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
| ||
|
Date: Mon, 15 Aug 2022 14:37:38 +0200 From: Peter Zijlstra <peterz@...radead.org> To: Jiri Olsa <olsajiri@...il.com> Cc: Steven Rostedt <rostedt@...dmis.org>, Alexei Starovoitov <alexei.starovoitov@...il.com>, Alexei Starovoitov <ast@...nel.org>, Daniel Borkmann <daniel@...earbox.net>, Andrii Nakryiko <andrii@...nel.org>, Ingo Molnar <mingo@...hat.com>, bpf <bpf@...r.kernel.org>, Martin KaFai Lau <kafai@...com>, Song Liu <songliubraving@...com>, Yonghong Song <yhs@...com>, John Fastabend <john.fastabend@...il.com>, KP Singh <kpsingh@...omium.org>, Stanislav Fomichev <sdf@...gle.com>, Hao Luo <haoluo@...gle.com>, LKML <linux-kernel@...r.kernel.org>, Josh Poimboeuf <jpoimboe@...hat.com> Subject: Re: [RFC] ftrace: Add support to keep some functions out of ftrace On Mon, Aug 15, 2022 at 11:44:32AM +0200, Jiri Olsa wrote: > On Mon, Aug 15, 2022 at 10:03:17AM +0200, Peter Zijlstra wrote: > > On Sat, Aug 13, 2022 at 03:02:52PM -0400, Steven Rostedt wrote: > > > On Fri, 12 Aug 2022 23:18:15 +0200 > > > Jiri Olsa <olsajiri@...il.com> wrote: > > > > > > > the patch below moves the bpf function into sepatate object and switches > > > > off the -mrecord-mcount for it.. so the function gets profile call > > > > generated but it's not visible to ftrace > > > > Why ?!? > > there's bpf dispatcher code that updates bpf_dispatcher_xdp_func > function with bpf_arch_text_poke and that can race with ftrace update > if the function is traced I thought bpf_arch_text_poke() wasn't allowed to touch kernel code and ftrace is in full control of it ?
Powered by blists - more mailing lists