Commit Graph

983578 Commits

Author SHA1 Message Date
Alexei Starovoitov
f2dd3b3946 bpf: Compute program stats for sleepable programs
Since sleepable programs don't migrate from the cpu the excution stats can be
computed for them as well. Reuse the same infrastructure for both sleepable and
non-sleepable programs.

run_cnt     -> the number of times the program was executed.
run_time_ns -> the program execution time in nanoseconds including the
               off-cpu time when the program was sleeping.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/bpf/20210210033634.62081-4-alexei.starovoitov@gmail.com
2021-02-11 16:19:06 +01:00
Alexei Starovoitov
031d6e02dd bpf: Run sleepable programs with migration disabled
In older non-RT kernels migrate_disable() was the same as preempt_disable().
Since commit 74d862b682 ("sched: Make migrate_disable/enable() independent of RT")
migrate_disable() is real and doesn't prevent sleeping.

Running sleepable programs with migration disabled allows to add support for
program stats and per-cpu maps later.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/bpf/20210210033634.62081-3-alexei.starovoitov@gmail.com
2021-02-11 16:18:55 +01:00
Alexei Starovoitov
700d4796ef bpf: Optimize program stats
Move bpf_prog_stats from prog->aux into prog to avoid one extra load
in critical path of program execution.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210210033634.62081-2-alexei.starovoitov@gmail.com
2021-02-11 16:17:50 +01:00
Marco Elver
6df8fb8330 bpf_lru_list: Read double-checked variable once without lock
For double-checked locking in bpf_common_lru_push_free(), node->type is
read outside the critical section and then re-checked under the lock.
However, concurrent writes to node->type result in data races.

For example, the following concurrent access was observed by KCSAN:

  write to 0xffff88801521bc22 of 1 bytes by task 10038 on cpu 1:
   __bpf_lru_node_move_in        kernel/bpf/bpf_lru_list.c:91
   __local_list_flush            kernel/bpf/bpf_lru_list.c:298
   ...
  read to 0xffff88801521bc22 of 1 bytes by task 10043 on cpu 0:
   bpf_common_lru_push_free      kernel/bpf/bpf_lru_list.c:507
   bpf_lru_push_free             kernel/bpf/bpf_lru_list.c:555
   ...

Fix the data races where node->type is read outside the critical section
(for double-checked locking) by marking the access with READ_ONCE() as
well as ensuring the variable is only accessed once.

Fixes: 3a08c2fd76 ("bpf: LRU List")
Reported-by: syzbot+3536db46dfa58c573458@syzkaller.appspotmail.com
Reported-by: syzbot+516acdb03d3e27d91bcd@syzkaller.appspotmail.com
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210209112701.3341724-1-elver@google.com
2021-02-10 15:54:26 -08:00
Jiapeng Chong
bd2d4e6c6e selftests/bpf: Simplify the calculation of variables
Fix the following coccicheck warnings:

./tools/testing/selftests/bpf/xdpxceiver.c:954:28-30: WARNING !A || A &&
B is equivalent to !A || B.

./tools/testing/selftests/bpf/xdpxceiver.c:932:28-30: WARNING !A || A &&
B is equivalent to !A || B.

./tools/testing/selftests/bpf/xdpxceiver.c:909:28-30: WARNING !A || A &&
B is equivalent to !A || B.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1612860398-102839-1-git-send-email-jiapeng.chong@linux.alibaba.com
2021-02-10 12:14:27 -08:00
Ilya Leoshkevich
45df305268 selftests/bpf: Fix endianness issues in atomic tests
Atomic tests store a DW, but then load it back as a W from the same
address. This doesn't work on big-endian systems, and since the point
of those tests is not testing narrow loads, fix simply by loading a
DW.

Fixes: 98d666d05a ("bpf: Add tests for new BPF atomic operations")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210210020713.77911-1-iii@linux.ibm.com
2021-02-10 11:55:22 -08:00
Alexei Starovoitov
cf2d0a5e78 Merge branch 'allow variable-offset stack acces'
Andrei Matei says:

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

Before this patch, variable offset access to the stack was dissalowed
for regular instructions, but was allowed for "indirect" accesses (i.e.
helpers). This patch removes the restriction, allowing reading and
writing to the stack through stack pointers with variable offsets. This
makes stack-allocated buffers more usable in programs, and brings stack
pointers closer to other types of pointers.

The motivation is being able to use stack-allocated buffers for data
manipulation. When the stack size limit is sufficient, allocating
buffers on the stack is simpler than per-cpu arrays, or other
alternatives.

