From: Maxim Mikityanskiy maxim@isovalent.com
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@isovalent.com Acked-by: Eduard Zingerman eddyz87@gmail.com --- .../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 57eb70e100a3..cc6c5a3b464b 100644 --- a/tools/testing/selftests/bpf/progs/verifier_spill_fill.c +++ b/tools/testing/selftests/bpf/progs/verifier_spill_fill.c @@ -899,4 +899,31 @@ 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";