* [PATCH bpf-next] libbpf: allow disabling auto attach
@ 2022-08-16 21:49 Hao Luo
2022-08-16 22:00 ` Andrii Nakryiko
0 siblings, 1 reply; 5+ messages in thread
From: Hao Luo @ 2022-08-16 21:49 UTC (permalink / raw)
To: linux-kernel, bpf, netdev
Cc: Alexei Starovoitov, Andrii Nakryiko, Daniel Borkmann,
Martin KaFai Lau, Song Liu, Yonghong Song, KP Singh,
John Fastabend, Stanislav Fomichev, Yosry Ahmed, Jiri Olsa,
Hao Luo
Add libbpf APIs for disabling auto-attach for individual functions.
This is motivated by the use case of cgroup iter [1]. Some iter
types require their parameters to be non-zero, therefore applying
auto-attach on them will fail. With these two new APIs, Users who
want to use auto-attach and these types of iters can disable
auto-attach for them and perform manual attach.
[1] https://lore.kernel.org/bpf/CAEf4BzZ+a2uDo_t6kGBziqdz--m2gh2_EUwkGLDtMd65uwxUjA@mail.gmail.com/
Signed-off-by: Hao Luo <haoluo@google.com>
---
tools/lib/bpf/libbpf.c | 16 ++++++++++++++++
tools/lib/bpf/libbpf.h | 2 ++
2 files changed, 18 insertions(+)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index aa05a99b913d..25f654d25b46 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -417,6 +417,7 @@ struct bpf_program {
int fd;
bool autoload;
+ bool autoattach;
bool mark_btf_static;
enum bpf_prog_type type;
enum bpf_attach_type expected_attach_type;
@@ -755,6 +756,8 @@ bpf_object__init_prog(struct bpf_object *obj, struct bpf_program *prog,
prog->autoload = true;
}
+ prog->autoattach = true;
+
/* inherit object's log_level */
prog->log_level = obj->log_level;
@@ -8314,6 +8317,16 @@ int bpf_program__set_autoload(struct bpf_program *prog, bool autoload)
return 0;
}
+bool bpf_program__autoattach(const struct bpf_program *prog)
+{
+ return prog->autoattach;
+}
+
+void bpf_program__set_autoattach(struct bpf_program *prog, bool autoattach)
+{
+ prog->autoattach = autoattach;
+}
+
const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog)
{
return prog->insns;
@@ -12349,6 +12362,9 @@ int bpf_object__attach_skeleton(struct bpf_object_skeleton *s)
if (!prog->autoload)
continue;
+ if (!prog->autoattach)
+ continue;
+
/* auto-attaching not supported for this program */
if (!prog->sec_def || !prog->sec_def->prog_attach_fn)
continue;
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 61493c4cddac..88a1ac34b12a 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -260,6 +260,8 @@ LIBBPF_API const char *bpf_program__name(const struct bpf_program *prog);
LIBBPF_API const char *bpf_program__section_name(const struct bpf_program *prog);
LIBBPF_API bool bpf_program__autoload(const struct bpf_program *prog);
LIBBPF_API int bpf_program__set_autoload(struct bpf_program *prog, bool autoload);
+LIBBPF_API bool bpf_program__autoattach(const struct bpf_program *prog);
+LIBBPF_API void bpf_program__set_autoattach(struct bpf_program *prog, bool autoattach);
struct bpf_insn;
--
2.37.1.595.g718a3a8f04-goog
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH bpf-next] libbpf: allow disabling auto attach
2022-08-16 21:49 [PATCH bpf-next] libbpf: allow disabling auto attach Hao Luo
@ 2022-08-16 22:00 ` Andrii Nakryiko
2022-08-16 22:16 ` Hao Luo
0 siblings, 1 reply; 5+ messages in thread
From: Andrii Nakryiko @ 2022-08-16 22:00 UTC (permalink / raw)
To: Hao Luo
Cc: linux-kernel, bpf, netdev, Alexei Starovoitov, Andrii Nakryiko,
Daniel Borkmann, Martin KaFai Lau, Song Liu, Yonghong Song,
KP Singh, John Fastabend, Stanislav Fomichev, Yosry Ahmed,
Jiri Olsa
On Tue, Aug 16, 2022 at 2:49 PM Hao Luo <haoluo@google.com> wrote:
>
> Add libbpf APIs for disabling auto-attach for individual functions.
