Messages in this thread Patch in this message | | | Subject | patch uio-fix-mapping-of-logical-and-virtual-memory.patch added to gregkh-2.6 tree | From | <> | Date | Wed, 01 Oct 2008 14:15:19 -0700 |
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This is a note to let you know that I've just added the patch titled
Subject: UIO: Fix mapping of logical and virtual memory
to my gregkh-2.6 tree. Its filename is
uio-fix-mapping-of-logical-and-virtual-memory.patch
This tree can be found at http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/patches/
From hjk@linutronix.de Wed Oct 1 14:01:23 2008 From: Andrew Harvey <agh@cisco.com> Date: Wed, 24 Sep 2008 01:10:02 +0200 Subject: UIO: Fix mapping of logical and virtual memory To: LKML <linux-kernel@vger.kernel.org> Cc: Greg KH <gregkh@suse.de>, "Andrew G. Harvey" <agh@cisco.com> Message-ID: <20080923230959.GB4066@local> Content-Disposition: inline
From: "Andrew G. Harvey" <agh@cisco.com>
mmap() doesn't work as expected for UIO_MEM_LOGICAL or UIO_MEM_VIRTUAL mappings. The offset into the memory needs to be added, otherwise uio_vma_fault always returns the first page only. Note that for UIO userspace calls mmap() with offset = N * getpagesize() to access mapping N. This must be compensated when calculating the offset. A comment was added to explain this since it is not obvious.
Signed-off-by: Andrew G. Harvey <agh@cisco.com> Signed-off-by: Hans J. Koch <hjk@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- drivers/uio/uio.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
--- a/drivers/uio/uio.c +++ b/drivers/uio/uio.c @@ -490,15 +490,23 @@ static int uio_vma_fault(struct vm_area_ { struct uio_device *idev = vma->vm_private_data; struct page *page; + unsigned long offset; int mi = uio_find_mem_index(vma); if (mi < 0) return VM_FAULT_SIGBUS; + /* + * We need to subtract mi because userspace uses offset = N*PAGE_SIZE + * to use mem[N]. + */ + offset = (vmf->pgoff - mi) << PAGE_SHIFT; + if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL) - page = virt_to_page(idev->info->mem[mi].addr); + page = virt_to_page(idev->info->mem[mi].addr + offset); else - page = vmalloc_to_page((void*)idev->info->mem[mi].addr); + page = vmalloc_to_page((void *)idev->info->mem[mi].addr + + offset); get_page(page); vmf->page = page; return 0;
Patches currently in gregkh-2.6 which might be from agh@cisco.com are
driver-core/uio-fix-mapping-of-logical-and-virtual-memory.patch
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