diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index e8d8856..5d444b5 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -779,6 +779,11 @@ ENDPROC(__switch_to)
  * earlier processors just for the sake of not using these kernel helpers
  * if your compiled code is not going to use the new instructions for other
  * purpose.
+ *
+ * New helpers may be added over time, so an older kernel may be missing
+ * some helpers present in a newer kernel.  For this reason, programs
+ * must check the value of __kernel_helper_version (see below) before
+ * assuming that it is safe to call any particular helper.
  */
  THUMB(	.arm	)
 
@@ -819,11 +824,7 @@ __kuser_helper_start:
  * Apply any needed memory barrier to preserve consistency with data modified
  * manually and __kuser_cmpxchg usage.
  *
- * This could be used as follows:
- *
- * #define __kernel_dmb() \
- *         asm volatile ( "mov r0, #0xffff0fff; mov lr, pc; sub pc, r0, #95" \
- *	        : : : "r0", "lr","cc" )
+ * Do not attempt to call this function unless __kernel_helper_version >= 3.
  */
 
 __kuser_memory_barrier:				@ 0xffff0fa0
@@ -855,7 +856,8 @@ __kuser_memory_barrier:				@ 0xffff0fa0
  *
  * Definition and user space usage example:
  *
- *	typedef int (__kernel_cmpxchg_t)(int oldval, int newval, int *ptr);
+ *	typedef int (__kernel_cmpxchg_t)(int oldval, int newval,
+ *					 int volatile *ptr);
  *	#define __kernel_cmpxchg (*(__kernel_cmpxchg_t *)0xffff0fc0)
  *
  * Atomically store newval in *ptr if *ptr is equal to oldval for user space.
@@ -863,27 +865,25 @@ __kuser_memory_barrier:				@ 0xffff0fa0
  * The C flag is also set if *ptr was changed to allow for assembly
  * optimization in the calling code.
  *
+ * Do not attempt to call this function unless __kernel_helper_version >= 2.
+ *
  * Notes:
  *
  *    - This routine already includes memory barriers as needed.
  *
  * For example, a user space atomic_add implementation could look like this:
  *
- * #define atomic_add(ptr, val) \
- *	({ register unsigned int *__ptr asm("r2") = (ptr); \
- *	   register unsigned int __result asm("r1"); \
- *	   asm volatile ( \
- *	       "1: @ atomic_add\n\t" \
- *	       "ldr	r0, [r2]\n\t" \
- *	       "mov	r3, #0xffff0fff\n\t" \
- *	       "add	lr, pc, #4\n\t" \
- *	       "add	r1, r0, %2\n\t" \
- *	       "add	pc, r3, #(0xffff0fc0 - 0xffff0fff)\n\t" \
- *	       "bcc	1b" \
- *	       : "=&r" (__result) \
- *	       : "r" (__ptr), "rIL" (val) \
- *	       : "r0","r3","ip","lr","cc","memory" ); \
- *	   __result; })
+ * int atomic_add(int volatile *ptr, int val)
+ * {
+ *	int newval;
+ *	do {
+ *		int oldval = *ptr;
+ *
+ *		newval = oldval + val;
+ *	while(__kernel_cmpxchg(oldval, newval, ptr));
+ *
+ *	return newval;
+ * }
  */
 
 __kuser_cmpxchg:				@ 0xffff0fc0
@@ -983,13 +983,7 @@ kuser_cmpxchg_fixup:
  *
  * Get the TLS value as previously set via the __ARM_NR_set_tls syscall.
  *
- * This could be used as follows:
- *
- * #define __kernel_get_tls() \
- *	({ register unsigned int __val asm("r0"); \
- *         asm( "mov r0, #0xffff0fff; mov lr, pc; sub pc, r0, #31" \
- *	        : "=r" (__val) : : "lr","cc" ); \
- *	   __val; })
+ * Do not attempt to call this function unless __kernel_helper_version >= 1.
  */
 
 __kuser_get_tls:				@ 0xffff0fe0
@@ -1011,6 +1005,11 @@ __kuser_get_tls:				@ 0xffff0fe0
  *
  * User space may read this to determine the curent number of helpers
  * available.
+ *
+ * User space may assume that the value of this field never changes
+ * during the lifetime of any single process.  This means that this
+ * field can be read once during the initialisation of a library or
+ * startup phase of a program.
  */
 
 __kuser_helper_version:				@ 0xffff0ffc