| Message ID | 1567585051-1354-1-git-send-email-nkristam@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | USB: usbfs: check cpu address range before remap | expand |
On Wed, Sep 04, 2019 at 01:47:31PM +0530, Nagarjuna Kristam wrote: > In usbfs mmap, usb_alloc_coherent is used to allocate memory. > This Memory is then remapped to user space memory using remap_pfn_range. > remap_pfn_range needs phy address of memory, for which virt_to_phy API > is used. This API works only if memory is allocated using kmalloc. But > usb_alloc_coherent can allocate memory in vmalloc range and this causes > wrong remap of user memory. > > Check if address returned by usb_alloc_coherent failed in vmalloc range > and if yes, use remap_vmalloc_range API, else use remap_pfn_range to remap > address to user space. > > Signed-off-by: Nagarjuna Kristam <nkristam@nvidia.com> > --- > drivers/usb/core/devio.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c > index a945ad7..20999de 100644 > --- a/drivers/usb/core/devio.c > +++ b/drivers/usb/core/devio.c > @@ -250,7 +250,12 @@ static int usbdev_mmap(struct file *file, struct vm_area_struct *vma) > usbm->vma_use_count = 1; > INIT_LIST_HEAD(&usbm->memlist); > > - if (remap_pfn_range(vma, vma->vm_start, > + if (is_vmalloc_addr(usbm->mem)) { > + if (remap_vmalloc_range(vma, usbm->mem, 0) < 0) { > + dec_usb_memory_use_count(usbm, &usbm->vma_use_count); > + return -EAGAIN; > + } > + } else if (remap_pfn_range(vma, vma->vm_start, > virt_to_phys(usbm->mem) >> PAGE_SHIFT, > size, vma->vm_page_prot) < 0) { > dec_usb_memory_use_count(usbm, &usbm->vma_use_count); > -- > 2.7.4 > With the recent dma changes, is this patch still needed and correct? thanks, greg k-h
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c index a945ad7..20999de 100644 --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -250,7 +250,12 @@ static int usbdev_mmap(struct file *file, struct vm_area_struct *vma) usbm->vma_use_count = 1; INIT_LIST_HEAD(&usbm->memlist); - if (remap_pfn_range(vma, vma->vm_start, + if (is_vmalloc_addr(usbm->mem)) { + if (remap_vmalloc_range(vma, usbm->mem, 0) < 0) { + dec_usb_memory_use_count(usbm, &usbm->vma_use_count); + return -EAGAIN; + } + } else if (remap_pfn_range(vma, vma->vm_start, virt_to_phys(usbm->mem) >> PAGE_SHIFT, size, vma->vm_page_prot) < 0) { dec_usb_memory_use_count(usbm, &usbm->vma_use_count);
In usbfs mmap, usb_alloc_coherent is used to allocate memory. This Memory is then remapped to user space memory using remap_pfn_range. remap_pfn_range needs phy address of memory, for which virt_to_phy API is used. This API works only if memory is allocated using kmalloc. But usb_alloc_coherent can allocate memory in vmalloc range and this causes wrong remap of user memory. Check if address returned by usb_alloc_coherent failed in vmalloc range and if yes, use remap_vmalloc_range API, else use remap_pfn_range to remap address to user space. Signed-off-by: Nagarjuna Kristam <nkristam@nvidia.com> --- drivers/usb/core/devio.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)