[PATCH] x86_64: Implement is_compat_task the right way

By setting a flag during a 32bit system call only

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 6 insertions, 0 deletions

diff --git a/include/asm-x86_64/compat.h b/include/asm-x86_64/compat.h
index f0155c38f639..3863a7da372b 100644
--- a/include/asm-x86_64/compat.h
+++ b/include/asm-x86_64/compat.h
@@ -202,4 +202,9 @@ static __inline__ void __user *compat_alloc_user_space(long len)
         return (void __user *)regs->rsp - len; 
 }
 
+static inline int is_compat_task(void)
+{
+        return current_thread_info()->status & TS_COMPAT;
+}
+
 #endif /* _ASM_X86_64_COMPAT_H */
diff --git a/include/asm-x86_64/thread_info.h b/include/asm-x86_64/thread_info.h
index 08eb6e4f3737..eb7c5fda1870 100644
--- a/include/asm-x86_64/thread_info.h
+++ b/include/asm-x86_64/thread_info.h
@@ -138,6 +138,7 @@ static inline struct thread_info *stack_thread_info(void)
  * have to worry about atomic accesses.
  */
 #define TS_USEDFPU              0x0001  /* FPU was used by this task this quantum (SMP) */
+#define TS_COMPAT               0x0002  /* 32bit syscall active */
 
 #endif /* __KERNEL__ */