Commit Graph

1121150 Commits

Author SHA1 Message Date
Benjamin Tissoires
b88df69796 bpf: prepare for more bpf syscall to be used from kernel and user space.
Add BPF_MAP_GET_FD_BY_ID and BPF_MAP_DELETE_PROG.

Only BPF_MAP_GET_FD_BY_ID needs to be amended to be able
to access the bpf pointer either from the userspace or the kernel.

Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20220824134055.1328882-7-benjamin.tissoires@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-25 18:52:05 -07:00
Hao Luo
d4ffb6f39f bpf: Add CGROUP prefix to cgroup_iter_order
bpf_cgroup_iter_order is globally visible but the entries do not have
CGROUP prefix. As requested by Andrii, put a CGROUP in the names
in bpf_cgroup_iter_order.

This patch fixes two previous commits: one introduced the API and
the other uses the API in bpf selftest (that is, the selftest
cgroup_hierarchical_stats).

I tested this patch via the following command:

  test_progs -t cgroup,iter,btf_dump

Fixes: d4ccaf58a8 ("bpf: Introduce cgroup iter")
Fixes: 88886309d2 ("selftests/bpf: add a selftest for cgroup hierarchical stats collection")
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Hao Luo <haoluo@google.com>
Link: https://lore.kernel.org/r/20220825223936.1865810-1-haoluo@google.com
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
2022-08-25 16:26:37 -07:00
Eyal Birger
0a0d55ef3e bpf/scripts: Assert helper enum value is aligned with comment order
The helper value is ABI as defined by enum bpf_func_id.
As bpf_helper_defs.h is used for the userpace part, it must be consistent
with this enum.

Before this change the comments order was used by the bpf_doc script in
order to set the helper values defined in the helpers file.

When adding new helpers it is very puzzling when the userspace application
breaks in weird places if the comment is inserted instead of appended -
because the generated helper ABI is incorrect and shifted.

This commit sets the helper value to the enum value.

In addition it is currently the practice to have the comments appended
and kept in the same order as the enum. As such, add an assertion
validating the comment order is consistent with enum value.

In case a different comments ordering is desired, this assertion can
be lifted.

Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20220824181043.1601429-1-eyal.birger@gmail.com
2022-08-25 11:49:14 -07:00
Lam Thai
7184aef9c0 bpftool: Fix a wrong type cast in btf_dumper_int
When `data` points to a boolean value, casting it to `int *` is problematic
and could lead to a wrong value being passed to `jsonw_bool`. Change the
cast to `bool *` instead.

Fixes: b12d6ec097 ("bpf: btf: add btf print functionality")
Signed-off-by: Lam Thai <lamthai@arista.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20220824225859.9038-1-lamthai@arista.com
2022-08-25 11:43:08 -07:00
Alexei Starovoitov
eef3c3d337 Merge branch 'bpf: rstat: cgroup hierarchical'
Hao Luo says:

====================

This patch series allows for using bpf to collect hierarchical cgroup
stats efficiently by integrating with the rstat framework. The rstat
framework provides an efficient way to collect cgroup stats percpu and
propagate them through the cgroup hierarchy.

The stats are exposed to userspace in textual form by reading files in
bpffs, similar to cgroupfs stats by using a cgroup_iter program.
cgroup_iter is a type of bpf_iter. It walks over cgroups in four modes:
- walking a cgroup's descendants in pre-order.
- walking a cgroup's descendants in post-order.
- walking a cgroup's ancestors.
- process only a single object.

When attaching cgroup_iter, one needs to set a cgroup to the iter_link
created from attaching. This cgroup can be passed either as a file
descriptor or a cgroup id. That cgroup serves as the starting point of
the walk.

One can also terminate the walk early by returning 1 from the iter
program.

Note that because walking cgroup hierarchy holds cgroup_mutex, the iter
program is called with cgroup_mutex held.

** Background on rstat for stats collection **
(I am using a subscriber analogy that is not commonly used)

The rstat framework maintains a tree of cgroups that have updates and
which cpus have updates. A subscriber to the rstat framework maintains
their own stats. The framework is used to tell the subscriber when
and what to flush, for the most efficient stats propagation. The
workflow is as follows:

- When a subscriber updates a cgroup on a cpu, it informs the rstat
  framework by calling cgroup_rstat_updated(cgrp, cpu).

- When a subscriber wants to read some stats for a cgroup, it asks
  the rstat framework to initiate a stats flush (propagation) by calling
  cgroup_rstat_flush(cgrp).

- When the rstat framework initiates a flush, it makes callbacks to
  subscribers to aggregate stats on cpus that have updates, and
  propagate updates to their parent.

Currently, the main subscribers to the rstat framework are cgroup
subsystems (e.g. memory, block). This patch series allow bpf programs to
become subscribers as well.

Patches in this series are organized as follows:
* Patches 1-2 introduce cgroup_iter prog, and a selftest.
* Patches 3-5 allow bpf programs to integrate with rstat by adding the
  necessary hook points and kfunc. A comprehensive selftest that
  demonstrates the entire workflow for using bpf and rstat to
  efficiently collect and output cgroup stats is added.
---
Changelog:
v8 -> v9:
- Make UNSPEC (an invalid option) as the default order for cgroup_iter.
- Use enum for specifying cgroup_iter order, instead of u32.
- Add BPF_ITER_RESHCED to cgroup_iter.
- Add cgroup_hierarchical_stats to s390x denylist.

v7 -> v8:
- Removed the confusing BPF_ITER_DEFAULT (Andrii)
- s/SELF/SELF_ONLY/g
- Fixed typo (e.g. outputing) (Andrii)
- Use "descendants_pre", "descendants_post" etc. instead of "pre",
  "post" (Andrii)

v6 -> v7:
- Updated commit/comments in cgroup_iter for read() behavior (Yonghong)
- Extracted BPF_ITER_SELF and other options out of cgroup_iter, so
  that they can be used in other iters. Also renamed them. (Andrii)
- Supports both cgroup_fd and cgroup_id when specifying target cgroup.
  (Andrii)
- Avoided using macro for formatting expected output in cgroup_iter
  selftest. (Andrii)
- Applied 'static' on all vars and functions in cgroup_iter selftest.
  (Andrii)
- Fixed broken buf reading in cgroup_iter selftest. (Andrii)
- Switched to use bpf_link__destroy() unconditionally. (Andrii)
- Removed 'volatile' for non-const global vars in selftests. (Andrii)
- Started using bpf_core_enum_value() to get memory_cgrp_id. (Andrii)

v5 -> v6:
- Rebased on bpf-next
- Tidy up cgroup_hierarchical_stats test (Andrii)
  * 'static' and 'inline'
  * avoid using libbpf_get_error()
  * string literals of cgroup paths.
- Rename patch 8/8 to 'selftests/bpf' (Yonghong)
- Fix cgroup_iter comments (e.g. PAGE_SIZE and uapi) (Yonghong)
- Make sure further read() returns OK after previous read() finished
  properly (Yonghong)
- Release cgroup_mutex before the last call of show() (Kumar)

v4 -> v5:
- Rebased on top of new kfunc flags infrastructure, updated patch 1 and
  patch 6 accordingly.
- Added docs for sleepable kfuncs.

