linux-kernel - Re: [RFC] New codectl(2) system call for sframe registration

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: <9aabd05c-5769-41fc-a825-e6c6866d9fe4@efficios.com>
Date: Wed, 23 Jul 2025 11:09:20 -0400
From: Mathieu Desnoyers <mathieu.desnoyers@...icios.com>
To: Steven Rostedt <rostedt@...dmis.org>, Indu Bhagat <indu.bhagat@...cle.com>
Cc: "Jose E. Marchesi" <jemarch@....org>, linux-kernel@...r.kernel.org,
 linux-trace-kernel@...r.kernel.org, bpf@...r.kernel.org, x86@...nel.org,
 Masami Hiramatsu <mhiramat@...nel.org>, Josh Poimboeuf
 <jpoimboe@...nel.org>, Peter Zijlstra <peterz@...radead.org>,
 Ingo Molnar <mingo@...nel.org>, Jiri Olsa <jolsa@...nel.org>,
 Namhyung Kim <namhyung@...nel.org>, Thomas Gleixner <tglx@...utronix.de>,
 Andrii Nakryiko <andrii@...nel.org>,
 Beau Belgrave <beaub@...ux.microsoft.com>, Jens Remus
 <jremus@...ux.ibm.com>, Linus Torvalds <torvalds@...ux-foundation.org>,
 Andrew Morton <akpm@...ux-foundation.org>, Jens Axboe <axboe@...nel.dk>,
 Florian Weimer <fweimer@...hat.com>, Sam James <sam@...too.org>,
 Brian Robbins <brianrob@...rosoft.com>,
 Elena Zannoni <elena.zannoni@...cle.com>
Subject: Re: [RFC] New codectl(2) system call for sframe registration

On 2025-07-22 17:13, Steven Rostedt wrote:
> On Tue, 22 Jul 2025 14:04:37 -0700
> Indu Bhagat <indu.bhagat@...cle.com> wrote:
> 
>> Yes and No.  The offset at which the text is loaded is _one_ part of the
>> information to "fill in the blanks".  The other part is what to do with
>> that information (text_vma) or how to relocate the SFrame section itself
>> a.k.a. the relocation entries.  To know the relocations, one will need
>> to get access to the respective relocation section, and hence access to
>> the ELF section headers.
> 
> You mean to find where in the sframe section itself that needs to be update?
> 
> OK, that makes sense. So sframes does need to still be in an ELF file for
> its own relocations and such.
> 
> It will be interesting on how to do compression and on-demand page loading.
> 
> There would need to be a table as well that will denote where in the
> decompressed pages that relocations need to be performed.

If we can find a way to express all sframe "pointers" as offsets from a
text_vma base, then there is no need for relocations. This would
minimize complexity.

Thanks,

Mathieu

-- 
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com