From: "Frank Ch. Eigler" <fche@redhat.com>
To: Kees Cook <keescook@chromium.org>
Cc: Joe Lawrence <joe.lawrence@redhat.com>,
Evgenii Shatokhin <eshatokhin@virtuozzo.com>,
Kristen Carlson Accardi <kristen@linux.intel.com>,
Miroslav Benes <mbenes@suse.cz>,
tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
arjan@linux.intel.com, x86@kernel.org,
linux-kernel@vger.kernel.org,
kernel-hardening@lists.openwall.com, rick.p.edgecombe@intel.com,
live-patching@vger.kernel.org,
Josh Poimboeuf <jpoimboe@redhat.com>,
Jessica Yu <jeyu@kernel.org>
Subject: Re: [PATCH v4 00/10] Function Granular KASLR
Date: Mon, 3 Aug 2020 20:48:17 -0400 [thread overview]
Message-ID: <20200804004817.GD30810@redhat.com> (raw)
In-Reply-To: <202008031439.F1399A588@keescook>
Hi -
> > We have relocated based on sections, not some subset of function
> > symbols accessible that way, partly because DWARF line- and DIE- based
> > probes can map to addresses some way away from function symbols, into
> > function interiors, or cloned/moved bits of optimized code. It would
> > take some work to prove that function-symbol based heuristic
> > arithmetic would have just as much reach.
>
> Interesting. Do you have an example handy?
No, I'm afraid I don't have one that I know cannot possibly be
expressed by reference to a function symbol only. I'd look at
systemtap (4.3) probe point lists like:
% stap -vL 'kernel.statement("*@kernel/*verif*.c:*")'
% stap -vL 'module("amdgpu").statement("*@*execution*.c:*")'
which give an impression of computed PC addresses.
> It seems like something like that would reference the enclosing
> section, which means we can't just leave them out of the sysfs
> list... (but if such things never happen in the function-sections,
> then we *can* remove them...)
I'm not sure we can easily prove they can never happen there.
- FChE
next prev parent reply other threads:[~2020-08-04 11:45 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-17 16:59 [PATCH v4 00/10] Function Granular KASLR Kristen Carlson Accardi
2020-07-17 16:59 ` [PATCH v4 01/10] objtool: Do not assume order of parent/child functions Kristen Carlson Accardi
2020-07-17 16:59 ` [PATCH v4 02/10] x86: tools/relocs: Support >64K section headers Kristen Carlson Accardi
2020-07-17 17:00 ` [PATCH v4 03/10] x86/boot: Allow a "silent" kaslr random byte fetch Kristen Carlson Accardi
2020-07-17 17:00 ` [PATCH v4 04/10] x86: Makefile: Add build and config option for CONFIG_FG_KASLR Kristen Carlson Accardi
2020-07-17 17:00 ` [PATCH v4 05/10] x86: Make sure _etext includes function sections Kristen Carlson Accardi
2020-07-17 17:00 ` [PATCH v4 06/10] x86/tools: Add relative relocs for randomized functions Kristen Carlson Accardi
2020-07-17 17:00 ` [PATCH v4 07/10] x86/boot/compressed: Avoid duplicate malloc() implementations Kristen Carlson Accardi
2020-07-17 17:00 ` [PATCH v4 08/10] x86: Add support for function granular KASLR Kristen Carlson Accardi
2020-07-17 17:00 ` [PATCH v4 09/10] kallsyms: Hide layout Kristen Carlson Accardi
2020-07-20 1:25 ` Kees Cook
2020-07-20 16:59 ` Kristen Carlson Accardi
2020-07-17 17:00 ` [PATCH v4 10/10] module: Reorder functions Kristen Carlson Accardi
2020-07-28 17:29 ` Jessica Yu
2020-07-22 9:27 ` [PATCH v4 00/10] Function Granular KASLR Miroslav Benes
2020-07-22 14:39 ` Kees Cook
2020-07-22 14:51 ` Joe Lawrence
2020-07-22 14:56 ` Joe Lawrence
2020-07-22 18:24 ` Kristen Carlson Accardi
2020-07-22 16:07 ` Josh Poimboeuf
2020-07-22 19:42 ` Kees Cook
2020-07-22 19:56 ` Kristen Carlson Accardi
2020-07-22 21:33 ` Josh Poimboeuf
2020-08-21 23:02 ` Kristen Carlson Accardi
2020-08-25 16:16 ` Joe Lawrence
2020-08-28 10:21 ` Miroslav Benes
2020-08-28 19:24 ` Josh Poimboeuf
2021-01-23 22:59 ` Fangrui Song
2021-01-25 17:21 ` Josh Poimboeuf
2020-08-03 11:39 ` Evgenii Shatokhin
2020-08-03 17:45 ` Kees Cook
2020-08-03 18:17 ` Joe Lawrence
2020-08-03 19:38 ` Frank Ch. Eigler
2020-08-03 20:11 ` Kees Cook
2020-08-03 21:12 ` Frank Ch. Eigler
2020-08-03 21:41 ` Kees Cook
2020-08-04 0:48 ` Frank Ch. Eigler [this message]
2020-08-04 17:04 ` Jessica Yu
2020-08-04 18:23 ` Joe Lawrence
2020-08-07 16:38 ` Kristen Carlson Accardi
2020-08-07 17:20 ` Kees Cook
2020-08-10 16:10 ` Kristen Carlson Accardi
2020-08-12 17:18 ` Kristen Carlson Accardi
2020-08-06 15:32 ` Ingo Molnar
2020-08-06 19:24 ` Kristen Carlson Accardi
2020-08-06 19:27 ` Kees Cook
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