v3 -> v4:
- cgroup_iter:
  * reorder fields in bpf_link_info to avoid break uapi (Yonghong)
  * comment the behavior when cgroup_fd=0 (Yonghong)
  * comment on the limit of number of cgroups supported by cgroup_iter.
    (Yonghong)
- cgroup_hierarchical_stats selftest:
  * Do not return -1 if stats are not found (causes overflow in userspace).
  * Check if child process failed to join cgroup.
  * Make buf and path arrays in get_cgroup_vmscan_delay() static.
  * Increase the test map sizes to accomodate cgroups that are not
    created by the test.

v2 -> v3:
- cgroup_iter:
  * Added conditional compilation of cgroup_iter.c in kernel/bpf/Makefile
    (kernel test) and dropped the !CONFIG_CGROUP patch.
  * Added validation of traversal_order when attaching (Yonghong).
  * Fixed previous wording "two modes" to "three modes" (Yonghong).
  * Fixed the btf_dump selftest broken by this patch (Yonghong).
  * Fixed ctx_arg_info[0] to use "PTR_TO_BTF_ID_OR_NULL" instead of
    "PTR_TO_BTF_ID", because the "cgroup" pointer passed to iter prog can
     be null.
- Use __diag_push to eliminate __weak noinline warning in
  bpf_rstat_flush().
- cgroup_hierarchical_stats selftest:
  * Added write_cgroup_file_parent() helper.
  * Added error handling for failed map updates.
  * Added null check for cgroup in vmscan_flush.
  * Fixed the signature of vmscan_[start/end].
  * Correctly return error code when attaching trace programs fail.
  * Make sure all links are destroyed correctly and not leaking in
    cgroup_hierarchical_stats selftest.
  * Use memory.reclaim instead of memory.high as a more reliable way to
    invoke reclaim.
  * Eliminated sleeps, the test now runs faster.

v1 -> v2:
- Redesign of cgroup_iter from v1, based on Alexei's idea [1]:
  * supports walking cgroup subtree.
  * supports walking ancestors of a cgroup. (Andrii)
  * supports terminating the walk early.
  * uses fd instead of cgroup_id as parameter for iter_link. Using fd is
    a convention in bpf.
  * gets cgroup's ref at attach time and deref at detach.
  * brought back cgroup1 support for cgroup_iter.
- Squashed the patches adding the rstat flush hook points and kfuncs
  (Tejun).
- Added a comment explaining why bpf_rstat_flush() needs to be weak
  (Tejun).
- Updated the final selftest with the new cgroup_iter design.
- Changed CHECKs in the selftest with ASSERTs (Yonghong, Andrii).
- Removed empty line at the end of the selftest (Yonghong).
- Renamed test files to cgroup_hierarchical_stats.c.
- Reordered CGROUP_PATH params order to match struct declaration
  in the selftest (Michal).
- Removed memory_subsys_enabled() and made sure memcg controller
  enablement checks make sense and are documented (Michal).

RFC v2 -> v1:
- Instead of introducing a new program type for rstat flushing, add an
  empty hook point, bpf_rstat_flush(), and use fentry bpf programs to
  attach to it and flush bpf stats.
- Instead of using helpers, use kfuncs for rstat functions.
- These changes simplify the patchset greatly, with minimal changes to
  uapi.

RFC v1 -> RFC v2:
- Instead of rstat flush programs attach to subsystems, they now attach
  to rstat (global flushers, not per-subsystem), based on discussions
  with Tejun. The first patch is entirely rewritten.
- Pass cgroup pointers to rstat flushers instead of cgroup ids. This is
  much more flexibility and less likely to need a uapi update later.
- rstat helpers are now only defined if CGROUP_CONFIG.
- Most of the code is now only defined if CGROUP_CONFIG and
  CONFIG_BPF_SYSCALL.
- Move rstat helper protos from bpf_base_func_proto() to
  tracing_prog_func_proto().
- rstat helpers argument (cgroup pointer) is now ARG_PTR_TO_BTF_ID, not
  ARG_ANYTHING.
- Rewrote the selftest to use the cgroup helpers.
- Dropped bpf_map_lookup_percpu_elem (already added by Feng).
- Dropped patch to support cgroup v1 for cgroup_iter.
- Dropped patch to define some cgroup_put() when !CONFIG_CGROUP. The
  code that calls it is no longer compiled when !CONFIG_CGROUP.

cgroup_iter was originally introduced in a different patch series[2].
Hao and I agreed that it fits better as part of this series.
RFC v1 of this patch series had the following changes from [2]:
- Getting the cgroup's reference at the time at attaching, instead of
  at the time when iterating. (Yonghong)
- Remove .init_seq_private and .fini_seq_private callbacks for
  cgroup_iter. They are not needed now. (Yonghong)

[1] https://lore.kernel.org/bpf/20220520221919.jnqgv52k4ajlgzcl@MBP-98dd607d3435.dhcp.thefacebook.com/
[2] https://lore.kernel.org/lkml/20220225234339.2386398-9-haoluo@google.com/

Hao Luo (2):
  bpf: Introduce cgroup iter
  selftests/bpf: Test cgroup_iter.
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-25 11:35:38 -07:00
Yosry Ahmed
88886309d2 selftests/bpf: add a selftest for cgroup hierarchical stats collection
Add a selftest that tests the whole workflow for collecting,
aggregating (flushing), and displaying cgroup hierarchical stats.

TL;DR:
- Userspace program creates a cgroup hierarchy and induces memcg reclaim
  in parts of it.
- Whenever reclaim happens, vmscan_start and vmscan_end update
  per-cgroup percpu readings, and tell rstat which (cgroup, cpu) pairs
  have updates.
- When userspace tries to read the stats, vmscan_dump calls rstat to flush
  the stats, and outputs the stats in text format to userspace (similar
  to cgroupfs stats).
- rstat calls vmscan_flush once for every (cgroup, cpu) pair that has
  updates, vmscan_flush aggregates cpu readings and propagates updates
  to parents.
- Userspace program makes sure the stats are aggregated and read
  correctly.

