| Message ID | 20210506153153.30454-13-pali@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | PCI: aardvark: Various driver fixes | expand |
On Thu, 06 May 2021 16:31:23 +0100, Pali Rohár <pali@kernel.org> wrote: > > It is possible that we receive spurious INTx interrupt. So add needed check > before calling generic_handle_irq() function. > > Signed-off-by: Pali Rohár <pali@kernel.org> > Reviewed-by: Marek Behún <kabel@kernel.org> > Cc: stable@vger.kernel.org > --- > drivers/pci/controller/pci-aardvark.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c > index 362faddae935..e7089db11f79 100644 > --- a/drivers/pci/controller/pci-aardvark.c > +++ b/drivers/pci/controller/pci-aardvark.c > @@ -1106,7 +1106,10 @@ static void advk_pcie_handle_int(struct advk_pcie *pcie) > PCIE_ISR1_REG); > > virq = irq_find_mapping(pcie->irq_domain, i); > - generic_handle_irq(virq); > + if (virq) > + generic_handle_irq(virq); > + else > + dev_err(&pcie->pdev->dev, "unexpected INT%c IRQ\n", (char)i+'A'); Please don't scream like this. This is the best way to get into a DoS situation if you interrupt rate is high enough. At least rate-limit it. M.
On Friday 07 May 2021 10:15:39 Marc Zyngier wrote: > On Thu, 06 May 2021 16:31:23 +0100, > Pali Rohár <pali@kernel.org> wrote: > > > > It is possible that we receive spurious INTx interrupt. So add needed check > > before calling generic_handle_irq() function. > > > > Signed-off-by: Pali Rohár <pali@kernel.org> > > Reviewed-by: Marek Behún <kabel@kernel.org> > > Cc: stable@vger.kernel.org > > --- > > drivers/pci/controller/pci-aardvark.c | 5 ++++- > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c > > index 362faddae935..e7089db11f79 100644 > > --- a/drivers/pci/controller/pci-aardvark.c > > +++ b/drivers/pci/controller/pci-aardvark.c > > @@ -1106,7 +1106,10 @@ static void advk_pcie_handle_int(struct advk_pcie *pcie) > > PCIE_ISR1_REG); > > > > virq = irq_find_mapping(pcie->irq_domain, i); > > - generic_handle_irq(virq); > > + if (virq) > > + generic_handle_irq(virq); > > + else > > + dev_err(&pcie->pdev->dev, "unexpected INT%c IRQ\n", (char)i+'A'); > > Please don't scream like this. This is the best way to get into a DoS > situation if you interrupt rate is high enough. At least rate-limit > it. Ok, I will fix it! Just to note that this code pattern is used also in other drivers. So other drivers should fixed too...
On Fri, 04 Jun 2021 17:24:51 +0100, Pali Rohár <pali@kernel.org> wrote: > > On Friday 07 May 2021 10:15:39 Marc Zyngier wrote: > > On Thu, 06 May 2021 16:31:23 +0100, > > Pali Rohár <pali@kernel.org> wrote: > > > > > > It is possible that we receive spurious INTx interrupt. So add needed check > > > before calling generic_handle_irq() function. > > > > > > Signed-off-by: Pali Rohár <pali@kernel.org> > > > Reviewed-by: Marek Behún <kabel@kernel.org> > > > Cc: stable@vger.kernel.org > > > --- > > > drivers/pci/controller/pci-aardvark.c | 5 ++++- > > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c > > > index 362faddae935..e7089db11f79 100644 > > > --- a/drivers/pci/controller/pci-aardvark.c > > > +++ b/drivers/pci/controller/pci-aardvark.c > > > @@ -1106,7 +1106,10 @@ static void advk_pcie_handle_int(struct advk_pcie *pcie) > > > PCIE_ISR1_REG); > > > > > > virq = irq_find_mapping(pcie->irq_domain, i); > > > - generic_handle_irq(virq); > > > + if (virq) > > > + generic_handle_irq(virq); > > > + else > > > + dev_err(&pcie->pdev->dev, "unexpected INT%c IRQ\n", (char)i+'A'); > > > > Please don't scream like this. This is the best way to get into a DoS > > situation if you interrupt rate is high enough. At least rate-limit > > it. > > Ok, I will fix it! > > Just to note that this code pattern is used also in other drivers. > So other drivers should fixed too... "We should fix the kernel" is a common theme. Please go ahead. M.
diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 362faddae935..e7089db11f79 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -1106,7 +1106,10 @@ static void advk_pcie_handle_int(struct advk_pcie *pcie) PCIE_ISR1_REG); virq = irq_find_mapping(pcie->irq_domain, i); - generic_handle_irq(virq); + if (virq) + generic_handle_irq(virq); + else + dev_err(&pcie->pdev->dev, "unexpected INT%c IRQ\n", (char)i+'A'); } }