[PATCH] timekeeping: Update offsets on sequence counter retry in ktime_get_update_offsets_now()

[Thomas Weißschuh (Schneider Electric)]

The sequence counter of the cwsseq target is modified during the
sequence counter loop. If the loop retries, cwsseq will now match
but the offsets contain the values from the previous loop iteration.
These are not guaranteed to be consistent in themselves or with the
current loops "now.

Save the target's original sequence counter value so that the update
also happens on loop retries.

Fixes: 868a3e915f7f ("hrtimer: Make offset update smarter")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Thomas Weißschuh (Schneider Electric) <thomas.weissschuh@xxxxxxxxxxxxx>
---
 kernel/time/timekeeping.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index d54c4d303db6..ff1c08a500c9 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -2850,6 +2850,7 @@ ktime_t ktime_get_update_offsets_now(u32 *cwsseq, ktime_t *offs_real,
 				     ktime_t *offs_boot, ktime_t *offs_tai)
 {
 	struct timekeeper *tk = &tk_core.timekeeper;
+	u32 cwsseq_orig = *cwsseq;
 	unsigned int seq;
 	ktime_t base;
 	u64 nsecs;
@@ -2861,7 +2862,7 @@ ktime_t ktime_get_update_offsets_now(u32 *cwsseq, ktime_t *offs_real,
 		nsecs = timekeeping_get_ns(&tk->tkr_mono);
 		base = ktime_add_ns(base, nsecs);
 
-		if (*cwsseq != tk->clock_was_set_seq) {
+		if (cwsseq_orig != tk->clock_was_set_seq) {
 			*cwsseq = tk->clock_was_set_seq;
 			*offs_real = tk->offs_real;
 			*offs_boot = tk->offs_boot;

---
base-commit: 348f54c435bf3177baa78201952810b255d44b30
change-id: 20261023-timekeeping-clock_was_set_seq-d23a278dce89

Best regards,
--  
Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx>