Re: [PATCH][next] arm64: fix the mm build error in mm/kfence/core.c

From: Marco Elver <elver@google.com>
To: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Hui Su <sh_def@163.com>, Alexander Potapenko <glider@google.com>,
	Dmitry Vyukov <dvyukov@google.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	kasan-dev <kasan-dev@googlegroups.com>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH][next] arm64: fix the mm build error in mm/kfence/core.c
Date: Sun, 6 Dec 2020 23:08:46 +0100	[thread overview]
Message-ID: <CANpmjNPifOwd9w34dSJhsvmP2sUkKa0ESPiJ7gj+gUDffhPO3A@mail.gmail.com> (raw)
In-Reply-To: <20201207082300.38f5207f@canb.auug.org.au>

On Sun, 6 Dec 2020 at 22:23, Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> Hi all,
>
> [Cc'd Andrew Morton]
>
> On Sun, 6 Dec 2020 01:22:07 +0800 Hui Su <sh_def@163.com> wrote:
> >
> > When I build kernel with ARCH=arm64, the building errors came out like
> > this:
> >   CC      mm/kfence/core.o
> > In file included from ../mm/kfence/core.c:21:
> > ../arch/arm64/include/asm/kfence.h: In function ‘kfence_protect_page’:
> > ../arch/arm64/include/asm/kfence.h:12:2: error: implicit declaration of
> > function ‘set_memory_valid’ [-Werror=implicit-function-declaration]
> >    12 |  set_memory_valid(addr, 1, !protect);
> >       |  ^~~~~~~~~~~~~~~~
> > cc1: some warnings being treated as errors
> >
> > which introduced by commit d54febeba2ff ("kfence: use pt_regs to
> > generate stack trace on faults").
> >
> > Signed-off-by: Hui Su <sh_def@163.com>
> > ---
> >  arch/arm64/include/asm/kfence.h | 1 +
> >  1 file changed, 1 insertion(+)

Thanks, but a patch for this is already in the -mm tree:
https://lore.kernel.org/mm-commits/20201205011409.o9PNsRntR%25akpm@linux-foundation.org/

Perhaps try the latest -next?

> > diff --git a/arch/arm64/include/asm/kfence.h b/arch/arm64/include/asm/kfence.h
> > index 6c0afeeab635..4d73e34da59d 100644
> > --- a/arch/arm64/include/asm/kfence.h
> > +++ b/arch/arm64/include/asm/kfence.h
> > @@ -4,6 +4,7 @@
> >  #define __ASM_KFENCE_H
> >
> >  #include <asm/cacheflush.h>
> > +#include <linux/set_memory.h>
> >
> >  static inline bool arch_kfence_init_pool(void) { return true; }
> >
> > --
> > 2.25.1
>
> Added to linux-next today.  I think it actually fixes patch "arm64,
> kfence: enable KFENCE for ARM64" since that actually introduces the
> set_memory_valid() call?

The patch that moved the declaration was after the kfence patch, so
it'd be the other way around:
https://lkml.kernel.org/r/X8otwahnmGQGLpge@elver.google.com

Thanks,
-- Marco