[PATCH 5.17 089/158] ptp: ocp: have adjtime handle negative delta_ns correctly

Greg Kroah-Hartman
2022-05-23T18:03:10Z

From: Jonathan Lemon <jonathan.lemon@gmail.com>

[ Upstream commit da2172a9bfec858ceeb0271b9d444378490398c8 ]

delta_ns is a s64, but it was being passed ptp_ocp_adjtime_coarse
as an u64. Also, it turns out that timespec64_add_ns() only handles
positive values, so perform the math with set_normalized_timespec().

Fixes: 90f8f4c0e3ce ("ptp: ocp: Add ptp_ocp_adjtime_coarse for large adjustments")
Suggested-by: Vadim Fedorenko <vfedorenko@novek.ru>
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Acked-by: Vadim Fedorenko <vfedorenko@novek.ru>
Link: https://lore.kernel.org/r/20220513225231.1412-1-jonathan.lemon@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/ptp/ptp_ocp.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c
index 17ad5f0d13b2..6585789ed695 100644
--- a/drivers/ptp/ptp_ocp.c
+++ b/drivers/ptp/ptp_ocp.c
@@ -625,7 +625,7 @@ __ptp_ocp_adjtime_locked(struct ptp_ocp *bp, u32 adj_val)
}

static void
-ptp_ocp_adjtime_coarse(struct ptp_ocp *bp, u64 delta_ns)
+ptp_ocp_adjtime_coarse(struct ptp_ocp *bp, s64 delta_ns)
{
struct timespec64 ts;
unsigned long flags;
@@ -634,7 +634,8 @@ ptp_ocp_adjtime_coarse(struct ptp_ocp *bp, u64 delta_ns)
spin_lock_irqsave(&bp->lock, flags);
err = __ptp_ocp_gettime_locked(bp, &ts, NULL);
if (likely(!err)) {
- timespec64_add_ns(&ts, delta_ns);
+ set_normalized_timespec64(&ts, ts.tv_sec,
+ ts.tv_nsec + delta_ns);
__ptp_ocp_settime_locked(bp, &ts);
}
spin_unlock_irqrestore(&bp->lock, flags);
--
2.35.1