From: Alexei Starovoitov <alexei.starovoitov@gmail.com>
To: Leon Hwang <hffilwlqm@gmail.com>
Cc: Andrii Nakryiko <andrii@kernel.org>,
Kumar Kartikeya Dwivedi <memxor@gmail.com>,
Menglong Dong <menglong.dong@linux.dev>,
Menglong Dong <menglong8.dong@gmail.com>,
Alexei Starovoitov <ast@kernel.org>, bpf <bpf@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
linux-trace-kernel <linux-trace-kernel@vger.kernel.org>,
jiang.biao@linux.dev
Subject: Re: bpf_errno. Was: [PATCH RFC bpf-next 1/3] bpf: report probe fault to BPF stderr
Date: Thu, 9 Oct 2025 07:45:58 -0700 [thread overview]
Message-ID: <CAADnVQK8Rw19Z6ib0CfK0cMHUsYBuhEv8_464knZ4qFZ6Gfv2g@mail.gmail.com> (raw)
In-Reply-To: <405caf71-315d-46a4-af35-c1fd53470b91@gmail.com>
On Thu, Oct 9, 2025 at 7:15 AM Leon Hwang <hffilwlqm@gmail.com> wrote:
>
>
> The verifier can rewrite 'bpf_reg_aux()' into the following instructions:
>
> dst_reg = BPF_REG_AUX;
> BPF_REG_AUX = 0; /* clear BPF_REG_AUX */
>
> As for the architecture-specific implementation, BPF_REG_AUX can be
> mapped to an appropriate register per arch — for example, r11 on x86_64.
it's taken. There are no free registers.
next prev parent reply other threads:[~2025-10-09 14:46 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-27 6:12 [PATCH RFC bpf-next 0/3] bpf: report probe fault to BPF stderr Menglong Dong
2025-09-27 6:12 ` [PATCH RFC bpf-next 1/3] " Menglong Dong
2025-10-02 2:03 ` Alexei Starovoitov
2025-10-07 6:14 ` Menglong Dong
2025-10-08 14:40 ` Leon Hwang
2025-10-08 16:27 ` bpf_errno. Was: " Alexei Starovoitov
2025-10-08 17:08 ` Kumar Kartikeya Dwivedi
2025-10-08 19:34 ` Eduard Zingerman
2025-10-08 20:08 ` Kumar Kartikeya Dwivedi
2025-10-08 20:30 ` Eduard Zingerman
2025-10-08 20:59 ` Kumar Kartikeya Dwivedi
2025-10-09 14:29 ` Leon Hwang
2025-10-09 15:15 ` Leon Hwang
2025-10-10 12:05 ` Menglong Dong
2025-10-10 15:10 ` Menglong Dong
2025-10-10 18:55 ` Eduard Zingerman
2025-10-11 1:23 ` Menglong Dong
2025-10-09 14:15 ` Leon Hwang
2025-10-09 14:45 ` Alexei Starovoitov [this message]
2025-10-10 14:22 ` Leon Hwang
2025-09-27 6:12 ` [PATCH RFC bpf-next 2/3] x86,bpf: use bpf_prog_report_probe_violation for x86 Menglong Dong
2025-09-27 6:12 ` [PATCH RFC bpf-next 3/3] selftests/bpf: add testcase for probe read fault Menglong Dong
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