Detailed explanation:
- The test loads tracing bpf programs, vmscan_start and vmscan_end, to
  measure the latency of cgroup reclaim. Per-cgroup readings are stored in
  percpu maps for efficiency. When a cgroup reading is updated on a cpu,
  cgroup_rstat_updated(cgroup, cpu) is called to add the cgroup to the
  rstat updated tree on that cpu.

- A cgroup_iter program, vmscan_dump, is loaded and pinned to a file, for
  each cgroup. Reading this file invokes the program, which calls
  cgroup_rstat_flush(cgroup) to ask rstat to propagate the updates for all
  cpus and cgroups that have updates in this cgroup's subtree. Afterwards,
  the stats are exposed to the user. vmscan_dump returns 1 to terminate
  iteration early, so that we only expose stats for one cgroup per read.

- An ftrace program, vmscan_flush, is also loaded and attached to
  bpf_rstat_flush. When rstat flushing is ongoing, vmscan_flush is invoked
  once for each (cgroup, cpu) pair that has updates. cgroups are popped
  from the rstat tree in a bottom-up fashion, so calls will always be
  made for cgroups that have updates before their parents. The program
  aggregates percpu readings to a total per-cgroup reading, and also
  propagates them to the parent cgroup. After rstat flushing is over, all
  cgroups will have correct updated hierarchical readings (including all
  cpus and all their descendants).

- Finally, the test creates a cgroup hierarchy and induces memcg reclaim
  in parts of it, and makes sure that the stats collection, aggregation,
  and reading workflow works as expected.

Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Hao Luo <haoluo@google.com>
Link: https://lore.kernel.org/r/20220824233117.1312810-6-haoluo@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-25 11:35:37 -07:00
Yosry Ahmed
434992bb60 selftests/bpf: extend cgroup helpers
This patch extends bpf selft cgroup_helpers [ID] n various ways:
- Add enable_controllers() that allows tests to enable all or a
  subset of controllers for a specific cgroup.
- Add join_cgroup_parent(). The cgroup workdir is based on the pid,
  therefore a spawned child cannot join the same cgroup hierarchy of the
  test through join_cgroup(). join_cgroup_parent() is used in child
  processes to join a cgroup under the parent's workdir.
- Add write_cgroup_file() and write_cgroup_file_parent() (similar to
  join_cgroup_parent() above).
- Add get_root_cgroup() for tests that need to do checks on root cgroup.
- Distinguish relative and absolute cgroup paths in function arguments.
  Now relative paths are called relative_path, and absolute paths are
  called cgroup_path.

Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Hao Luo <haoluo@google.com>
Link: https://lore.kernel.org/r/20220824233117.1312810-5-haoluo@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-25 11:35:37 -07:00
Yosry Ahmed
a319185be9 cgroup: bpf: enable bpf programs to integrate with rstat
Enable bpf programs to make use of rstat to collect cgroup hierarchical
stats efficiently:
- Add cgroup_rstat_updated() kfunc, for bpf progs that collect stats.
- Add cgroup_rstat_flush() sleepable kfunc, for bpf progs that read stats.
- Add an empty bpf_rstat_flush() hook that is called during rstat
  flushing, for bpf progs that flush stats to attach to. Attaching a bpf
  prog to this hook effectively registers it as a flush callback.

Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Hao Luo <haoluo@google.com>
Link: https://lore.kernel.org/r/20220824233117.1312810-4-haoluo@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-25 11:35:37 -07:00
Hao Luo
fe0dd9d4b7 selftests/bpf: Test cgroup_iter.
Add a selftest for cgroup_iter. The selftest creates a mini cgroup tree
of the following structure:

    ROOT (working cgroup)
     |
   PARENT
  /      \
CHILD1  CHILD2

and tests the following scenarios:

 - invalid cgroup fd.
 - pre-order walk over descendants from PARENT.
 - post-order walk over descendants from PARENT.
 - walk of ancestors from PARENT.
 - process only a single object (i.e. PARENT).
 - early termination.

Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Hao Luo <haoluo@google.com>
Link: https://lore.kernel.org/r/20220824233117.1312810-3-haoluo@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-25 11:35:37 -07:00
Hao Luo
d4ccaf58a8 bpf: Introduce cgroup iter
Cgroup_iter is a type of bpf_iter. It walks over cgroups in four modes:

 - walking a cgroup's descendants in pre-order.
 - walking a cgroup's descendants in post-order.
 - walking a cgroup's ancestors.
 - process only the given cgroup.

When attaching cgroup_iter, one can set a cgroup to the iter_link
created from attaching. This cgroup is passed as a file descriptor
or cgroup id and serves as the starting point of the walk. If no
cgroup is specified, the starting point will be the root cgroup v2.

For walking descendants, one can specify the order: either pre-order or
post-order. For walking ancestors, the walk starts at the specified
cgroup and ends at the root.

One can also terminate the walk early by returning 1 from the iter
program.

Note that because walking cgroup hierarchy holds cgroup_mutex, the iter
program is called with cgroup_mutex held.

Currently only one session is supported, which means, depending on the
volume of data bpf program intends to send to user space, the number
of cgroups that can be walked is limited. For example, given the current
buffer size is 8 * PAGE_SIZE, if the program sends 64B data for each
cgroup, assuming PAGE_SIZE is 4kb, the total number of cgroups that can
be walked is 512. This is a limitation of cgroup_iter. If the output
data is larger than the kernel buffer size, after all data in the
kernel buffer is consumed by user space, the subsequent read() syscall
will signal EOPNOTSUPP. In order to work around, the user may have to
update their program to reduce the volume of data sent to output. For
example, skip some uninteresting cgroups. In future, we may extend
bpf_iter flags to allow customizing buffer size.

Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Hao Luo <haoluo@google.com>
Link: https://lore.kernel.org/r/20220824233117.1312810-2-haoluo@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-25 11:35:37 -07:00
Yang Yingliang
7e165d1939 selftests/bpf: Fix wrong size passed to bpf_setsockopt()
sizeof(new_cc) is not real memory size that new_cc points to; introduce
a new_cc_len to store the size and then pass it to bpf_setsockopt().

Fixes: 31123c0360 ("selftests/bpf: bpf_setsockopt tests")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220824013907.380448-1-yangyingliang@huawei.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-24 18:59:04 -07:00
Daniel Müller
b03914f7ff selftests/bpf: Add cb_refs test to s390x deny list
The cb_refs BPF selftest is failing execution on s390x machines. This is
a newly added test that requires a feature not presently supported on
this architecture.

Denylist the test for this architecture.

