Subject: Re: [PATCH stable 4.9] powerpc/lib: fix book3s/32 boot failure due to code patching

From: Greg KH <[email-masked]>
Date: Wed, 15 May 2019 15:08:25 +0200

On Wed, May 15, 2019 at 02:35:36PM +0200, Christophe Leroy wrote:
> 
> 
> Le 15/05/2019 à 10:29, Greg KH a écrit :
> > On Wed, May 15, 2019 at 06:40:47AM +0000, Christophe Leroy wrote:
> > > [Backport of upstream commit b45ba4a51cde29b2939365ef0c07ad34c8321789]
> > > 
> > > On powerpc32, patch_instruction() is called by apply_feature_fixups()
> > > which is called from early_init()
> > > 
> > > There is the following note in front of early_init():
> > >   * Note that the kernel may be running at an address which is different
> > >   * from the address that it was linked at, so we must use RELOC/PTRRELOC
> > >   * to access static data (including strings).  -- paulus
> > > 
> > > Therefore init_mem_is_free must be accessed with PTRRELOC()
> > > 
> > > Fixes: 1c38a84d4586 ("powerpc: Avoid code patching freed init sections")
> > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=203597
> > > Signed-off-by: Christophe Leroy <[email-masked]>
> > > 
> > > ---
> > > Can't apply the upstream commit as such due to several other unrelated stuff
> > > like for instance STRICT_KERNEL_RWX which are missing.
> > > So instead, using same approach as for commit 252eb55816a6f69ef9464cad303cdb3326cdc61d
> > 
> > Now queued up, thanks.
> > 
> 
> Should go to 4.4 as well since the commit it fixes is now queued for 4.4
> ([PATCH 4.4 056/266] powerpc: Avoid code patching freed init sections)

Ok, can someone send me a backport that actually applies there?

thanks,

greg k-h