool is_inner,
const char *pin_root_path)
{
const struct btf_type *t;
@@ -2036,10 +2041,79 @@ static int parse_btf_map_def(struct bpf_object *obj,
}
map->def.value_size = sz;
map->btf_value_type_id = t->type;
+ }
+ else if (strcmp(name, "values") == 0) {
+ int err;
+
+ if (is_inner) {
+ pr_warn("map '%s': multi-level inner maps not supported.\n",
+ map->name);
+ return -ENOTSUP;
+ }
+ if (i != vlen - 1) {
+ pr_warn("map '%s': '%s' member should be last.\n",
+ map->name, name);
+ return -EINVAL;
+ }
+ if (!bpf_map_type__is_map_in_map(map->def.type)) {
+ pr_warn("map '%s': should be map-in-map.\n",
+ map->name);
+ return -ENOTSUP;
+ }
+ if (map->def.value_size && map->def.value_size != 4) {
+ pr_warn("map '%s': conflicting value size %u != 4.\n",
+ map->name, map->def.value_size);
+ return -EINVAL;
+ }
+ map->def.value_size = 4;
+ t = btf__type_by_id(obj->btf, m->type);
+ if (!t) {
+ pr_warn("map '%s': map-in-map inner type [%d] not found.\n",
+ map->name, m->type);
+ return -EINVAL;
+ }
+ if (!btf_is_array(t) || btf_array(t)->nelems) {
+ pr_warn("map '%s': map-in-map inner spec is not a zero-sized array.\n",
+ map->name);
+ return -EINVAL;
+ }
+ t = skip_mods_and_typedefs(obj->btf, btf_array(t)->type,
+ NULL);
+ if (!btf_is_ptr(t)) {
+ pr_warn("map '%s': map-in-map inner def is of unexpected kind %u.\n",
+ map->name, btf_kind(t));
+ return -EINVAL;
+ }
+ t = skip_mods_and_typedefs(obj->btf, t->type, NULL);
+ if (!btf_is_struct(t)) {
+ pr_warn("map '%s': map-in-map inner def is of unexpected kind %u.\n",
+ map->name, btf_kind(t));
+ return -EINVAL;
+ }
+
+ map->inner_map = calloc(1, sizeof(*map->inner_map));
+ if (!map->inner_map)
+ return -ENOMEM;
+ map->inner_map->sec_idx = obj->efile.btf_maps_shndx;
+ map->inner_map->name = malloc(strlen(map->name) +
+ sizeof(".inner") + 1);
+ if (!map->inner_map->name)
+ return -ENOMEM;
+ sprintf(map->inner_map->name, "%s.inner", map->name);
+
+ err = parse_btf_map_def(obj, map->inner_map, t, strict,
+ true /* is_inner */, NULL);
+ if (err)
+ return err;
} else if (strcmp(name, "pinning") == 0) {
__u32 val;
int err;
+ if (is_inner) {
+ pr_debug("map '%s': inner def can't be pinned.\n",
+ map->name);
+ return -EINVAL;
+ }
if (!get_map_field_int(map->name, obj->btf, m, &val))
return -EINVAL;
pr_debug("map '%s': found pinning = %u.\n",
@@ -2138,10 +2212,11 @@ static int bpf_object__init_user_btf_map(struct bpf_object *obj,
map->def.type = BPF_MAP_TYPE_UNSPEC;
map->sec_idx = sec_idx;
map->sec_offset = vi->offset;
+ map->btf_var_idx = var_idx;
pr_debug("map '%s': at sec_idx %d, offset %zu.\n",
map_name, map->sec_idx, map->sec_offset);
- return parse_btf_map_def(obj, map, def, strict, pin_root_path);
+ return parse_btf_map_def(obj, map, def, strict, false, pin_root_path);
}
static int bpf_object__init_user_btf_maps(struct bpf_object *obj, bool strict,
@@ -2174,6 +2249,7 @@ static int bpf_object__init_user_btf_maps(struct bpf_object *obj, bool strict,