V2 -> V3

- var-offset writes mark all the stack slots in range as initialized, so
  that future reads are not rejected.
- rewrote the C test to not use uprobes, as per Andrii's suggestion.
- addressed other review comments from Alexei.

V1 -> V2

- add support for var-offset stack writes, in addition to reads
- add a C test
- made variable offset direct reads no longer destroy spilled registers
  in the access range
- address review nits
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2021-02-10 11:10:45 -08:00
Andrei Matei
0fd7562af1 selftest/bpf: Add test for var-offset stack access
Add a higher-level test (C BPF program) for the new functionality -
variable access stack reads and writes.

Signed-off-by: Andrei Matei <andreimatei1@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210207011027.676572-5-andreimatei1@gmail.com
2021-02-10 11:05:34 -08:00
Andrei Matei
7a22930c41 selftest/bpf: Verifier tests for var-off access
Add tests for the new functionality - reading and writing to the stack
through a variable-offset pointer.

Signed-off-by: Andrei Matei <andreimatei1@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210207011027.676572-4-andreimatei1@gmail.com
2021-02-10 10:44:19 -08:00
Andrei Matei
a680cb3d8e selftest/bpf: Adjust expected verifier errors
The verifier errors around stack accesses have changed slightly in the
previous commit (generally for the better).

Signed-off-by: Andrei Matei <andreimatei1@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210207011027.676572-3-andreimatei1@gmail.com
2021-02-10 10:44:19 -08:00
Andrei Matei
01f810ace9 bpf: Allow variable-offset stack access
Before this patch, variable offset access to the stack was dissalowed
for regular instructions, but was allowed for "indirect" accesses (i.e.
helpers). This patch removes the restriction, allowing reading and
writing to the stack through stack pointers with variable offsets. This
makes stack-allocated buffers more usable in programs, and brings stack
pointers closer to other types of pointers.

The motivation is being able to use stack-allocated buffers for data
manipulation. When the stack size limit is sufficient, allocating
buffers on the stack is simpler than per-cpu arrays, or other
alternatives.

In unpriviledged programs, variable-offset reads and writes are
disallowed (they were already disallowed for the indirect access case)
because the speculative execution checking code doesn't support them.
Additionally, when writing through a variable-offset stack pointer, if
any pointers are in the accessible range, there's possilibities of later
leaking pointers because the write cannot be tracked precisely.

Writes with variable offset mark the whole range as initialized, even
though we don't know which stack slots are actually written. This is in
order to not reject future reads to these slots. Note that this doesn't
affect writes done through helpers; like before, helpers need the whole
stack range to be initialized to begin with.
All the stack slots are in range are considered scalars after the write;
variable-offset register spills are not tracked.

For reads, all the stack slots in the variable range needs to be
initialized (but see above about what writes do), otherwise the read is
rejected. All register spilled in stack slots that might be read are
marked as having been read, however reads through such pointers don't do
register filling; the target register will always be either a scalar or
a constant zero.

Signed-off-by: Andrei Matei <andreimatei1@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210207011027.676572-2-andreimatei1@gmail.com
2021-02-10 10:44:19 -08:00
Andrii Nakryiko
ee5cc0363e Merge branch 'kbuild/resolve_btfids: Invoke resolve_btfids'
Jiri Olsa says:

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

hi,
resolve_btfids tool is used during the kernel build,
so we should clean it on kernel's make clean.

v2 changes:
  - add Song's acks on patches 1 and 4 (others changed) [Song]
  - add missing / [Andrii]
  - change srctree variable initialization [Andrii]
  - shifted ifdef for clean target [Andrii]

thanks,
jirka
====================

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2021-02-08 21:21:39 -08:00
Jiri Olsa
50d3a3f816 kbuild: Add resolve_btfids clean to root clean target
The resolve_btfids tool is used during the kernel build,
so we should clean it on kernel's make clean.

Invoking the the resolve_btfids clean as part of root
'make clean'.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210205124020.683286-5-jolsa@kernel.org
2021-02-08 21:21:39 -08:00
Jiri Olsa
7962cb9b64 tools/resolve_btfids: Set srctree variable unconditionally
We want this clean to be called from tree's root Makefile,
which defines same srctree variable and that will screw
the make setup.

We actually do not use srctree being passed from outside,
so we can solve this by setting current srctree value
directly.

Also changing the way how srctree is initialized as suggested
by Andrri.

Also root Makefile does not define the implicit RM variable,
so adding RM initialization.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210205124020.683286-4-jolsa@kernel.org
2021-02-08 21:21:39 -08:00
Jiri Olsa
f23130979c tools/resolve_btfids: Check objects before removing
We want this clean to be called from tree's root clean
and that one is silent if there's nothing to clean.

