On 1/21/19 8:45 PM, Quentin Monnet wrote:
2019-01-21 16:25 UTC+0900 ~ Taeung Song <treeze.tae...@gmail.com>
We need to let users check their wrong ELF section name
with proper ELF section names when failed to get a prog/attach type from it.
Because users can't realize libbpf guess prog/attach types from
given ELF section names.
For example, when a 'cgroup' section name of a BPF program is used,
show available ELF section names(types).
Before:
$ bpftool prog load bpf-prog.o /sys/fs/bpf/prog1
Error: failed to guess program type based on ELF section name cgroup
After:
libbpf: failed to guess program type based on ELF section name 'cgroup'
libbpf: supported section(type) names are: socket kprobe/ kretprobe/
classifier action tracepoint/ raw_tracepoint/ xdp perf_event lwt_in lwt_out
lwt_xmit lwt_seg6local cgroup_skb/ingress cgroup_skb/egress cgroup/skb
cgroup/sock cgroup/post_bind4 cgroup/post_bind6 cgroup/dev sockops
sk_skb/stream_parser sk_skb/stream_verdict sk_skb sk_msg lirc_mode2
flow_dissector cgroup/bind4 cgroup/bind6 cgroup/connect4 cgroup/connect6
cgroup/sendmsg4 cgroup/sendmsg6
Reviewed-by: Jakub Kicinski <jakub.kicin...@netronome.com>
Reviewed-by: Quentin Monnet <quentin.mon...@netronome.com>
Please do not add "Reviewed-by" tags unless offered by the reviewers. I
cannot remember either Jakub or I giving the tag for this series so far.
Just in case, more details on the usage of this tag are available in
Documentation/process/submitting-patches.rst, in section
"Using Reported-by:, Tested-by:, Reviewed-by:, Suggested-by: and Fixes:"
I got it, thanks for pointing out this.
Cc: Andrey Ignatov <r...@fb.com>
Signed-off-by: Taeung Song <treeze.tae...@gmail.com>
This version of the patch looks better, thanks! A few additional
comments below.
---
tools/bpf/bpftool/prog.c | 10 ++----
tools/lib/bpf/libbpf.c | 34 +++++++++++++++++--
.../selftests/bpf/test_socket_cookie.c | 4 +--
3 files changed, 36 insertions(+), 12 deletions(-)
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 2d1bb7d6ff51..0640e9bc0ada 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -930,10 +930,9 @@ static int load_with_options(int argc, char **argv, bool
first_prog_only)
err = libbpf_prog_type_by_name(type, &attr.prog_type,
&expected_attach_type);
free(type);
- if (err < 0) {
- p_err("unknown program type '%s'", *argv);
+ if (err < 0)
goto err_free_reuse_maps;
- }
+
NEXT_ARG();
} else if (is_prefix(*argv, "map")) {
void *new_map_replace;
@@ -1028,11 +1027,8 @@ static int load_with_options(int argc, char **argv, bool
first_prog_only)
err = libbpf_prog_type_by_name(sec_name, &prog_type,
&expected_attach_type);
- if (err < 0) {
- p_err("failed to guess program type based on section
name %s\n",
- sec_name);
+ if (err < 0)
goto err_close_obj;
- }
}
bpf_program__set_ifindex(pos, ifindex);
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 169e347c76f6..ea44d7a05149 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -2667,10 +2667,31 @@ static const struct {
#undef BPF_EAPROG_SEC
#undef BPF_APROG_COMPAT
+#define MAX_TYPE_NAME_SIZE 32
+
+static char *libbpf_get_type_names(bool attach_type)
+{
+ int i, len = ARRAY_SIZE(section_names) * MAX_TYPE_NAME_SIZE;
+ char *buf = malloc(len);
I'd rather have the malloc() on a line separate from variable
declaration, like this:
char *buf;
buf = malloc(len);
Also, can you please make sure that malloc() succeeds? (if (!buf) ...)
OK, will check it.
+
+ buf[0] = '\0';
+ /* Forge string buf with all available names */
+ for (i = 0; i < ARRAY_SIZE(section_names); i++) {
Could you please add a check on "buf"'s length to make sure there is no
overflow? It seems very unlikely that we add a section name so long as
to make this happen, but just in case.
+ if (attach_type && !section_names[i].is_attachable)
+ continue;
+
+ strcat(buf, " ");
+ strcat(buf, section_names[i].sec);
+ }
+
+ return buf;
The code in this function uses a mix of tabs and spaces for indents.
Please stick to tabs.
Oops, I modified it.
+}
+
int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
enum bpf_attach_type *expected_attach_type)
{
int i;
+ char *type_names;
Please declare variables in reverse-Christmas-tree order.
if (!name)
return -EINVAL;
@@ -2682,6 +2703,11 @@ int libbpf_prog_type_by_name(const char *name, enum
bpf_prog_type *prog_type,
*expected_attach_type = section_names[i].expected_attach_type;
return 0;
}
+ pr_warning("failed to guess program type based on ELF section name
'%s'\n", name);
+ type_names = libbpf_get_type_names(false);
+ pr_info("supported section(type) names are:%s\n", type_names);
+ free(type_names);
+
return -EINVAL;
}
@@ -2689,6 +2715,7 @@ int libbpf_attach_type_by_name(const char *name,
enum bpf_attach_type *attach_type)
{
int i;
+ char *type_names;
(same comment on variables' order)
OK, will send v4 soon !
Thanks,
Taeung
if (!name)
return -EINVAL;
@@ -2701,6 +2728,11 @@ int libbpf_attach_type_by_name(const char *name,
*attach_type = section_names[i].attach_type;
return 0;
}
+ pr_warning("failed to guess attach type based on ELF section name
'%s'\n", name);
+ type_names = libbpf_get_type_names(true);
+ pr_info("attachable section(type) names are:%s\n", type_names);
+ free(type_names);
+
return -EINVAL;
}
@@ -2907,8 +2939,6 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
err = bpf_program__identify_section(prog, &prog_type,
&expected_attach_type);
if (err < 0) {
- pr_warning("failed to guess program type based on
section name %s\n",
- prog->section_name);
bpf_object__close(obj);
return -EINVAL;
}
diff --git a/tools/testing/selftests/bpf/test_socket_cookie.c
b/tools/testing/selftests/bpf/test_socket_cookie.c
index fc7832ee566b..e51d63786ff8 100644
--- a/tools/testing/selftests/bpf/test_socket_cookie.c
+++ b/tools/testing/selftests/bpf/test_socket_cookie.c
@@ -158,10 +158,8 @@ static int run_test(int cgfd)
bpf_object__for_each_program(prog, pobj) {
prog_name = bpf_program__title(prog, /*needs_copy*/ false);
- if (libbpf_attach_type_by_name(prog_name, &attach_type)) {
- log_err("Unexpected prog: %s", prog_name);
+ if (libbpf_attach_type_by_name(prog_name, &attach_type))
goto err;
- }
err = bpf_prog_attach(bpf_program__fd(prog), cgfd, attach_type,
BPF_F_ALLOW_OVERRIDE);