> This is motivated by the use case of cgroup iter [1]. Some iter
> types require their parameters to be non-zero, therefore applying
> auto-attach on them will fail. With these two new APIs, Users who
> want to use auto-attach and these types of iters can disable
> auto-attach for them and perform manual attach.
>
> [1] https://lore.kernel.org/bpf/CAEf4BzZ+a2uDo_t6kGBziqdz--m2gh2_EUwkGLDtMd65uwxUjA@mail.gmail.com/
>
> Signed-off-by: Hao Luo <haoluo@google.com>
> ---
> tools/lib/bpf/libbpf.c | 16 ++++++++++++++++
> tools/lib/bpf/libbpf.h | 2 ++
> 2 files changed, 18 insertions(+)
>
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index aa05a99b913d..25f654d25b46 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -417,6 +417,7 @@ struct bpf_program {
>
> int fd;
> bool autoload;
> + bool autoattach;
> bool mark_btf_static;
> enum bpf_prog_type type;
> enum bpf_attach_type expected_attach_type;
> @@ -755,6 +756,8 @@ bpf_object__init_prog(struct bpf_object *obj, struct bpf_program *prog,
> prog->autoload = true;
> }
>
> + prog->autoattach = true;
> +
> /* inherit object's log_level */
> prog->log_level = obj->log_level;
>
> @@ -8314,6 +8317,16 @@ int bpf_program__set_autoload(struct bpf_program *prog, bool autoload)
> return 0;
> }
>
> +bool bpf_program__autoattach(const struct bpf_program *prog)
> +{
> + return prog->autoattach;
> +}
> +
> +void bpf_program__set_autoattach(struct bpf_program *prog, bool autoattach)
> +{
> + prog->autoattach = autoattach;
> +}
> +
> const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog)
> {
> return prog->insns;
> @@ -12349,6 +12362,9 @@ int bpf_object__attach_skeleton(struct bpf_object_skeleton *s)
> if (!prog->autoload)
> continue;
>
> + if (!prog->autoattach)
> + continue;
> +
nit: I'd combine as if (!prog->autoload || !prog->autoattach), they
are very coupled in this sense
> /* auto-attaching not supported for this program */
> if (!prog->sec_def || !prog->sec_def->prog_attach_fn)
> continue;
> diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
> index 61493c4cddac..88a1ac34b12a 100644
> --- a/tools/lib/bpf/libbpf.h
> +++ b/tools/lib/bpf/libbpf.h
> @@ -260,6 +260,8 @@ LIBBPF_API const char *bpf_program__name(const struct bpf_program *prog);
> LIBBPF_API const char *bpf_program__section_name(const struct bpf_program *prog);
> LIBBPF_API bool bpf_program__autoload(const struct bpf_program *prog);
> LIBBPF_API int bpf_program__set_autoload(struct bpf_program *prog, bool autoload);
> +LIBBPF_API bool bpf_program__autoattach(const struct bpf_program *prog);
> +LIBBPF_API void bpf_program__set_autoattach(struct bpf_program *prog, bool autoattach);
please add these APIs to libbpf.map as well
it would be also nice to have a simple test validating that skeleton's
auto-attach doesn't attach program (no link will be created) if
bpf_program__set_autoattach(false) is called before. Can you please
add that as well?