Fixes: 3cf7e7d8685c ("selftests/bpf: Add tests for reference state fixes for callbacks")
Signed-off-by: Daniel Müller <deso@posteo.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220824163906.1186832-1-deso@posteo.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-24 18:59:04 -07:00
Alexei Starovoitov
096830808c Merge branch 'Fix reference state management for synchronous callbacks'
Kumar Kartikeya Dwivedi says:

====================

This is patch 1, 2 + their individual tests split into a separate series from
the RFC, so that these can be taken in, while we continue working towards a fix
for handling stack access inside the callback.

Changelog:
----------
v1 -> v2:
v1: https://lore.kernel.org/bpf/20220822131923.21476-1-memxor@gmail.com

  * Fix error for test_progs-no_alu32 due to distinct alloc_insn in errstr

RFC v1 -> v1:
RFC v1: https://lore.kernel.org/bpf/20220815051540.18791-1-memxor@gmail.com

  * Fix up commit log to add more explanation (Alexei)
  * Split reference state fix out into a separate series
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-24 17:54:44 -07:00
Kumar Kartikeya Dwivedi
35f14dbd2f selftests/bpf: Add tests for reference state fixes for callbacks
These are regression tests to ensure we don't end up in invalid runtime
state for helpers that execute callbacks multiple times. It exercises
the fixes to verifier callback handling for reference state in previous
patches.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220823013226.24988-1-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-24 17:54:40 -07:00
Kumar Kartikeya Dwivedi
9d9d00ac29 bpf: Fix reference state management for synchronous callbacks
Currently, verifier verifies callback functions (sync and async) as if
they will be executed once, (i.e. it explores execution state as if the
function was being called once). The next insn to explore is set to
start of subprog and the exit from nested frame is handled using
curframe > 0 and prepare_func_exit. In case of async callback it uses a
customized variant of push_stack simulating a kind of branch to set up
custom state and execution context for the async callback.

While this approach is simple and works when callback really will be
executed only once, it is unsafe for all of our current helpers which
are for_each style, i.e. they execute the callback multiple times.

A callback releasing acquired references of the caller may do so
multiple times, but currently verifier sees it as one call inside the
frame, which then returns to caller. Hence, it thinks it released some
reference that the cb e.g. got access through callback_ctx (register
filled inside cb from spilled typed register on stack).

Similarly, it may see that an acquire call is unpaired inside the
callback, so the caller will copy the reference state of callback and
then will have to release the register with new ref_obj_ids. But again,
the callback may execute multiple times, but the verifier will only
account for acquired references for a single symbolic execution of the
callback, which will cause leaks.

Note that for async callback case, things are different. While currently
we have bpf_timer_set_callback which only executes it once, even for
multiple executions it would be safe, as reference state is NULL and
check_reference_leak would force program to release state before
BPF_EXIT. The state is also unaffected by analysis for the caller frame.
Hence async callback is safe.

Since we want the reference state to be accessible, e.g. for pointers
loaded from stack through callback_ctx's PTR_TO_STACK, we still have to
copy caller's reference_state to callback's bpf_func_state, but we
enforce that whatever references it adds to that reference_state has
been released before it hits BPF_EXIT. This requires introducing a new
callback_ref member in the reference state to distinguish between caller
vs callee references. Hence, check_reference_leak now errors out if it
sees we are in callback_fn and we have not released callback_ref refs.
Since there can be multiple nested callbacks, like frame 0 -> cb1 -> cb2
etc. we need to also distinguish between whether this particular ref
belongs to this callback frame or parent, and only error for our own, so
we store state->frameno (which is always non-zero for callbacks).

In short, callbacks can read parent reference_state, but cannot mutate
it, to be able to use pointers acquired by the caller. They must only
undo their changes (by releasing their own acquired_refs before
BPF_EXIT) on top of caller reference_state before returning (at which
point the caller and callback state will match anyway, so no need to
copy it back to caller).

Fixes: 69c087ba62 ("bpf: Add bpf_for_each_map_elem() helper")
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220823013125.24938-1-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-24 17:54:08 -07:00
Kumar Kartikeya Dwivedi
5679ff2f13 bpf: Move bpf_loop and bpf_for_each_map_elem under CAP_BPF
They would require func_info which needs prog BTF anyway. Loading BTF
and setting the prog btf_fd while loading the prog indirectly requires
CAP_BPF, so just to reduce confusion, move both these helpers taking
callback under bpf_capable() protection as well, since they cannot be
used without CAP_BPF.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220823013117.24916-1-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-23 16:21:59 -07:00
Alexei Starovoitov
f52c894734 Merge branch 'bpf: expose bpf_{g,s}et_retval to more cgroup hooks'
Stanislav Fomichev says:

====================

Apparently, only a small subset of cgroup hooks actually falls
back to cgroup_base_func_proto. This leads to unexpected result
where not all cgroup helpers have bpf_{g,s}et_retval.

It's getting harder and harder to manage which helpers are exported
to which hooks. We now have the following call chains:

- cg_skb_func_proto
  - sk_filter_func_proto
    - bpf_sk_base_func_proto
      - bpf_base_func_proto

So by looking at cg_skb_func_proto it's pretty hard to understand
what's going on.

For cgroup helpers, I'm proposing we do the following instead:

  func_proto = cgroup_common_func_proto();
  if (func_proto) return func_proto;

  /* optional, if hook has 'current' */
  func_proto = cgroup_current_func_proto();
  if (func_proto) return func_proto;

  ...

  switch (func_id) {
  /* hook specific helpers */
  case BPF_FUNC_hook_specific_helper:
    return &xyz;
  default:
    /* always fall back to plain bpf_base_func_proto */
    bpf_base_func_proto(func_id);
  }

If this turns out more workable, we can follow up with converting
the rest to the same pattern.

v5:
- remove net/cls_cgroup.h include from patch 1/5 (Martin)
- move endif changes from patch 1/5 to 3/5 (Martin)
- don't define __weak protos, the ones in core.c suffice (Martin)

v4:
- don't touch existing helper.c helpers (Martin)
- drop unneeded CONFIG_CGROUP_BPF in bpf_lsm_func_proto (Martin)

v3:
- expose strtol/strtoul everywhere (Martin)
- move helpers declarations from bpf.h to bpf-cgroup.h (Martin)
- revise bpf_{g,s}et_retval documentation (Martin)
- don't expose bpf_{g,s}et_retval to cg_skb hooks (Martin)

v2:
- move everything into kernel/bpf/cgroup.c instead (Martin)
- use cgroup_common_func_proto in lsm (Martin)
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-23 16:08:22 -07:00
Stanislav Fomichev
e7215f5740 selftests/bpf: Make sure bpf_{g,s}et_retval is exposed everywhere
For each hook, have a simple bpf_set_retval(bpf_get_retval) program
and make sure it loads for the hooks we want. The exceptions are
the hooks which don't propagate the error to the callers:

- sockops
- recvmsg
- getpeername
- getsockname
- cg_skb ingress and egress

Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20220823222555.523590-6-sdf@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-23 16:08:22 -07:00
Stanislav Fomichev
2172fb8007 bpf: update bpf_{g,s}et_retval documentation
* replace 'syscall' with 'upper layers', still mention that it's being
  exported via syscall errno
* describe what happens in set_retval(-EPERM) + return 1
* describe what happens with bind's 'return 3'

Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20220823222555.523590-5-sdf@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-23 16:08:22 -07:00
Stanislav Fomichev
8a67f2de9b bpf: expose bpf_strtol and bpf_strtoul to all program types
bpf_strncmp is already exposed everywhere. The motivation is to keep
those helpers in kernel/bpf/helpers.c. Otherwise it's tempting to move
them under kernel/bpf/cgroup.c because they are currently only used
by sysctl prog types.