Adding check for all object to clean and display CLEAN
messages only if there are objects to remove.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210205124020.683286-3-jolsa@kernel.org
2021-02-08 21:21:39 -08:00
Jiri Olsa
fc6b48f692 tools/resolve_btfids: Build libbpf and libsubcmd in separate directories
Setting up separate build directories for libbpf and libpsubcmd,
so it's separated from other objects and we don't get them mixed
in the future.

It also simplifies cleaning, which is now simple rm -rf.

Also there's no need for FEATURE-DUMP.libbpf and bpf_helper_defs.h
files in .gitignore anymore.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210205124020.683286-2-jolsa@kernel.org
2021-02-08 21:21:39 -08:00
Jiapeng Chong
0a1b0fd929 bpf: Simplify bool comparison
Fix the following coccicheck warning:

./tools/bpf/bpf_dbg.c:893:32-36: WARNING: Comparison to bool.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1612777416-34339-1-git-send-email-jiapeng.chong@linux.alibaba.com
2021-02-08 17:55:38 -08:00
Brendan Jackman
1589a1fa4e selftests/bpf: Add missing cleanup in atomic_bounds test
Add missing skeleton destroy call.

Fixes: 37086bfdc7 ("bpf: Propagate stack bounds to registers in atomics w/ BPF_FETCH")
Reported-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210208123737.963172-1-jackmanb@google.com
2021-02-08 17:55:01 -08:00
Yang Li
11da9f0c6d selftests/bpf: Remove unneeded semicolon
Eliminate the following coccicheck warning:
./tools/testing/selftests/bpf/test_flow_dissector.c:506:2-3: Unneeded
semicolon

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1612780213-84583-1-git-send-email-yang.lee@linux.alibaba.com
2021-02-08 17:54:24 -08:00
Yang Li
215cb7d382 bpf/benchs/bench_ringbufs: Remove unneeded semicolon
Eliminate the following coccicheck warning:
./tools/testing/selftests/bpf/benchs/bench_ringbufs.c:322:2-3: Unneeded
semicolon

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1612684360-115910-1-git-send-email-yang.lee@linux.alibaba.com
2021-02-08 13:41:24 -08:00
Yonghong Song
23a2d70c7a bpf: Refactor BPF_PSEUDO_CALL checking as a helper function
There is no functionality change. This refactoring intends
to facilitate next patch change with BPF_PSEUDO_FUNC.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210204234827.1628953-1-yhs@fb.com
2021-02-04 21:51:47 -08:00
Andrii Nakryiko
ecda49c522 Merge branch 'BPF ring buffer + sleepable programs'
KP Singh says:

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

- Use ring_buffer__consume without BPF_RB_FORCE_WAKEUP as suggested by
  Andrii
- Use ASSERT_OK_PTR macro

Sleepable programs currently do not have access to any ringbuffer and
since the perf ring buffer is a per-cpu map, it would not be trivial to
enable for sleepable programs. Our specific use-case is to use the
bpf_ima_inode_hash helper and write the hash to a ring buffer from a
sleepable LSM hook.

This series allows the BPF ringbuffer to be used in sleepable programs
(tracing and lsm). Since the helper prototypes were already exposed
the only change required was have the verifier allow
BPF_MAP_TYPE_RINGBUF for sleepable programs. The ima test is also
modified to use the ringbuffer instead of global variables.

Based on dicussions we had over the BPF office hours and enabling all
the possible debug options, I could not find any issues or warnings when
using the ring buffer from sleepable programs.
====================

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2021-02-04 16:35:05 -08:00
KP Singh
f446b570ac bpf/selftests: Update the IMA test to use BPF ring buffer
Instead of using shared global variables between userspace and BPF, use
the ring buffer to send the IMA hash on the BPF ring buffer. This helps
in validating both IMA and the usage of the ringbuffer in sleepable
programs.

Signed-off-by: KP Singh <kpsingh@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210204193622.3367275-3-kpsingh@kernel.org
2021-02-04 16:35:05 -08:00
KP Singh
ba90c2cc02 bpf: Allow usage of BPF ringbuffer in sleepable programs
The BPF ringbuffer map is pre-allocated and the implementation logic
does not rely on disabling preemption or per-cpu data structures. Using
the BPF ringbuffer sleepable LSM and tracing programs does not trigger
any warnings with DEBUG_ATOMIC_SLEEP, DEBUG_PREEMPT,
PROVE_RCU and PROVE_LOCKING and LOCKDEP enabled.