name = btf__name_by_offset(obj->btf, t->name_off);
if (strcmp(name, MAPS_ELF_SEC) == 0) {
sec = t;
+ obj->efile.btf_maps_sec_btf_id = i;
break;
}
}
@@ -2560,7 +2636,8 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
/* Only do relo for section with exec instructions */
if (!section_have_execinstr(obj, sec) &&
- strcmp(name, ".rel" STRUCT_OPS_SEC)) {
+ strcmp(name, ".rel" STRUCT_OPS_SEC) &&
+ strcmp(name, ".rel" MAPS_ELF_SEC)) {
pr_debug("skip relo %s(%d) for section(%d)\n",
name, idx, sec);
continue;
@@ -3538,6 +3615,22 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map)
create_attr.btf_value_type_id = map->btf_value_type_id;
}
+ if (bpf_map_type__is_map_in_map(def->type)) {
+ if (map->inner_map) {
+ int err;
+
+ err = bpf_object__create_map(obj, map->inner_map);
+ if (err) {
+ pr_warn("map '%s': failed to create inner map: %d\n",
+ map->name, err);
+ return err;
+ }
+ map->inner_map_fd = bpf_map__fd(map->inner_map);
+ }
+ if (map->inner_map_fd >= 0)
+ create_attr.inner_map_fd = map->inner_map_fd;
+ }
+
map->fd = bpf_create_map_xattr(&create_attr);
if (map->fd < 0 && (create_attr.btf_key_type_id ||
create_attr.btf_value_type_id)) {
@@ -3558,6 +3651,11 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map)
if (map->fd < 0)
return -errno;
+ if (bpf_map_type__is_map_in_map(def->type) && map->inner_map) {
+ bpf_map__destroy(map->inner_map);
+ zfree(&map->inner_map);
+ }
+
return 0;
}
@@ -3602,6 +3700,31 @@ bpf_object__create_maps(struct bpf_object *obj)
}
}
+ if (map->init_slots_sz) {
+ for (j = 0; j < map->init_slots_sz; j++) {
+ const struct bpf_map *targ_map;
+ int fd;
+
+ if (!map->init_slots[j])
+ continue;
+
+ targ_map = map->init_slots[j];
+ fd = bpf_map__fd(targ_map);
+ err = bpf_map_update_elem(map->fd, &j, &fd, 0);
+ if (err) {
+ err = -errno;
+ pr_warn("map '%s': failed to initialize slot [%d] to map '%s' fd=%d: %d\n",
+ map->name, j, targ_map->name,
+ fd, err);
+ goto err_out;
+ }
+ pr_debug("map '%s': slot [%d] set to map '%s' fd=%d\n",
+ map->name, j, targ_map->name, fd);
+ }
+ zfree(&map->init_slots);
+ map->init_slots_sz = 0;
+ }
+
if (map->pin_path && !map->pinned) {
err = bpf_map__pin(map, NULL);
if (err) {
@@ -4873,9 +4996,118 @@ bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path)
return 0;
}
-static int bpf_object__collect_struct_ops_map_reloc(struct bpf_object *obj,
- GElf_Shdr *shdr,
- Elf_Data *data);
+static int bpf_object__collect_st_ops_relos(struct bpf_object *obj,
+ GElf_Shdr *shdr, Elf_Data *data);
+
+static int bpf_object__collect_map_relos(struct bpf_object *obj,
+ GElf_Shdr *shdr, Elf_Data *data)
+{
+ int i, j, nrels, new_sz, ptr_sz = sizeof(void *);
+ const struct btf_type *sec, *var, *def;
+ const struct btf_var_secinfo *vi;
+ const struct btf_member *member;
+ struct bpf_map *map, *targ_map;
+ const char *name, *mname;
+ Elf_Data *symbols;
+ unsigned int moff;
+ GElf_Sym sym;
+ GElf_Rel rel;
+ void *tmp;
+
+ if (!obj->efile.btf_maps_sec_btf_id || !obj->btf)
