diff mbox series

[bpf-next,v8,1/3] bpftool: Add autoattach for bpf prog load|loadall

Message ID 1665399601-29668-2-git-send-email-wangyufen@huawei.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series bpftool: Add autoattach for bpf prog load|loadall | expand

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bpf/vmtest-bpf-next-PR fail PR summary
bpf/vmtest-bpf-next-VM_Test-6 success Logs for test_maps on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-9 success Logs for test_progs on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-12 success Logs for test_progs_no_alu32 on s390x with gcc
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bpf/vmtest-bpf-next-VM_Test-16 success Logs for test_verifier on x86_64 with gcc
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bpf/vmtest-bpf-next-VM_Test-7 success Logs for test_maps on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-8 success Logs for test_maps on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-10 fail Logs for test_progs on x86_64 with gcc
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bpf/vmtest-bpf-next-VM_Test-14 fail Logs for test_progs_no_alu32 on x86_64 with llvm-16
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Commit Message

wangyufen Oct. 10, 2022, 10:59 a.m. UTC 
Add autoattach optional to support one-step load-attach-pin_link.

For example,
   $ bpftool prog loadall test.o /sys/fs/bpf/test autoattach

   $ bpftool link
   26: tracing  name test1  tag f0da7d0058c00236  gpl
   	loaded_at 2022-09-09T21:39:49+0800  uid 0
   	xlated 88B  jited 55B  memlock 4096B  map_ids 3
   	btf_id 55
   28: kprobe  name test3  tag 002ef1bef0723833  gpl
   	loaded_at 2022-09-09T21:39:49+0800  uid 0
   	xlated 88B  jited 56B  memlock 4096B  map_ids 3
   	btf_id 55
   57: tracepoint  name oncpu  tag 7aa55dfbdcb78941  gpl
   	loaded_at 2022-09-09T21:41:32+0800  uid 0
   	xlated 456B  jited 265B  memlock 4096B  map_ids 17,13,14,15
   	btf_id 82

   $ bpftool link
   1: tracing  prog 26
   	prog_type tracing  attach_type trace_fentry
   3: perf_event  prog 28
   10: perf_event  prog 57

The autoattach optional can support tracepoints, k(ret)probes,
u(ret)probes.

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Wang Yufen <wangyufen@huawei.com>
---
 tools/bpf/bpftool/prog.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 76 insertions(+), 2 deletions(-)

Comments

Andrii Nakryiko Oct. 13, 2022, 7:47 p.m. UTC | #1 
On Mon, Oct 10, 2022 at 3:40 AM Wang Yufen <wangyufen@huawei.com> wrote:
>
> Add autoattach optional to support one-step load-attach-pin_link.
>
> For example,
>    $ bpftool prog loadall test.o /sys/fs/bpf/test autoattach
>
>    $ bpftool link
>    26: tracing  name test1  tag f0da7d0058c00236  gpl
>         loaded_at 2022-09-09T21:39:49+0800  uid 0
>         xlated 88B  jited 55B  memlock 4096B  map_ids 3
>         btf_id 55
>    28: kprobe  name test3  tag 002ef1bef0723833  gpl
>         loaded_at 2022-09-09T21:39:49+0800  uid 0
>         xlated 88B  jited 56B  memlock 4096B  map_ids 3
>         btf_id 55
>    57: tracepoint  name oncpu  tag 7aa55dfbdcb78941  gpl
>         loaded_at 2022-09-09T21:41:32+0800  uid 0
>         xlated 456B  jited 265B  memlock 4096B  map_ids 17,13,14,15
>         btf_id 82
>
>    $ bpftool link
>    1: tracing  prog 26
>         prog_type tracing  attach_type trace_fentry
>    3: perf_event  prog 28
>    10: perf_event  prog 57
>
> The autoattach optional can support tracepoints, k(ret)probes,
> u(ret)probes.
>
> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
> Signed-off-by: Wang Yufen <wangyufen@huawei.com>
> ---
>  tools/bpf/bpftool/prog.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 76 insertions(+), 2 deletions(-)
>
> diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
> index c81362a..8f3afce 100644
> --- a/tools/bpf/bpftool/prog.c
> +++ b/tools/bpf/bpftool/prog.c
> @@ -1453,6 +1453,69 @@ static int do_run(int argc, char **argv)
>         return ret;
>  }
>
> +static int
> +auto_attach_program(struct bpf_program *prog, const char *path)
> +{
> +       struct bpf_link *link;
> +       int err;
> +
> +       link = bpf_program__attach(prog);
> +       if (!link) {
> +               p_info("Program %s does not support autoattach, falling back to pinning",
> +                      bpf_program__name(prog));
> +               return bpf_obj_pin(bpf_program__fd(prog), path);
> +       }
> +       err = bpf_link__pin(link, path);
> +       if (err) {
> +               bpf_link__destroy(link);
> +               return err;
> +       }

leaking link here, destroy it unconditionally. If pinning succeeded,
you don't need to hold link's FD open anymore.

