4.9-stable review patch. If anyone has any objections, please let me know.
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From: Paul Burton paul.burton@mips.com
commit 38c0a74fe06da3be133cae3fb7bde6a9438e698b upstream.
The MIPS implementation of pci_resource_to_user() introduced in v3.12 by commit 4c2924b725fb ("MIPS: PCI: Use pci_resource_to_user to map pci memory space properly") incorrectly sets *end to the address of the byte after the resource, rather than the last byte of the resource.
This results in userland seeing resources as a byte larger than they actually are, for example a 32 byte BAR will be reported by a tool such as lspci as being 33 bytes in size:
Region 2: I/O ports at 1000 [disabled] [size=33]
Correct this by subtracting one from the calculated end address, reporting the correct address to userland.
Signed-off-by: Paul Burton paul.burton@mips.com Reported-by: Rui Wang rui.wang@windriver.com Fixes: 4c2924b725fb ("MIPS: PCI: Use pci_resource_to_user to map pci memory space properly") Cc: James Hogan jhogan@kernel.org Cc: Ralf Baechle ralf@linux-mips.org Cc: Wolfgang Grandegger wg@grandegger.com Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org # v3.12+ Patchwork: https://patchwork.linux-mips.org/patch/19829/ Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/mips/pci/pci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/mips/pci/pci.c +++ b/arch/mips/pci/pci.c @@ -55,7 +55,7 @@ void pci_resource_to_user(const struct p phys_addr_t size = resource_size(rsrc);
*start = fixup_bigphys_addr(rsrc->start, size); - *end = rsrc->start + size; + *end = rsrc->start + size - 1; }
int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,