>
> struct bpf_insn;
>
> --
> 2.37.1.595.g718a3a8f04-goog
>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH bpf-next] libbpf: allow disabling auto attach
2022-08-16 22:00 ` Andrii Nakryiko
@ 2022-08-16 22:16 ` Hao Luo
2022-08-16 22:55 ` Andrii Nakryiko
0 siblings, 1 reply; 5+ messages in thread
From: Hao Luo @ 2022-08-16 22:16 UTC (permalink / raw)
To: Andrii Nakryiko
Cc: linux-kernel, bpf, netdev, Alexei Starovoitov, Andrii Nakryiko,
Daniel Borkmann, Martin KaFai Lau, Song Liu, Yonghong Song,
KP Singh, John Fastabend, Stanislav Fomichev, Yosry Ahmed,
Jiri Olsa
On Tue, Aug 16, 2022 at 3:01 PM Andrii Nakryiko
<andrii.nakryiko@gmail.com> wrote:
>
> On Tue, Aug 16, 2022 at 2:49 PM Hao Luo <haoluo@google.com> wrote:
> >
> > Add libbpf APIs for disabling auto-attach for individual functions.
> > This is motivated by the use case of cgroup iter [1]. Some iter
> > types require their parameters to be non-zero, therefore applying
> > auto-attach on them will fail. With these two new APIs, Users who
> > want to use auto-attach and these types of iters can disable
> > auto-attach for them and perform manual attach.
> >
> > [1] https://lore.kernel.org/bpf/CAEf4BzZ+a2uDo_t6kGBziqdz--m2gh2_EUwkGLDtMd65uwxUjA@mail.gmail.com/
> >
> > Signed-off-by: Hao Luo <haoluo@google.com>
> > ---
> > tools/lib/bpf/libbpf.c | 16 ++++++++++++++++
> > tools/lib/bpf/libbpf.h | 2 ++
> > 2 files changed, 18 insertions(+)
> >
> > diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> > index aa05a99b913d..25f654d25b46 100644
> > --- a/tools/lib/bpf/libbpf.c
> > +++ b/tools/lib/bpf/libbpf.c
[...]
> > const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog)
> > {
> > return prog->insns;
> > @@ -12349,6 +12362,9 @@ int bpf_object__attach_skeleton(struct bpf_object_skeleton *s)
> > if (!prog->autoload)
> > continue;
> >
> > + if (!prog->autoattach)
> > + continue;
> > +
>
> nit: I'd combine as if (!prog->autoload || !prog->autoattach), they
> are very coupled in this sense
>
Sure.
> > /* auto-attaching not supported for this program */
> > if (!prog->sec_def || !prog->sec_def->prog_attach_fn)
> > continue;
> > diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
> > index 61493c4cddac..88a1ac34b12a 100644
> > --- a/tools/lib/bpf/libbpf.h
> > +++ b/tools/lib/bpf/libbpf.h
> > @@ -260,6 +260,8 @@ LIBBPF_API const char *bpf_program__name(const struct bpf_program *prog);
> > LIBBPF_API const char *bpf_program__section_name(const struct bpf_program *prog);
> > LIBBPF_API bool bpf_program__autoload(const struct bpf_program *prog);
> > LIBBPF_API int bpf_program__set_autoload(struct bpf_program *prog, bool autoload);
> > +LIBBPF_API bool bpf_program__autoattach(const struct bpf_program *prog);
> > +LIBBPF_API void bpf_program__set_autoattach(struct bpf_program *prog, bool autoattach);
>
> please add these APIs to libbpf.map as well
>
Ok. Which section? LIBBPF_1.0.0? Do the items in each section have a
particular order?
> it would be also nice to have a simple test validating that skeleton's
> auto-attach doesn't attach program (no link will be created) if
> bpf_program__set_autoattach(false) is called before. Can you please
> add that as well?
>
Ok. Will add a test and send v2.
