linux-kernel - Re: [PATCH v10 00/14] unwind_user: x86: Deferred unwinding infrastructure

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] [day] [month] [year] [list]

Message-ID: <CAEf4BzY4JtvZa=ubyiO8AKGcKpOjk_YX2yHqW5JzaBLjM5gjDw@mail.gmail.com>
Date: Thu, 12 Jun 2025 16:30:00 -0700
From: Andrii Nakryiko <andrii.nakryiko@...il.com>
To: Josh Poimboeuf <jpoimboe@...nel.org>
Cc: Steven Rostedt <rostedt@...dmis.org>, linux-kernel@...r.kernel.org, 
	linux-trace-kernel@...r.kernel.org, bpf@...r.kernel.org, x86@...nel.org, 
	Masami Hiramatsu <mhiramat@...nel.org>, Mathieu Desnoyers <mathieu.desnoyers@...icios.com>, 
	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>, Indu Bhagat <indu.bhagat@...cle.com>, 
	"Jose E. Marchesi" <jemarch@....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>
Subject: Re: [PATCH v10 00/14] unwind_user: x86: Deferred unwinding infrastructure

On Thu, Jun 12, 2025 at 3:02 PM Josh Poimboeuf <jpoimboe@...nel.org> wrote:
>
> On Thu, Jun 12, 2025 at 02:44:18PM -0700, Andrii Nakryiko wrote:
> > On Tue, Jun 10, 2025 at 6:03 PM Steven Rostedt <rostedt@...dmis.org> wrote:
> > >
> > >
> > > Hi Peter and Ingo,
> > >
> > > This is the first patch series of a set that will make it possible to be able
> > > to use SFrames[1] in the Linux kernel. A quick recap of the motivation for
> > > doing this.
> > >
> > > Currently the only way to get a user space stack trace from a stack
> > > walk (and not just copying large amount of user stack into the kernel
> > > ring buffer) is to use frame pointers. This has a few issues. The biggest
> > > one is that compiling frame pointers into every application and library
> > > has been shown to cause performance overhead.
> > >
> > > Another issue is that the format of the frames may not always be consistent
> > > between different compilers and some architectures (s390) has no defined
> > > format to do a reliable stack walk. The only way to perform user space
> > > profiling on these architectures is to copy the user stack into the kernel
> > > buffer.
> > >
> > > SFrames is now supported in gcc binutils and soon will also be supported
> > > by LLVM. SFrames acts more like ORC, and lives in the ELF executable
> >
> > Is there any upstream PR or discussion for SFrames support in LLVM to
> > keep track of?
>
> https://github.com/llvm/llvm-project/issues/64449

Great, thank you!

>
> --
> Josh