linux.git/tools/lib/bpf/libbpf.h, branch v5.5

libbpf: Add support for attaching BPF programs to other BPF programs

2019-11-15T22:45:37+00:00

Extend libbpf api to pass attach_prog_fd into bpf_object__open.

Signed-off-by: Alexei Starovoitov 
Signed-off-by: Daniel Borkmann 
Acked-by: Song Liu 
Link: https://lore.kernel.org/bpf/20191114185720.1641606-19-ast@kernel.org

libbpf: Add support to attach to fentry/fexit tracing progs

2019-11-15T22:42:31+00:00

Teach libbpf to recognize tracing programs types and attach them to
fentry/fexit.

Signed-off-by: Alexei Starovoitov 
Signed-off-by: Daniel Borkmann 
Acked-by: Song Liu 
Acked-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20191114185720.1641606-7-ast@kernel.org

libbpf: Add getter for program size

2019-11-11T03:26:30+00:00

This adds a new getter for the BPF program size (in bytes). This is useful
for a caller that is trying to predict how much memory will be locked by
loading a BPF object into the kernel.

Signed-off-by: Toke Høiland-Jørgensen 
Signed-off-by: Alexei Starovoitov 
Acked-by: Andrii Nakryiko 
Acked-by: David S. Miller 
Acked-by: Song Liu 
Link: https://lore.kernel.org/bpf/157333185272.88376.10996937115395724683.stgit@toke.dk

libbpf: Add bpf_get_link_xdp_info() function to get more XDP information

2019-11-11T03:26:30+00:00

Currently, libbpf only provides a function to get a single ID for the XDP
program attached to the interface. However, it can be useful to get the
full set of program IDs attached, along with the attachment mode, in one
go. Add a new getter function to support this, using an extendible
structure to carry the information. Express the old bpf_get_link_id()
function in terms of the new function.

Signed-off-by: Toke Høiland-Jørgensen 
Signed-off-by: Alexei Starovoitov 
Acked-by: David S. Miller 
Acked-by: Song Liu 
Acked-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/157333185164.88376.7520653040667637246.stgit@toke.dk

libbpf: Add auto-pinning of maps when loading BPF objects

2019-11-02T19:35:07+00:00

This adds support to libbpf for setting map pinning information as part of
the BTF map declaration, to get automatic map pinning (and reuse) on load.
The pinning type currently only supports a single PIN_BY_NAME mode, where
each map will be pinned by its name in a path that can be overridden, but
defaults to /sys/fs/bpf.

Since auto-pinning only does something if any maps actually have a
'pinning' BTF attribute set, we default the new option to enabled, on the
assumption that seamless pinning is what most callers want.

When a map has a pin_path set at load time, libbpf will compare the map
pinned at that location (if any), and if the attributes match, will re-use
that map instead of creating a new one. If no existing map is found, the
newly created map will instead be pinned at the location.

Programs wanting to customise the pinning can override the pinning paths
using bpf_map__set_pin_path() before calling bpf_object__load() (including
setting it to NULL to disable pinning of a particular map).

Signed-off-by: Toke Høiland-Jørgensen 
Signed-off-by: Alexei Starovoitov 
Acked-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/157269298092.394725.3966306029218559681.stgit@toke.dk

libbpf: Store map pin path and status in struct bpf_map

2019-11-02T19:35:07+00:00

Support storing and setting a pin path in struct bpf_map, which can be used
for automatic pinning. Also store the pin status so we can avoid attempts
to re-pin a map that has already been pinned (or reused from a previous
pinning).

The behaviour of bpf_object__{un,}pin_maps() is changed so that if it is
called with a NULL path argument (which was previously illegal), it will
(un)pin only those maps that have a pin_path set.

Signed-off-by: Toke Høiland-Jørgensen 
Signed-off-by: Alexei Starovoitov 
Acked-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/157269297876.394725.14782206533681896279.stgit@toke.dk

libbpf: Add support for prog_tracing

2019-10-31T14:16:59+00:00

Cleanup libbpf from expected_attach_type == attach_btf_id hack
and introduce BPF_PROG_TYPE_TRACING.

Signed-off-by: Alexei Starovoitov 
Signed-off-by: Daniel Borkmann 
Acked-by: Andrii Nakryiko 
Acked-by: Martin KaFai Lau 
Link: https://lore.kernel.org/bpf/20191030223212.953010-3-ast@kernel.org

libbpf: Make DECLARE_LIBBPF_OPTS macro strictly a variable declaration

2019-10-22T19:35:03+00:00

LIBBPF_OPTS is implemented as a mix of field declaration and memset
+ assignment. This makes it neither variable declaration nor purely
statements, which is a problem, because you can't mix it with either
other variable declarations nor other function statements, because C90
compiler mode emits warning on mixing all that together.

This patch changes LIBBPF_OPTS into a strictly declaration of variable
and solves this problem, as can be seen in case of bpftool, which
previously would emit compiler warning, if done this way (LIBBPF_OPTS as
part of function variables declaration block).

This patch also renames LIBBPF_OPTS into DECLARE_LIBBPF_OPTS to follow
kernel convention for similar macros more closely.

v1->v2:
- rename LIBBPF_OPTS into DECLARE_LIBBPF_OPTS (Jakub Sitnicki).

Signed-off-by: Andrii Nakryiko 
Signed-off-by: Daniel Borkmann 
Acked-by: Toke Høiland-Jørgensen 
Link: https://lore.kernel.org/bpf/20191022172100.3281465-1-andriin@fb.com

libbpf: Add bpf_program__get_{type, expected_attach_type) APIs

2019-10-21T12:49:12+00:00

There are bpf_program__set_type() and
bpf_program__set_expected_attach_type(), but no corresponding getters,
which seems rather incomplete. Fix this.

Signed-off-by: Andrii Nakryiko 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20191021033902.3856966-3-andriin@fb.com

libbpf: Add support for field existance CO-RE relocation

2019-10-15T23:06:05+00:00

Add support for BPF_FRK_EXISTS relocation kind to detect existence of
captured field in a destination BTF, allowing conditional logic to
handle incompatible differences between kernels.

Also introduce opt-in relaxed CO-RE relocation handling option, which
makes libbpf emit warning for failed relocations, but proceed with other
relocations. Instruction, for which relocation failed, is patched with
(u32)-1 value.

Signed-off-by: Andrii Nakryiko 
Signed-off-by: Alexei Starovoitov 
Link: https://lore.kernel.org/bpf/20191015182849.3922287-4-andriin@fb.com