> >
> > struct bpf_insn;
> >
> > --
> > 2.37.1.595.g718a3a8f04-goog
> >
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH bpf-next] libbpf: allow disabling auto attach
2022-08-16 22:16 ` Hao Luo
@ 2022-08-16 22:55 ` Andrii Nakryiko
2022-08-16 23:00 ` Hao Luo
0 siblings, 1 reply; 5+ messages in thread
From: Andrii Nakryiko @ 2022-08-16 22:55 UTC (permalink / raw)
To: Hao Luo
Cc: linux-kernel, bpf, netdev, Alexei Starovoitov, Andrii Nakryiko,
Daniel Borkmann, Martin KaFai Lau, Song Liu, Yonghong Song,
KP Singh, John Fastabend, Stanislav Fomichev, Yosry Ahmed,
Jiri Olsa
On Tue, Aug 16, 2022 at 3:16 PM Hao Luo <haoluo@google.com> wrote:
>
> On Tue, Aug 16, 2022 at 3:01 PM Andrii Nakryiko
> <andrii.nakryiko@gmail.com> wrote:
> >
> > On Tue, Aug 16, 2022 at 2:49 PM Hao Luo <haoluo@google.com> wrote:
> > >
> > > Add libbpf APIs for disabling auto-attach for individual functions.
> > > This is motivated by the use case of cgroup iter [1]. Some iter
> > > types require their parameters to be non-zero, therefore applying
> > > auto-attach on them will fail. With these two new APIs, Users who
> > > want to use auto-attach and these types of iters can disable
> > > auto-attach for them and perform manual attach.
> > >
> > > [1] https://lore.kernel.org/bpf/CAEf4BzZ+a2uDo_t6kGBziqdz--m2gh2_EUwkGLDtMd65uwxUjA@mail.gmail.com/
> > >
> > > Signed-off-by: Hao Luo <haoluo@google.com>
> > > ---
> > > tools/lib/bpf/libbpf.c | 16 ++++++++++++++++
> > > tools/lib/bpf/libbpf.h | 2 ++
> > > 2 files changed, 18 insertions(+)
> > >
> > > diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> > > index aa05a99b913d..25f654d25b46 100644
> > > --- a/tools/lib/bpf/libbpf.c
> > > +++ b/tools/lib/bpf/libbpf.c
> [...]
> > > const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog)
> > > {
> > > return prog->insns;
> > > @@ -12349,6 +12362,9 @@ int bpf_object__attach_skeleton(struct bpf_object_skeleton *s)
> > > if (!prog->autoload)
> > > continue;
> > >
> > > + if (!prog->autoattach)
> > > + continue;
> > > +
> >
> > nit: I'd combine as if (!prog->autoload || !prog->autoattach), they
> > are very coupled in this sense
> >
>
> Sure.
>
> > > /* auto-attaching not supported for this program */
> > > if (!prog->sec_def || !prog->sec_def->prog_attach_fn)
> > > continue;
> > > diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
> > > index 61493c4cddac..88a1ac34b12a 100644
> > > --- a/tools/lib/bpf/libbpf.h
> > > +++ b/tools/lib/bpf/libbpf.h
> > > @@ -260,6 +260,8 @@ LIBBPF_API const char *bpf_program__name(const struct bpf_program *prog);
> > > LIBBPF_API const char *bpf_program__section_name(const struct bpf_program *prog);
> > > LIBBPF_API bool bpf_program__autoload(const struct bpf_program *prog);
> > > LIBBPF_API int bpf_program__set_autoload(struct bpf_program *prog, bool autoload);
> > > +LIBBPF_API bool bpf_program__autoattach(const struct bpf_program *prog);
> > > +LIBBPF_API void bpf_program__set_autoattach(struct bpf_program *prog, bool autoattach);
> >
> > please add these APIs to libbpf.map as well
> >
>
> Ok. Which section? LIBBPF_1.0.0? Do the items in each section have a
> particular order?
