[PATCH 4.14 033/125] mmc: via-sdmmc: Fix data race bug

Greg Kroah-Hartman
2020-11-03T21:09:53Z

From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>

[ Upstream commit 87d7ad089b318b4f319bf57f1daa64eb6d1d10ad ]

via_save_pcictrlreg() should be called with host->lock held
as it writes to pm_pcictrl_reg, otherwise there can be a race
condition between via_sd_suspend() and via_sdc_card_detect().
The same pattern is used in the function via_reset_pcictrl()
as well, where via_save_pcictrlreg() is called with host->lock
held.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Link: https://lore.kernel.org/r/20200822061528.7035-1-madhuparnabhowmik10@gmail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/mmc/host/via-sdmmc.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/mmc/host/via-sdmmc.c b/drivers/mmc/host/via-sdmmc.c
index a863a345fc59b..8c0e348c6053c 100644
--- a/drivers/mmc/host/via-sdmmc.c
+++ b/drivers/mmc/host/via-sdmmc.c
@@ -1275,11 +1275,14 @@ static void via_init_sdc_pm(struct via_crdr_mmc_host *host)
static int via_sd_suspend(struct pci_dev *pcidev, pm_message_t state)
{
struct via_crdr_mmc_host *host;
+ unsigned long flags;

host = pci_get_drvdata(pcidev);

+ spin_lock_irqsave(&host->lock, flags);
via_save_pcictrlreg(host);
via_save_sdcreg(host);
+ spin_unlock_irqrestore(&host->lock, flags);

pci_save_state(pcidev);
pci_enable_wake(pcidev, pci_choose_state(pcidev, state), 0);
--
2.27.0