[PATCH] powerpc: Implement PR_[GS]ET_UNALIGN prctls for powerpc

This gives the ability to control whether alignment exceptions get
fixed up or reported to the process as a SIGBUS, using the existing
PR_SET_UNALIGN and PR_GET_UNALIGN prctls.  We do not implement the
option of logging a message on alignment exceptions.

Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-powerpc/processor.h b/include/asm-powerpc/processor.h
index fa61632..d2c2c95 100644
--- a/include/asm-powerpc/processor.h
+++ b/include/asm-powerpc/processor.h
@@ -149,6 +149,7 @@
 		unsigned int val;	/* Floating point status */
 	} fpscr;
 	int		fpexc_mode;	/* floating-point exception mode */
+	unsigned int	align_ctl;	/* alignment handling control */
 #ifdef CONFIG_PPC64
 	unsigned long	start_tb;	/* Start purr when proc switched in */
 	unsigned long	accum_tb;	/* Total accumilated purr for process */
@@ -217,6 +218,12 @@
 extern int get_endian(struct task_struct *tsk, unsigned long adr);
 extern int set_endian(struct task_struct *tsk, unsigned int val);
 
+#define GET_UNALIGN_CTL(tsk, adr)	get_unalign_ctl((tsk), (adr))
+#define SET_UNALIGN_CTL(tsk, val)	set_unalign_ctl((tsk), (val))
+
+extern int get_unalign_ctl(struct task_struct *tsk, unsigned long adr);
+extern int set_unalign_ctl(struct task_struct *tsk, unsigned int val);
+
 static inline unsigned int __unpack_fe01(unsigned long msr_bits)
 {
 	return ((msr_bits & MSR_FE0) >> 10) | ((msr_bits & MSR_FE1) >> 8);