[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <ZS6F46vJfca5f6f8@gmail.com>
Date: Tue, 17 Oct 2023 15:02:27 +0200
From: Ingo Molnar <mingo@...nel.org>
To: Hou Wenlong <houwenlong.hwl@...group.com>
Cc: linux-kernel@...r.kernel.org,
Lai Jiangshan <jiangshan.ljs@...group.com>,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
Dave Hansen <dave.hansen@...ux.intel.com>,
"maintainer:X86 ARCHITECTURE 32-BIT AND 64-BIT" <x86@...nel.org>,
"H. Peter Anvin" <hpa@...or.com>,
Josh Poimboeuf <jpoimboe@...nel.org>,
Anshuman Khandual <anshuman.khandual@....com>,
Mike Rapoport <rppt@...nel.org>,
Pasha Tatashin <pasha.tatashin@...een.com>
Subject: Re: [PATCH RFC 1/7] x86/head/64: Mark startup_gdt and
startup_gdt_descr as __initdata
* Hou Wenlong <houwenlong.hwl@...group.com> wrote:
> Hi Ingo,
>
> I have sent patch #6 separately for x86. Do you have any ideas about
> building the head code as PIE? Should I resend the patchset for the PIE
> feature?
So I had a brief look, and despite reading 0/43 it was unclear to me what
the precise advantages of building as PIE are.
Ie. could you please outline:
- *Exactly* how much PIE based KASLR randomization would gain us in terms
of randomization granularity and effective number of randomization bits,
compared to the current status quo?
- How is code generation changed at the instruction level - how does
kernel size change and what are the micro-advantages/disadvantages?
- Are there any other advantages/motivation than improving KASLR?
Ie. before asking us to apply ~50 patches and add a whole new build mode
and the maintainance overhead to support it into infinity and beyond, could
you please offer a better list of pros and cons?
Thanks,
Ingo
Powered by blists - more mailing lists