3 Commits

Author SHA1 Message Date
Hao Sun
85eb035e6c selftests/bpf: Add test for immediate spilled to stack
Add a test to check if the verifier correctly reason about the sign
of an immediate spilled to stack by BPF_ST instruction.

Signed-off-by: Hao Sun <sunhao.th@gmail.com>
Link: https://lore.kernel.org/r/20231101-fix-check-stack-write-v3-2-f05c2b1473d5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-11-01 22:30:27 -07:00
Eduard Zingerman
2a33c5a25e selftests/bpf: check if BPF_ST with variable offset preserves STACK_ZERO
A test case to verify that variable offset BPF_ST instruction
preserves STACK_ZERO marks when writes zeros, e.g. in the following
situation:

  *(u64*)(r10 - 8) = 0   ; STACK_ZERO marks for fp[-8]
  r0 = random(-7, -1)    ; some random number in range of [-7, -1]
  r0 += r10              ; r0 is now variable offset pointer to stack
  *(u8*)(r0) = 0         ; BPF_ST writing zero, STACK_ZERO mark for
                         ; fp[-8] should be preserved.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230214232030.1502829-5-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-02-15 11:48:48 -08:00
Eduard Zingerman
1a24af65bb selftests/bpf: check if verifier tracks constants spilled by BPF_ST_MEM
Check that verifier tracks the value of 'imm' spilled to stack by
BPF_ST_MEM instruction. Cover the following cases:
- write of non-zero constant to stack;
- write of a zero constant to stack.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230214232030.1502829-3-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-02-15 11:48:47 -08:00