Re: [PATCH bpf-next v2 2/2] selftests/bpf: Add test for BPF_JGT on same register

[KaFai Wan <kafai.wan@linux.dev>]

On Mon, 2025-10-27 at 12:40 -0700, Eduard Zingerman wrote:
> On Sat, 2025-10-25 at 13:30 +0800, KaFai Wan wrote:
> > 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 <kafai.wan@linux.dev>
> > ---
> 
> Could you please add test cases for JSET and for one of the *E
> variants?

ok, i will add the tests in v3.
> 
> >  .../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";

-- 
Thanks,
KaFai