s390/stp: clock_delta should be signed

commit 5ace65e upstream.

clock_delta is declared as unsigned long in various places. However,
the clock sync delta can be negative. This would add a huge positive
offset in clock_sync_global where clock_delta is added to clk.eitod
which is a 72 bit integer. Declare it as signed long to fix this.

Cc: stable@vger.kernel.org
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/s390/include/asm/cio.h

@@ -369,7 +369,7 @@ void cio_gp_dma_destroy(struct gen_pool *gp_dma, struct device *dma_dev);
 struct gen_pool *cio_gp_dma_create(struct device *dma_dev, int nr_pages);
 
 /* Function from drivers/s390/cio/chsc.c */
-int chsc_sstpc(void *page, unsigned int op, u16 ctrl, u64 *clock_delta);
+int chsc_sstpc(void *page, unsigned int op, u16 ctrl, long *clock_delta);
 int chsc_sstpi(void *page, void *result, size_t size);
 int chsc_stzi(void *page, void *result, size_t size);
 int chsc_sgib(u32 origin);

arch/s390/kernel/time.c

@@ -364,7 +364,7 @@ static inline int check_sync_clock(void)
  * Apply clock delta to the global data structures.
  * This is called once on the CPU that performed the clock sync.
  */
-static void clock_sync_global(unsigned long delta)
+static void clock_sync_global(long delta)
 {
 	unsigned long now, adj;
 	struct ptff_qto qto;
@@ -400,7 +400,7 @@ static void clock_sync_global(unsigned long delta)
  * Apply clock delta to the per-CPU data structures of this CPU.
  * This is called for each online CPU after the call to clock_sync_global.
  */
-static void clock_sync_local(unsigned long delta)
+static void clock_sync_local(long delta)
 {
 	/* Add the delta to the clock comparator. */
 	if (S390_lowcore.clock_comparator != clock_comparator_max) {
@@ -424,7 +424,7 @@ static void __init time_init_wq(void)
 struct clock_sync_data {
 	atomic_t cpus;
 	int in_sync;
-	unsigned long clock_delta;
+	long clock_delta;
 };
 
 /*
@@ -544,7 +544,7 @@ static int stpinfo_valid(void)
 static int stp_sync_clock(void *data)
 {
 	struct clock_sync_data *sync = data;
-	u64 clock_delta, flags;
+	long clock_delta, flags;
 	static int first;
 	int rc;
 

drivers/s390/cio/chsc.c

@@ -1255,7 +1255,7 @@ chsc_determine_css_characteristics(void)
 EXPORT_SYMBOL_GPL(css_general_characteristics);
 EXPORT_SYMBOL_GPL(css_chsc_characteristics);
 
-int chsc_sstpc(void *page, unsigned int op, u16 ctrl, u64 *clock_delta)
+int chsc_sstpc(void *page, unsigned int op, u16 ctrl, long *clock_delta)
 {
 	struct {
 		struct chsc_header request;
@@ -1266,7 +1266,7 @@ int chsc_sstpc(void *page, unsigned int op, u16 ctrl, u64 *clock_delta)
 		unsigned int rsvd2[5];
 		struct chsc_header response;
 		unsigned int rsvd3[3];
-		u64 clock_delta;
+		s64 clock_delta;
 		unsigned int rsvd4[2];
 	} *rr;
 	int rc;