From: Eduard Zingerman <eddyz87@gmail.com>
To: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Hao Sun <sunhao.th@gmail.com>,
Alexei Starovoitov <ast@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>, bpf <bpf@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [Bug Report] bpf: incorrectly pruning runtime execution path
Date: Fri, 15 Dec 2023 03:43:32 +0200 [thread overview]
Message-ID: <feffb6294801f156ed049d47483164e0d51aa77b.camel@gmail.com> (raw)
In-Reply-To: <2b49b96de9f8a1cd6d78cc5aebe7c35776cd2c19.camel@gmail.com>
On Fri, 2023-12-15 at 03:24 +0200, Eduard Zingerman wrote:
[...]
> Here is an option that would fix the test in question, but I'm not
> sure if it covers all cases:
> 1. At the last instruction of each state (first instruction to be
> backtracked) we know the set of IDs that should be tracked for
> precision, as currently marked by mark_precise_scalar_ids().
> 2. In jump history we can record IDs for src and dst registers when new
> entry is pushed.
> 3. While backtracking 'if' statement, if one of the recorded IDs is in
> the set identified at (1), add src/dst regs to precise registers set.
Nah... this won't work for "second order" ids.
--- suppose r2.id == r3.id here
if r3 > 10 goto exit;
r1 += r2
... use r1 as precise ...
next prev parent reply other threads:[~2023-12-15 1:43 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-11 15:31 [Bug Report] bpf: incorrectly pruning runtime execution path Hao Sun
2023-12-13 0:51 ` Andrii Nakryiko
2023-12-13 10:25 ` Hao Sun
2023-12-13 23:30 ` Andrii Nakryiko
2023-12-14 0:08 ` Eduard Zingerman
2023-12-14 0:36 ` Andrii Nakryiko
2023-12-13 23:35 ` Eduard Zingerman
2023-12-13 23:40 ` Andrii Nakryiko
2023-12-13 23:47 ` Eduard Zingerman
2023-12-13 23:50 ` Andrii Nakryiko
2023-12-14 9:38 ` Hao Sun
2023-12-14 15:10 ` Eduard Zingerman
2023-12-14 16:26 ` Eduard Zingerman
2023-12-15 0:06 ` Andrii Nakryiko
2023-12-15 0:16 ` Eduard Zingerman
2023-12-15 0:49 ` Eduard Zingerman
2023-12-15 1:24 ` Eduard Zingerman
2023-12-15 1:43 ` Eduard Zingerman [this message]
2023-12-15 2:16 ` Alexei Starovoitov
2023-12-15 2:28 ` Eduard Zingerman
2023-12-15 5:20 ` Andrii Nakryiko
2023-12-15 16:22 ` Eduard Zingerman
2023-12-15 17:01 ` Andrii Nakryiko
2023-12-15 20:55 ` Eduard Zingerman
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