powerpc: Fix personality handling in ppc64_personality()

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@suse.cz>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/arch/powerpc/kernel/syscalls.c b/arch/powerpc/kernel/syscalls.c
index f2496f2faeccc37231110392363d0914d599e5b5..4e3cc47f26b90e157ebb5c2a1cd156918e655930 100644 (file)
--- 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 = (personality & ~PER_MASK) | PER_LINUX32;
        ret = sys_personality(personality);
-       if (ret == PER_LINUX32)
-               ret = PER_LINUX;
+       if (personality(ret) == PER_LINUX32)
+               ret = (ret & ~PER_MASK) | PER_LINUX;
        return ret;
 }
 #endif