Merge branch 'map-pinning'

Toke Høiland-Jørgensen says:

====================
This series fixes a few bugs in libbpf that I discovered while playing around
with the new auto-pinning code, and writin

Merge branch 'map-pinning'

Toke Høiland-Jørgensen says:

====================
This series fixes a few bugs in libbpf that I discovered while playing around
with the new auto-pinning code, and writing the first utility in xdp-tools[0]:

- If object loading fails, libbpf does not clean up the pinnings created by the
auto-pinning mechanism.
- EPERM is not propagated to the caller on program load
- Netlink functions write error messages directly to stderr

In addition, libbpf currently only has a somewhat limited getter function for
XDP link info, which makes it impossible to discover whether an attached program
is in SKB mode or not. So the last patch in the series adds a new getter for XDP
link info which returns all the information returned via netlink (and which can
be extended later).

Finally, add a getter for BPF program size, which can be used by the caller to
estimate the amount of locked memory needed to load a program.

A selftest is added for the pinning change, while the other features were tested
in the xdp-filter tool from the xdp-tools repo. The 'new-libbpf-features' branch
contains the commits that make use of the new XDP getter and the corrected EPERM
error code.

[0] https://github.com/xdp-project/xdp-tools

Changelog:

v4:
- Don't do any size checks on struct xdp_info, just copy (and/or zero)
whatever size the caller supplied.

v3:
- Pass through all kernel error codes on program load (instead of just EPERM).
- No new bpf_object__unload() variant, just do the loop at the caller
- Don't reject struct xdp_info sizes that are bigger than what we expect.
- Add a comment noting that bpf_program__size() returns the size in bytes

v2:
- Keep function names in libbpf.map sorted properly
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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selftests/bpf: Add tests for automatic map unpinning on load failure

This add tests for the different variations of automatic map unpinning on
load failure.

Signed-off-by: Toke Høiland-Jørgensen <t

selftests/bpf: Add tests for automatic map unpinning on load failure

This add tests for the different variations of automatic map unpinning on
load failure.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/157333184838.88376.8243704248624814775.stgit@toke.dk

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Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Alexei Starovoitov says:

====================
pull-request: bpf-next 2019-11-02

The following pull-request contains BPF updates for

Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Alexei Starovoitov says:

====================
pull-request: bpf-next 2019-11-02

The following pull-request contains BPF updates for your *net-next* tree.

We've added 30 non-merge commits during the last 7 day(s) which contain
a total of 41 files changed, 1864 insertions(+), 474 deletions(-).

The main changes are:

1) Fix long standing user vs kernel access issue by introducing
bpf_probe_read_user() and bpf_probe_read_kernel() helpers, from Daniel.

2) Accelerated xskmap lookup, from Björn and Maciej.

3) Support for automatic map pinning in libbpf, from Toke.

4) Cleanup of BTF-enabled raw tracepoints, from Alexei.

5) Various fixes to libbpf and selftests.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

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Merge branch 'map-pinning'

Toke Høiland-Jørgensen says:

====================
This series adds support to libbpf for reading 'pinning' settings from BTF-based
map definitions. It introduces a new op

Merge branch 'map-pinning'

Toke Høiland-Jørgensen says:

====================
This series adds support to libbpf for reading 'pinning' settings from BTF-based
map definitions. It introduces a new open option which can set the pinning path;
if no path is set, /sys/fs/bpf is used as the default. Callers can customise the
pinning between open and load by setting the pin path per map, and still get the
automatic reuse feature.

The semantics of the pinning is similar to the iproute2 "PIN_GLOBAL" setting,
and the eventual goal is to move the iproute2 implementation to be based on
libbpf and the functions introduced in this series.

Changelog:

v6:
- Fix leak of struct bpf_object in selftest
- Make struct bpf_map arg const in bpf_map__is_pinned() and bpf_map__get_pin_path()

v5:
- Don't pin maps with pinning set, but with a value of LIBBPF_PIN_NONE
- Add a few more selftests:
- Should not pin map with pinning set, but value LIBBPF_PIN_NONE
- Should fail to load a map with an invalid pinning value
- Should fail to re-use maps with parameter mismatch
- Alphabetise libbpf.map
- Whitespace and typo fixes

v4:
- Don't check key_type_id and value_type_id when checking for map reuse
compatibility.
- Move building of map->pin_path into init_user_btf_map()
- Get rid of 'pinning' attribute in struct bpf_map
- Make sure we also create parent directory on auto-pin (new patch 3).
- Abort the selftest on error instead of attempting to continue.
- Support unpinning all pinned maps with bpf_object__unpin_maps(obj, NULL)
- Support pinning at map->pin_path with bpf_object__pin_maps(obj, NULL)
- Make re-pinning a map at the same path a noop
- Rename the open option to pin_root_path
- Add a bunch more self-tests for pin_maps(NULL) and unpin_maps(NULL)
- Fix a couple of smaller nits

v3:
- Drop bpf_object__pin_maps_opts() and just use an open option to customise
the pin path; also don't touch bpf_object__{un,}pin_maps()
- Integrate pinning and reuse into bpf_object__create_maps() instead of having
multiple loops though the map structure
- Make errors in map reuse and pinning fatal to the load procedure
- Add selftest to exercise pinning feature
- Rebase series to latest bpf-next

v2:
- Drop patch that adds mounting of bpffs
- Only support a single value of the pinning attribute
- Add patch to fixup error handling in reuse_fd()
- Implement the full automatic pinning and map reuse logic on load
====================

Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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selftests: Add tests for automatic map pinning

This adds a new BPF selftest to exercise the new automatic map pinning
code.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Al

selftests: Add tests for automatic map pinning

This adds a new BPF selftest to exercise the new automatic map pinning
code.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157269298209.394725.15420085139296213182.stgit@toke.dk

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