| Message ID | 20170720234613.GF18698@decadent.org.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
Acked-by: Dan Carpenter <dan.carpenter@oracle.com>
regards,
dan carpenter
Hi Ben, Às 12:46 AM de 7/21/2017, Ben Hutchings escreveu: > Commit 1b497e6493c4 "PCI: dwc: Fix uninitialized variable in > dw_handle_msi_irq()" fixed one problem for 64-bit architectures but > left another. The find_next_bit() function assumes native ordering of > bits within each word (unsigned long), so passing a pointer to a u32 > variable will cause it to scan the following 32 bits on a 64-bit > big-endian configuration. Alternately it could result in an alignment > fault on some architectures. > > Copy the status to an unsigned long variable before using > find_next_bit(). > > Fixes: 1b497e6493c4 ("PCI: dwc: Fix uninitialized variable in ...") > Signed-off-by: Ben Hutchings <ben@decadent.org.uk> > --- > This is compile-tested only. > > Ben. > > drivers/pci/dwc/pcie-designware-host.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/pci/dwc/pcie-designware-host.c b/drivers/pci/dwc/pcie-designware-host.c > index d29c020da082..511fc9188f98 100644 > --- a/drivers/pci/dwc/pcie-designware-host.c > +++ b/drivers/pci/dwc/pcie-designware-host.c > @@ -57,6 +57,7 @@ static struct irq_chip dw_msi_irq_chip = { > irqreturn_t dw_handle_msi_irq(struct pcie_port *pp) > { > u32 val; > + unsigned long bits; Could you please declare the variable in a ordered fashion (after "int i, pos, irq;")? I suggest to change the variable name to "status" and val would be a temporary variable only. > int i, pos, irq; > irqreturn_t ret = IRQ_NONE; > > @@ -65,11 +66,11 @@ irqreturn_t dw_handle_msi_irq(struct pcie_port *pp) > &val); > if (!val) > continue; > + bits = val; > > ret = IRQ_HANDLED; > pos = 0; > - while ((pos = find_next_bit((unsigned long *) &val, 32, > - pos)) != 32) { > + while ((pos = find_next_bit(&bits, 32, pos)) != 32) { > irq = irq_find_mapping(pp->irq_domain, i * 32 + pos); > dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_STATUS + i * 12, > 4, 1 << pos); > Thanks, Joao
diff --git a/drivers/pci/dwc/pcie-designware-host.c b/drivers/pci/dwc/pcie-designware-host.c index d29c020da082..511fc9188f98 100644 --- a/drivers/pci/dwc/pcie-designware-host.c +++ b/drivers/pci/dwc/pcie-designware-host.c @@ -57,6 +57,7 @@ static struct irq_chip dw_msi_irq_chip = { irqreturn_t dw_handle_msi_irq(struct pcie_port *pp) { u32 val; + unsigned long bits; int i, pos, irq; irqreturn_t ret = IRQ_NONE; @@ -65,11 +66,11 @@ irqreturn_t dw_handle_msi_irq(struct pcie_port *pp) &val); if (!val) continue; + bits = val; ret = IRQ_HANDLED; pos = 0; - while ((pos = find_next_bit((unsigned long *) &val, 32, - pos)) != 32) { + while ((pos = find_next_bit(&bits, 32, pos)) != 32) { irq = irq_find_mapping(pp->irq_domain, i * 32 + pos); dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_STATUS + i * 12, 4, 1 << pos);
Commit 1b497e6493c4 "PCI: dwc: Fix uninitialized variable in dw_handle_msi_irq()" fixed one problem for 64-bit architectures but left another. The find_next_bit() function assumes native ordering of bits within each word (unsigned long), so passing a pointer to a u32 variable will cause it to scan the following 32 bits on a 64-bit big-endian configuration. Alternately it could result in an alignment fault on some architectures. Copy the status to an unsigned long variable before using find_next_bit(). Fixes: 1b497e6493c4 ("PCI: dwc: Fix uninitialized variable in ...") Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- This is compile-tested only. Ben. drivers/pci/dwc/pcie-designware-host.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)