Re: linux-next: build failure after merge of the akpm tree

From: Stephen Rothwell
Date: Thu Jan 21 2016 - 19:24:50 EST


Hi all,

On Thu, 21 Jan 2016 07:38:59 +1100 Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
>
> On Wed, 20 Jan 2016 15:09:47 +0100 Takashi Iwai <tiwai@xxxxxxx> wrote:
> >
> > On Sat, 16 Jan 2016 09:51:29 +0100,
> > Takashi Iwai wrote:
> > >
> > > There are a few ways to fix this, but all are not comfortable.
> > >
> > > A. Disable compress API for powerpc.
>
> This also affects alpha, mips and (maybe) sparc.

This was exposed on PowerPC by commit bf76f73c5f65 ("powerpc: enable
UBSAN support") which is in Linus' tree as of this morning. The only
relevant change that made was in the compiler flags (I tested this by
building the file without that commit but with these new compiler flags:

-fsanitize=shift -fsanitize=integer-divide-by-zero
-fsanitize=unreachable -fsanitize=vla-bound -fsanitize=null
-fsanitize=signed-integer-overflow -fsanitize=bounds
-fsanitize=object-size -fsanitize=returns-nonnull-attribute
-fsanitize=bool -fsanitize=enum -fsanitize=alignment

The preprocessed file is the same in both cases, but with these flags
the compiler errors.

--
Cheers,
Stephen Rothwell sfr@xxxxxxxxxxxxxxxx