[v2] drivers: mmc: host: via-sdmmc: Fix data race bug
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Message ID 20200822061528.7035-1-madhuparnabhowmik10@gmail.com
State In Next
Commit 755907e1fdf7ffbdb8665144ed50c397bac67b91
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  • [v2] drivers: mmc: host: via-sdmmc: Fix data race bug
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Commit Message

Madhuparna Bhowmik Aug. 22, 2020, 6:15 a.m. UTC
From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>

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>
---
v2: Rebase v5.9-rc1

 drivers/mmc/host/via-sdmmc.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Ulf Hansson Aug. 24, 2020, 9:51 a.m. UTC | #1
On Sat, 22 Aug 2020 at 08:15, <madhuparnabhowmik10@gmail.com> wrote:
>
> From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
>
> 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>

Applied for next, thanks!

Kind regards
Uffe


> ---
> v2: Rebase v5.9-rc1
>
>  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 49dab9f42b6d..9b755ea0fa03 100644
> --- a/drivers/mmc/host/via-sdmmc.c
> +++ b/drivers/mmc/host/via-sdmmc.c
> @@ -1257,11 +1257,14 @@ static void __maybe_unused via_init_sdc_pm(struct via_crdr_mmc_host *host)
>  static int __maybe_unused via_sd_suspend(struct device *dev)
>  {
>         struct via_crdr_mmc_host *host;
> +       unsigned long flags;
>
>         host = dev_get_drvdata(dev);
>
> +       spin_lock_irqsave(&host->lock, flags);
>         via_save_pcictrlreg(host);
>         via_save_sdcreg(host);
> +       spin_unlock_irqrestore(&host->lock, flags);
>
>         device_wakeup_enable(dev);
>
> --
> 2.17.1
>

Patch
diff mbox series

diff --git a/drivers/mmc/host/via-sdmmc.c b/drivers/mmc/host/via-sdmmc.c
index 49dab9f42b6d..9b755ea0fa03 100644
--- a/drivers/mmc/host/via-sdmmc.c
+++ b/drivers/mmc/host/via-sdmmc.c
@@ -1257,11 +1257,14 @@  static void __maybe_unused via_init_sdc_pm(struct via_crdr_mmc_host *host)
 static int __maybe_unused via_sd_suspend(struct device *dev)
 {
 	struct via_crdr_mmc_host *host;
+	unsigned long flags;
 
 	host = dev_get_drvdata(dev);
 
+	spin_lock_irqsave(&host->lock, flags);
 	via_save_pcictrlreg(host);
 	via_save_sdcreg(host);
+	spin_unlock_irqrestore(&host->lock, flags);
 
 	device_wakeup_enable(dev);