| Message ID | 20230328084549.20695-1-jgross@suse.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 4d0ac2a4056bb02c76bb681e5311a04bf04a3935 |
| Headers | show |
| Series | xen/pciback: don't call pcistub_device_put() under lock | expand |
On 28.03.23 11:45, Juergen Gross wrote: Hello Juergen > pcistub_device_put() shouldn't be called under spinlock, as it can > sleep. > > For this reason pcistub_device_get_pci_dev() needs to be modified: > instead of always calling pcistub_device_get() just do the call of > pcistub_device_get() only if it is really needed. This removes the > need to call pcistub_device_put(). > > Reported-by: Dan Carpenter <error27@gmail.com> > Link: https://urldefense.com/v3/__https://lore.kernel.org/lkml/Y*JUIl64UDmdkboh@kadam/__;Kw!!GF_29dbcQIUBPA!wO4HR1jCrDMOfB1Ih2qEZs2jnqcieZUZnc6cPwh7Ta8hiLRKwS1Gs-1tmQP-NuEYoz9LhYWI8aFazIwIa8Lh$ [lore[.]kernel[.]org] > Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> > --- > drivers/xen/xen-pciback/pci_stub.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c > index bba527620507..e34b623e4b41 100644 > --- a/drivers/xen/xen-pciback/pci_stub.c > +++ b/drivers/xen/xen-pciback/pci_stub.c > @@ -194,8 +194,6 @@ static struct pci_dev *pcistub_device_get_pci_dev(struct xen_pcibk_device *pdev, > struct pci_dev *pci_dev = NULL; > unsigned long flags; > > - pcistub_device_get(psdev); > - > spin_lock_irqsave(&psdev->lock, flags); > if (!psdev->pdev) { > psdev->pdev = pdev; > @@ -203,8 +201,8 @@ static struct pci_dev *pcistub_device_get_pci_dev(struct xen_pcibk_device *pdev, > } > spin_unlock_irqrestore(&psdev->lock, flags); > > - if (!pci_dev) > - pcistub_device_put(psdev); > + if (pci_dev) > + pcistub_device_get(psdev); > > return pci_dev; > }
diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c index bba527620507..e34b623e4b41 100644 --- a/drivers/xen/xen-pciback/pci_stub.c +++ b/drivers/xen/xen-pciback/pci_stub.c @@ -194,8 +194,6 @@ static struct pci_dev *pcistub_device_get_pci_dev(struct xen_pcibk_device *pdev, struct pci_dev *pci_dev = NULL; unsigned long flags; - pcistub_device_get(psdev); - spin_lock_irqsave(&psdev->lock, flags); if (!psdev->pdev) { psdev->pdev = pdev; @@ -203,8 +201,8 @@ static struct pci_dev *pcistub_device_get_pci_dev(struct xen_pcibk_device *pdev, } spin_unlock_irqrestore(&psdev->lock, flags); - if (!pci_dev) - pcistub_device_put(psdev); + if (pci_dev) + pcistub_device_get(psdev); return pci_dev; }
pcistub_device_put() shouldn't be called under spinlock, as it can sleep. For this reason pcistub_device_get_pci_dev() needs to be modified: instead of always calling pcistub_device_get() just do the call of pcistub_device_get() only if it is really needed. This removes the need to call pcistub_device_put(). Reported-by: Dan Carpenter <error27@gmail.com> Link: https://lore.kernel.org/lkml/Y+JUIl64UDmdkboh@kadam/ Signed-off-by: Juergen Gross <jgross@suse.com> --- drivers/xen/xen-pciback/pci_stub.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)