> +       return 0;
> +}
> +
> +static int pathname_concat(const char *path, const char *name, char *buf)

why you didn't do the same as in libbpf? Pass buffer size explicitly
instead of assuming PATH_MAX

> +{
> +       int len;
> +
> +       len = snprintf(buf, PATH_MAX, "%s/%s", path, name);
> +       if (len < 0)
> +               return -EINVAL;
> +       if (len >= PATH_MAX)
> +               return -ENAMETOOLONG;
> +
> +       return 0;
> +}
> +
> +static int
> +auto_attach_programs(struct bpf_object *obj, const char *path)
> +{
> +       struct bpf_program *prog;
> +       char buf[PATH_MAX];
> +       int err;
> +
> +       bpf_object__for_each_program(prog, obj) {
> +               err = pathname_concat(path, bpf_program__name(prog), buf);
> +               if (err)
> +                       goto err_unpin_programs;
> +
> +               err = auto_attach_program(prog, buf);
> +               if (err)
> +                       goto err_unpin_programs;
> +       }
> +
> +       return 0;
> +
> +err_unpin_programs:
> +       while ((prog = bpf_object__prev_program(obj, prog))) {
> +               if (pathname_concat(path, bpf_program__name(prog), buf))
> +                       continue;
> +
> +               bpf_program__unpin(prog, buf);
> +       }
> +
> +       return err;
> +}
> +
>  static int load_with_options(int argc, char **argv, bool first_prog_only)
>  {
>         enum bpf_prog_type common_prog_type = BPF_PROG_TYPE_UNSPEC;
> @@ -1464,6 +1527,7 @@ static int load_with_options(int argc, char **argv, bool first_prog_only)
>         struct bpf_program *prog = NULL, *pos;
>         unsigned int old_map_fds = 0;
>         const char *pinmaps = NULL;
> +       bool auto_attach = false;
>         struct bpf_object *obj;
>         struct bpf_map *map;
>         const char *pinfile;
> @@ -1583,6 +1647,9 @@ static int load_with_options(int argc, char **argv, bool first_prog_only)
>                                 goto err_free_reuse_maps;
>
>                         pinmaps = GET_ARG();
> +               } else if (is_prefix(*argv, "autoattach")) {
> +                       auto_attach = true;
> +                       NEXT_ARG();
>                 } else {
>                         p_err("expected no more arguments, 'type', 'map' or 'dev', got: '%s'?",
>                               *argv);
> @@ -1692,14 +1759,20 @@ static int load_with_options(int argc, char **argv, bool first_prog_only)
>                         goto err_close_obj;
>                 }
>
> -               err = bpf_obj_pin(bpf_program__fd(prog), pinfile);
> +               if (auto_attach)
> +                       err = auto_attach_program(prog, pinfile);
> +               else
> +                       err = bpf_obj_pin(bpf_program__fd(prog), pinfile);
>                 if (err) {
>                         p_err("failed to pin program %s",
>                               bpf_program__section_name(prog));
>                         goto err_close_obj;
>                 }
>         } else {
> -               err = bpf_object__pin_programs(obj, pinfile);
> +               if (auto_attach)
> +                       err = auto_attach_programs(obj, pinfile);
> +               else
> +                       err = bpf_object__pin_programs(obj, pinfile);
>                 if (err) {
>                         p_err("failed to pin all programs");
>                         goto err_close_obj;
> @@ -2338,6 +2411,7 @@ static int do_help(int argc, char **argv)
>                 "                         [type TYPE] [dev NAME] \\\n"
>                 "                         [map { idx IDX | name NAME } MAP]\\\n"
>                 "                         [pinmaps MAP_DIR]\n"
> +               "                         [autoattach]\n"
>                 "       %1$s %2$s attach PROG ATTACH_TYPE [MAP]\n"
>                 "       %1$s %2$s detach PROG ATTACH_TYPE [MAP]\n"
>                 "       %1$s %2$s run PROG \\\n"
> --
> 1.8.3.1
>
wangyufen Oct. 14, 2022, 2:24 a.m. UTC | #2 
在 2022/10/14 3:47, Andrii Nakryiko 写道:
> On Mon, Oct 10, 2022 at 3:40 AM Wang Yufen <wangyufen@huawei.com> wrote:
>> Add autoattach optional to support one-step load-attach-pin_link.
>>
>> For example,
>>     $ bpftool prog loadall test.o /sys/fs/bpf/test autoattach
>>
>>     $ bpftool link
>>     26: tracing  name test1  tag f0da7d0058c00236  gpl
>>          loaded_at 2022-09-09T21:39:49+0800  uid 0
>>          xlated 88B  jited 55B  memlock 4096B  map_ids 3
>>          btf_id 55
>>     28: kprobe  name test3  tag 002ef1bef0723833  gpl
>>          loaded_at 2022-09-09T21:39:49+0800  uid 0
>>          xlated 88B  jited 56B  memlock 4096B  map_ids 3
>>          btf_id 55
>>     57: tracepoint  name oncpu  tag 7aa55dfbdcb78941  gpl
>>          loaded_at 2022-09-09T21:41:32+0800  uid 0
>>          xlated 456B  jited 265B  memlock 4096B  map_ids 17,13,14,15
>>          btf_id 82
>>
>>     $ bpftool link
>>     1: tracing  prog 26
>>          prog_type tracing  attach_type trace_fentry
>>     3: perf_event  prog 28
>>     10: perf_event  prog 57
>>
>> The autoattach optional can support tracepoints, k(ret)probes,
>> u(ret)probes.
>>
>> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
>> Signed-off-by: Wang Yufen <wangyufen@huawei.com>
>> ---
>>   tools/bpf/bpftool/prog.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++--
>>   1 file changed, 76 insertions(+), 2 deletions(-)
>>
>> diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
>> index c81362a..8f3afce 100644
>> --- a/tools/bpf/bpftool/prog.c
>> +++ b/tools/bpf/bpftool/prog.c
>> @@ -1453,6 +1453,69 @@ static int do_run(int argc, char **argv)
>>          return ret;
>>   }
>>
>> +static int
>> +auto_attach_program(struct bpf_program *prog, const char *path)
>> +{
>> +       struct bpf_link *link;
>> +       int err;
>> +
>> +       link = bpf_program__attach(prog);
>> +       if (!link) {
>> +               p_info("Program %s does not support autoattach, falling back to pinning",
>> +                      bpf_program__name(prog));
>> +               return bpf_obj_pin(bpf_program__fd(prog), path);
>> +       }
>> +       err = bpf_link__pin(link, path);
>> +       if (err) {
>> +               bpf_link__destroy(link);
>> +               return err;
>> +       }
> leaking link here, destroy it unconditionally. If pinning succeeded,
> you don't need to hold link's FD open anymore.

