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authorNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>2019-06-13 00:21:39 +0530
committerDaniel Borkmann <daniel@iogearbox.net>2019-06-13 23:07:00 +0200
commit3e0682695199bad51dd898fe064d1564637ff77a (patch)
treea63884494c3ac859560d7056cb1def9095b1c4fa
parent0e265747491cb182429adfbef7d002164566f25c (diff)
bpf: fix div64 overflow tests to properly detect errors
If the result of the division is LLONG_MIN, current tests do not detect the error since the return value is truncated to a 32-bit value and ends up being 0. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
-rw-r--r--tools/testing/selftests/bpf/verifier/div_overflow.c14
1 files changed, 10 insertions, 4 deletions
diff --git a/tools/testing/selftests/bpf/verifier/div_overflow.c b/tools/testing/selftests/bpf/verifier/div_overflow.c
index bd3f38dbe796..acab4f00819f 100644
--- a/tools/testing/selftests/bpf/verifier/div_overflow.c
+++ b/tools/testing/selftests/bpf/verifier/div_overflow.c
@@ -29,8 +29,11 @@
"DIV64 overflow, check 1",
.insns = {
BPF_MOV64_IMM(BPF_REG_1, -1),
- BPF_LD_IMM64(BPF_REG_0, LLONG_MIN),
- BPF_ALU64_REG(BPF_DIV, BPF_REG_0, BPF_REG_1),
+ BPF_LD_IMM64(BPF_REG_2, LLONG_MIN),
+ BPF_ALU64_REG(BPF_DIV, BPF_REG_2, BPF_REG_1),
+ BPF_MOV32_IMM(BPF_REG_0, 0),
+ BPF_JMP_REG(BPF_JEQ, BPF_REG_0, BPF_REG_2, 1),
+ BPF_MOV32_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
@@ -40,8 +43,11 @@
{
"DIV64 overflow, check 2",
.insns = {
- BPF_LD_IMM64(BPF_REG_0, LLONG_MIN),
- BPF_ALU64_IMM(BPF_DIV, BPF_REG_0, -1),
+ BPF_LD_IMM64(BPF_REG_1, LLONG_MIN),
+ BPF_ALU64_IMM(BPF_DIV, BPF_REG_1, -1),
+ BPF_MOV32_IMM(BPF_REG_0, 0),
+ BPF_JMP_REG(BPF_JEQ, BPF_REG_0, BPF_REG_1, 1),
+ BPF_MOV32_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,