Add a test case to verify that conditional jumps on the same register (e.g., JGT r0 > r0) do not trigger verifier BUG warnings when the register holds a scalar with range.
Signed-off-by: KaFai Wan <[email protected]> --- .../selftests/bpf/progs/verifier_bounds.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/tools/testing/selftests/bpf/progs/verifier_bounds.c b/tools/testing/selftests/bpf/progs/verifier_bounds.c index 0a72e0228ea9..620095635af5 100644 --- a/tools/testing/selftests/bpf/progs/verifier_bounds.c +++ b/tools/testing/selftests/bpf/progs/verifier_bounds.c @@ -1709,4 +1709,21 @@ __naked void jeq_disagreeing_tnums(void *ctx) : __clobber_all); } +SEC("socket") +__description("JGT on same register") +__success __log_level(2) +__naked void jgt_same_register(void *ctx) +{ + asm volatile(" \ + call %[bpf_get_prandom_u32]; \ + w8 = 0x80000000; \ + r0 &= r8; \ + if r0 > r0 goto +1; \ + call %[bpf_get_prandom_u32]; \ + exit; \ +" : + : __imm(bpf_get_prandom_u32) + : __clobber_all); +} + char _license[] SEC("license") = "GPL"; -- 2.43.0