I got it, will change. Thanks！

>
>> +       return 0;
>> +}
>> +
>> +static int pathname_concat(const char *path, const char *name, char *buf)
> why you didn't do the same as in libbpf? Pass buffer size explicitly
> instead of assuming PATH_MAX

The pathname_concat function is invoked only in one place and is not a
general function here. So, not modified. Or, can I change the "pathname_concat"
of libbpf to "LIBBPF_API int libbpf_pathname_concat" and use the
libbpf_pathname_concat directly?


>
>> +{
>> +       int len;
>> +
>> +       len = snprintf(buf, PATH_MAX, "%s/%s", path, name);
>> +       if (len < 0)
>> +               return -EINVAL;
>> +       if (len >= PATH_MAX)
>> +               return -ENAMETOOLONG;
>> +
>> +       return 0;
>> +}
>> +
>> +static int
>> +auto_attach_programs(struct bpf_object *obj, const char *path)
>> +{
>> +       struct bpf_program *prog;
>> +       char buf[PATH_MAX];
>> +       int err;
>> +
>> +       bpf_object__for_each_program(prog, obj) {
>> +               err = pathname_concat(path, bpf_program__name(prog), buf);
>> +               if (err)
>> +                       goto err_unpin_programs;
>> +
>> +               err = auto_attach_program(prog, buf);
>> +               if (err)
>> +                       goto err_unpin_programs;
>> +       }
>> +
>> +       return 0;
>> +
>> +err_unpin_programs:
>> +       while ((prog = bpf_object__prev_program(obj, prog))) {
>> +               if (pathname_concat(path, bpf_program__name(prog), buf))
>> +                       continue;
>> +
>> +               bpf_program__unpin(prog, buf);
>> +       }
>> +
>> +       return err;
>> +}
>> +
>>   static int load_with_options(int argc, char **argv, bool first_prog_only)
>>   {
>>          enum bpf_prog_type common_prog_type = BPF_PROG_TYPE_UNSPEC;
>> @@ -1464,6 +1527,7 @@ static int load_with_options(int argc, char **argv, bool first_prog_only)
>>          struct bpf_program *prog = NULL, *pos;
>>          unsigned int old_map_fds = 0;
>>          const char *pinmaps = NULL;
>> +       bool auto_attach = false;
>>          struct bpf_object *obj;
>>          struct bpf_map *map;
>>          const char *pinfile;
>> @@ -1583,6 +1647,9 @@ static int load_with_options(int argc, char **argv, bool first_prog_only)
>>                                  goto err_free_reuse_maps;
>>
>>                          pinmaps = GET_ARG();
>> +               } else if (is_prefix(*argv, "autoattach")) {
>> +                       auto_attach = true;
>> +                       NEXT_ARG();
>>                  } else {
>>                          p_err("expected no more arguments, 'type', 'map' or 'dev', got: '%s'?",
>>                                *argv);
>> @@ -1692,14 +1759,20 @@ static int load_with_options(int argc, char **argv, bool first_prog_only)
>>                          goto err_close_obj;
>>                  }
>>
>> -               err = bpf_obj_pin(bpf_program__fd(prog), pinfile);
>> +               if (auto_attach)
>> +                       err = auto_attach_program(prog, pinfile);
>> +               else
>> +                       err = bpf_obj_pin(bpf_program__fd(prog), pinfile);
>>                  if (err) {
>>                          p_err("failed to pin program %s",
>>                                bpf_program__section_name(prog));
>>                          goto err_close_obj;
>>                  }
>>          } else {
>> -               err = bpf_object__pin_programs(obj, pinfile);
>> +               if (auto_attach)
>> +                       err = auto_attach_programs(obj, pinfile);
>> +               else
>> +                       err = bpf_object__pin_programs(obj, pinfile);
>>                  if (err) {
>>                          p_err("failed to pin all programs");
