linux-kernel - Re: [PATCH v3 09/19] unwind: Introduce sframe user space unwinding

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: <CAKwvOdmZYFhz0djG0_CgQ94BLaW8rUmdW+zaoZ0G+r76Esf2+Q@mail.gmail.com>
Date: Thu, 31 Oct 2024 14:00:24 -0700
From: Nick Desaulniers <ndesaulniers@...gle.com>
To: Andrii Nakryiko <andrii.nakryiko@...il.com>
Cc: Josh Poimboeuf <jpoimboe@...nel.org>, x86@...nel.org, 
	Peter Zijlstra <peterz@...radead.org>, Steven Rostedt <rostedt@...dmis.org>, 
	Ingo Molnar <mingo@...nel.org>, Arnaldo Carvalho de Melo <acme@...nel.org>, linux-kernel@...r.kernel.org, 
	Indu Bhagat <indu.bhagat@...cle.com>, Mark Rutland <mark.rutland@....com>, 
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>, Jiri Olsa <jolsa@...nel.org>, 
	Namhyung Kim <namhyung@...nel.org>, Ian Rogers <irogers@...gle.com>, 
	Adrian Hunter <adrian.hunter@...el.com>, linux-perf-users@...r.kernel.org, 
	Mark Brown <broonie@...nel.org>, linux-toolchains@...r.kernel.org, 
	Jordan Rome <jordalgo@...a.com>, Sam James <sam@...too.org>, linux-trace-kernel@...r.kerne.org, 
	Jens Remus <jremus@...ux.ibm.com>, Mathieu Desnoyers <mathieu.desnoyers@...icios.com>, 
	Florian Weimer <fweimer@...hat.com>, Andy Lutomirski <luto@...nel.org>, 
	Arthur Eubanks <aeubanks@...gle.com>
Subject: Re: [PATCH v3 09/19] unwind: Introduce sframe user space unwinding

On Thu, Oct 31, 2024 at 1:57 PM Andrii Nakryiko
<andrii.nakryiko@...il.com> wrote:
>
> On Tue, Oct 29, 2024 at 10:53 PM Josh Poimboeuf <jpoimboe@...nel.org> wrote:
> >
> > On Tue, Oct 29, 2024 at 04:32:40PM -0700, Andrii Nakryiko wrote:
> > > > +static int find_fde(struct sframe_section *sec, unsigned long ip,
> > > > +                   struct sframe_fde *fde)
> > > > +{
> > > > +       struct sframe_fde __user *first, *last, *found = NULL;
> > > > +       u32 ip_off, func_off_low = 0, func_off_high = -1;
> > > > +
> > > > +       ip_off = ip - sec->sframe_addr;
> > >
> > > what if ip_off is larger than 4GB? ELF section can be bigger than 4GB, right?
> >
> > That's baked into sframe v2.
>
> I believe we do have large production binaries with more than 4GB of
> text, what are we going to do about them? It would be interesting to
> hear sframe people's opinion. Adding such a far-reaching new format in
> 2024 with these limitations is kind of sad. At the very least maybe we
> should allow some form of chaining sframe definitions to cover more
> than 4GB segments? Please CC relevant folks, I'm wondering what
> they're thinking about this.

FWIW, Google has such large binaries, too.
https://llvm.org/devmtg/2023-10/slides/quicktalks/Eubanks-CompromisesWithLargeX86-64Binaries.pdf
-- 
Thanks,
~Nick Desaulniers