linux-stable.git/tools/testing/selftests/bpf, branch v5.10

selftests/bpf: Fix "dubious pointer arithmetic" test

2020-12-10T21:11:30+00:00

The verifier trace changed following a bugfix. After checking the 64-bit
sign, only the upper bit mask is known, not bit 31. Update the test
accordingly.

Signed-off-by: Jean-Philippe Brucker 
Acked-by: John Fastabend 
Signed-off-by: Alexei Starovoitov

selftests/bpf: Fix array access with signed variable test

2020-12-10T21:11:30+00:00

The test fails because of a recent fix to the verifier, even though this
program is valid. In details what happens is:

    7: (61) r1 = *(u32 *)(r0 +0)

Load a 32-bit value, with signed bounds [S32_MIN, S32_MAX]. The bounds
of the 64-bit value are [0, U32_MAX]...

    8: (65) if r1 s> 0xffffffff goto pc+1

... therefore this is always true (the operand is sign-extended).

    10: (b4) w2 = 11
    11: (6d) if r2 s> r1 goto pc+1

When true, the 64-bit bounds become [0, 10]. The 32-bit bounds are still
[S32_MIN, 10].

    13: (64) w1 <<= 2

Because this is a 32-bit operation, the verifier propagates the new
32-bit bounds to the 64-bit ones, and the knowledge gained from insn 11
is lost.

    14: (0f) r0 += r1
    15: (7a) *(u64 *)(r0 +0) = 4

Then the verifier considers r0 unbounded here, rejecting the test. To
make the test work, change insn 8 to check the sign of the 32-bit value.

Signed-off-by: Jean-Philippe Brucker 
Acked-by: John Fastabend 
Signed-off-by: Alexei Starovoitov

selftests/bpf: Add test for signed 32-bit bound check bug

2020-12-10T21:11:30+00:00

After a 32-bit load followed by a branch, the verifier would reduce the
maximum bound of the register to 0x7fffffff, allowing a user to bypass
bound checks. Ensure such a program is rejected.

In the second test, the 64-bit compare should not sufficient to
determine whether the signed 32-bit lower bound is 0, so the verifier
should reject the second branch.

Signed-off-by: Jean-Philippe Brucker 
Acked-by: John Fastabend 
Signed-off-by: Alexei Starovoitov

selftests/bpf/test_offload.py: Filter bpftool internal map when counting maps

2020-12-09T15:27:42+00:00

A few of the tests in test_offload.py expects to see a certain number of
maps created, and checks this by counting the number of maps returned by
bpftool. There is already a filter that will remove any maps already there
at the beginning of the test, but bpftool now creates a map for the PID
iterator rodata on each invocation, which makes the map count wrong. Fix
this by also filtering the pid_iter.rodata map by name when counting.

Fixes: d53dee3fe013 ("tools/bpftool: Show info for processes holding BPF map/prog/link/btf FDs")
Signed-off-by: Toke Høiland-Jørgensen 
Signed-off-by: Daniel Borkmann 
Acked-by: Jakub Kicinski 
Link: https://lore.kernel.org/bpf/160752226387.110217.9887866138149423444.stgit@toke.dk

selftests/bpf/test_offload.py: Reset ethtool features after failed setting

2020-12-09T15:27:42+00:00

When setting the ethtool feature flag fails (as expected for the test), the
kernel now tracks that the feature was requested to be 'off' and refuses to
subsequently disable it again. So reset it back to 'on' so a subsequent
disable (that's not supposed to fail) can succeed.

Fixes: 417ec26477a5 ("selftests/bpf: add offload test based on netdevsim")
Signed-off-by: Toke Høiland-Jørgensen 
Signed-off-by: Daniel Borkmann 
Acked-by: Jakub Kicinski 
Link: https://lore.kernel.org/bpf/160752226280.110217.10696241563705667871.stgit@toke.dk

selftests/bpf/test_offload.py: Fix expected case of extack messages

2020-12-09T15:27:42+00:00

Commit 7f0a838254bd ("bpf, xdp: Maintain info on attached XDP BPF programs
in net_device") changed the case of some of the extack messages being
returned when attaching of XDP programs failed. This broke test_offload.py,
so let's fix the test to reflect this.

Fixes: 7f0a838254bd ("bpf, xdp: Maintain info on attached XDP BPF programs in net_device")
Signed-off-by: Toke Høiland-Jørgensen 
Signed-off-by: Daniel Borkmann 
Acked-by: Jakub Kicinski 
Link: https://lore.kernel.org/bpf/160752226175.110217.11214100824416344952.stgit@toke.dk

selftests/bpf/test_offload.py: Only check verifier log on verification fails

2020-12-09T15:27:42+00:00

Since commit 6f8a57ccf851 ("bpf: Make verifier log more relevant by
default"), the verifier discards log messages for successfully-verified
programs. This broke test_offload.py which is looking for a verification
message from the driver callback. Change test_offload.py to use the toggle
in netdevsim to make the verification fail before looking for the
verification message.

Fixes: 6f8a57ccf851 ("bpf: Make verifier log more relevant by default")
Signed-off-by: Toke Høiland-Jørgensen 
Signed-off-by: Daniel Borkmann 
Acked-by: Jakub Kicinski 
Link: https://lore.kernel.org/bpf/160752226069.110217.12370824996153348073.stgit@toke.dk

selftests/bpf/test_offload.py: Remove check for program load flags match

2020-12-09T15:27:42+00:00

Since we just removed the xdp_attachment_flags_ok() callback, also remove
the check for it in test_offload.py, and replace it with a test for the new
ambiguity-avoid check when multiple programs are loaded.

Fixes: 7f0a838254bd ("bpf, xdp: Maintain info on attached XDP BPF programs in net_device")
Signed-off-by: Toke Høiland-Jørgensen 
Signed-off-by: Daniel Borkmann 
Acked-by: Jakub Kicinski 
Link: https://lore.kernel.org/bpf/160752225858.110217.13036901876869496246.stgit@toke.dk

selftests/bpf: Drain ringbuf samples at the end of test

2020-12-02T04:21:45+00:00

Avoid occasional test failures due to the last sample being delayed to
another ring_buffer__poll() call. Instead, drain samples completely with
ring_buffer__consume(). This is supposed to fix a rare and non-deterministic
test failure in libbpf CI.

Fixes: cb1c9ddd5525 ("selftests/bpf: Add BPF ringbuf selftests")
Signed-off-by: Andrii Nakryiko 
Signed-off-by: Alexei Starovoitov 
Link: https://lore.kernel.org/bpf/20201130223336.904192-2-andrii@kernel.org

libbpf: Fix ring_buffer__poll() to return number of consumed samples

2020-12-02T04:21:45+00:00

Fix ring_buffer__poll() to return the number of non-discarded records
consumed, just like its documentation states. It's also consistent with
ring_buffer__consume() return. Fix up selftests with wrong expected results.

Fixes: bf99c936f947 ("libbpf: Add BPF ring buffer support")
Fixes: cb1c9ddd5525 ("selftests/bpf: Add BPF ringbuf selftests")
Signed-off-by: Andrii Nakryiko 
Signed-off-by: Alexei Starovoitov 
Link: https://lore.kernel.org/bpf/20201130223336.904192-1-andrii@kernel.org