>>                          goto err_close_obj;
>> @@ -2338,6 +2411,7 @@ static int do_help(int argc, char **argv)
>>                  "                         [type TYPE] [dev NAME] \\\n"
>>                  "                         [map { idx IDX | name NAME } MAP]\\\n"
>>                  "                         [pinmaps MAP_DIR]\n"
>> +               "                         [autoattach]\n"
>>                  "       %1$s %2$s attach PROG ATTACH_TYPE [MAP]\n"
>>                  "       %1$s %2$s detach PROG ATTACH_TYPE [MAP]\n"
>>                  "       %1$s %2$s run PROG \\\n"
>> --
>> 1.8.3.1
>>
Andrii Nakryiko Oct. 14, 2022, 3:43 a.m. UTC | #3 
On Thu, Oct 13, 2022 at 7:24 PM wangyufen <wangyufen@huawei.com> wrote:
>
>
> 在 2022/10/14 3:47, Andrii Nakryiko 写道:
> > On Mon, Oct 10, 2022 at 3:40 AM Wang Yufen <wangyufen@huawei.com> wrote:
> >> Add autoattach optional to support one-step load-attach-pin_link.
> >>
> >> For example,
> >>     $ bpftool prog loadall test.o /sys/fs/bpf/test autoattach
> >>
> >>     $ bpftool link
> >>     26: tracing  name test1  tag f0da7d0058c00236  gpl
> >>          loaded_at 2022-09-09T21:39:49+0800  uid 0
> >>          xlated 88B  jited 55B  memlock 4096B  map_ids 3
> >>          btf_id 55
> >>     28: kprobe  name test3  tag 002ef1bef0723833  gpl
> >>          loaded_at 2022-09-09T21:39:49+0800  uid 0
> >>          xlated 88B  jited 56B  memlock 4096B  map_ids 3
> >>          btf_id 55
> >>     57: tracepoint  name oncpu  tag 7aa55dfbdcb78941  gpl
> >>          loaded_at 2022-09-09T21:41:32+0800  uid 0
> >>          xlated 456B  jited 265B  memlock 4096B  map_ids 17,13,14,15
> >>          btf_id 82
> >>
> >>     $ bpftool link
> >>     1: tracing  prog 26
> >>          prog_type tracing  attach_type trace_fentry
> >>     3: perf_event  prog 28
> >>     10: perf_event  prog 57
> >>
> >> The autoattach optional can support tracepoints, k(ret)probes,
> >> u(ret)probes.
> >>
> >> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
> >> Signed-off-by: Wang Yufen <wangyufen@huawei.com>
> >> ---
> >>   tools/bpf/bpftool/prog.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++--
> >>   1 file changed, 76 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
> >> index c81362a..8f3afce 100644
> >> --- a/tools/bpf/bpftool/prog.c
> >> +++ b/tools/bpf/bpftool/prog.c
> >> @@ -1453,6 +1453,69 @@ static int do_run(int argc, char **argv)
> >>          return ret;
> >>   }
> >>
> >> +static int
> >> +auto_attach_program(struct bpf_program *prog, const char *path)
> >> +{
> >> +       struct bpf_link *link;
> >> +       int err;
> >> +
> >> +       link = bpf_program__attach(prog);
> >> +       if (!link) {
> >> +               p_info("Program %s does not support autoattach, falling back to pinning",
> >> +                      bpf_program__name(prog));
> >> +               return bpf_obj_pin(bpf_program__fd(prog), path);
> >> +       }
> >> +       err = bpf_link__pin(link, path);
> >> +       if (err) {
> >> +               bpf_link__destroy(link);
> >> +               return err;
> >> +       }
> > leaking link here, destroy it unconditionally. If pinning succeeded,
> > you don't need to hold link's FD open anymore.
>
> I got it, will change. Thanks！
>
> >
> >> +       return 0;
> >> +}
> >> +
> >> +static int pathname_concat(const char *path, const char *name, char *buf)
> > why you didn't do the same as in libbpf? Pass buffer size explicitly
> > instead of assuming PATH_MAX
>
> The pathname_concat function is invoked only in one place and is not a
> general function here. So, not modified. Or, can I change the "pathname_concat"
> of libbpf to "LIBBPF_API int libbpf_pathname_concat" and use the
> libbpf_pathname_concat directly?

