2020-08-03 07:32:33

by Madhuparna Bhowmik

Subject: [PATCH] drivers: mmc: host: via-sdmmc: Fix data race bug

From: Madhuparna Bhowmik <[email protected]>

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 <[email protected]>
---
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 ef95bce50889..e4d8126cd4e5 100644
--- a/drivers/mmc/host/via-sdmmc.c
+++ b/drivers/mmc/host/via-sdmmc.c
@@ -1259,11 +1259,14 @@ 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);
--
2.17.1

2020-08-21 12:52:51

by Ulf Hansson

Subject: Re: [PATCH] drivers: mmc: host: via-sdmmc: Fix data race bug

On Mon, 3 Aug 2020 at 09:29, <[email protected]> wrote:
>
> From: Madhuparna Bhowmik <[email protected]>
>
> 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 <[email protected]>

This doesn't apply to my mmc tree, can you please rebase and submit a
new version.

Kind regards
Uffe

> ---
> 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 ef95bce50889..e4d8126cd4e5 100644
> --- a/drivers/mmc/host/via-sdmmc.c
> +++ b/drivers/mmc/host/via-sdmmc.c
> @@ -1259,11 +1259,14 @@ 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);
> --
> 2.17.1
>

2020-08-22 06:22:27

by Madhuparna Bhowmik

Subject: Re: [PATCH] drivers: mmc: host: via-sdmmc: Fix data race bug

On Fri, Aug 21, 2020 at 02:48:37PM +0200, Ulf Hansson wrote:
> On Mon, 3 Aug 2020 at 09:29, <[email protected]> wrote:
> >
> > From: Madhuparna Bhowmik <[email protected]>
> >
> > 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 <[email protected]>
>
> This doesn't apply to my mmc tree, can you please rebase and submit a
> new version.
>
Sure, I have rebased it to v5.9-rc1, please have a look.

Thanks,
Madhuparna

> Kind regards
> Uffe
>
> > ---
> > 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 ef95bce50889..e4d8126cd4e5 100644
> > --- a/drivers/mmc/host/via-sdmmc.c
> > +++ b/drivers/mmc/host/via-sdmmc.c
> > @@ -1259,11 +1259,14 @@ 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);
> > --
> > 2.17.1
> >