Suggested-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20220823222555.523590-4-sdf@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-23 16:08:21 -07:00
Stanislav Fomichev
bed89185af bpf: Use cgroup_{common,current}_func_proto in more hooks
The following hooks are per-cgroup hooks but they are not
using cgroup_{common,current}_func_proto, fix it:

* BPF_PROG_TYPE_CGROUP_SKB (cg_skb)
* BPF_PROG_TYPE_CGROUP_SOCK_ADDR (cg_sock_addr)
* BPF_PROG_TYPE_CGROUP_SOCK (cg_sock)
* BPF_PROG_TYPE_LSM+BPF_LSM_CGROUP

Also:

* move common func_proto's into cgroup func_proto handlers
* make sure bpf_{g,s}et_retval are not accessible from recvmsg,
  getpeername and getsockname (return/errno is ignored in these
  places)
* as a side effect, expose get_current_pid_tgid, get_current_comm_proto,
  get_current_ancestor_cgroup_id, get_cgroup_classid to more cgroup
  hooks

Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20220823222555.523590-3-sdf@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-23 16:08:21 -07:00
Stanislav Fomichev
dea6a4e170 bpf: Introduce cgroup_{common,current}_func_proto
Split cgroup_base_func_proto into the following:

* cgroup_common_func_proto - common helpers for all cgroup hooks
* cgroup_current_func_proto - common helpers for all cgroup hooks
  running in the process context (== have meaningful 'current').

Move bpf_{g,s}et_retval and other cgroup-related helpers into
kernel/bpf/cgroup.c so they closer to where they are being used.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220823222555.523590-2-sdf@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-23 16:08:21 -07:00
Quentin Monnet
92ec1cc378 scripts/bpf: Set date attribute for bpf-helpers(7) man page
The bpf-helpers(7) manual page shipped in the man-pages project is
generated from the documentation contained in the BPF UAPI header, in
the Linux repository, parsed by script/bpf_doc.py and then fed to
rst2man.

The man page should contain the date of last modification of the
documentation. This commit adds the relevant date when generating the
page.

Before:

    $ ./scripts/bpf_doc.py helpers | rst2man | grep '\.TH'
    .TH BPF-HELPERS 7 "" "Linux v5.19-14022-g30d2a4d74e11" ""

After:

    $ ./scripts/bpf_doc.py helpers | rst2man | grep '\.TH'
    .TH BPF-HELPERS 7 "2022-08-15" "Linux v5.19-14022-g30d2a4d74e11" ""

We get the version by using "git log" to look for the commit date of the
latest change to the section of the BPF header containing the
documentation. If the command fails, we just skip the date field. and
keep generating the page.

Reported-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Alejandro Colomar <alx.manpages@gmail.com>
Link: https://lore.kernel.org/bpf/20220823155327.98888-2-quentin@isovalent.com
2022-08-23 22:51:04 +02:00
Quentin Monnet
fd0a38f9c3 scripts/bpf: Set version attribute for bpf-helpers(7) man page
The bpf-helpers(7) manual page shipped in the man-pages project is
generated from the documentation contained in the BPF UAPI header, in
the Linux repository, parsed by script/bpf_doc.py and then fed to
rst2man.

After a recent update of that page [0], Alejandro reported that the
linter used to validate the man pages complains about the generated
document [1]. The header for the page is supposed to contain some
attributes that we do not set correctly with the script. This commit
updates the "project and version" field. We discussed the format of
those fields in [1] and [2].

Before:

    $ ./scripts/bpf_doc.py helpers | rst2man | grep '\.TH'
    .TH BPF-HELPERS 7 "" "" ""

After:

    $ ./scripts/bpf_doc.py helpers | rst2man | grep '\.TH'
    .TH BPF-HELPERS 7 "" "Linux v5.19-14022-g30d2a4d74e11" ""

We get the version from "git describe", but if unavailable, we fall back
on "make kernelversion". If none works, for example because neither git
nore make are installed, we just set the field to "Linux" and keep
generating the page.

[0] https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/commit/man7/bpf-helpers.7?id=19c7f78393f2b038e76099f87335ddf43a87f039
[1] https://lore.kernel.org/all/20220823084719.13613-1-quentin@isovalent.com/t/#m58a418a318642c6428e14ce9bb84eba5183b06e8
[2] https://lore.kernel.org/all/20220721110821.8240-1-alx.manpages@gmail.com/t/#m8e689a822e03f6e2530a0d6de9d128401916c5de

Reported-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Alejandro Colomar <alx.manpages@gmail.com>
Link: https://lore.kernel.org/bpf/20220823155327.98888-1-quentin@isovalent.com
2022-08-23 22:51:04 +02:00
Shmulik Ladkani
d6513727c2 bpf, selftests: Test BPF_FLOW_DISSECTOR_CONTINUE
The dissector program returns BPF_FLOW_DISSECTOR_CONTINUE (and avoids
setting skb->flow_keys or last_dissection map) in case it encounters
IP packets whose (outer) source address is 127.0.0.127.

Additional test is added to prog_tests/flow_dissector.c which sets
this address as test's pkk.iph.saddr, with the expected retval of
BPF_FLOW_DISSECTOR_CONTINUE.

Also, legacy test_flow_dissector.sh was similarly augmented.

Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20220821113519.116765-5-shmulik.ladkani@gmail.com
2022-08-23 22:48:12 +02:00
Shmulik Ladkani
5deedfbee8 bpf, test_run: Propagate bpf_flow_dissect's retval to user's bpf_attr.test.retval
Formerly, a boolean denoting whether bpf_flow_dissect returned BPF_OK
was set into 'bpf_attr.test.retval'.

Augment this, so users can check the actual return code of the dissector
program under test.

Existing prog_tests/flow_dissector*.c tests were correspondingly changed
to check against each test's expected retval.

