This patch added support to print function signature
if btf func_info is available. Note that ksym
now uses function name instead of prog_name as
prog_name has a limit of 16 bytes including
ending '\0'.
The following is a sample output for selftests
test_btf with file test_btf_haskv.o:
$ bpftool prog dump jited id 1
int _dummy_tracepoint(struct dummy_tracepoint_args * ):
bpf_prog_b07ccb89267cf242__dummy_tracepoint:
0: push %rbp
1: mov %rsp,%rbp
......
3c: add $0x28,%rbp
40: leaveq
41: retq
int test_long_fname_1(struct dummy_tracepoint_args * ):
bpf_prog_2dcecc18072623fc_test_long_fname_1:
0: push %rbp
1: mov %rsp,%rbp
......
3a: add $0x28,%rbp
3e: leaveq
3f: retq
int test_long_fname_2(struct dummy_tracepoint_args * ):
bpf_prog_89d64e4abf0f0126_test_long_fname_2:
0: push %rbp
1: mov %rsp,%rbp
......
80: add $0x28,%rbp
84: leaveq
85: retq
Signed-off-by: Yonghong Song <y...@fb.com>
---
tools/bpf/bpftool/btf_dumper.c | 96 ++++++++++++++++++++++++++++++++++
tools/bpf/bpftool/main.h | 2 +
tools/bpf/bpftool/prog.c | 54 +++++++++++++++++++
3 files changed, 152 insertions(+)
diff --git a/tools/bpf/bpftool/btf_dumper.c b/tools/bpf/bpftool/btf_dumper.c
index 55bc512a1831..a31df4202335 100644
--- a/tools/bpf/bpftool/btf_dumper.c
+++ b/tools/bpf/bpftool/btf_dumper.c
@@ -249,3 +249,99 @@ int btf_dumper_type(const struct btf_dumper *d, __u32
type_id,
{
return btf_dumper_do_type(d, type_id, 0, data);
}
+
+#define BTF_PRINT_STRING(str) \
+ { \
+ pos += snprintf(func_sig + pos, size - pos, str); \
+ if (pos >= size) \
+ return -1; \
+ }
+#define BTF_PRINT_ONE_ARG(fmt, arg) \
+ { \
+ pos += snprintf(func_sig + pos, size - pos, fmt, arg); \
+ if (pos >= size) \
+ return -1; \
+ }
+#define BTF_PRINT_TYPE_ONLY(type) \
+ { \
+ pos = __btf_dumper_type_only(btf, type, func_sig, \
+ pos, size); \
+ if (pos == -1) \
+ return -1; \
+ }
+
+static int __btf_dumper_type_only(struct btf *btf, __u32 type_id,
+ char *func_sig, int pos, int size)
+{
+ const struct btf_type *t = btf__type_by_id(btf, type_id);
+ const struct btf_array *array;
+ int i, vlen;
+
+ switch (BTF_INFO_KIND(t->info)) {
+ case BTF_KIND_INT:
+ BTF_PRINT_ONE_ARG("%s ",
+ btf__name_by_offset(btf, t->name_off));
+ break;
+ case BTF_KIND_STRUCT:
+ BTF_PRINT_ONE_ARG("struct %s ",
+ btf__name_by_offset(btf, t->name_off));
+ break;
+ case BTF_KIND_UNION:
+ BTF_PRINT_ONE_ARG("union %s ",
+ btf__name_by_offset(btf, t->name_off));
+ break;
+ case BTF_KIND_ENUM:
+ BTF_PRINT_ONE_ARG("enum %s ",
+ btf__name_by_offset(btf, t->name_off));
+ break;
+ case BTF_KIND_ARRAY:
+ array = (struct btf_array *)(t + 1);
+ BTF_PRINT_TYPE_ONLY(array->type);
+ BTF_PRINT_ONE_ARG("[%d]", array->nelems);
+ break;
+ case BTF_KIND_PTR:
+ BTF_PRINT_TYPE_ONLY(t->type);
+ BTF_PRINT_STRING("* ");
+ break;
+ case BTF_KIND_UNKN:
+ case BTF_KIND_FWD:
+ case BTF_KIND_TYPEDEF:
+ return -1;
+ case BTF_KIND_VOLATILE:
+ BTF_PRINT_STRING("volatile ");
+ BTF_PRINT_TYPE_ONLY(t->type);
+ break;
+ case BTF_KIND_CONST:
+ BTF_PRINT_STRING("const ");
+ BTF_PRINT_TYPE_ONLY(t->type);
+ break;
+ case BTF_KIND_RESTRICT:
+ BTF_PRINT_STRING("restrict ");
+ BTF_PRINT_TYPE_ONLY(t->type);
+ break;
+ case BTF_KIND_FUNC:
+ case BTF_KIND_FUNC_PROTO:
+ BTF_PRINT_TYPE_ONLY(t->type);
+ BTF_PRINT_ONE_ARG("%s(", btf__name_by_offset(btf, t->name_off));
+ vlen = BTF_INFO_VLEN(t->info);
+ for (i = 0; i < vlen; i++) {
+ __u32 arg_type = ((__u32 *)(t + 1))[i];
+
+ BTF_PRINT_TYPE_ONLY(arg_type);
+ if (i != (vlen - 1))
+ BTF_PRINT_STRING(", ");
+ }
+ BTF_PRINT_STRING(")");
+ break;
+ default:
+ return -1;
+ }
+
+ return pos;
+}
+
+int btf_dumper_type_only(struct btf *btf, __u32 type_id, char *func_sig,
+ int size)
+{
+ return __btf_dumper_type_only(btf, type_id, func_sig, 0, size);