This allows helpers like bpf_copy_from_user and bpf_ima_inode_hash to
write to the BPF ring buffer from sleepable BPF programs.

Signed-off-by: KP Singh <kpsingh@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210204193622.3367275-2-kpsingh@kernel.org
2021-02-04 16:35:00 -08:00
Andrii Nakryiko
ec45c5faa2 Merge branch 'BPF selftest helper script'
KP Singh says:

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

# v4 -> v5

- Use %Y (modification time) instead of %W (creation time) of the local
  copy of the kernel config to check for newer upstream config.
- Rename the script to vmtest.sh

# v3 -> v4

- Fix logic for updating kernel config to not download the file
  if there are no upstream modifications and avoid extraneous
  kernel compilation as suggested by Andrii.
- This also removes the need for the -k flag.

# v2 -> v3

- Fixes to silence verbose commands
- Fixed output buffering without being teed out
- Fixed the clobbered error code of the script
- Other fixes suggested by Andrii

# v1 -> v2

- The script now compiles the kernel by default, and the -k option
  implies "keep the kernel"
- Pointer to the script in the docs.
- Some minor simplifications.

Allow developers and contributors to understand if their changes would
end up breaking the BPF CI and avoid the back and forth required for
fixing the test cases in the CI environment. The se
====================

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2021-02-04 16:03:17 -08:00
KP Singh
881949f770 bpf/selftests: Add a short note about vmtest.sh in README.rst
Add a short note to make contributors aware of the existence of the
script. The documentation does not intentionally document all the
options of the script to avoid mentioning it in two places (it's
available in the usage / help message of the script).

Signed-off-by: KP Singh <kpsingh@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210204194544.3383814-3-kpsingh@kernel.org
2021-02-04 16:03:16 -08:00
KP Singh
c9709f5238 bpf: Helper script for running BPF presubmit tests
The script runs the BPF selftests locally on the same kernel image
as they would run post submit in the BPF continuous integration
framework.

The goal of the script is to allow contributors to run selftests locally
in the same environment to check if their changes would end up breaking
the BPF CI and reduce the back-and-forth between the maintainers and the
developers.

Signed-off-by: KP Singh <kpsingh@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/bpf/20210204194544.3383814-2-kpsingh@kernel.org
2021-02-04 16:03:16 -08:00
Alexei Starovoitov
4c5de12759 bpf: Emit explicit NULL pointer checks for PROBE_LDX instructions.
PTR_TO_BTF_ID registers contain either kernel pointer or NULL.
Emit the NULL check explicitly by JIT instead of going into
do_user_addr_fault() on NULL deference.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210202053837.95909-1-alexei.starovoitov@gmail.com
2021-02-04 16:46:44 +01:00
Andrii Nakryiko
5f10c1aac8 libbpf: Stop using feature-detection Makefiles
Libbpf's Makefile relies on Linux tools infrastructure's feature detection
framework, but libbpf's needs are very modest: it detects the presence of
libelf and libz, both of which are mandatory. So it doesn't benefit much from
the framework, but pays significant costs in terms of maintainability and
debugging experience, when something goes wrong. The other feature detector,
testing for the presernce of minimal BPF API in system headers is long
obsolete as well, providing no value.

So stop using feature detection and just assume the presence of libelf and
libz during build time. Worst case, user will get a clear and actionable
linker error, e.g.:

  /usr/bin/ld: cannot find -lelf

On the other hand, we completely bypass recurring issues various users
reported over time with false negatives of feature detection (libelf or libz
not being detected, while they are actually present in the system).

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/bpf/20210203203445.3356114-1-andrii@kernel.org
2021-02-04 01:22:00 +01:00
Lorenzo Bianconi
65e6dcf733 net, veth: Alloc skb in bulk for ndo_xdp_xmit
Split ndo_xdp_xmit and ndo_start_xmit use cases in veth_xdp_rcv routine
in order to alloc skbs in bulk for XDP_PASS verdict.

