summaryrefslogtreecommitdiff
path: root/tools/lib/bpf/libbpf.c
diff options
context:
space:
mode:
Diffstat (limited to 'tools/lib/bpf/libbpf.c')
-rw-r--r--tools/lib/bpf/libbpf.c118
1 files changed, 96 insertions, 22 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 8f5a81b672e1..dd3b2f57082d 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -50,7 +50,6 @@
#include "libbpf.h"
#include "bpf.h"
#include "btf.h"
-#include "str_error.h"
#include "libbpf_internal.h"
#include "hashmap.h"
#include "bpf_gen_internal.h"
@@ -318,8 +317,6 @@ static void pr_perm_msg(int err)
buf);
}
-#define STRERR_BUFSIZE 128
-
/* Copied from tools/perf/util/util.h */
#ifndef zfree
# define zfree(ptr) ({ free(*ptr); *ptr = NULL; })
@@ -496,6 +493,7 @@ struct bpf_program {
__u32 line_info_rec_size;
__u32 line_info_cnt;
__u32 prog_flags;
+ __u8 hash[SHA256_DIGEST_LENGTH];
};
struct bpf_struct_ops {
@@ -575,6 +573,7 @@ struct bpf_map {
bool autocreate;
bool autoattach;
__u64 map_extra;
+ struct bpf_program *excl_prog;
};
enum extern_type {
@@ -1013,35 +1012,33 @@ find_struct_ops_kern_types(struct bpf_object *obj, const char *tname_raw,
const struct btf_member *kern_data_member;
struct btf *btf = NULL;
__s32 kern_vtype_id, kern_type_id;
- char tname[256];
+ char tname[192], stname[256];
__u32 i;
snprintf(tname, sizeof(tname), "%.*s",
(int)bpf_core_essential_name_len(tname_raw), tname_raw);
- kern_type_id = find_ksym_btf_id(obj, tname, BTF_KIND_STRUCT,
- &btf, mod_btf);
- if (kern_type_id < 0) {
- pr_warn("struct_ops init_kern: struct %s is not found in kernel BTF\n",
- tname);
- return kern_type_id;
- }
- kern_type = btf__type_by_id(btf, kern_type_id);
+ snprintf(stname, sizeof(stname), "%s%s", STRUCT_OPS_VALUE_PREFIX, tname);
- /* Find the corresponding "map_value" type that will be used
- * in map_update(BPF_MAP_TYPE_STRUCT_OPS). For example,
- * find "struct bpf_struct_ops_tcp_congestion_ops" from the
- * btf_vmlinux.
+ /* Look for the corresponding "map_value" type that will be used
+ * in map_update(BPF_MAP_TYPE_STRUCT_OPS) first, figure out the btf
+ * and the mod_btf.
+ * For example, find "struct bpf_struct_ops_tcp_congestion_ops".
*/
- kern_vtype_id = find_btf_by_prefix_kind(btf, STRUCT_OPS_VALUE_PREFIX,
- tname, BTF_KIND_STRUCT);
+ kern_vtype_id = find_ksym_btf_id(obj, stname, BTF_KIND_STRUCT, &btf, mod_btf);
if (kern_vtype_id < 0) {
- pr_warn("struct_ops init_kern: struct %s%s is not found in kernel BTF\n",
- STRUCT_OPS_VALUE_PREFIX, tname);
+ pr_warn("struct_ops init_kern: struct %s is not found in kernel BTF\n", stname);
return kern_vtype_id;
}
kern_vtype = btf__type_by_id(btf, kern_vtype_id);
+ kern_type_id = btf__find_by_name_kind(btf, tname, BTF_KIND_STRUCT);
+ if (kern_type_id < 0) {
+ pr_warn("struct_ops init_kern: struct %s is not found in kernel BTF\n", tname);
+ return kern_type_id;
+ }
+ kern_type = btf__type_by_id(btf, kern_type_id);
+
/* Find "struct tcp_congestion_ops" from
* struct bpf_struct_ops_tcp_congestion_ops {
* [ ... ]
@@ -1054,8 +1051,8 @@ find_struct_ops_kern_types(struct bpf_object *obj, const char *tname_raw,
break;
}
if (i == btf_vlen(kern_vtype)) {
- pr_warn("struct_ops init_kern: struct %s data is not found in struct %s%s\n",
- tname, STRUCT_OPS_VALUE_PREFIX, tname);
+ pr_warn("struct_ops init_kern: struct %s data is not found in struct %s\n",
+ tname, stname);
return -EINVAL;
}
@@ -4485,6 +4482,44 @@ bpf_object__section_to_libbpf_map_type(const struct bpf_object *obj, int shndx)
}
}
+static int bpf_prog_compute_hash(struct bpf_program *prog)
+{
+ struct bpf_insn *purged;
+ int i, err = 0;
+
+ purged = calloc(prog->insns_cnt, BPF_INSN_SZ);
+ if (!purged)
+ return -ENOMEM;
+
+ /* If relocations have been done, the map_fd needs to be
+ * discarded for the digest calculation.
