From: Daniel Borkmann <daniel@iogearbox.net>
Date: Thu, 3 Oct 2019 01:45:12 +0200
Subject: bpf: Add loop test case with 32 bit reg comparison against 0
Patch-mainline: v5.5-rc1
Git-commit: 4bbbf164f1a5e970543dcdb7a396fc1cf477725b
References: bsc#1177028
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>
Acked-by: Gary Lin <glin@suse.com>
---
tools/testing/selftests/bpf/verifier/loops1.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
--- 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,
+},