Introduce xdp_alloc_skb_bulk utility routine to alloc skb bulk list.
The proposed approach has been tested in the following scenario:

eth (ixgbe) --> XDP_REDIRECT --> veth0 --> (remote-ns) veth1 --> XDP_PASS

XDP_REDIRECT: xdp_redirect_map bpf sample
XDP_PASS: xdp_rxq_info bpf sample

traffic generator: pkt_gen sending udp traffic on a remote device

bpf-next master: ~3.64Mpps
bpf-next + skb bulking allocation: ~3.79Mpps

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Toshiaki Makita <toshiaki.makita1@gmail.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Link: https://lore.kernel.org/bpf/a14a30d3c06fff24e13f836c733d80efc0bd6eb5.1611957532.git.lorenzo@kernel.org
2021-02-04 01:00:07 +01:00
Andrei Matei
060fd10358 selftest/bpf: Testing for multiple logs on REJECT
This patch adds support to verifier tests to check for a succession of
verifier log messages on program load failure. This makes the errstr
field work uniformly across REJECT and VERBOSE_ACCEPT checks.

This patch also increases the maximum size of a message in the series of
messages to test from 80 chars to 200 chars. This is in order to keep
existing tests working, which sometimes test for messages larger than 80
chars (which was accepted in the REJECT case, when testing for a single
message, but not in the VERBOSE_ACCEPT case, when testing for possibly
multiple messages).

And example of such a long, checked message is in bounds.c: "R1 has
unknown scalar with mixed signed bounds, pointer arithmetic with it
prohibited for !root"

Signed-off-by: Andrei Matei <andreimatei1@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210130220150.59305-1-andreimatei1@gmail.com
2021-02-03 22:01:25 +01:00
Yang Li
1132b9987a samples: bpf: Remove unneeded semicolon
Eliminate the following coccicheck warning:
./samples/bpf/cookie_uid_helper_example.c:316:3-4: Unneeded semicolon

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1612322248-35398-1-git-send-email-yang.lee@linux.alibaba.com
2021-02-02 21:37:59 -08:00
KP Singh
15075bb722 selftests/bpf: Fix a compiler warning in local_storage test
Some compilers trigger a warning when tmp_dir_path is allocated
with a fixed size of 64-bytes and used in the following snprintf:

  snprintf(tmp_exec_path, sizeof(tmp_exec_path), "%s/copy_of_rm",
	   tmp_dir_path);

  warning: ‘/copy_of_rm’ directive output may be truncated writing 11
  bytes into a region of size between 1 and 64 [-Wformat-truncation=]

This is because it assumes that tmp_dir_path can be a maximum of 64
bytes long and, therefore, the end-result can get truncated. Fix it by
not using a fixed size in the initialization of tmp_dir_path which
allows the compiler to track actual size of the array better.

Fixes: 2f94ac1918 ("bpf: Update local storage test to check handling of null ptrs")
Signed-off-by: KP Singh <kpsingh@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210202213730.1906931-1-kpsingh@kernel.org
2021-02-02 21:21:55 -08:00
Brendan Jackman
37086bfdc7 bpf: Propagate stack bounds to registers in atomics w/ BPF_FETCH
When BPF_FETCH is set, atomic instructions load a value from memory
into a register. The current verifier code first checks via
check_mem_access whether we can access the memory, and then checks
via check_reg_arg whether we can write into the register.

For loads, check_reg_arg has the side-effect of marking the
register's value as unkonwn, and check_mem_access has the side effect
of propagating bounds from memory to the register. This currently only
takes effect for stack memory.

Therefore with the current order, bounds information is thrown away,
but by simply reversing the order of check_reg_arg
vs. check_mem_access, we can instead propagate bounds smartly.

A simple test is added with an infinite loop that can only be proved
unreachable if this propagation is present. This is implemented both
with C and directly in test_verifier using assembly.

Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210202135002.4024825-1-jackmanb@google.com
2021-02-02 18:23:29 -08:00
Tiezhu Yang
058107abaf samples/bpf: Add include dir for MIPS Loongson64 to fix build errors
There exists many build errors when make M=samples/bpf on the Loongson
platform. This issue is MIPS related, x86 compiles just fine.

Here are some errors:

  CLANG-bpf  samples/bpf/sockex2_kern.o
In file included from samples/bpf/sockex2_kern.c:2:
In file included from ./include/uapi/linux/in.h:24:
In file included from ./include/linux/socket.h:8:
In file included from ./include/linux/uio.h:8:
In file included from ./include/linux/kernel.h:11:
In file included from ./include/linux/bitops.h:32:
In file included from ./arch/mips/include/asm/bitops.h:19:
In file included from ./arch/mips/include/asm/barrier.h:11:
./arch/mips/include/asm/addrspace.h:13:10: fatal error: 'spaces.h' file not found
         ^~~~~~~~~~
1 error generated.