+ return -EINVAL;
+ sec = btf__type_by_id(obj->btf, obj->efile.btf_maps_sec_btf_id);
+ if (!sec)
+ return -EINVAL;
+
+ symbols = obj->efile.symbols;
+ nrels = shdr->sh_size / shdr->sh_entsize;
+ for (i = 0; i < nrels; i++) {
+ if (!gelf_getrel(data, i, &rel)) {
+ pr_warn(".maps relo #%d: failed to get ELF relo\n", i);
+ return -LIBBPF_ERRNO__FORMAT;
+ }
+ if (!gelf_getsym(symbols, GELF_R_SYM(rel.r_info), &sym)) {
+ pr_warn(".maps relo #%d: symbol %zx not found\n",
+ i, (size_t)GELF_R_SYM(rel.r_info));
+ return -LIBBPF_ERRNO__FORMAT;
+ }
+ name = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
+ sym.st_name) ? : "<?>";
+ if (sym.st_shndx != obj->efile.btf_maps_shndx) {
+ pr_warn(".maps relo #%d: '%s' isn't a BTF-defined map\n",
+ i, name);
+ return -LIBBPF_ERRNO__RELOC;
+ }
+
+ pr_debug(".maps relo #%d: for %zd value %zd rel.r_offset %zu name %d ('%s')\n",
+ i, (ssize_t)(rel.r_info >> 32), (size_t)sym.st_value,
+ (size_t)rel.r_offset, sym.st_name, name);
+
+ for (j = 0; j < obj->nr_maps; j++) {
+ map = &obj->maps[j];
+ if (map->sec_idx != obj->efile.btf_maps_shndx)
+ continue;
+
+ vi = btf_var_secinfos(sec) + map->btf_var_idx;
+ if (vi->offset <= rel.r_offset &&
+ rel.r_offset + sizeof(void *) <= vi->offset + vi->size)
+ break;
+ }
+ if (j == obj->nr_maps) {
+ pr_warn(".maps relo #%d: cannot find map '%s' at rel.r_offset %zu\n",
+ i, name, (size_t)rel.r_offset);
+ return -EINVAL;
+ }
+
+ if (!bpf_map_type__is_map_in_map(map->def.type))
+ return -EINVAL;
+ if (map->def.type == BPF_MAP_TYPE_HASH_OF_MAPS &&
+ map->def.key_size != sizeof(int)) {
+ pr_warn(".maps relo #%d: hash-of-maps '%s' should have key size %zu.\n",
+ i, map->name, sizeof(int));
+ return -EINVAL;
+ }
+
+ targ_map = bpf_object__find_map_by_name(obj, name);
+ if (!targ_map)
+ return -ESRCH;
+
+ var = btf__type_by_id(obj->btf, vi->type);
+ def = skip_mods_and_typedefs(obj->btf, var->type, NULL);
+ if (btf_vlen(def) == 0)
+ return -EINVAL;
+ member = btf_members(def) + btf_vlen(def) - 1;
+ mname = btf__name_by_offset(obj->btf, member->name_off);
+ if (strcmp(mname, "values"))
+ return -EINVAL;
+
+ moff = btf_member_bit_offset(def, btf_vlen(def) - 1) / 8;
+ if (rel.r_offset - vi->offset < moff)
+ return -EINVAL;
+
+ moff = rel.r_offset - vi->offset - moff;
+ if (moff % ptr_sz)
+ return -EINVAL;
+ moff /= ptr_sz;
+ if (moff >= map->init_slots_sz) {
+ new_sz = moff + 1;
+ tmp = realloc(map->init_slots, new_sz * ptr_sz);
+ if (!tmp)
+ return -ENOMEM;
+ map->init_slots = tmp;
+ memset(map->init_slots + map->init_slots_sz, 0,
+ (new_sz - map->init_slots_sz) * ptr_sz);
+ map->init_slots_sz = new_sz;
+ }
+ map->init_slots[moff] = targ_map;
+
+ pr_debug(".maps relo #%d: map '%s' slot [%d] points to map '%s'\n",
+ i, map->name, moff, name);
+ }
+
+ return 0;
+}
static int bpf_object__collect_reloc(struct bpf_object *obj)
{
@@ -4898,21 +5130,17 @@ static int bpf_object__collect_reloc(struct bpf_object *obj)
}
if (idx == obj->efile.st_ops_shndx) {
