Re: [PATCH v2 2/3] MIPS: Move kernel head into a standalone section
From: Thomas Bogendoerfer
Date: Wed May 27 2020 - 09:34:12 EST
On Wed, May 27, 2020 at 08:05:22PM +0800, Jiaxun Yang wrote:
> On Wed, 27 May 2020 13:53:54 +0200
> Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx> wrote:
> > On Wed, May 27, 2020 at 02:34:33PM +0800, Jiaxun Yang wrote:
> > > That's what already done by Arm64 and other architectures.
> > > That would allow us put more things like PE headers safely into
> > > the header.
> > >
> > > Signed-off-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
> > > ---
> > > arch/mips/kernel/head.S | 4 ++--
> > > arch/mips/kernel/vmlinux.lds.S | 8 ++++++--
> > > 2 files changed, 8 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/arch/mips/kernel/head.S b/arch/mips/kernel/head.S
> > > index c7c2795837e7..8081a905a71c 100644
> > > --- a/arch/mips/kernel/head.S
> > > +++ b/arch/mips/kernel/head.S
> > > @@ -59,6 +59,8 @@
> > > #endif
> > > .endm
> > >
> > > + __HEAD
> > > +_head:
> > > #ifndef CONFIG_NO_EXCEPT_FILL
> > > /*
> > > * Reserved space for exception handlers.
> > I'm adding the missing piece, why this change ist broken:
> > * Necessary for machines which link their kernels at KSEG0.
> > by putting something in front of that will probably break platforms
> > making use of "feature". If we can make sure, we don't need it
> > anymore, we should first remove this and then add __HEAD part.
> __HEAD is just marking the section of code.
> It will not add anything to the binary.
oops, should have looked it up first. You mentioned PE headers and
I thought it will be added this way.
> Btw: I just noticed this patch may break relocatable kernel. I'll delay
> it for next merge window.
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea. [ RFC1925, 2.3 ]