Also, tests' resulting 'flow_keys' are verified only in case the expected
retval is BPF_OK. This allows adding new tests that expect non BPF_OK.

Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20220821113519.116765-4-shmulik.ladkani@gmail.com
2022-08-23 22:48:03 +02:00
Shmulik Ladkani
91350fe152 bpf, flow_dissector: Introduce BPF_FLOW_DISSECTOR_CONTINUE retcode for bpf progs
Currently, attaching BPF_PROG_TYPE_FLOW_DISSECTOR programs completely
replaces the flow-dissector logic with custom dissection logic. This
forces implementors to write programs that handle dissection for any
flows expected in the namespace.

It makes sense for flow-dissector BPF programs to just augment the
dissector with custom logic (e.g. dissecting certain flows or custom
protocols), while enjoying the broad capabilities of the standard
dissector for any other traffic.

Introduce BPF_FLOW_DISSECTOR_CONTINUE retcode. Flow-dissector BPF
programs may return this to indicate no dissection was made, and
fallback to the standard dissector is requested.

Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20220821113519.116765-3-shmulik.ladkani@gmail.com
2022-08-23 22:47:55 +02:00
Shmulik Ladkani
0ba985024a flow_dissector: Make 'bpf_flow_dissect' return the bpf program retcode
Let 'bpf_flow_dissect' callers know the BPF program's retcode and act
accordingly.

Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20220821113519.116765-2-shmulik.ladkani@gmail.com
2022-08-23 22:47:42 +02:00
Martin KaFai Lau
b979f005d9 selftest/bpf: Add setget_sockopt to DENYLIST.s390x
Trampoline is not supported in s390.

Fixes: 31123c0360 ("selftests/bpf: bpf_setsockopt tests")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220819192155.91713-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-19 12:46:18 -07:00
Colin Ian King
e918cd231e selftests/bpf: Fix spelling mistake.
There is a spelling mistake in an ASSERT_OK literal string. Fix it.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Acked-by: Mykola Lysenko <mykolal@fb.com>
Link: https://lore.kernel.org/r/20220817213242.101277-1-colin.i.king@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-19 12:45:14 -07:00
Alexei Starovoitov
75179e2b7f Merge branch 'bpf: net: Remove duplicated code from bpf_setsockopt()'
Martin KaFai Lau says:

====================

The code in bpf_setsockopt() is mostly a copy-and-paste from
the sock_setsockopt(), do_tcp_setsockopt(), do_ipv6_setsockopt(),
and do_ip_setsockopt().  As the allowed optnames in bpf_setsockopt()
grows, so are the duplicated code.  The code between the copies
also slowly drifted.

This set is an effort to clean this up and reuse the existing
{sock,do_tcp,do_ipv6,do_ip}_setsockopt() as much as possible.

After the clean up, this set also adds a few allowed optnames
that we need to the bpf_setsockopt().

The initial attempt was to clean up both bpf_setsockopt() and
bpf_getsockopt() together.  However, the patch set was getting
too long.  It is beneficial to leave the bpf_getsockopt()
out for another patch set.  Thus, this set is focusing
on the bpf_setsockopt().

v4:
- This set now depends on the commit f574f7f839 ("net: bpf: Use the protocol's set_rcvlowat behavior if there is one")
  in the net-next tree.  The commit calls a specific protocol's
  set_rcvlowat and it changed the bpf_setsockopt
  which this set has also changed.

  Because of this, patch 9 of this set has also adjusted
  and a 'sock' NULL check is added to the sk_setsockopt()
  because some of the bpf hooks have a NULL sk->sk_socket.
  This removes more dup code from the bpf_setsockopt() side.
- Avoid mentioning specific prog types in the comment of
  the has_current_bpf_ctx(). (Andrii)
- Replace signed with unsigned int bitfield in the
  patch 15 selftest. (Daniel)

v3:
- s/in_bpf/has_current_bpf_ctx/ (Andrii)
- Add comment to has_current_bpf_ctx() and sockopt_lock_sock()
  (Stanislav)
- Use vmlinux.h in selftest and add defines to bpf_tracing_net.h
  (Stanislav)
- Use bpf_getsockopt(SO_MARK) in selftest (Stanislav)
- Use BPF_CORE_READ_BITFIELD in selftest (Yonghong)

v2:
- A major change is to use in_bpf() to test if a setsockopt()
  is called by a bpf prog and use in_bpf() to skip capable
  check.  Suggested by Stanislav.
- Instead of passing is_locked through sockptr_t or through an extra
  argument to sk_setsockopt, v2 uses in_bpf() to skip the lock_sock()
  also because bpf prog has the lock acquired.
- No change to the current sockptr_t in this revision
- s/codes/code/
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-18 17:06:14 -07:00
Martin KaFai Lau
31123c0360 selftests/bpf: bpf_setsockopt tests
This patch adds tests to exercise optnames that are allowed
in bpf_setsockopt().

Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061847.4182339-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-18 17:06:14 -07:00
Martin KaFai Lau
7e41df5dbb bpf: Add a few optnames to bpf_setsockopt
This patch adds a few optnames for bpf_setsockopt:
SO_REUSEADDR, IPV6_AUTOFLOWLABEL, TCP_MAXSEG, TCP_NODELAY,
and TCP_THIN_LINEAR_TIMEOUTS.

Thanks to the previous patches of this set, all additions can reuse
the sk_setsockopt(), do_ipv6_setsockopt(), and do_tcp_setsockopt().
The only change here is to allow them in bpf_setsockopt.

The bpf prog has been able to read all members of a sk by
using PTR_TO_BTF_ID of a sk.  The optname additions here can also be
read by the same approach.  Meaning there is a way to read
the values back.

These optnames can also be added to bpf_getsockopt() later with
another patch set that makes the bpf_getsockopt() to reuse
the sock_getsockopt(), tcp_getsockopt(), and ip[v6]_getsockopt().
Thus, this patch does not add more duplicated code to
bpf_getsockopt() now.

Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061841.4181642-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-18 17:06:14 -07:00
Martin KaFai Lau
75b64b68ee bpf: Change bpf_setsockopt(SOL_IPV6) to reuse do_ipv6_setsockopt()
After the prep work in the previous patches,
this patch removes the dup code from bpf_setsockopt(SOL_IPV6)
and reuses the implementation in do_ipv6_setsockopt().

ipv6 could be compiled as a module.  Like how other code solved it
with stubs in ipv6_stubs.h, this patch adds the do_ipv6_setsockopt
to the ipv6_bpf_stub.

The current bpf_setsockopt(IPV6_TCLASS) does not take the
INET_ECN_MASK into the account for tcp.  The
do_ipv6_setsockopt(IPV6_TCLASS) will handle it correctly.

