From: Andrii Nakryiko andrii@kernel.org
mainline inclusion from mainline-5.11-rc1 commit cecaf4a0f2dcbd7e76156f6d63748b84c176b95b category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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Display vmlinux BTF name and kernel module names when listing available BTFs on the system.
In human-readable output mode, module BTFs are reported with "name [module-name]", while vmlinux BTF will be reported as "name [vmlinux]". Square brackets are added by bpftool and follow kernel convention when displaying modules in human-readable text outputs.
[vmuser@archvm bpf]$ sudo ../../../bpf/bpftool/bpftool btf s 1: name [vmlinux] size 4082281B 6: size 2365B prog_ids 8,6 map_ids 3 7: name [button] size 46895B 8: name [pcspkr] size 42328B 9: name [serio_raw] size 39375B 10: name [floppy] size 57185B 11: name [i2c_core] size 76186B 12: name [crc32c_intel] size 16036B 13: name [i2c_piix4] size 50497B 14: name [irqbypass] size 14124B 15: name [kvm] size 197985B 16: name [kvm_intel] size 123564B 17: name [cryptd] size 42466B 18: name [crypto_simd] size 17187B 19: name [glue_helper] size 39205B 20: name [aesni_intel] size 41034B 25: size 36150B pids bpftool(2519)
In JSON mode, two fields (boolean "kernel" and string "name") are reported for each BTF object. vmlinux BTF is reported with name "vmlinux" (kernel itself returns and empty name for vmlinux BTF).
[vmuser@archvm bpf]$ sudo ../../../bpf/bpftool/bpftool btf s -jp [{ "id": 1, "size": 4082281, "prog_ids": [], "map_ids": [], "kernel": true, "name": "vmlinux" },{ "id": 6, "size": 2365, "prog_ids": [8,6 ], "map_ids": [3 ], "kernel": false },{ "id": 7, "size": 46895, "prog_ids": [], "map_ids": [], "kernel": true, "name": "button" },{
...
Signed-off-by: Andrii Nakryiko andrii@kernel.org Signed-off-by: Alexei Starovoitov ast@kernel.org Tested-by: Alan Maguire alan.maguire@oracle.com Link: https://lore.kernel.org/bpf/20201110011932.3201430-6-andrii@kernel.org (cherry picked from commit cecaf4a0f2dcbd7e76156f6d63748b84c176b95b) Signed-off-by: Wang Yufen wangyufen@huawei.com --- tools/bpf/bpftool/btf.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-)
diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c index 112797055117..3dc13419a2df 100644 --- a/tools/bpf/bpftool/btf.c +++ b/tools/bpf/bpftool/btf.c @@ -746,9 +746,14 @@ show_btf_plain(struct bpf_btf_info *info, int fd, struct btf_attach_table *btf_map_table) { struct btf_attach_point *obj; + const char *name = u64_to_ptr(info->name); int n;
printf("%u: ", info->id); + if (info->kernel_btf) + printf("name [%s] ", name); + else if (name && name[0]) + printf("name %s ", name); printf("size %uB", info->btf_size);
n = 0; @@ -775,6 +780,7 @@ show_btf_json(struct bpf_btf_info *info, int fd, struct btf_attach_table *btf_map_table) { struct btf_attach_point *obj; + const char *name = u64_to_ptr(info->name);
jsonw_start_object(json_wtr); /* btf object */ jsonw_uint_field(json_wtr, "id", info->id); @@ -800,6 +806,11 @@ show_btf_json(struct bpf_btf_info *info, int fd,
emit_obj_refs_json(&refs_table, info->id, json_wtr); /* pids */
+ jsonw_bool_field(json_wtr, "kernel", info->kernel_btf); + + if (name && name[0]) + jsonw_string_field(json_wtr, "name", name); + jsonw_end_object(json_wtr); /* btf object */ }
@@ -807,15 +818,30 @@ static int show_btf(int fd, struct btf_attach_table *btf_prog_table, struct btf_attach_table *btf_map_table) { - struct bpf_btf_info info = {}; + struct bpf_btf_info info; __u32 len = sizeof(info); + char name[64]; int err;
+ memset(&info, 0, sizeof(info)); err = bpf_obj_get_info_by_fd(fd, &info, &len); if (err) { p_err("can't get BTF object info: %s", strerror(errno)); return -1; } + /* if kernel support emitting BTF object name, pass name pointer */ + if (info.name_len) { + memset(&info, 0, sizeof(info)); + info.name_len = sizeof(name); + info.name = ptr_to_u64(name); + len = sizeof(info); + + err = bpf_obj_get_info_by_fd(fd, &info, &len); + if (err) { + p_err("can't get BTF object info: %s", strerror(errno)); + return -1; + } + }
if (json_output) show_btf_json(&info, fd, btf_prog_table, btf_map_table);