> -----Original Message----- > From: devel [mailto:driverdev-devel-boun...@linuxdriverproject.org] On > Behalf Of Long Li > Sent: Tuesday, November 8, 2016 8:57 AM > To: Greg KH <gre...@linuxfoundation.org> > Cc: linux-...@vger.kernel.org; Haiyang Zhang <haiya...@microsoft.com>; > linux-ker...@vger.kernel.org; Bjorn Helgaas <bhelg...@google.com>; > de...@linuxdriverproject.org > Subject: RE: [Resend] [PATCH] pci-hyperv: use kmalloc to allocate hypercall > params buffer > > This sender failed our fraud detection checks and may not be who they > appear to be. Learn about spoofing at http://aka.ms/LearnAboutSpoofing > > > -----Original Message----- > > From: Greg KH [mailto:gre...@linuxfoundation.org] > > Sent: Monday, November 7, 2016 11:00 PM > > To: Long Li <lon...@microsoft.com> > > Cc: KY Srinivasan <k...@microsoft.com>; Haiyang Zhang > > <haiya...@microsoft.com>; Bjorn Helgaas <bhelg...@google.com>; > > de...@linuxdriverproject.org; linux-ker...@vger.kernel.org; linux- > > p...@vger.kernel.org > > Subject: Re: [Resend] [PATCH] pci-hyperv: use kmalloc to allocate > > hypercall params buffer > > > > On Tue, Nov 08, 2016 at 12:14:14AM -0800, Long Li wrote: > > > From: Long Li <lon...@microsoft.com> > > > > > > hv_do_hypercall assumes that we pass a segment from a physically > > continuous buffer. Buffer allocated on the stack may not work if > > CONFIG_VMAP_STACK=y is set. Use kmalloc to allocate this buffer. > > > > Please wrap your changelog at 72 columns. > > > > > > > > Signed-off-by: Long Li <lon...@microsoft.com> > > > Reported-by: Haiyang Zhang <haiya...@microsoft.com> > > > --- > > > drivers/pci/host/pci-hyperv.c | 24 +++++++++++++----------- > > > 1 file changed, 13 insertions(+), 11 deletions(-) > > > > > > diff --git a/drivers/pci/host/pci-hyperv.c > > > b/drivers/pci/host/pci-hyperv.c index 763ff87..97e6daf 100644 > > > --- a/drivers/pci/host/pci-hyperv.c > > > +++ b/drivers/pci/host/pci-hyperv.c > > > @@ -378,6 +378,7 @@ struct hv_pcibus_device { > > > struct msi_domain_info msi_info; > > > struct msi_controller msi_chip; > > > struct irq_domain *irq_domain; > > > + struct retarget_msi_interrupt retarget_msi_interrupt_params; > > > > Can you handle potentially unaligned accesses like this? Is there > > some lock preventing you from using this structure more than once at the > same time? > > > > > }; > > > > > > /* > > > @@ -774,7 +775,7 @@ void hv_irq_unmask(struct irq_data *data) { > > > struct msi_desc *msi_desc = irq_data_get_msi_desc(data); > > > struct irq_cfg *cfg = irqd_cfg(data); > > > - struct retarget_msi_interrupt params; > > > + struct retarget_msi_interrupt *params; > > > struct hv_pcibus_device *hbus; > > > struct cpumask *dest; > > > struct pci_bus *pbus; > > > @@ -785,23 +786,24 @@ void hv_irq_unmask(struct irq_data *data) > > > pdev = msi_desc_to_pci_dev(msi_desc); > > > pbus = pdev->bus; > > > hbus = container_of(pbus->sysdata, struct hv_pcibus_device, > > > sysdata); > > > - > > > - memset(¶ms, 0, sizeof(params)); > > > - params.partition_id = HV_PARTITION_ID_SELF; > > > - params.source = 1; /* MSI(-X) */ > > > - params.address = msi_desc->msg.address_lo; > > > - params.data = msi_desc->msg.data; > > > - params.device_id = (hbus->hdev->dev_instance.b[5] << 24) | > > > + params = &hbus->retarget_msi_interrupt_params; > > > + > > > + memset(params, 0, sizeof(*params)); > > > + params->partition_id = HV_PARTITION_ID_SELF; > > > + params->source = 1; /* MSI(-X) */ > > > + params->address = msi_desc->msg.address_lo; > > > + params->data = msi_desc->msg.data; > > > + params->device_id = (hbus->hdev->dev_instance.b[5] << 24) | > > > (hbus->hdev->dev_instance.b[4] << 16) | > > > (hbus->hdev->dev_instance.b[7] << 8) | > > > (hbus->hdev->dev_instance.b[6] & 0xf8) | > > > PCI_FUNC(pdev->devfn); > > > - params.vector = cfg->vector; > > > + params->vector = cfg->vector; > > > > > > for_each_cpu_and(cpu, dest, cpu_online_mask) > > > - params.vp_mask |= (1ULL << > > vmbus_cpu_number_to_vp_number(cpu)); > > > + params->vp_mask |= (1ULL << > > vmbus_cpu_number_to_vp_number(cpu)); > > > > > > - hv_do_hypercall(HVCALL_RETARGET_INTERRUPT, ¶ms, NULL); > > > + hv_do_hypercall(HVCALL_RETARGET_INTERRUPT, params, NULL); > > > > As you only use this in one spot, why not just allocate it here and > > then free it? Why add it to the pcibus device structure? > > Thanks Greg. I will send a V2.
Sorry forgot to address the reason why we don't just allocate the buffer here. This function cannot fail. So it's better to pre-allocate the buffer. > > > > > thanks, > > > > greg k-h > _______________________________________________ > devel mailing list > de...@linuxdriverproject.org > https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fdriverd > ev.linuxdriverproject.org%2Fmailman%2Flistinfo%2Fdriverdev- > devel&data=02%7C01%7Clongli%40microsoft.com%7C6e28f5459da345cdb5e > 408d407f836f0%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636142 > 210041216500&sdata=vvVxGQUet7KMuRgs9%2BRbR8JE70rKF1AJo%2Fu3zx% > 2FQNwY%3D&reserved=0 _______________________________________________ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