  CLANG-bpf  samples/bpf/sockex2_kern.o
In file included from samples/bpf/sockex2_kern.c:2:
In file included from ./include/uapi/linux/in.h:24:
In file included from ./include/linux/socket.h:8:
In file included from ./include/linux/uio.h:8:
In file included from ./include/linux/kernel.h:11:
In file included from ./include/linux/bitops.h:32:
In file included from ./arch/mips/include/asm/bitops.h:22:
In file included from ./arch/mips/include/asm/cpu-features.h:13:
In file included from ./arch/mips/include/asm/cpu-info.h:15:
In file included from ./include/linux/cache.h:6:
./arch/mips/include/asm/cache.h:12:10: fatal error: 'kmalloc.h' file not found
         ^~~~~~~~~~~
1 error generated.

  CLANG-bpf  samples/bpf/sockex2_kern.o
In file included from samples/bpf/sockex2_kern.c:2:
In file included from ./include/uapi/linux/in.h:24:
In file included from ./include/linux/socket.h:8:
In file included from ./include/linux/uio.h:8:
In file included from ./include/linux/kernel.h:11:
In file included from ./include/linux/bitops.h:32:
In file included from ./arch/mips/include/asm/bitops.h:22:
./arch/mips/include/asm/cpu-features.h:15:10: fatal error: 'cpu-feature-overrides.h' file not found
         ^~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.

$ find arch/mips/include/asm -name spaces.h | sort
arch/mips/include/asm/mach-ar7/spaces.h
...
arch/mips/include/asm/mach-generic/spaces.h
...
arch/mips/include/asm/mach-loongson64/spaces.h
...
arch/mips/include/asm/mach-tx49xx/spaces.h

$ find arch/mips/include/asm -name kmalloc.h | sort
arch/mips/include/asm/mach-generic/kmalloc.h
arch/mips/include/asm/mach-ip32/kmalloc.h
arch/mips/include/asm/mach-tx49xx/kmalloc.h

$ find arch/mips/include/asm -name cpu-feature-overrides.h | sort
arch/mips/include/asm/mach-ath25/cpu-feature-overrides.h
...
arch/mips/include/asm/mach-generic/cpu-feature-overrides.h
...
arch/mips/include/asm/mach-loongson64/cpu-feature-overrides.h
...
arch/mips/include/asm/mach-tx49xx/cpu-feature-overrides.h

In the arch/mips/Makefile, there exists the following board-dependent
options:

include arch/mips/Kbuild.platforms
cflags-y += -I$(srctree)/arch/mips/include/asm/mach-generic

So we can do the similar things in samples/bpf/Makefile, just add
platform specific and generic include dir for MIPS Loongson64 to
fix the build errors.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/1611669925-25315-1-git-send-email-yangtiezhu@loongson.cn
2021-02-02 23:30:14 +01:00
Tobias Klauser
61ca36c8c4 bpf: Simplify cases in bpf_base_func_proto
!perfmon_capable() is checked before the last switch(func_id) in
bpf_base_func_proto. Thus, the cases BPF_FUNC_trace_printk and
BPF_FUNC_snprintf_btf can be moved to that last switch(func_id) to omit
the inline !perfmon_capable() checks.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210127174615.3038-1-tklauser@distanz.ch
2021-01-29 02:20:28 +01:00
Stanislav Fomichev
4c3384d7ab bpf: Enable bpf_{g,s}etsockopt in BPF_CGROUP_UDP{4,6}_RECVMSG
Those hooks run as BPF_CGROUP_RUN_SA_PROG_LOCK and operate on a locked socket.

Note that we could remove the switch for prog->expected_attach_type altogether
since all current sock_addr attach types are covered. However, it makes sense
to keep it as a safe-guard in case new sock_addr attach types are added that
might not operate on a locked socket. Therefore, avoid to let this slip through.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210127232853.3753823-5-sdf@google.com
2021-01-29 02:09:31 +01:00
Stanislav Fomichev
3574906016 selftests/bpf: Rewrite recvmsg{4,6} asm progs to c in test_sock_addr
I'll extend them in the next patch. It's easier to work with C
than with asm.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210127232853.3753823-4-sdf@google.com
2021-01-29 02:09:05 +01:00
Stanislav Fomichev
073f4ec124 bpf: Enable bpf_{g,s}etsockopt in BPF_CGROUP_INET{4,6}_GET{PEER,SOCK}NAME
Those hooks run as BPF_CGROUP_RUN_SA_PROG_LOCK and operate on
a locked socket.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210127232853.3753823-3-sdf@google.com
2021-01-29 02:09:05 +01:00
Stanislav Fomichev
62476cc1bf bpf: Enable bpf_{g,s}etsockopt in BPF_CGROUP_UDP{4,6}_SENDMSG
Can be used to query/modify socket state for unconnected UDP sendmsg.
Those hooks run as BPF_CGROUP_RUN_SA_PROG_LOCK and operate on
a locked socket.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210127232853.3753823-2-sdf@google.com
2021-01-29 02:09:05 +01:00
Sedat Dilek
211a741cd3 tools: Factor Clang, LLC and LLVM utils definitions
When dealing with BPF/BTF/pahole and DWARF v5 I wanted to build bpftool.

