Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1280403

Re: [PATCH] ARM: avoid ARCH_MMAP_RND_BITS for NOMMU

Show all headers | View raw

Thank you for this.  I will add this to the recently posted patchset
v4.   Without CONFIG_MMU, arch_pick_mmap_layout() is a no-op and the
arch/$ARCH/mm/mmap.c source is not included, so this change makes
sense.  In addition, we should drop the nommu default and add
depends-on for the Kconfig portions.

-Dan

On Fri, Nov 27, 2015 at 6:04 AM, Arnd Bergmann <arnd@arndb.de> wrote:
> ARM kernels with MMU disabled fail to build because of CONFIG_ARCH_MMAP_RND_BITS:
>
> kernel/built-in.o:(.data+0x754): undefined reference to `mmap_rnd_bits'
> kernel/built-in.o:(.data+0x76c): undefined reference to `mmap_rnd_bits_min'
> kernel/built-in.o:(.data+0x770): undefined reference to `mmap_rnd_bits_max'
>
> This changes the newly added line to only select this allow for
> MMU-enabled kernels.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Fixes: 14570b3fd31a ("arm: mm: support ARCH_MMAP_RND_BITS")
> ---
> Found on yesterday's linux-next with ARM randconfig. The commit that
> introduced this is currently in Andrew's tree.
>
> If you don't already have a fix, please either apply this patch on top,
> or fold it into the original patch.
>
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index b64f64d124c4..5a0957e3ea36 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -34,7 +34,7 @@ config ARM
>         select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6
>         select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
>         select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
> -       select HAVE_ARCH_MMAP_RND_BITS
> +       select HAVE_ARCH_MMAP_RND_BITS if MMU
>         select HAVE_ARCH_SECCOMP_FILTER if (AEABI && !OABI_COMPAT)
>         select HAVE_ARCH_TRACEHOOK
>         select HAVE_BPF_JIT
>



-- 
Dan Cashman
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH] ARM: avoid ARCH_MMAP_RND_BITS for NOMMU Arnd Bergmann <arnd@arndb.de> - 2015-11-27 15:10 +0100
  Re: [PATCH] ARM: avoid ARCH_MMAP_RND_BITS for NOMMU Daniel Cashman <dcashman@google.com> - 2015-12-01 00:50 +0100
  Re: [PATCH] ARM: avoid ARCH_MMAP_RND_BITS for NOMMU Uwe Kleine-König   <u.kleine-koenig@pengutronix.de> - 2015-12-07 08:30 +0100

csiph-web