linux-kernel - Re: [PATCH v4 3/9] bpf/btf: Add a function to search a member of a struct/union

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

Message-ID: <20230802143845.3ce6ed61@gandalf.local.home>
Date:   Wed, 2 Aug 2023 14:38:45 -0400
From:   Steven Rostedt <rostedt@...dmis.org>
To:     Alexei Starovoitov <alexei.starovoitov@...il.com>
Cc:     Masami Hiramatsu <mhiramat@...nel.org>,
        linux-trace-kernel@...r.kernel.org,
        LKML <linux-kernel@...r.kernel.org>,
        Martin KaFai Lau <martin.lau@...ux.dev>,
        bpf <bpf@...r.kernel.org>, Sven Schnelle <svens@...ux.ibm.com>,
        Alexei Starovoitov <ast@...nel.org>,
        Jiri Olsa <jolsa@...nel.org>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        Alan Maguire <alan.maguire@...cle.com>,
        Mark Rutland <mark.rutland@....com>,
        Florent Revest <revest@...omium.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [PATCH v4 3/9] bpf/btf: Add a function to search a member of a
 struct/union

On Wed, 2 Aug 2023 11:24:12 -0700
Alexei Starovoitov <alexei.starovoitov@...il.com> wrote:

> This is a non starter.
> bpf progs expect arch dependent 'struct pt_regs *' and we cannot change that.

If the progs are compiled into native code, isn't there optimizations that
could be done? That is, if ftrace_regs is available, and the bpf program is
just using the subset of pt_regs, is it possible that it could be compiled
to use ftrace_regs?

Forgive my ignorance on how BPF programs turn into executables when running
in the kernel.

-- Steve