On Mon, Dec 28, 2020 at 10:30:36PM +0000, Paul Cercueil wrote:
> Le lun. 28 déc. 2020 à 23:25, Thomas Bogendoerfer
> <tsbogend@xxxxxxxxxxxxxxxx> a écrit :
> > On Wed, Dec 16, 2020 at 11:39:56PM +0000, Paul Cercueil wrote:
> > > The compressed payload is not necesarily 4-byte aligned, at least
> > > when
> > > compiling with Clang. In that case, the 4-byte value appended to the
> > > compressed payload that corresponds to the uncompressed kernel image
> > > size must be read using get_unaligned_le().
> > >
> > > This fixes Clang-built kernels not booting on MIPS (tested on a
> > > Ingenic
> > > JZ4770 board).
> > >
> > > Fixes: b8f54f2cde78 ("MIPS: ZBOOT: copy appended dtb to the end of
> > > the kernel")
> > > Cc: <stable@xxxxxxxxxxxxxxx> # v4.7
> > > Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
> > > ---
> > > arch/mips/boot/compressed/decompress.c | 2 +-
> > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/arch/mips/boot/compressed/decompress.c
> > > b/arch/mips/boot/compressed/decompress.c
> > > index c61c641674e6..47c07990432b 100644
> > > --- a/arch/mips/boot/compressed/decompress.c
> > > +++ b/arch/mips/boot/compressed/decompress.c
> > > @@ -117,7 +117,7 @@ void decompress_kernel(unsigned long
> > > boot_heap_start)
> > > dtb_size = fdt_totalsize((void *)&__appended_dtb);
> > >
> > > /* last four bytes is always image size in little endian */
> > > - image_size = le32_to_cpup((void *)&__image_end - 4);
> > > + image_size = get_unaligned_le32((void *)&__image_end - 4);
> >
> > gives me following error
> >
> > arch/mips/boot/compressed/decompress.c:120:16: error: implicit
> > declaration of function ‘get_unaligned_le32’
> > [-Werror=implicit-function-declaration]
> > image_size = get_unaligned_le32((void *)&__image_end - 4);
> >
> > I've added
> >
> > #include <asm/unaligned.h>
> >
> > which fixes the compile error, but I'm wondering why the patch compiled
> > for you ?
>
> No idea - but it does compile fine without the include here. Probably a
> defconfig difference.
# CONFIG_KERNEL_LZO is not set
# CONFIG_KERNEL_LZ4 is not set
this makes the difference. Both decompress.c files include asm/unaligned.h.
I've added the #include, fixed the get_unaligned_le32 in the description
and applied it to mips-fixes.
Thomas.
--
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea. [ RFC1925, 2.3 ]