+}
diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h
index 28ee769bd11b..f887564476dc 100644
--- a/tools/bpf/bpftool/main.h
+++ b/tools/bpf/bpftool/main.h
@@ -168,6 +168,8 @@ struct btf_dumper {
*/
int btf_dumper_type(const struct btf_dumper *d, __u32 type_id,
const void *data);
+int btf_dumper_type_only(struct btf *btf, __u32 func_type_id, char *func_only,
+ int size);
struct nlattr;
struct ifinfomsg;
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 335028968dfb..e78632a30ea3 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -47,6 +47,7 @@
#include <linux/err.h>
#include <bpf.h>
+#include <btf.h>
#include <libbpf.h>
#include "cfg.h"
@@ -447,9 +448,11 @@ static int do_show(int argc, char **argv)
static int do_dump(int argc, char **argv)
{
unsigned long *func_ksyms = NULL;
+ unsigned int *func_types = NULL;
struct bpf_prog_info info = {};
unsigned int *func_lens = NULL;
unsigned int nr_func_ksyms;
+ unsigned int nr_func_types;
unsigned int nr_func_lens;
struct dump_data dd = {};
__u32 len = sizeof(info);
@@ -546,6 +549,16 @@ static int do_dump(int argc, char **argv)
}
}
+ nr_func_types = info.nr_jited_func_types;
+ if (nr_func_types) {
+ func_types = malloc(nr_func_types * sizeof(__u32));
+ if (!func_types) {
+ p_err("mem alloc failed");
+ close(fd);
+ goto err_free;
+ }
+ }
+
memset(&info, 0, sizeof(info));
*member_ptr = ptr_to_u64(buf);
@@ -554,6 +567,8 @@ static int do_dump(int argc, char **argv)
info.nr_jited_ksyms = nr_func_ksyms;
info.jited_func_lens = ptr_to_u64(func_lens);
info.nr_jited_func_lens = nr_func_lens;
+ info.jited_func_types = ptr_to_u64(func_types);
+ info.nr_jited_func_types = nr_func_types;
err = bpf_obj_get_info_by_fd(fd, &info, &len);
close(fd);
@@ -577,6 +592,11 @@ static int do_dump(int argc, char **argv)
goto err_free;
}
+ if (info.nr_jited_func_types > nr_func_types) {
+ p_err("too many types returned");
+ goto err_free;
+ }
+
if ((member_len == &info.jited_prog_len &&
info.jited_prog_insns == 0) ||
(member_len == &info.xlated_prog_len &&
@@ -585,6 +605,12 @@ static int do_dump(int argc, char **argv)
goto err_free;
}
+ if (info.btf_id &&
+ info.nr_jited_func_lens != info.nr_jited_func_types) {
+ p_err("unequal jited func lens and types");
+ goto err_free;
+ }
+
if (filepath) {
fd = open(filepath, O_WRONLY | O_CREAT | O_TRUNC, 0600);
if (fd < 0) {
@@ -618,7 +644,9 @@ static int do_dump(int argc, char **argv)
struct kernel_sym *sym = NULL;
char sym_name[SYM_MAX_NAME];
unsigned char *img = buf;
+ struct btf *btf = NULL;
__u64 *ksyms = NULL;
+ char func_sig[1024];
__u32 *lens;
__u32 i;
@@ -627,6 +655,14 @@ static int do_dump(int argc, char **argv)
ksyms = (__u64 *) info.jited_ksyms;
}
+ if (info.btf_id) {
+ err = btf_get_from_id(info.btf_id, &btf);
+ if (err) {
+ p_err("failed to get btf");
+ goto err_free;
+ }
+ }
+
if (json_output)
jsonw_start_array(json_wtr);
@@ -642,12 +678,28 @@ static int do_dump(int argc, char **argv)
strcpy(sym_name, "unknown");
}
+ func_sig[0] = '\0';
+ if (btf) {
+ err = btf_dumper_type_only(btf,
+
func_types[i],
+ func_sig,
+
sizeof(func_sig));
+ if (err < 0)
+ func_sig[0] = '\0';
+ }
+
if (json_output) {
jsonw_start_object(json_wtr);
+ if (func_sig[0] != '\0') {
+ jsonw_name(json_wtr, "proto");
+ jsonw_string(json_wtr,
func_sig);
+ }
jsonw_name(json_wtr, "name");
jsonw_string(json_wtr, sym_name);
jsonw_name(json_wtr, "insns");
} else {
+ if (func_sig[0] != '\0')
+ printf("%s:\n", func_sig);
printf("%s:\n", sym_name);
}
@@ -685,12 +737,14 @@ static int do_dump(int argc, char **argv)
free(buf);
free(func_ksyms);
free(func_lens);
+ free(func_types);
return 0;
err_free:
free(buf);
free(func_ksyms);
free(func_lens);
+ free(func_types);
return -1;
}
--
2.17.1
