Re: [PATCH stable 4.4] powerpc/lib: fix book3s/32 boot failure due to code patching

From: Greg KH
Date: Wed May 15 2019 - 10:17:57 EST


On Wed, May 15, 2019 at 01:30:42PM +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()
>
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=203597
> Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
>
> ---
> 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
>
> Removed the Fixes: tag as I don't know yet the commit Id of the fixed commit on 4.4 branch.
> ---
> arch/powerpc/lib/code-patching.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

Now added, thanks.

greg k-h