Signed-off-by: Edward Cree <ec...@solarflare.com>
---
tools/testing/selftests/bpf/test_align.c | 39 ++++++++++++++++++++++++++++++++
1 file changed, 39 insertions(+)
diff --git a/tools/testing/selftests/bpf/test_align.c
b/tools/testing/selftests/bpf/test_align.c
index 8591c89c0828..24c6757b4c51 100644
--- a/tools/testing/selftests/bpf/test_align.c
+++ b/tools/testing/selftests/bpf/test_align.c
@@ -601,6 +601,45 @@ static struct bpf_align_test tests[] = {
{20,
"R5=pkt(id=2,off=0,r=4,umin_value=2,umax_value=1082,var_off=(0x2; 0x7fc))"},
},
},
+ {
+ .descr = "unknown shift negative",
+ /* This isn't really a test of the alignment code, rather of the
+ * signed min/max value handling, but it makes use of the
+ * register-state-extracting code in do_test_single(), which
+ * test_verifier.c doesn't have.
+ */
+ .insns = {
+ LOAD_UNKNOWN(BPF_REG_3),
+ BPF_ALU64_IMM(BPF_SUB, BPF_REG_3, 0xff),
+ BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
+ LOAD_UNKNOWN(BPF_REG_4),
+ BPF_ALU64_IMM(BPF_SUB, BPF_REG_4, 0xff),
+ BPF_MOV64_REG(BPF_REG_5, BPF_REG_4),
+ BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
+ BPF_ALU64_IMM(BPF_SUB, BPF_REG_5, 1),
+ BPF_ALU64_IMM(BPF_RSH, BPF_REG_5, 1),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ .matches = {
+ {7, "R0=pkt(id=0,off=8,r=8,imm=0)"},
+ {7, "R3=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
+ {8, "R3=inv(id=0,smin_value=-255,smax_value=0)"},
+ /* All the verifier knows is, it's even. While we could
+ * conclude something tighter (the sign bit does not
+ * change), the verifier doesn't bother right now.
+ */
+ {9,
"R3=inv(id=0,smax_value=9223372036854775806,umax_value=18446744073709551614,var_off=(0x0;
0xfffffffffffffffe))"},
+ {16, "R3=pkt_end(id=0,off=0,imm=0)"},
+ {16, "R4=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
+ {17, "R4=inv(id=0,smin_value=-255,smax_value=0)"},
+ /* both 0 and 0x7f...fff are possible */
+ {19,
"R4=inv(id=0,umax_value=9223372036854775807,var_off=(0x0;
0x7fffffffffffffff))"},
+ {20,
"R5=inv(id=0,umin_value=18446744073709551360,var_off=(0xffffffffffffff00;
0xff))"},
+ {21,
"R5=inv(id=0,umin_value=9223372036854775680,umax_value=9223372036854775807,var_off=(0x7fffffffffffff80;
0x7f))"},
+ },
+ },
};
static int probe_filter_length(const struct bpf_insn *fp)