While looking into the source code I found duplicate assignments in misc tools
for the LLVM eco system, e.g. clang and llvm-objcopy.

Move the Clang, LLC and/or LLVM utils definitions to tools/scripts/Makefile.include
file and add missing includes where needed. Honestly, I was inspired by the commit
c8a950d0d3 ("tools: Factor HOSTCC, HOSTLD, HOSTAR definitions").

I tested with bpftool and perf on Debian/testing AMD64 and LLVM/Clang v11.1.0-rc1.

Build instructions:

[ make and make-options ]
MAKE="make V=1"
MAKE_OPTS="HOSTCC=clang HOSTCXX=clang++ HOSTLD=ld.lld CC=clang LD=ld.lld LLVM=1 LLVM_IAS=1"
MAKE_OPTS="$MAKE_OPTS PAHOLE=/opt/pahole/bin/pahole"

[ clean-up ]
$MAKE $MAKE_OPTS -C tools/ clean

[ bpftool ]
$MAKE $MAKE_OPTS -C tools/bpf/bpftool/

[ perf ]
PYTHON=python3 $MAKE $MAKE_OPTS -C tools/perf/

I was careful with respecting the user's wish to override custom compiler, linker,
GNU/binutils and/or LLVM utils settings.

Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com> # tools/build and tools/perf
Link: https://lore.kernel.org/bpf/20210128015117.20515-1-sedat.dilek@gmail.com
2021-01-29 01:25:34 +01:00
Stanislav Fomichev
8259fdeb30 selftests/bpf: Verify that rebinding to port < 1024 from BPF works
Return 3 to indicate that permission check for port 111
should be skipped.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210127193140.3170382-2-sdf@google.com
2021-01-27 18:18:15 -08:00
Stanislav Fomichev
772412176f bpf: Allow rewriting to ports under ip_unprivileged_port_start
At the moment, BPF_CGROUP_INET{4,6}_BIND hooks can rewrite user_port
to the privileged ones (< ip_unprivileged_port_start), but it will
be rejected later on in the __inet_bind or __inet6_bind.

Let's add another return value to indicate that CAP_NET_BIND_SERVICE
check should be ignored. Use the same idea as we currently use
in cgroup/egress where bit #1 indicates CN. Instead, for
cgroup/bind{4,6}, bit #1 indicates that CAP_NET_BIND_SERVICE should
be bypassed.

v5:
- rename flags to be less confusing (Andrey Ignatov)
- rework BPF_PROG_CGROUP_INET_EGRESS_RUN_ARRAY to work on flags
  and accept BPF_RET_SET_CN (no behavioral changes)

v4:
- Add missing IPv6 support (Martin KaFai Lau)

v3:
- Update description (Martin KaFai Lau)
- Fix capability restore in selftest (Martin KaFai Lau)

v2:
- Switch to explicit return code (Martin KaFai Lau)

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
Link: https://lore.kernel.org/bpf/20210127193140.3170382-1-sdf@google.com
2021-01-27 18:18:15 -08:00
Cong Wang
8063e184e4 skmsg: Make sk_psock_destroy() static
sk_psock_destroy() is a RCU callback, I can't see any reason why
it could be used outside.

Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Jakub Sitnicki <jakub@cloudflare.com>
Cc: Lorenz Bauer <lmb@cloudflare.com>
Link: https://lore.kernel.org/bpf/20210127221501.46866-1-xiyou.wangcong@gmail.com
2021-01-28 00:35:03 +01:00
Menglong Dong
60e578e82b bpf: Change 'BPF_ADD' to 'BPF_AND' in print_bpf_insn()
This 'BPF_ADD' is duplicated, and I belive it should be 'BPF_AND'.

Fixes: 981f94c3e9 ("bpf: Add bitwise atomic instructions")
Signed-off-by: Menglong Dong <dong.menglong@zte.com.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Brendan Jackman <jackmanb@google.com>
Link: https://lore.kernel.org/bpf/20210127022507.23674-1-dong.menglong@zte.com.cn
2021-01-27 22:23:46 +01:00
Andrii Nakryiko
86ce322d21 selftests/bpf: Don't exit on failed bpf_testmod unload
Fix bug in handling bpf_testmod unloading that will cause test_progs exiting
prematurely if bpf_testmod unloading failed. This is especially problematic
when running a subset of test_progs that doesn't require root permissions and
doesn't rely on bpf_testmod, yet will fail immediately due to exit(1) in
unload_bpf_testmod().

