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>
This commit is contained in:
Naveen N. Rao 2019-06-13 00:21:39 +05:30 committed by Daniel Borkmann
parent 0e26574749
commit 3e06826951

View File

@ -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,