The existing optname white-list is refactored into a new
function sol_ipv6_setsockopt().

After this last SOL_IPV6 dup code removal, the __bpf_setsockopt()
is simplified enough that the extra "{ }" around the if statement
can be removed.

Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061834.4181198-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-18 17:06:13 -07:00
Martin KaFai Lau
ee7f1e1302 bpf: Change bpf_setsockopt(SOL_IP) to reuse do_ip_setsockopt()
After the prep work in the previous patches,
this patch removes the dup code from bpf_setsockopt(SOL_IP)
and reuses the implementation in do_ip_setsockopt().

The existing optname white-list is refactored into a new
function sol_ip_setsockopt().

NOTE,
the current bpf_setsockopt(IP_TOS) is quite different from the
the do_ip_setsockopt(IP_TOS).  For example, it does not take
the INET_ECN_MASK into the account for tcp and also does not adjust
sk->sk_priority.  It looks like the current bpf_setsockopt(IP_TOS)
was referencing the IPV6_TCLASS implementation instead of IP_TOS.
This patch tries to rectify that by using the do_ip_setsockopt(IP_TOS).
While this is a behavior change,  the do_ip_setsockopt(IP_TOS) behavior
is arguably what the user is expecting.  At least, the INET_ECN_MASK bits
should be masked out for tcp.

Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061826.4180990-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-18 17:06:13 -07:00
Martin KaFai Lau
0c751f7071 bpf: Change bpf_setsockopt(SOL_TCP) to reuse do_tcp_setsockopt()
After the prep work in the previous patches,
this patch removes all the dup code from bpf_setsockopt(SOL_TCP)
and reuses the do_tcp_setsockopt().

The existing optname white-list is refactored into a new
function sol_tcp_setsockopt().  The sol_tcp_setsockopt()
also calls the bpf_sol_tcp_setsockopt() to handle
the TCP_BPF_XXX specific optnames.

bpf_setsockopt(TCP_SAVE_SYN) now also allows a value 2 to
save the eth header also and it comes for free from
do_tcp_setsockopt().

Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061819.4180146-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-18 17:06:13 -07:00
Martin KaFai Lau
57db31a1a3 bpf: Refactor bpf specific tcp optnames to a new function
The patch moves all bpf specific tcp optnames (TCP_BPF_XXX)
to a new function bpf_sol_tcp_setsockopt().  This will make
the next patch easier to follow.

Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061812.4179645-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-18 17:06:13 -07:00
Martin KaFai Lau
29003875bd bpf: Change bpf_setsockopt(SOL_SOCKET) to reuse sk_setsockopt()
After the prep work in the previous patches,
this patch removes most of the dup code from bpf_setsockopt(SOL_SOCKET)
and reuses them from sk_setsockopt().

The sock ptr test is added to the SO_RCVLOWAT because
the sk->sk_socket could be NULL in some of the bpf hooks.

The existing optname white-list is refactored into a new
function sol_socket_setsockopt().

Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061804.4178920-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-18 17:06:13 -07:00
Martin KaFai Lau
ebf9e8e653 bpf: Embed kernel CONFIG check into the if statement in bpf_setsockopt
This patch moves the "#ifdef CONFIG_XXX" check into the "if/else"
statement itself.  The change is done for the bpf_setsockopt()
function only.  It will make the latter patches easier to follow
without the surrounding ifdef macro.

Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061758.4178374-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-18 17:06:13 -07:00
Martin KaFai Lau
2b5a2ecbfd bpf: Initialize the bpf_run_ctx in bpf_iter_run_prog()
The bpf-iter-prog for tcp and unix sk can do bpf_setsockopt()
which needs has_current_bpf_ctx() to decide if it is called by a
bpf prog.  This patch initializes the bpf_run_ctx in
bpf_iter_run_prog() for the has_current_bpf_ctx() to use.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061751.4177657-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-18 17:06:13 -07:00
Martin KaFai Lau
40cd308ea5 bpf: net: Change do_ipv6_setsockopt() to use the sockopt's lock_sock() and capable()
Similar to the earlier patch that avoids sk_setsockopt() from
taking sk lock and doing capable test when called by bpf.  This patch
changes do_ipv6_setsockopt() to use the sockopt_{lock,release}_sock()
and sockopt_[ns_]capable().

Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061744.4176893-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-18 17:06:13 -07:00
Martin KaFai Lau
1df055d3c7 bpf: net: Change do_ip_setsockopt() to use the sockopt's lock_sock() and capable()
Similar to the earlier patch that avoids sk_setsockopt() from
taking sk lock and doing capable test when called by bpf.  This patch
changes do_ip_setsockopt() to use the sockopt_{lock,release}_sock()
and sockopt_[ns_]capable().

Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061737.4176402-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-18 17:06:13 -07:00
Martin KaFai Lau
cb388e7ee3 bpf: net: Change do_tcp_setsockopt() to use the sockopt's lock_sock() and capable()
Similar to the earlier patch that avoids sk_setsockopt() from
taking sk lock and doing capable test when called by bpf.  This patch
changes do_tcp_setsockopt() to use the sockopt_{lock,release}_sock()
and sockopt_[ns_]capable().

Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061730.4176021-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-18 17:06:12 -07:00
Martin KaFai Lau
e42c7beee7 bpf: net: Consider has_current_bpf_ctx() when testing capable() in sk_setsockopt()
When bpf program calling bpf_setsockopt(SOL_SOCKET),
it could be run in softirq and doesn't make sense to do the capable
check.  There was a similar situation in bpf_setsockopt(TCP_CONGESTION).
In commit 8d650cdeda ("tcp: fix tcp_set_congestion_control() use from bpf hook"),
tcp_set_congestion_control(..., cap_net_admin) was added to skip
the cap check for bpf prog.

This patch adds sockopt_ns_capable() and sockopt_capable() for
the sk_setsockopt() to use.  They will consider the
has_current_bpf_ctx() before doing the ns_capable() and capable() test.
They are in EXPORT_SYMBOL for the ipv6 module to use in a latter patch.

Suggested-by: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061723.4175820-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-18 17:06:12 -07:00
Martin KaFai Lau
24426654ed bpf: net: Avoid sk_setsockopt() taking sk lock when called from bpf
Most of the code in bpf_setsockopt(SOL_SOCKET) are duplicated from
the sk_setsockopt().  The number of supported optnames are
increasing ever and so as the duplicated code.

One issue in reusing sk_setsockopt() is that the bpf prog
has already acquired the sk lock.  This patch adds a
has_current_bpf_ctx() to tell if the sk_setsockopt() is called from
a bpf prog.  The bpf prog calling bpf_setsockopt() is either running
in_task() or in_serving_softirq().  Both cases have the current->bpf_ctx
initialized.  Thus, the has_current_bpf_ctx() only needs to
test !!current->bpf_ctx.