+ */
+ for (i = 0; i < prog->insns_cnt; i++) {
+ purged[i] = prog->insns[i];
+ if (purged[i].code == (BPF_LD | BPF_IMM | BPF_DW) &&
+ (purged[i].src_reg == BPF_PSEUDO_MAP_FD ||
+ purged[i].src_reg == BPF_PSEUDO_MAP_VALUE)) {
+ purged[i].imm = 0;
+ i++;
+ if (i >= prog->insns_cnt ||
+ prog->insns[i].code != 0 ||
+ prog->insns[i].dst_reg != 0 ||
+ prog->insns[i].src_reg != 0 ||
+ prog->insns[i].off != 0) {
+ err = -EINVAL;
+ goto out;
+ }
+ purged[i] = prog->insns[i];
+ purged[i].imm = 0;
+ }
+ }
+ libbpf_sha256(purged, prog->insns_cnt * sizeof(struct bpf_insn),
+ prog->hash);
+out:
+ free(purged);
+ return err;
+}
+
static int bpf_program__record_reloc(struct bpf_program *prog,
struct reloc_desc *reloc_desc,
__u32 insn_idx, const char *sym_name,
@@ -5093,6 +5128,16 @@ static bool map_is_reuse_compat(const struct bpf_map *map, int map_fd)
return false;
}
+ /*
+ * bpf_get_map_info_by_fd() for DEVMAP will always return flags with
+ * BPF_F_RDONLY_PROG set, but it generally is not set at map creation time.
+ * Thus, ignore the BPF_F_RDONLY_PROG flag in the flags returned from
+ * bpf_get_map_info_by_fd() when checking for compatibility with an
+ * existing DEVMAP.
+ */
+ if (map->def.type == BPF_MAP_TYPE_DEVMAP || map->def.type == BPF_MAP_TYPE_DEVMAP_HASH)
+ map_info.map_flags &= ~BPF_F_RDONLY_PROG;
+
return (map_info.type == map->def.type &&
map_info.key_size == map->def.key_size &&
map_info.value_size == map->def.value_size &&
@@ -5224,6 +5269,14 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b
create_attr.token_fd = obj->token_fd;
if (obj->token_fd)
create_attr.map_flags |= BPF_F_TOKEN_FD;
+ if (map->excl_prog) {
+ err = bpf_prog_compute_hash(map->excl_prog);
+ if (err)
+ return err;
+
+ create_attr.excl_prog_hash = map->excl_prog->hash;
+ create_attr.excl_prog_hash_size = SHA256_DIGEST_LENGTH;
+ }
if (bpf_map__is_struct_ops(map)) {
create_attr.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
@@ -10514,6 +10567,27 @@ int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd)
return 0;
}
+int bpf_map__set_exclusive_program(struct bpf_map *map, struct bpf_program *prog)
+{
+ if (map_is_created(map)) {
+ pr_warn("exclusive programs must be set before map creation\n");
+ return libbpf_err(-EINVAL);
+ }
+
+ if (map->obj != prog->obj) {
+ pr_warn("excl_prog and map must be from the same bpf object\n");
+ return libbpf_err(-EINVAL);
+ }
+
+ map->excl_prog = prog;
+ return 0;
+}
+
+struct bpf_program *bpf_map__exclusive_program(struct bpf_map *map)
+{
+ return map->excl_prog;
+}
+
static struct bpf_map *
__bpf_map__iter(const struct bpf_map *m, const struct bpf_object *obj, int i)
{
generated by cgit (git 2.34.1) at 2025-10-04 14:55:51 +0000