Fixes: 9f7fa22589 ("selftests/bpf: Add bpf_testmod kernel module for testing")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210126065019.1268027-1-andrii@kernel.org
2021-01-26 17:02:00 +01:00
Tiezhu Yang
190d1c921a samples/bpf: Set flag __SANE_USERSPACE_TYPES__ for MIPS to fix build warnings
There exists many build warnings when make M=samples/bpf on the Loongson
platform, this issue is MIPS related, x86 compiles just fine.

Here are some warnings:

  CC  samples/bpf/ibumad_user.o
samples/bpf/ibumad_user.c: In function ‘dump_counts’:
samples/bpf/ibumad_user.c:46:24: warning: format ‘%llu’ expects argument of type ‘long long unsigned int’, but argument 3 has type ‘__u64’ {aka ‘long unsigned int’} [-Wformat=]
    printf("0x%02x : %llu\n", key, value);
                     ~~~^          ~~~~~
                     %lu
  CC  samples/bpf/offwaketime_user.o
samples/bpf/offwaketime_user.c: In function ‘print_ksym’:
samples/bpf/offwaketime_user.c:34:17: warning: format ‘%llx’ expects argument of type ‘long long unsigned int’, but argument 3 has type ‘__u64’ {aka ‘long unsigned int’} [-Wformat=]
   printf("%s/%llx;", sym->name, addr);
              ~~~^               ~~~~
              %lx
samples/bpf/offwaketime_user.c: In function ‘print_stack’:
samples/bpf/offwaketime_user.c:68:17: warning: format ‘%lld’ expects argument of type ‘long long int’, but argument 3 has type ‘__u64’ {aka ‘long unsigned int’} [-Wformat=]
  printf(";%s %lld\n", key->waker, count);
              ~~~^                 ~~~~~
              %ld

MIPS needs __SANE_USERSPACE_TYPES__ before <linux/types.h> to select
'int-ll64.h' in arch/mips/include/uapi/asm/types.h, then it can avoid
build warnings when printing __u64 with %llu, %llx or %lld.

The header tools/include/linux/types.h defines __SANE_USERSPACE_TYPES__,
it seems that we can include <linux/types.h> in the source files which
have build warnings, but it has no effect due to actually it includes
usr/include/linux/types.h instead of tools/include/linux/types.h, the
problem is that "usr/include" is preferred first than "tools/include"
in samples/bpf/Makefile, that sounds like a ugly hack to -Itools/include
before -Iusr/include.

So define __SANE_USERSPACE_TYPES__ for MIPS in samples/bpf/Makefile
is proper, if add "TPROGS_CFLAGS += -D__SANE_USERSPACE_TYPES__" in
samples/bpf/Makefile, it appears the following error:

Auto-detecting system features:
...                        libelf: [ on  ]
...                          zlib: [ on  ]
...                           bpf: [ OFF ]

BPF API too old
make[3]: *** [Makefile:293: bpfdep] Error 1
make[2]: *** [Makefile:156: all] Error 2

With #ifndef __SANE_USERSPACE_TYPES__  in tools/include/linux/types.h,
the above error has gone and this ifndef change does not hurt other
compilations.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/1611551146-14052-1-git-send-email-yangtiezhu@loongson.cn
2021-01-26 00:19:10 +01:00
Florian Lehner
726bf76fcd tools, headers: Sync struct bpf_perf_event_data
Update struct bpf_perf_event_data with the addr field to match the
tools headers with the kernel headers.

Signed-off-by: Florian Lehner <dev@der-flo.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210123185221.23946-1-dev@der-flo.net
2021-01-26 00:15:03 +01:00
Björn Töpel
095af98652 selftests/bpf: Avoid useless void *-casts
There is no need to cast to void * when the argument is void *. Avoid
cluttering of code.

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210122154725.22140-13-bjorn.topel@gmail.com
2021-01-26 00:05:02 +01:00
Björn Töpel
d08a17d6de selftests/bpf: Consistent malloc/calloc usage
Use calloc instead of malloc where it makes sense, and avoid C++-style
void *-cast.

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210122154725.22140-12-bjorn.topel@gmail.com
2021-01-26 00:05:02 +01:00