- err = bpf_object__collect_struct_ops_map_reloc(obj,
- shdr,
- data);
- if (err)
- return err;
- continue;
- }
-
- prog = bpf_object__find_prog_by_idx(obj, idx);
- if (!prog) {
- pr_warn("relocation failed: no section(%d)\n", idx);
- return -LIBBPF_ERRNO__RELOC;
+ err = bpf_object__collect_st_ops_relos(obj, shdr, data);
+ } else if (idx == obj->efile.btf_maps_shndx) {
+ err = bpf_object__collect_map_relos(obj, shdr, data);
+ } else {
+ prog = bpf_object__find_prog_by_idx(obj, idx);
+ if (!prog) {
+ pr_warn("relocation failed: no prog in section(%d)\n", idx);
+ return -LIBBPF_ERRNO__RELOC;
+ }
+ err = bpf_program__collect_reloc(prog, shdr, data, obj);
}
-
- err = bpf_program__collect_reloc(prog, shdr, data, obj);
if (err)
return err;
}
@@ -5984,6 +6212,14 @@ static void bpf_map__destroy(struct bpf_map *map)
map->priv = NULL;
map->clear_priv = NULL;
+ if (map->inner_map) {
+ bpf_map__destroy(map->inner_map);
+ zfree(&map->inner_map);
+ }
+
+ zfree(&map->init_slots);
+ map->init_slots_sz = 0;
+
if (map->mmaped) {
munmap(map->mmaped, bpf_map_mmap_sz(map));
map->mmaped = NULL;
@@ -6543,9 +6779,8 @@ static struct bpf_map *find_struct_ops_map_by_offset(struct bpf_object *obj,
}
/* Collect the reloc from ELF and populate the st_ops->progs[] */
-static int bpf_object__collect_struct_ops_map_reloc(struct bpf_object *obj,
- GElf_Shdr *shdr,
- Elf_Data *data)
+static int bpf_object__collect_st_ops_relos(struct bpf_object *obj,
+ GElf_Shdr *shdr, Elf_Data *data)
{
const struct btf_member *member;
struct bpf_struct_ops *st_ops;
diff --git a/tools/testing/selftests/bpf/prog_tests/btf_map_in_map.c b/tools/testing/selftests/bpf/prog_tests/btf_map_in_map.c
new file mode 100644
index 000000000000..f7ee8fa377ad
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/btf_map_in_map.c
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+
+#include <test_progs.h>
+
+#include "test_btf_map_in_map.skel.h"
+
+void test_btf_map_in_map(void)
+{
+ int duration = 0, err, key = 0, val;
+ struct test_btf_map_in_map* skel;
+
+ skel = test_btf_map_in_map__open_and_load();
+ if (CHECK(!skel, "skel_open", "failed to open&load skeleton\n"))
+ return;
+
+ err = test_btf_map_in_map__attach(skel);
+ if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err))
+ goto cleanup;
+
+ /* inner1 = input, inner2 = input + 1 */
+ val = bpf_map__fd(skel->maps.inner_map1);
+ bpf_map_update_elem(bpf_map__fd(skel->maps.outer_arr), &key, &val, 0);
+ val = bpf_map__fd(skel->maps.inner_map2);
+ bpf_map_update_elem(bpf_map__fd(skel->maps.outer_hash), &key, &val, 0);
+ skel->bss->input = 1;
+ usleep(1);
+
+ bpf_map_lookup_elem(bpf_map__fd(skel->maps.inner_map1), &key, &val);
+ CHECK(val != 1, "inner1", "got %d != exp %d\n", val, 1);
+ bpf_map_lookup_elem(bpf_map__fd(skel->maps.inner_map2), &key, &val);
+ CHECK(val != 2, "inner2", "got %d != exp %d\n", val, 2);
+
+ /* inner1 = input + 1, inner2 = input */
+ val = bpf_map__fd(skel->maps.inner_map2);
