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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Sven Schnelle <svens@linux.ibm.com>,
        Heiko Carstens <hca@linux.ibm.com>
Subject: [PATCH 5.15 560/667] s390/stp: clock_delta should be signed
Date:   Tue,  7 Jun 2022 19:03:45 +0200
Message-Id: <20220607164951.493923337@linuxfoundation.org>
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From: Sven Schnelle <svens@linux.ibm.com>

commit 5ace65ebb5ce9fe1cc8fdbdd97079fb566ef0ea4 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 |    2 +-
 arch/s390/kernel/time.c     |    8 ++++----
 drivers/s390/cio/chsc.c     |    4 ++--
 3 files changed, 7 insertions(+), 7 deletions(-)

--- a/arch/s390/include/asm/cio.h
+++ b/arch/s390/include/asm/cio.h
@@ -369,7 +369,7 @@ void cio_gp_dma_destroy(struct gen_pool
 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);
--- a/arch/s390/kernel/time.c
+++ b/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 l
  * 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;
 
--- a/drivers/s390/cio/chsc.c
+++ b/drivers/s390/cio/chsc.c
@@ -1255,7 +1255,7 @@ exit:
 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
 		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;