Re: [PATCH v2] powerpc: fix personality handling inppc64_personality()

From: Benjamin Herrenschmidt
Date: Tue Sep 04 2012 - 22:54:28 EST


On Thu, 2012-08-02 at 09:10 +0200, Jiri Kosina wrote:
> Directly comparing current->personality against PER_LINUX32 doesn't work
> in cases when any of the personality flags stored in the top three bytes
> are used.
>
> Directly forcefully setting personality to PER_LINUX32 or PER_LINUX
> discards any flags stored in the top three bytes
>
> Use personality() macro to compare only PER_MASK bytes and make sure that
> we are setting only the bits that should be set, instead of
> overwriting the whole value.
>
> Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
> ---
>
> changed since v1: fix the bit ops to reflect the fact that PER_LINUX is
> actually 0

Had already merged v1 (oops.. didn't spot the issue with PER_LINUX being
0). Can you send an incremental fixup ?

Cheers,
Ben.

> arch/powerpc/kernel/syscalls.c | 8 ++++----
> 1 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/powerpc/kernel/syscalls.c b/arch/powerpc/kernel/syscalls.c
> index f2496f2..dc1558e 100644
> --- a/arch/powerpc/kernel/syscalls.c
> +++ b/arch/powerpc/kernel/syscalls.c
> @@ -107,11 +107,11 @@ long ppc64_personality(unsigned long personality)
> long ret;
>
> if (personality(current->personality) == PER_LINUX32
> - && personality == PER_LINUX)
> - personality = PER_LINUX32;
> + && personality(personality) == PER_LINUX)
> + personality |= PER_LINUX32;
> ret = sys_personality(personality);
> - if (ret == PER_LINUX32)
> - ret = PER_LINUX;
> + if (personality(ret) == PER_LINUX32)
> + ret &= ~PER_LINUX32;
> return ret;
> }
> #endif
> --
> 1.7.3.1
>


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