no need to reuse libbpf's helper, but I do think it's cleaner to
specify not just buffer pointer, but also it's size, just like you do
with any other string buffer API (like snprintf)

>
>
> >
> >> +{
> >> +       int len;
> >> +
> >> +       len = snprintf(buf, PATH_MAX, "%s/%s", path, name);
> >> +       if (len < 0)
> >> +               return -EINVAL;
> >> +       if (len >= PATH_MAX)
> >> +               return -ENAMETOOLONG;
> >> +
> >> +       return 0;
> >> +}
> >> +
> >> +static int
> >> +auto_attach_programs(struct bpf_object *obj, const char *path)
> >> +{
> >> +       struct bpf_program *prog;
> >> +       char buf[PATH_MAX];
> >> +       int err;
> >> +
> >> +       bpf_object__for_each_program(prog, obj) {
> >> +               err = pathname_concat(path, bpf_program__name(prog), buf);
> >> +               if (err)
> >> +                       goto err_unpin_programs;
> >> +
> >> +               err = auto_attach_program(prog, buf);
> >> +               if (err)
> >> +                       goto err_unpin_programs;
> >> +       }
> >> +
> >> +       return 0;
> >> +
> >> +err_unpin_programs:
> >> +       while ((prog = bpf_object__prev_program(obj, prog))) {
> >> +               if (pathname_concat(path, bpf_program__name(prog), buf))
> >> +                       continue;
> >> +
> >> +               bpf_program__unpin(prog, buf);
> >> +       }
> >> +
> >> +       return err;
> >> +}
> >> +
> >>   static int load_with_options(int argc, char **argv, bool first_prog_only)
> >>   {
> >>          enum bpf_prog_type common_prog_type = BPF_PROG_TYPE_UNSPEC;
> >> @@ -1464,6 +1527,7 @@ static int load_with_options(int argc, char **argv, bool first_prog_only)
> >>          struct bpf_program *prog = NULL, *pos;
> >>          unsigned int old_map_fds = 0;
> >>          const char *pinmaps = NULL;
> >> +       bool auto_attach = false;
> >>          struct bpf_object *obj;
> >>          struct bpf_map *map;
> >>          const char *pinfile;
> >> @@ -1583,6 +1647,9 @@ static int load_with_options(int argc, char **argv, bool first_prog_only)
> >>                                  goto err_free_reuse_maps;
> >>
> >>                          pinmaps = GET_ARG();
> >> +               } else if (is_prefix(*argv, "autoattach")) {
> >> +                       auto_attach = true;
> >> +                       NEXT_ARG();
> >>                  } else {
> >>                          p_err("expected no more arguments, 'type', 'map' or 'dev', got: '%s'?",
> >>                                *argv);
> >> @@ -1692,14 +1759,20 @@ static int load_with_options(int argc, char **argv, bool first_prog_only)
> >>                          goto err_close_obj;
> >>                  }
> >>
> >> -               err = bpf_obj_pin(bpf_program__fd(prog), pinfile);
> >> +               if (auto_attach)
> >> +                       err = auto_attach_program(prog, pinfile);
> >> +               else
> >> +                       err = bpf_obj_pin(bpf_program__fd(prog), pinfile);
> >>                  if (err) {
> >>                          p_err("failed to pin program %s",
> >>                                bpf_program__section_name(prog));
> >>                          goto err_close_obj;
> >>                  }
> >>          } else {
> >> -               err = bpf_object__pin_programs(obj, pinfile);
> >> +               if (auto_attach)
> >> +                       err = auto_attach_programs(obj, pinfile);
> >> +               else
> >> +                       err = bpf_object__pin_programs(obj, pinfile);
> >>                  if (err) {
> >>                          p_err("failed to pin all programs");
> >>                          goto err_close_obj;
> >> @@ -2338,6 +2411,7 @@ static int do_help(int argc, char **argv)
> >>                  "                         [type TYPE] [dev NAME] \\\n"
