Re: [PATCH 4.9 00/92] 4.9.81-stable review

[Greg Kroah-Hartman]

On Sat, Feb 17, 2018 at 09:35:59AM -0800, Guenter Roeck wrote:
> On 02/17/2018 05:45 AM, Greg Kroah-Hartman wrote:
> > On Sat, Feb 17, 2018 at 02:31:53PM +0100, Yves-Alexis Perez wrote:
> > > On Tue, 2018-02-13 at 16:29 +0100, Greg Kroah-Hartman wrote:
> > > > > arch/powerpc/kernel/entry_64.S: Assembler messages:
> > > > > arch/powerpc/kernel/entry_64.S:260: Error: unrecognized opcode: `rfi_to_user'
> > > > > arch/powerpc/kernel/entry_64.S:270: Error: unrecognized opcode: `rfi_to_kernel'
> > > > > arch/powerpc/kernel/entry_64.S:885: Error: unrecognized opcode: `rfi_to_user'
> > > > > arch/powerpc/kernel/entry_64.S:900: Error: unrecognized opcode: `rfi_to_kernel'
> > > > > 
> > > > > Looks like 222f20f140623 ("powerpc/64s: Simple RFI macro conversions") is missing,
> > > > > or at least part of it. Unfortunately it doesn't apply cleanly.
> > > > 
> > > > Ugh.  Let's see if the ppc developers care about this or not :)
> > > 
> > > Hi,
> > > 
> > > in Debian we extracted the following hunk from 222f20f140623 to fix build on
> > > powerpc/ppc64el. Only compile tested against Debian builds though.
> > > 
> > > diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
> > > index 3320bcac7192..e68faa4d1b13 100644
> > > --- a/arch/powerpc/kernel/entry_64.S
> > > +++ b/arch/powerpc/kernel/entry_64.S
> > > @@ -37,6 +37,11 @@
> > >   #include <asm/tm.h>
> > >   #include <asm/ppc-opcode.h>
> > >   #include <asm/export.h>
> > > +#ifdef CONFIG_PPC_BOOK3S
> > > +#include <asm/exception-64s.h>
> > > +#else
> > > +#include <asm/exception-64e.h>
> > > +#endif
> > 
> > Ah, thanks!  I've now queued up this portion of the patch.
> > 
> 
> Hmm, that chunk really doesn't do what the original patch is supposed to do,
> meaning it won't provide the vulnerability protection it is supposed to provide
> (AFAICS that is Meltdown). Just a note in case anyone is concerned about
> actually providing that protection.

Good point, I've renamed this patch now to make it more obvious what is
going on.

thanks,

greg k-h