linux-stable.git/lib/test_bpf.c, branch v5.16.2

bpf, tests: Add module parameter test_suite to test_bpf module

2021-10-28T09:41:16+00:00

After commit 9298e63eafea ("bpf/tests: Add exhaustive tests of ALU
operand magnitudes"), when modprobe test_bpf.ko with JIT on mips64,
there exists segment fault due to the following reason:

  [...]
  ALU64_MOV_X: all register value magnitudes jited:1
  Break instruction in kernel code[#1]
  [...]

It seems that the related JIT implementations of some test cases
in test_bpf() have problems. At this moment, I do not care about
the segment fault while I just want to verify the test cases of
tail calls.

Based on the above background and motivation, add the following
module parameter test_suite to the test_bpf.ko:

  test_suite=: only the specified test suite will be run, the
  string can be "test_bpf", "test_tail_calls" or "test_skb_segment".

If test_suite is not specified, but test_id, test_name or test_range
is specified, set 'test_bpf' as the default test suite. This is useful
to only test the corresponding test suite when specifying the valid
test_suite string.

Any invalid test suite will result in -EINVAL being returned and no
tests being run. If the test_suite is not specified or specified as
empty string, it does not change the current logic, all of the test
cases will be run.

Here are some test results:

 # dmesg -c
 # modprobe test_bpf
 # dmesg | grep Summary
 test_bpf: Summary: 1009 PASSED, 0 FAILED, [0/997 JIT'ed]
 test_bpf: test_tail_calls: Summary: 8 PASSED, 0 FAILED, [0/8 JIT'ed]
 test_bpf: test_skb_segment: Summary: 2 PASSED, 0 FAILED

 # rmmod test_bpf
 # dmesg -c
 # modprobe test_bpf test_suite=test_bpf
 # dmesg | tail -1
 test_bpf: Summary: 1009 PASSED, 0 FAILED, [0/997 JIT'ed]

 # rmmod test_bpf
 # dmesg -c
 # modprobe test_bpf test_suite=test_tail_calls
 # dmesg
 test_bpf: #0 Tail call leaf jited:0 21 PASS
 [...]
 test_bpf: #7 Tail call error path, index out of range jited:0 32 PASS
 test_bpf: test_tail_calls: Summary: 8 PASSED, 0 FAILED, [0/8 JIT'ed]

 # rmmod test_bpf
 # dmesg -c
 # modprobe test_bpf test_suite=test_skb_segment
 # dmesg
 test_bpf: #0 gso_with_rx_frags PASS
 test_bpf: #1 gso_linear_no_head_frag PASS
 test_bpf: test_skb_segment: Summary: 2 PASSED, 0 FAILED

 # rmmod test_bpf
 # dmesg -c
 # modprobe test_bpf test_id=1
 # dmesg
 test_bpf: test_bpf: set 'test_bpf' as the default test_suite.
 test_bpf: #1 TXA jited:0 54 51 50 PASS
 test_bpf: Summary: 1 PASSED, 0 FAILED, [0/1 JIT'ed]

 # rmmod test_bpf
 # dmesg -c
 # modprobe test_bpf test_suite=test_bpf test_name=TXA
 # dmesg
 test_bpf: #1 TXA jited:0 54 50 51 PASS
 test_bpf: Summary: 1 PASSED, 0 FAILED, [0/1 JIT'ed]

 # rmmod test_bpf
 # dmesg -c
 # modprobe test_bpf test_suite=test_tail_calls test_range=6,7
 # dmesg
 test_bpf: #6 Tail call error path, NULL target jited:0 41 PASS
 test_bpf: #7 Tail call error path, index out of range jited:0 32 PASS
 test_bpf: test_tail_calls: Summary: 2 PASSED, 0 FAILED, [0/2 JIT'ed]

 # rmmod test_bpf
 # dmesg -c
 # modprobe test_bpf test_suite=test_skb_segment test_id=1
 # dmesg
 test_bpf: #1 gso_linear_no_head_frag PASS
 test_bpf: test_skb_segment: Summary: 1 PASSED, 0 FAILED

By the way, the above segment fault has been fixed in the latest bpf-next
tree which contains the mips64 JIT rework.