> >>                  "                         [map { idx IDX | name NAME } MAP]\\\n"
> >>                  "                         [pinmaps MAP_DIR]\n"
> >> +               "                         [autoattach]\n"
> >>                  "       %1$s %2$s attach PROG ATTACH_TYPE [MAP]\n"
> >>                  "       %1$s %2$s detach PROG ATTACH_TYPE [MAP]\n"
> >>                  "       %1$s %2$s run PROG \\\n"
> >> --
> >> 1.8.3.1
> >>
wangyufen Oct. 14, 2022, 6:38 a.m. UTC | #4 
在 2022/10/14 11:43, Andrii Nakryiko 写道:
> On Thu, Oct 13, 2022 at 7:24 PM wangyufen <wangyufen@huawei.com> wrote:
>>
>> 在 2022/10/14 3:47, Andrii Nakryiko 写道:
>>> On Mon, Oct 10, 2022 at 3:40 AM Wang Yufen <wangyufen@huawei.com> wrote:
>>>> Add autoattach optional to support one-step load-attach-pin_link.
>>>>
>>>> For example,
>>>>      $ bpftool prog loadall test.o /sys/fs/bpf/test autoattach
>>>>
>>>>      $ bpftool link
>>>>      26: tracing  name test1  tag f0da7d0058c00236  gpl
>>>>           loaded_at 2022-09-09T21:39:49+0800  uid 0
>>>>           xlated 88B  jited 55B  memlock 4096B  map_ids 3
>>>>           btf_id 55
>>>>      28: kprobe  name test3  tag 002ef1bef0723833  gpl
>>>>           loaded_at 2022-09-09T21:39:49+0800  uid 0
>>>>           xlated 88B  jited 56B  memlock 4096B  map_ids 3
>>>>           btf_id 55
>>>>      57: tracepoint  name oncpu  tag 7aa55dfbdcb78941  gpl
>>>>           loaded_at 2022-09-09T21:41:32+0800  uid 0
>>>>           xlated 456B  jited 265B  memlock 4096B  map_ids 17,13,14,15
>>>>           btf_id 82
>>>>
>>>>      $ bpftool link
>>>>      1: tracing  prog 26
>>>>           prog_type tracing  attach_type trace_fentry
>>>>      3: perf_event  prog 28
>>>>      10: perf_event  prog 57
>>>>
>>>> The autoattach optional can support tracepoints, k(ret)probes,
>>>> u(ret)probes.
>>>>
>>>> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
>>>> Signed-off-by: Wang Yufen <wangyufen@huawei.com>
>>>> ---
>>>>    tools/bpf/bpftool/prog.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++--
>>>>    1 file changed, 76 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
>>>> index c81362a..8f3afce 100644
>>>> --- a/tools/bpf/bpftool/prog.c
>>>> +++ b/tools/bpf/bpftool/prog.c
>>>> @@ -1453,6 +1453,69 @@ static int do_run(int argc, char **argv)
>>>>           return ret;
>>>>    }
>>>>
>>>> +static int
>>>> +auto_attach_program(struct bpf_program *prog, const char *path)
>>>> +{
>>>> +       struct bpf_link *link;
>>>> +       int err;
>>>> +
>>>> +       link = bpf_program__attach(prog);
>>>> +       if (!link) {
>>>> +               p_info("Program %s does not support autoattach, falling back to pinning",
>>>> +                      bpf_program__name(prog));
>>>> +               return bpf_obj_pin(bpf_program__fd(prog), path);
>>>> +       }
>>>> +       err = bpf_link__pin(link, path);
>>>> +       if (err) {
>>>> +               bpf_link__destroy(link);
>>>> +               return err;
>>>> +       }
>>> leaking link here, destroy it unconditionally. If pinning succeeded,
>>> you don't need to hold link's FD open anymore.
>> I got it, will change. Thanks！
>>
>>>> +       return 0;
>>>> +}
>>>> +
>>>> +static int pathname_concat(const char *path, const char *name, char *buf)
>>> why you didn't do the same as in libbpf? Pass buffer size explicitly
>>> instead of assuming PATH_MAX
>> The pathname_concat function is invoked only in one place and is not a
>> general function here. So, not modified. Or, can I change the "pathname_concat"
>> of libbpf to "LIBBPF_API int libbpf_pathname_concat" and use the
>> libbpf_pathname_concat directly?
> no need to reuse libbpf's helper, but I do think it's cleaner to
> specify not just buffer pointer, but also it's size, just like you do
> with any other string buffer API (like snprintf)

