| Message ID | 1555340058-3065-1-git-send-email-wang6495@umn.edu |
|---|---|
| State | Superseded |
| Headers | show |
| Series | x86/PCI: fix a memory leak bug | expand |
* Wenwen Wang <wang6495@umn.edu> wrote: > In pcibios_irq_init(), the PCI IRQ routing table 'pirq_table' is firstly > found through pirq_find_routing_table(). If the table is not found and > 'CONFIG_PCI_BIOS' is defined, the table is then allocated in > pcibios_get_irq_routing_table() using kmalloc(). In the following > execution, if the I/O APIC is used, this table is actually not used. > However, in that case, the allocated table is not freed, which can lead to > a memory leak bug. > > To fix this issue, this patch frees the allocated table if it is not used. > > Signed-off-by: Wenwen Wang <wang6495@umn.edu> > --- > arch/x86/pci/irq.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/pci/irq.c b/arch/x86/pci/irq.c > index 52e5510..d9bcb96 100644 > --- a/arch/x86/pci/irq.c > +++ b/arch/x86/pci/irq.c > @@ -1119,6 +1119,8 @@ static const struct dmi_system_id pciirq_dmi_table[] __initconst = { > > void __init pcibios_irq_init(void) > { > + struct irq_routing_table *itable = NULL; > + Minor style nit: the canonical name of irq_routing_table local variables is usually 'rtable' or 'rt' - let's not add a third naming variant with 'itable'? > DBG(KERN_DEBUG "PCI: IRQ init\n"); > > if (raw_pci_ops == NULL) > @@ -1129,8 +1131,10 @@ void __init pcibios_irq_init(void) > pirq_table = pirq_find_routing_table(); > > #ifdef CONFIG_PCI_BIOS > - if (!pirq_table && (pci_probe & PCI_BIOS_IRQ_SCAN)) > + if (!pirq_table && (pci_probe & PCI_BIOS_IRQ_SCAN)) { > pirq_table = pcibios_get_irq_routing_table(); > + itable = pirq_table; > + } > #endif > if (pirq_table) { > pirq_peer_trick(); > @@ -1145,8 +1149,10 @@ void __init pcibios_irq_init(void) > * If we're using the I/O APIC, avoid using the PCI IRQ > * routing table > */ > - if (io_apic_assign_pci_irqs) > + if (io_apic_assign_pci_irqs) { > + kfree(itable); > pirq_table = NULL; > + } Reviewed-by: Ingo Molnar <mingo@kernel.org> Thanks, Ingo
On Tue, Apr 16, 2019 at 2:23 AM Ingo Molnar <mingo@kernel.org> wrote: > > > * Wenwen Wang <wang6495@umn.edu> wrote: > > > In pcibios_irq_init(), the PCI IRQ routing table 'pirq_table' is firstly > > found through pirq_find_routing_table(). If the table is not found and > > 'CONFIG_PCI_BIOS' is defined, the table is then allocated in > > pcibios_get_irq_routing_table() using kmalloc(). In the following > > execution, if the I/O APIC is used, this table is actually not used. > > However, in that case, the allocated table is not freed, which can lead to > > a memory leak bug. > > > > To fix this issue, this patch frees the allocated table if it is not used. > > > > Signed-off-by: Wenwen Wang <wang6495@umn.edu> > > --- > > arch/x86/pci/irq.c | 10 ++++++++-- > > 1 file changed, 8 insertions(+), 2 deletions(-) > > > > diff --git a/arch/x86/pci/irq.c b/arch/x86/pci/irq.c > > index 52e5510..d9bcb96 100644 > > --- a/arch/x86/pci/irq.c > > +++ b/arch/x86/pci/irq.c > > @@ -1119,6 +1119,8 @@ static const struct dmi_system_id pciirq_dmi_table[] __initconst = { > > > > void __init pcibios_irq_init(void) > > { > > + struct irq_routing_table *itable = NULL; > > + > > Minor style nit: the canonical name of irq_routing_table local variables > is usually 'rtable' or 'rt' - let's not add a third naming variant with > 'itable'? > Thanks for your comment! I will rework the patch. Wenwen > > DBG(KERN_DEBUG "PCI: IRQ init\n"); > > > > if (raw_pci_ops == NULL) > > @@ -1129,8 +1131,10 @@ void __init pcibios_irq_init(void) > > pirq_table = pirq_find_routing_table(); > > > > #ifdef CONFIG_PCI_BIOS > > - if (!pirq_table && (pci_probe & PCI_BIOS_IRQ_SCAN)) > > + if (!pirq_table && (pci_probe & PCI_BIOS_IRQ_SCAN)) { > > pirq_table = pcibios_get_irq_routing_table(); > > + itable = pirq_table; > > + } > > #endif > > if (pirq_table) { > > pirq_peer_trick(); > > @@ -1145,8 +1149,10 @@ void __init pcibios_irq_init(void) > > * If we're using the I/O APIC, avoid using the PCI IRQ > > * routing table > > */ > > - if (io_apic_assign_pci_irqs) > > + if (io_apic_assign_pci_irqs) { > > + kfree(itable); > > pirq_table = NULL; > > + } > > Reviewed-by: Ingo Molnar <mingo@kernel.org> > > Thanks, > > Ingo
diff --git a/arch/x86/pci/irq.c b/arch/x86/pci/irq.c index 52e5510..d9bcb96 100644 --- a/arch/x86/pci/irq.c +++ b/arch/x86/pci/irq.c @@ -1119,6 +1119,8 @@ static const struct dmi_system_id pciirq_dmi_table[] __initconst = { void __init pcibios_irq_init(void) { + struct irq_routing_table *itable = NULL; + DBG(KERN_DEBUG "PCI: IRQ init\n"); if (raw_pci_ops == NULL) @@ -1129,8 +1131,10 @@ void __init pcibios_irq_init(void) pirq_table = pirq_find_routing_table(); #ifdef CONFIG_PCI_BIOS - if (!pirq_table && (pci_probe & PCI_BIOS_IRQ_SCAN)) + if (!pirq_table && (pci_probe & PCI_BIOS_IRQ_SCAN)) { pirq_table = pcibios_get_irq_routing_table(); + itable = pirq_table; + } #endif if (pirq_table) { pirq_peer_trick(); @@ -1145,8 +1149,10 @@ void __init pcibios_irq_init(void) * If we're using the I/O APIC, avoid using the PCI IRQ * routing table */ - if (io_apic_assign_pci_irqs) + if (io_apic_assign_pci_irqs) { + kfree(itable); pirq_table = NULL; + } } x86_init.pci.fixup_irqs();
In pcibios_irq_init(), the PCI IRQ routing table 'pirq_table' is firstly found through pirq_find_routing_table(). If the table is not found and 'CONFIG_PCI_BIOS' is defined, the table is then allocated in pcibios_get_irq_routing_table() using kmalloc(). In the following execution, if the I/O APIC is used, this table is actually not used. However, in that case, the allocated table is not freed, which can lead to a memory leak bug. To fix this issue, this patch frees the allocated table if it is not used. Signed-off-by: Wenwen Wang <wang6495@umn.edu> --- arch/x86/pci/irq.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)