This patch also adds sockopt_{lock,release}_sock() helpers
for sk_setsockopt() to use.  These helpers will test
has_current_bpf_ctx() before acquiring/releasing the lock.  They are
in EXPORT_SYMBOL for the ipv6 module to use in a latter patch.

Note on the change in sock_setbindtodevice().  sockopt_lock_sock()
is done in sock_setbindtodevice() instead of doing the lock_sock
in sock_bindtoindex(..., lock_sk = true).

Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061717.4175589-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-18 17:06:12 -07:00
Martin KaFai Lau
4d748f9916 net: Add sk_setsockopt() to take the sk ptr instead of the sock ptr
A latter patch refactors bpf_setsockopt(SOL_SOCKET) with the
sock_setsockopt() to avoid code duplication and code
drift between the two duplicates.

The current sock_setsockopt() takes sock ptr as the argument.
The very first thing of this function is to get back the sk ptr
by 'sk = sock->sk'.

bpf_setsockopt() could be called when the sk does not have
the sock ptr created.  Meaning sk->sk_socket is NULL.  For example,
when a passive tcp connection has just been established but has yet
been accept()-ed.  Thus, it cannot use the sock_setsockopt(sk->sk_socket)
or else it will pass a NULL ptr.

This patch moves all sock_setsockopt implementation to the newly
added sk_setsockopt().  The new sk_setsockopt() takes a sk ptr
and immediately gets the sock ptr by 'sock = sk->sk_socket'

The existing sock_setsockopt(sock) is changed to call
sk_setsockopt(sock->sk).  All existing callers have both sock->sk
and sk->sk_socket pointer.

The latter patch will make bpf_setsockopt(SOL_SOCKET) call
sk_setsockopt(sk) directly.  The bpf_setsockopt(SOL_SOCKET) does
not use the optnames that require sk->sk_socket, so it will
be safe.

Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061711.4175048-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-18 17:06:12 -07:00
Maxime Chevallier
fb8d784b53 net: ethernet: altera: Add use of ethtool_op_get_ts_info
Add the ethtool_op_get_ts_info() callback to ethtool ops, so that we can
at least use software timestamping.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://lore.kernel.org/r/20220817095725.97444-1-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-18 10:25:39 -07:00
Wong Vee Khee
e34cfee65e stmmac: intel: remove unused 'has_crossts' flag
The 'has_crossts' flag was not used anywhere in the stmmac driver,
removing it from both header file and dwmac-intel driver.

Signed-off-by: Wong Vee Khee <veekhee@apple.com>
Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
Link: https://lore.kernel.org/r/20220817064324.10025-1-veekhee@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-17 20:40:52 -07:00
Jakub Kicinski
3f5f728a72 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Andrii Nakryiko says:

====================
bpf-next 2022-08-17

We've added 45 non-merge commits during the last 14 day(s) which contain
a total of 61 files changed, 986 insertions(+), 372 deletions(-).

The main changes are:

1) New bpf_ktime_get_tai_ns() BPF helper to access CLOCK_TAI, from Kurt
   Kanzenbach and Jesper Dangaard Brouer.

2) Few clean ups and improvements for libbpf 1.0, from Andrii Nakryiko.

3) Expose crash_kexec() as kfunc for BPF programs, from Artem Savkov.

4) Add ability to define sleepable-only kfuncs, from Benjamin Tissoires.

5) Teach libbpf's bpf_prog_load() and bpf_map_create() to gracefully handle
   unsupported names on old kernels, from Hangbin Liu.

6) Allow opting out from auto-attaching BPF programs by libbpf's BPF skeleton,
   from Hao Luo.

7) Relax libbpf's requirement for shared libs to be marked executable, from
   Henqgi Chen.

8) Improve bpf_iter internals handling of error returns, from Hao Luo.

9) Few accommodations in libbpf to support GCC-BPF quirks, from James Hilliard.

10) Fix BPF verifier logic around tracking dynptr ref_obj_id, from Joanne Koong.

11) bpftool improvements to handle full BPF program names better, from Manu
    Bretelle.

12) bpftool fixes around libcap use, from Quentin Monnet.

13) BPF map internals clean ups and improvements around memory allocations,
    from Yafang Shao.

14) Allow to use cgroup_get_from_file() on cgroupv1, allowing BPF cgroup
    iterator to work on cgroupv1, from Yosry Ahmed.

15) BPF verifier internal clean ups, from Dave Marchevsky and Joanne Koong.

16) Various fixes and clean ups for selftests/bpf and vmtest.sh, from Daniel
    Xu, Artem Savkov, Joanne Koong, Andrii Nakryiko, Shibin Koikkara Reeny.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (45 commits)
  selftests/bpf: Few fixes for selftests/bpf built in release mode
  libbpf: Clean up deprecated and legacy aliases
  libbpf: Streamline bpf_attr and perf_event_attr initialization
  libbpf: Fix potential NULL dereference when parsing ELF
  selftests/bpf: Tests libbpf autoattach APIs
  libbpf: Allows disabling auto attach
  selftests/bpf: Fix attach point for non-x86 arches in test_progs/lsm
  libbpf: Making bpf_prog_load() ignore name if kernel doesn't support
  selftests/bpf: Update CI kconfig
  selftests/bpf: Add connmark read test
  selftests/bpf: Add existing connection bpf_*_ct_lookup() test
  bpftool: Clear errno after libcap's checks
  bpf: Clear up confusion in bpf_skb_adjust_room()'s documentation
  bpftool: Fix a typo in a comment
  libbpf: Add names for auxiliary maps
  bpf: Use bpf_map_area_alloc consistently on bpf map creation
  bpf: Make __GFP_NOWARN consistent in bpf map creation
  bpf: Use bpf_map_area_free instread of kvfree
  bpf: Remove unneeded memset in queue_stack_map creation
  libbpf: preserve errno across pr_warn/pr_info/pr_debug
  ...
====================

Link: https://lore.kernel.org/r/20220817215656.1180215-1-andrii@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-17 20:29:36 -07:00
Andrii Nakryiko
df78da2726 selftests/bpf: Few fixes for selftests/bpf built in release mode
Fix few issues found when building and running test_progs in
release mode.

First, potentially uninitialized idx variable in xskxceiver,
force-initialize to zero to satisfy compiler.

Few instances of defining uprobe trigger functions break in release mode
unless marked as noinline, due to being static. Add noinline to make
sure everything works.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Hao Luo <haoluo@google.com>
Link: https://lore.kernel.org/bpf/20220816001929.369487-5-andrii@kernel.org
2022-08-17 22:43:58 +02:00