OK, will change in v9 too. Thanks！

>
>>
>>>> +{
>>>> +       int len;
>>>> +
>>>> +       len = snprintf(buf, PATH_MAX, "%s/%s", path, name);
>>>> +       if (len < 0)
>>>> +               return -EINVAL;
>>>> +       if (len >= PATH_MAX)
>>>> +               return -ENAMETOOLONG;
>>>> +
>>>> +       return 0;
>>>> +}
>>>> +
>>>> +static int
>>>> +auto_attach_programs(struct bpf_object *obj, const char *path)
>>>> +{
>>>> +       struct bpf_program *prog;
>>>> +       char buf[PATH_MAX];
>>>> +       int err;
>>>> +
>>>> +       bpf_object__for_each_program(prog, obj) {
>>>> +               err = pathname_concat(path, bpf_program__name(prog), buf);
>>>> +               if (err)
>>>> +                       goto err_unpin_programs;
>>>> +
>>>> +               err = auto_attach_program(prog, buf);
>>>> +               if (err)
>>>> +                       goto err_unpin_programs;
>>>> +       }
>>>> +
>>>> +       return 0;
>>>> +
>>>> +err_unpin_programs:
>>>> +       while ((prog = bpf_object__prev_program(obj, prog))) {
>>>> +               if (pathname_concat(path, bpf_program__name(prog), buf))
>>>> +                       continue;
>>>> +
>>>> +               bpf_program__unpin(prog, buf);
>>>> +       }
>>>> +
>>>> +       return err;
>>>> +}
>>>> +
>>>>    static int load_with_options(int argc, char **argv, bool first_prog_only)
>>>>    {
>>>>           enum bpf_prog_type common_prog_type = BPF_PROG_TYPE_UNSPEC;
>>>> @@ -1464,6 +1527,7 @@ static int load_with_options(int argc, char **argv, bool first_prog_only)
>>>>           struct bpf_program *prog = NULL, *pos;
>>>>           unsigned int old_map_fds = 0;
>>>>           const char *pinmaps = NULL;
>>>> +       bool auto_attach = false;
>>>>           struct bpf_object *obj;
>>>>           struct bpf_map *map;
>>>>           const char *pinfile;
>>>> @@ -1583,6 +1647,9 @@ static int load_with_options(int argc, char **argv, bool first_prog_only)
>>>>                                   goto err_free_reuse_maps;
>>>>
>>>>                           pinmaps = GET_ARG();
>>>> +               } else if (is_prefix(*argv, "autoattach")) {
>>>> +                       auto_attach = true;
>>>> +                       NEXT_ARG();
>>>>                   } else {
>>>>                           p_err("expected no more arguments, 'type', 'map' or 'dev', got: '%s'?",
>>>>                                 *argv);
>>>> @@ -1692,14 +1759,20 @@ static int load_with_options(int argc, char **argv, bool first_prog_only)
>>>>                           goto err_close_obj;
>>>>                   }
>>>>
>>>> -               err = bpf_obj_pin(bpf_program__fd(prog), pinfile);
>>>> +               if (auto_attach)
>>>> +                       err = auto_attach_program(prog, pinfile);
>>>> +               else
>>>> +                       err = bpf_obj_pin(bpf_program__fd(prog), pinfile);
>>>>                   if (err) {
>>>>                           p_err("failed to pin program %s",
>>>>                                 bpf_program__section_name(prog));
>>>>                           goto err_close_obj;
>>>>                   }
>>>>           } else {
>>>> -               err = bpf_object__pin_programs(obj, pinfile);
>>>> +               if (auto_attach)
>>>> +                       err = auto_attach_programs(obj, pinfile);
>>>> +               else
>>>> +                       err = bpf_object__pin_programs(obj, pinfile);
>>>>                   if (err) {
>>>>                           p_err("failed to pin all programs");
>>>>                           goto err_close_obj;
>>>> @@ -2338,6 +2411,7 @@ static int do_help(int argc, char **argv)
>>>>                   "                         [type TYPE] [dev NAME] \\\n"
>>>>                   "                         [map { idx IDX | name NAME } MAP]\\\n"
>>>>                   "                         [pinmaps MAP_DIR]\n"
>>>> +               "                         [autoattach]\n"
>>>>                   "       %1$s %2$s attach PROG ATTACH_TYPE [MAP]\n"
>>>>                   "       %1$s %2$s detach PROG ATTACH_TYPE [MAP]\n"
>>>>                   "       %1$s %2$s run PROG \\\n"
>>>> --
>>>> 1.8.3.1
>>>>
diff mbox series