Signed-off-by: Tiezhu Yang 
Signed-off-by: Daniel Borkmann 
Tested-by: Johan Almbladh 
Acked-by: Johan Almbladh 
Link: https://lore.kernel.org/bpf/1635384321-28128-1-git-send-email-yangtiezhu@loongson.cn

bpf, tests: Add more LD_IMM64 tests

2021-10-07T21:51:29+00:00

This patch adds new tests for the two-instruction LD_IMM64. The new tests
verify the operation with immediate values of different byte patterns.
Mainly intended to cover JITs that want to be clever when loading 64-bit
constants.

Signed-off-by: Johan Almbladh 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20211007143006.634308-1-johan.almbladh@anyfinetworks.com

bpf/tests: Add test of LDX_MEM with operand aliasing

2021-10-01T15:04:26+00:00

This patch adds a set of tests of BPF_LDX_MEM where both operand registers
are the same register. Mainly testing 32-bit JITs that may load a 64-bit
value in two 32-bit loads, and must not overwrite the address register.

Signed-off-by: Johan Almbladh 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20211001130348.3670534-11-johan.almbladh@anyfinetworks.com

bpf/tests: Add test of ALU shifts with operand register aliasing

2021-10-01T15:04:26+00:00

This patch adds a tests of ALU32 and ALU64 LSH/RSH/ARSH operations for the
case when the two operands are the same register. Mainly intended to test
JITs that implement ALU64 shifts with 32-bit CPU instructions.

Also renamed related helper functions for consistency with the new tests.

Signed-off-by: Johan Almbladh 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20211001130348.3670534-10-johan.almbladh@anyfinetworks.com

bpf/tests: Add exhaustive tests of BPF_ATOMIC register combinations

2021-10-01T15:04:26+00:00

This patch adds tests of all register combinations for BPF_ATOMIC
operations on both BPF_W and BPF_DW sizes.

Signed-off-by: Johan Almbladh 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20211001130348.3670534-9-johan.almbladh@anyfinetworks.com

bpf/tests: Add exhaustive tests of ALU register combinations

2021-10-01T15:04:26+00:00

This patch replaces the current register combination test with new
exhaustive tests. Before, only a subset of register combinations was
tested for ALU64 DIV. Now, all combinatons of operand registers are
tested, including the case when they are the same, and for all ALU32
and ALU64 operations.

Signed-off-by: Johan Almbladh 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20211001130348.3670534-8-johan.almbladh@anyfinetworks.com

bpf/tests: Minor restructuring of ALU tests

2021-10-01T15:04:26+00:00

This patch moves the ALU LSH/RSH/ARSH reference computations into the
common reference value function. Also fix typo in constants so they
now have the intended values.

Signed-off-by: Johan Almbladh 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20211001130348.3670534-7-johan.almbladh@anyfinetworks.com

bpf/tests: Add more tests for ALU and ATOMIC register clobbering

2021-10-01T15:04:26+00:00

This patch expands the register-clobbering-during-function-call tests
to cover more all ALU32/64 MUL, DIV and MOD operations and all ATOMIC
operations. In short, if a JIT implements a complex operation with
a call to an external function, it must make sure to save and restore
all its caller-saved registers that may be clobbered by the call.

Signed-off-by: Johan Almbladh 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20211001130348.3670534-6-johan.almbladh@anyfinetworks.com

bpf/tests: Add tests to check source register zero-extension

2021-10-01T15:04:26+00:00

This patch adds tests to check that the source register is preserved when
zero-extending a 32-bit value. In particular, it checks that the source
operand is not zero-extended in-place.

Signed-off-by: Johan Almbladh 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20211001130348.3670534-5-johan.almbladh@anyfinetworks.com

bpf/tests: Add exhaustive tests of BPF_ATOMIC magnitudes

2021-10-01T15:04:25+00:00

This patch adds a series of test to verify the operation of BPF_ATOMIC
with BPF_DW and BPF_W sizes, for all power-of-two magnitudes of the
register value operand.

Also fixes a confusing typo in the comment for a related test.

Signed-off-by: Johan Almbladh 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20211001130348.3670534-4-johan.almbladh@anyfinetworks.com