[PATCH] asm-generic/div64.h breakage

 - __div64_32(): remove __attribute_pure__ qualifier from the prototype
   since this function obviously clobbers memory through &(n);

 - do_div(): add a check to ensure (n) is type-compatible with uint64_t;

 - as_update_iohist(): Use sector_div() instead of do_div().
   (Whether the result of the addition should always be stored in 64bits
   regardless of CONFIG_LBD is still being discussed, therefore it's
   unadderessed here);

 - Fix all places where do_div() was being called with a bad divisor argument.

drivers/block/as-iosched.c

@@ -837,7 +837,7 @@ static void as_update_iohist(struct as_io_context *aic, struct request *rq)
 		aic->seek_total += 256*seek_dist;
 		if (aic->seek_samples) {
 			aic->seek_mean = aic->seek_total + 128;
-			do_div(aic->seek_mean, aic->seek_samples);
+			sector_div(aic->seek_mean, aic->seek_samples);
 		}
 		aic->seek_samples = (aic->seek_samples>>1)
 					+ (aic->seek_samples>>2);

include/asm-generic/div64.h

@@ -32,11 +32,15 @@
 
 #elif BITS_PER_LONG == 32
 
-extern uint32_t __div64_32(uint64_t *dividend, uint32_t divisor) __attribute_pure__;
+extern uint32_t __div64_32(uint64_t *dividend, uint32_t divisor);
 
+/* The unnecessary pointer compare is there
+ * to check for type safety (n must be 64bit)
+ */
 # define do_div(n,base) ({				\
 	uint32_t __base = (base);			\
 	uint32_t __rem;					\
+	(void)(((typeof((n)) *)0) == ((uint64_t *)0));	\
 	if (likely(((n) >> 32) == 0)) {			\
 		__rem = (uint32_t)(n) % __base;		\
 		(n) = (uint32_t)(n) / __base;		\

lib/vsprintf.c

@@ -127,7 +127,7 @@ static int skip_atoi(const char **s)
 #define SPECIAL	32		/* 0x */
 #define LARGE	64		/* use 'ABCDEF' instead of 'abcdef' */
 
-static char * number(char * buf, char * end, long long num, int base, int size, int precision, int type)
+static char * number(char * buf, char * end, unsigned long long num, int base, int size, int precision, int type)
 {
 	char c,sign,tmp[66];
 	const char *digits;

mm/vmscan.c

@@ -147,7 +147,7 @@ static int shrink_slab(long scanned, unsigned int gfp_mask)
 
 	pages = nr_used_zone_pages();
 	list_for_each_entry(shrinker, &shrinker_list, list) {
-		long long delta;
+		unsigned long long delta;
 
 		delta = scanned * shrinker->seeks;
 		delta *= (*shrinker->shrinker)(0, gfp_mask);