Commit 4bbbf164 authored Oct 03, 2019 by Daniel Borkmann Committed by Alexei Starovoitov Oct 04, 2019

bpf: Add loop test case with 32 bit reg comparison against 0



Add a loop test with 32 bit register against 0 immediate:

  # ./test_verifier 631
  #631/p taken loop with back jump to 1st insn, 2 OK

Disassembly:

  [...]
  1b:	test   %edi,%edi
  1d:	jne    0x0000000000000014
  [...]

Pretty much similar to prior "taken loop with back jump to 1st
insn" test case just as jmp32 variant.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>

parent 38f51c07

tools/testing/selftests/bpf/verifier/loops1.c

+17 −0

Original line number	Diff line number	Diff line
		@@ -187,3 +187,20 @@
		.prog_type = BPF_PROG_TYPE_XDP,
		.retval = 55,
		},
		{
		"taken loop with back jump to 1st insn, 2",
		.insns = {
		BPF_MOV64_IMM(BPF_REG_1, 10),
		BPF_MOV64_IMM(BPF_REG_2, 0),
		BPF_RAW_INSN(BPF_JMP \| BPF_CALL, 0, 1, 0, 1),
		BPF_EXIT_INSN(),
		BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_1),
		BPF_ALU64_IMM(BPF_SUB, BPF_REG_1, 1),
		BPF_JMP32_IMM(BPF_JNE, BPF_REG_1, 0, -3),
		BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
		BPF_EXIT_INSN(),
		},
		.result = ACCEPT,
		.prog_type = BPF_PROG_TYPE_XDP,
		.retval = 55,
		},

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