+ bpf_map_update_elem(bpf_map__fd(skel->maps.outer_arr), &key, &val, 0);
+ val = bpf_map__fd(skel->maps.inner_map1);
+ bpf_map_update_elem(bpf_map__fd(skel->maps.outer_hash), &key, &val, 0);
+ skel->bss->input = 3;
+ usleep(1);
+
+ bpf_map_lookup_elem(bpf_map__fd(skel->maps.inner_map1), &key, &val);
+ CHECK(val != 4, "inner1", "got %d != exp %d\n", val, 4);
+ bpf_map_lookup_elem(bpf_map__fd(skel->maps.inner_map2), &key, &val);
+ CHECK(val != 3, "inner2", "got %d != exp %d\n", val, 3);
+
+cleanup:
+ test_btf_map_in_map__destroy(skel);
+}
diff --git a/tools/testing/selftests/bpf/progs/test_btf_map_in_map.c b/tools/testing/selftests/bpf/progs/test_btf_map_in_map.c
new file mode 100644
index 000000000000..e5093796be97
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_btf_map_in_map.c
@@ -0,0 +1,76 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2020 Facebook */
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+struct inner_map {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __uint(max_entries, 1);
+ __type(key, int);
+ __type(value, int);
+} inner_map1 SEC(".maps"),
+ inner_map2 SEC(".maps");
+
+struct outer_arr {
+ __uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
+ __uint(max_entries, 3);
+ __uint(key_size, sizeof(int));
+ __uint(value_size, sizeof(int));
+ /* it's possible to use anonymous struct as inner map definition here */
+ __array(values, struct {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ /* changing max_entries to 2 will fail during load
+ * due to incompatibility with inner_map definition */
+ __uint(max_entries, 1);
+ __type(key, int);
+ __type(value, int);
+ });
+} outer_arr SEC(".maps") = {
+ /* (void *) cast is necessary because we didn't use `struct inner_map`
+ * in __inner(values, ...)
+ * Actually, a conscious effort is required to screw up initialization
+ * of inner map slots, which is a great thing!
+ */
+ .values = { (void *)&inner_map1, 0, (void *)&inner_map2 },
+};
+
+struct outer_hash {
+ __uint(type, BPF_MAP_TYPE_HASH_OF_MAPS);
+ __uint(max_entries, 5);
+ __uint(key_size, sizeof(int));
+ /* Here everything works flawlessly due to reuse of struct inner_map
+ * and compiler will complain at the attempt to use non-inner_map
+ * references below. This is great experience.
+ */
+ __array(values, struct inner_map);
+} outer_hash SEC(".maps") = {
+ .values = {
+ [0] = &inner_map2,
+ [4] = &inner_map1,
+ },
+};
+
+int input = 0;
+
+SEC("raw_tp/sys_enter")
+int handle__sys_enter(void *ctx)
+{
+ struct inner_map *inner_map;
+ int key = 0, val;
+
+ inner_map = bpf_map_lookup_elem(&outer_arr, &key);
+ if (!inner_map)
+ return 1;
+ val = input;
+ bpf_map_update_elem(inner_map, &key, &val, 0);
+
+ inner_map = bpf_map_lookup_elem(&outer_hash, &key);
+ if (!inner_map)
+ return 1;
+ val = input + 1;
+ bpf_map_update_elem(inner_map, &key, &val, 0);
+
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
generated by cgit v1.2.3 (git 2.39.0) at 2024-10-08 01:14:47 +0300