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From: Daniel Borkmann <daniel@iogearbox.net>
To: ast@kernel.org
Cc: bpf@vger.kernel.org, netdev@vger.kernel.org,
	Daniel Borkmann <daniel@iogearbox.net>
Subject: [PATCH bpf-next 2/2] bpf: Add loop test case with 32 bit reg comparison against 0
Date: Thu,  3 Oct 2019 01:45:12 +0200	[thread overview]
Message-ID: <20191002234512.25902-2-daniel@iogearbox.net> (raw)
In-Reply-To: <20191002234512.25902-1-daniel@iogearbox.net>

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>
---
 tools/testing/selftests/bpf/verifier/loops1.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/tools/testing/selftests/bpf/verifier/loops1.c b/tools/testing/selftests/bpf/verifier/loops1.c
index 1fc4e61e9f9f..1af37187dc12 100644
--- a/tools/testing/selftests/bpf/verifier/loops1.c
+++ b/tools/testing/selftests/bpf/verifier/loops1.c
@@ -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,
+},
-- 
2.17.1


  reply	other threads:[~2019-10-02 23:45 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-02 23:45 [PATCH bpf-next 1/2] bpf, x86: Small optimization in comparing against imm0 Daniel Borkmann
2019-10-02 23:45 ` Daniel Borkmann [this message]
2019-10-03 20:56   ` [PATCH bpf-next 2/2] bpf: Add loop test case with 32 bit reg comparison against 0 Song Liu
2019-10-03 20:52 ` [PATCH bpf-next 1/2] bpf, x86: Small optimization in comparing against imm0 Song Liu
2019-10-03 21:08   ` John Fastabend
2019-10-04 19:36     ` Alexei Starovoitov

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