[PATCH] powerpc: fix personality handling in ppc64_personality()

From: Jiri Kosina
Date: Wed Aug 01 2012 - 16:03:46 EST


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>
---

Found accidentally. Untested, I don't have the hardware.

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..4dcc7c6 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_LINUX | PER_LINUX32;
ret = sys_personality(personality);
- if (ret == PER_LINUX32)
- ret = PER_LINUX;
+ if (personality(ret) == PER_LINUX32)
+ ret &= ~PER_LINUX32 | PER_LINUX;
return ret;
}
#endif

--
Jiri Kosina
SUSE Labs
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