Yes, 1.0.0 section. All the functions are sorted alphabetically.
> > it would be also nice to have a simple test validating that skeleton's
> > auto-attach doesn't attach program (no link will be created) if
> > bpf_program__set_autoattach(false) is called before. Can you please
> > add that as well?
> >
>
> Ok. Will add a test and send v2.
>
> > >
> > > struct bpf_insn;
> > >
> > > --
> > > 2.37.1.595.g718a3a8f04-goog
> > >
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH bpf-next] libbpf: allow disabling auto attach
2022-08-16 22:55 ` Andrii Nakryiko
@ 2022-08-16 23:00 ` Hao Luo
0 siblings, 0 replies; 5+ messages in thread
From: Hao Luo @ 2022-08-16 23:00 UTC (permalink / raw)
To: Andrii Nakryiko
Cc: linux-kernel, bpf, netdev, Alexei Starovoitov, Andrii Nakryiko,
Daniel Borkmann, Martin KaFai Lau, Song Liu, Yonghong Song,
KP Singh, John Fastabend, Stanislav Fomichev, Yosry Ahmed,
Jiri Olsa
On Tue, Aug 16, 2022 at 3:55 PM Andrii Nakryiko
<andrii.nakryiko@gmail.com> wrote:
>
> On Tue, Aug 16, 2022 at 3:16 PM Hao Luo <haoluo@google.com> wrote:
> >
> > On Tue, Aug 16, 2022 at 3:01 PM Andrii Nakryiko
> > <andrii.nakryiko@gmail.com> wrote:
> > >
> > > On Tue, Aug 16, 2022 at 2:49 PM Hao Luo <haoluo@google.com> wrote:
> > > >
> > > > Add libbpf APIs for disabling auto-attach for individual functions.
> > > > This is motivated by the use case of cgroup iter [1]. Some iter
> > > > types require their parameters to be non-zero, therefore applying
> > > > auto-attach on them will fail. With these two new APIs, Users who
> > > > want to use auto-attach and these types of iters can disable
> > > > auto-attach for them and perform manual attach.
> > > >
> > > > [1] https://lore.kernel.org/bpf/CAEf4BzZ+a2uDo_t6kGBziqdz--m2gh2_EUwkGLDtMd65uwxUjA@mail.gmail.com/
> > > >
> > > > Signed-off-by: Hao Luo <haoluo@google.com>
> > > > ---
[...]
> > > > diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
> > > > index 61493c4cddac..88a1ac34b12a 100644
> > > > --- a/tools/lib/bpf/libbpf.h
> > > > +++ b/tools/lib/bpf/libbpf.h
> > > > @@ -260,6 +260,8 @@ LIBBPF_API const char *bpf_program__name(const struct bpf_program *prog);
> > > > LIBBPF_API const char *bpf_program__section_name(const struct bpf_program *prog);
> > > > LIBBPF_API bool bpf_program__autoload(const struct bpf_program *prog);
> > > > LIBBPF_API int bpf_program__set_autoload(struct bpf_program *prog, bool autoload);
> > > > +LIBBPF_API bool bpf_program__autoattach(const struct bpf_program *prog);
> > > > +LIBBPF_API void bpf_program__set_autoattach(struct bpf_program *prog, bool autoattach);
> > >
> > > please add these APIs to libbpf.map as well
> > >
> >
> > Ok. Which section? LIBBPF_1.0.0? Do the items in each section have a
> > particular order?
>
> Yes, 1.0.0 section. All the functions are sorted alphabetically.
>
Thanks for confirming. :)
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2022-08-16 23:00 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2022-08-16 21:49 [PATCH bpf-next] libbpf: allow disabling auto attach Hao Luo
2022-08-16 22:00 ` Andrii Nakryiko
2022-08-16 22:16 ` Hao Luo
2022-08-16 22:55 ` Andrii Nakryiko
2022-08-16 23:00 ` Hao Luo
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