[PATCH 5.5 284/399] staging: wfx: fix possible overflow on jiffies comparaison

Greg Kroah-Hartman
2020-02-21T07:55:51Z

From: Jérôme Pouiller <jerome.pouiller@silabs.com>

[ Upstream commit def39be019b6494acd3570ce6f3f11ba1c3203a3 ]

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It is recommended to use function time_*() to compare jiffies.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200115135338.14374-45-Jerome.Pouiller@silabs.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/staging/wfx/data_tx.c | 14 +++++---------
1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/drivers/staging/wfx/data_tx.c b/drivers/staging/wfx/data_tx.c
index b13d7341f8bba..0c6a3a1a1ddfd 100644
--- a/drivers/staging/wfx/data_tx.c
+++ b/drivers/staging/wfx/data_tx.c
@@ -282,8 +282,7 @@ void wfx_tx_policy_init(struct wfx_vif *wvif)
static int wfx_alloc_link_id(struct wfx_vif *wvif, const u8 *mac)
{
int i, ret = 0;
- unsigned long max_inactivity = 0;
- unsigned long now = jiffies;
+ unsigned long oldest;

spin_lock_bh(&wvif->ps_state_lock);
for (i = 0; i < WFX_MAX_STA_IN_AP_MODE; ++i) {
@@ -292,13 +291,10 @@ static int wfx_alloc_link_id(struct wfx_vif *wvif, const u8 *mac)
break;
} else if (wvif->link_id_db[i].status != WFX_LINK_HARD &&
!wvif->wdev->tx_queue_stats.link_map_cache[i + 1]) {
- unsigned long inactivity =
- now - wvif->link_id_db[i].timestamp;
-
- if (inactivity < max_inactivity)
- continue;
- max_inactivity = inactivity;
- ret = i + 1;
+ if (!ret || time_after(oldest, wvif->link_id_db[i].timestamp)) {
+ oldest = wvif->link_id_db[i].timestamp;
+ ret = i + 1;
+ }
}
}

--
2.20.1