From: Maxim Mikityanskiy <maxim@xxxxxxxxxxxxx>
The previous commit added tracking for unbounded scalars on spill. Add
the test case to check the new functionality.
Signed-off-by: Maxim Mikityanskiy <maxim@xxxxxxxxxxxxx>
---
.../selftests/bpf/progs/verifier_spill_fill.c | 27 +++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/tools/testing/selftests/bpf/progs/verifier_spill_fill.c b/tools/testing/selftests/bpf/progs/verifier_spill_fill.c
index 92e446b18e10..809a09732168 100644
--- a/tools/testing/selftests/bpf/progs/verifier_spill_fill.c
+++ b/tools/testing/selftests/bpf/progs/verifier_spill_fill.c
@@ -901,4 +901,31 @@ l0_%=: r0 = 0; \
: __clobber_all);
}
+SEC("xdp")
+__description("spill unbounded reg, then range check src")
+__success __retval(0)
+__naked void spill_unbounded(void)
+{
+ asm volatile (" \
+ /* Produce an unbounded scalar. */ \
+ call %[bpf_get_prandom_u32]; \
+ /* Spill r0 to stack. */ \
+ *(u64*)(r10 - 8) = r0; \
+ /* Boundary check on r0. */ \
+ if r0 > 16 goto l0_%=; \
+ /* Fill r0 from stack. */ \
+ r0 = *(u64*)(r10 - 8); \
+ /* Boundary check on r0 with predetermined result. */\
+ if r0 <= 16 goto l0_%=; \
+ /* Dead branch: the verifier should prune it. Do an invalid memory\
+ * access if the verifier follows it. \
+ */ \
+ r0 = *(u64*)(r9 + 0); \
+l0_%=: r0 = 0; \
+ exit; \
+" :
+ : __imm(bpf_get_prandom_u32)
+ : __clobber_all);
+}
+
char _license[] SEC("license") = "GPL";
--
2.42.1
