diff mbox series

[bpf,2/2] tools/bpf: add a verifier test for assigning 32bit reg states to 64bit ones

Message ID 20200528165044.1568896-1-yhs@fb.com
State Changes Requested
Delegated to: BPF Maintainers
Headers show
Series bpf: fix a verifier issue when assigning 32bit reg states to 64bit ones | expand

Commit Message

Yonghong Song May 28, 2020, 4:50 p.m. UTC 
Added a verifier test for assigning 32bit reg states to
64bit where 32bit reg holds a constant value of 0.

Without previous kernel verifier.c fix, the test in
this patch will fail.

Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/testing/selftests/bpf/verifier/bounds.c | 22 +++++++++++++++++++
 1 file changed, 22 insertions(+)
diff mbox series

Patch

diff --git a/tools/testing/selftests/bpf/verifier/bounds.c b/tools/testing/selftests/bpf/verifier/bounds.c
index a253a064e6e0..e2739ca2abec 100644
--- a/tools/testing/selftests/bpf/verifier/bounds.c
+++ b/tools/testing/selftests/bpf/verifier/bounds.c
@@ -539,3 +539,25 @@ 
 	},
 	.result = ACCEPT
 },
+{
+	"assigning 32bit bounds to 64bit for wA = 0, wB = wA",
+	.insns = {
+	BPF_LDX_MEM(BPF_W, BPF_REG_8, BPF_REG_1,
+		    offsetof(struct __sk_buff, data_end)),
+	BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_1,
+		    offsetof(struct __sk_buff, data)),
+	BPF_MOV32_IMM(BPF_REG_9, 0),
+	BPF_MOV32_REG(BPF_REG_2, BPF_REG_9),
+	BPF_MOV64_REG(BPF_REG_6, BPF_REG_7),
+	BPF_ALU64_REG(BPF_ADD, BPF_REG_6, BPF_REG_2),
+	BPF_MOV64_REG(BPF_REG_3, BPF_REG_6),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, 8),
+	BPF_JMP_REG(BPF_JGT, BPF_REG_3, BPF_REG_8, 1),
+	BPF_LDX_MEM(BPF_W, BPF_REG_5, BPF_REG_6, 0),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+	.result = ACCEPT,
+	.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
+},