Add a test to verify that conditional jumps using the BPF_JGT opcode on the same register (e.g., "if r0 > r0") do not trigger verifier BUG warnings when the register contains a scalar value with range information.
Signed-off-by: KaFai Wan <[email protected]> --- .../selftests/bpf/progs/verifier_bounds.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/tools/testing/selftests/bpf/progs/verifier_bounds.c b/tools/testing/selftests/bpf/progs/verifier_bounds.c index 0a72e0228ea9..1536235c3e87 100644 --- a/tools/testing/selftests/bpf/progs/verifier_bounds.c +++ b/tools/testing/selftests/bpf/progs/verifier_bounds.c @@ -1709,4 +1709,22 @@ __naked void jeq_disagreeing_tnums(void *ctx) : __clobber_all); } +SEC("socket") +__description("JGT on same register") +__success __log_level(2) +__retval(0) +__naked void jgt_same_register(void *ctx) +{ + asm volatile(" \ + call %[bpf_get_prandom_u32]; \ + w8 = 0x80000000; \ + r0 &= r8; \ + if r0 > r0 goto +1; \ + r0 = 0; \ + exit; \ +" : + : __imm(bpf_get_prandom_u32) + : __clobber_all); +} + char _license[] SEC("license") = "GPL"; -- 2.43.0
