From: Wei Fang wei.fang@nxp.com
stable inclusion from stable-v6.6.33 commit d470a8090476a6e7af53712cb90061a86470b16b category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IAD6H2
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit 3b1c92f8e5371700fada307cc8fd2c51fa7bc8c1 ]
The assignment of pps_enable is protected by tmreg_lock, but the read operation of pps_enable is not. So the Coverity tool reports a lock evasion warning which may cause data race to occur when running in a multithread environment. Although this issue is almost impossible to occur, we'd better fix it, at least it seems more logically reasonable, and it also prevents Coverity from continuing to issue warnings.
Fixes: 278d24047891 ("net: fec: ptp: Enable PPS output based on ptp clock") Signed-off-by: Wei Fang wei.fang@nxp.com Link: https://lore.kernel.org/r/20240521023800.17102-1-wei.fang@nxp.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Wang Hai wanghai38@huawei.com --- drivers/net/ethernet/freescale/fec_ptp.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/drivers/net/ethernet/freescale/fec_ptp.c b/drivers/net/ethernet/freescale/fec_ptp.c index 181d9bfbee22..e32f6724f568 100644 --- a/drivers/net/ethernet/freescale/fec_ptp.c +++ b/drivers/net/ethernet/freescale/fec_ptp.c @@ -104,14 +104,13 @@ static int fec_ptp_enable_pps(struct fec_enet_private *fep, uint enable) struct timespec64 ts; u64 ns;
- if (fep->pps_enable == enable) - return 0; - - fep->pps_channel = DEFAULT_PPS_CHANNEL; - fep->reload_period = PPS_OUPUT_RELOAD_PERIOD; - spin_lock_irqsave(&fep->tmreg_lock, flags);
+ if (fep->pps_enable == enable) { + spin_unlock_irqrestore(&fep->tmreg_lock, flags); + return 0; + } + if (enable) { /* clear capture or output compare interrupt status if have. */ @@ -532,6 +531,9 @@ static int fec_ptp_enable(struct ptp_clock_info *ptp, int ret = 0;
if (rq->type == PTP_CLK_REQ_PPS) { + fep->pps_channel = DEFAULT_PPS_CHANNEL; + fep->reload_period = PPS_OUPUT_RELOAD_PERIOD; + ret = fec_ptp_enable_pps(fep, on);
return ret;