Patch

diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index c81362a..8f3afce 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -1453,6 +1453,69 @@  static int do_run(int argc, char **argv)
 	return ret;
 }
 
+static int
+auto_attach_program(struct bpf_program *prog, const char *path)
+{
+	struct bpf_link *link;
+	int err;
+
+	link = bpf_program__attach(prog);
+	if (!link) {
+		p_info("Program %s does not support autoattach, falling back to pinning",
+		       bpf_program__name(prog));
+		return bpf_obj_pin(bpf_program__fd(prog), path);
+	}
+	err = bpf_link__pin(link, path);
+	if (err) {
+		bpf_link__destroy(link);
+		return err;
+	}
+	return 0;
+}
+
+static int pathname_concat(const char *path, const char *name, char *buf)
+{
+	int len;
+
+	len = snprintf(buf, PATH_MAX, "%s/%s", path, name);
+	if (len < 0)
+		return -EINVAL;
+	if (len >= PATH_MAX)
+		return -ENAMETOOLONG;
+
+	return 0;
+}
+
+static int
+auto_attach_programs(struct bpf_object *obj, const char *path)
+{
+	struct bpf_program *prog;
+	char buf[PATH_MAX];
+	int err;
+
+	bpf_object__for_each_program(prog, obj) {
+		err = pathname_concat(path, bpf_program__name(prog), buf);
+		if (err)
+			goto err_unpin_programs;
+
+		err = auto_attach_program(prog, buf);
+		if (err)
+			goto err_unpin_programs;
+	}
+
+	return 0;
+
+err_unpin_programs:
+	while ((prog = bpf_object__prev_program(obj, prog))) {
+		if (pathname_concat(path, bpf_program__name(prog), buf))
+			continue;
+
+		bpf_program__unpin(prog, buf);
+	}
+
+	return err;
+}
+
 static int load_with_options(int argc, char **argv, bool first_prog_only)
 {
 	enum bpf_prog_type common_prog_type = BPF_PROG_TYPE_UNSPEC;
@@ -1464,6 +1527,7 @@  static int load_with_options(int argc, char **argv, bool first_prog_only)
 	struct bpf_program *prog = NULL, *pos;
 	unsigned int old_map_fds = 0;
 	const char *pinmaps = NULL;
+	bool auto_attach = false;
 	struct bpf_object *obj;
 	struct bpf_map *map;
 	const char *pinfile;
@@ -1583,6 +1647,9 @@  static int load_with_options(int argc, char **argv, bool first_prog_only)
 				goto err_free_reuse_maps;
 
 			pinmaps = GET_ARG();
+		} else if (is_prefix(*argv, "autoattach")) {
+			auto_attach = true;
+			NEXT_ARG();
 		} else {
 			p_err("expected no more arguments, 'type', 'map' or 'dev', got: '%s'?",
 			      *argv);
@@ -1692,14 +1759,20 @@  static int load_with_options(int argc, char **argv, bool first_prog_only)
 			goto err_close_obj;
 		}
 
-		err = bpf_obj_pin(bpf_program__fd(prog), pinfile);
+		if (auto_attach)
+			err = auto_attach_program(prog, pinfile);
+		else
+			err = bpf_obj_pin(bpf_program__fd(prog), pinfile);
 		if (err) {
 			p_err("failed to pin program %s",
 			      bpf_program__section_name(prog));
 			goto err_close_obj;
 		}
 	} else {
-		err = bpf_object__pin_programs(obj, pinfile);
+		if (auto_attach)
+			err = auto_attach_programs(obj, pinfile);
+		else
+			err = bpf_object__pin_programs(obj, pinfile);
 		if (err) {
 			p_err("failed to pin all programs");
 			goto err_close_obj;
@@ -2338,6 +2411,7 @@  static int do_help(int argc, char **argv)
 		"                         [type TYPE] [dev NAME] \\\n"
 		"                         [map { idx IDX | name NAME } MAP]\\\n"
 		"                         [pinmaps MAP_DIR]\n"
+		"                         [autoattach]\n"
 		"       %1$s %2$s attach PROG ATTACH_TYPE [MAP]\n"
 		"       %1$s %2$s detach PROG ATTACH_TYPE [MAP]\n"
 		"       %1$s %2$s run PROG \\\n"