From: "H. Peter Anvin" <hpa@zytor.com>
To: Vivek Goyal <vgoyal@redhat.com>
Cc: Shaun Ruffell <sruffell@digium.com>,
linux-kernel@vger.kernel.org, kexec@lists.infradead.org,
ebiederm@xmission.com, mjg59@srcf.ucam.org, greg@kroah.com,
bp@alien8.de, dyoung@redhat.com, chaowang@redhat.com,
bhe@redhat.com, akpm@linux-foundation.org
Subject: Re: [PATCH 11/15] purgatory: Core purgatory functionality
Date: Mon, 11 Aug 2014 11:08:48 -0700 [thread overview]
Message-ID: <53E906B0.5040105@zytor.com> (raw)
In-Reply-To: <20140811180213.GC1863@redhat.com>
On 08/11/2014 11:02 AM, Vivek Goyal wrote:
>
> Hi hpa,
>
> I took it because kexec-tools uses it and in one of the committs Eric
> gave following reasoning.
>
> On x86_64 use -mcmodel=large so that the code is built without
> any 32bit assumptions. -mcmodel=medium and -mcmodel=small
> result int code that has 32bit relocations against variables
> that can live anywhere in the address space
>
> We do want to load purgatory anywhere in the address space.
>
> But if there are other ways to achieve the same thing, I will do that
> change.
>
> So when you say "small PIC", I need to use -mcmodel=small and -fPIC?
>
Actually -fPIE is probably better than -fPIC.
-mcmodel=large is incompatible with all other code out there, which
means that even though it is supposed to work it will be poorly tested
at best. So even despite the gcc version issue, using the small PIC
model would be better.
-hpa
next prev parent reply other threads:[~2014-08-11 18:10 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-26 20:33 [PATCH 00/15][V4] kexec: A new system call to allow in kernel loading Vivek Goyal
2014-06-26 20:33 ` [PATCH 01/15] bin2c: Move bin2c in scripts/basic Vivek Goyal
2014-06-26 20:33 ` [PATCH 02/15] kernel: Build bin2c based on config option CONFIG_BUILD_BIN2C Vivek Goyal
2014-06-26 20:33 ` [PATCH 03/15] kexec: rename unusebale_pages to unusable_pages Vivek Goyal
2014-06-26 20:33 ` [PATCH 04/15] kexec: Move segment verification code in a separate function Vivek Goyal
2014-06-26 20:33 ` [PATCH 05/15] kexec: Use common function for kimage_normal_alloc() and kimage_crash_alloc() Vivek Goyal
2014-06-26 20:33 ` [PATCH 06/15] resource: Provide new functions to walk through resources Vivek Goyal
2014-06-26 20:33 ` [PATCH 07/15] kexec: Make kexec_segment user buffer pointer a union Vivek Goyal
2014-06-26 20:33 ` [PATCH 08/15] kexec: New syscall kexec_file_load() declaration Vivek Goyal
2014-06-26 20:43 ` Vivek Goyal
2014-06-26 21:03 ` Andy Lutomirski
2014-06-27 11:50 ` Vivek Goyal
2014-06-27 12:20 ` Michael Kerrisk (man-pages)
2014-06-26 20:33 ` [PATCH 09/15] kexec: Implementation of new syscall kexec_file_load Vivek Goyal
2014-06-26 20:58 ` Andrew Morton
2014-06-27 16:31 ` Vivek Goyal
2014-07-01 20:25 ` Vivek Goyal
2014-06-26 20:33 ` [PATCH 10/15] purgatory/sha256: Provide implementation of sha256 in purgaotory context Vivek Goyal
2014-06-26 20:33 ` [PATCH 11/15] purgatory: Core purgatory functionality Vivek Goyal
2014-08-11 17:40 ` Shaun Ruffell
2014-08-11 17:51 ` H. Peter Anvin
2014-08-11 18:02 ` Vivek Goyal
2014-08-11 18:08 ` H. Peter Anvin [this message]
2014-08-11 18:15 ` Vivek Goyal
2014-08-11 20:23 ` Vivek Goyal
2014-06-26 20:33 ` [PATCH 12/15] kexec: Load and Relocate purgatory at kernel load time Vivek Goyal
2014-06-26 20:33 ` [PATCH 13/15] kexec-bzImage64: Support for loading bzImage using 64bit entry Vivek Goyal
2014-06-26 20:33 ` [PATCH 14/15] kexec: Support for kexec on panic using new system call Vivek Goyal
2014-06-26 20:33 ` [PATCH 15/15] kexec: Support kexec/kdump on EFI systems Vivek Goyal
2014-07-01 19:46 ` Matt Fleming
2014-07-01 20:14 ` Andrew Morton
2014-07-01 20:21 ` Vivek Goyal
2014-07-01 21:23 ` Matt Fleming
2014-07-01 20:09 ` [PATCH 17/15] kexec-bzimage: Change EFI helper function names Vivek Goyal
2014-06-26 20:39 ` [PATCH 00/15][V4] kexec: A new system call to allow in kernel loading Vivek Goyal
2014-06-26 20:58 ` Andrew Morton
2014-06-26 21:21 ` Borislav Petkov
2014-06-27 11:33 ` Vivek Goyal
2014-06-27 16:34 ` [PATCH 16/15] kexec: Fix freeing up for image loader data loading Vivek Goyal
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