linux-kernel - Re: [PATCH bpf-next v2 2/2] selftests/bpf: Add test for BPF

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <6aec43557116e371b4bf637d72d65d72fee96f44.camel@linux.dev>
Date: Tue, 28 Oct 2025 22:04:17 +0800
From: KaFai Wan <kafai.wan@...ux.dev>
To: Eduard Zingerman <eddyz87@...il.com>, ast@...nel.org,
 daniel@...earbox.net,  john.fastabend@...il.com, andrii@...nel.org,
 martin.lau@...ux.dev, song@...nel.org,  yonghong.song@...ux.dev,
 kpsingh@...nel.org, sdf@...ichev.me, haoluo@...gle.com,  jolsa@...nel.org,
 shuah@...nel.org, paul.chaignon@...il.com, m.shachnai@...il.com, 
 harishankar.vishwanathan@...il.com, colin.i.king@...il.com,
 luis.gerhorst@....de,  bpf@...r.kernel.org, linux-kernel@...r.kernel.org, 
 linux-kselftest@...r.kernel.org
Subject: Re: [PATCH bpf-next v2 2/2] selftests/bpf: Add test for BPF_JGT on
 same register

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@...ux.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