MIPS: Fix off-by-one in pci_resource_to_user()

The MIPS implementation of pci_resource_to_user() introduced in v3.12 by
commit 4c2924b725 ("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: 4c2924b725 ("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/
This commit is contained in:
Paul Burton 2018-07-12 09:33:04 -07:00
parent 9d3cce1e8b
commit 38c0a74fe0
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@ -54,5 +54,5 @@ void pci_resource_to_user(const struct pci_dev *dev, int bar,
phys_addr_t size = resource_size(rsrc);
*start = fixup_bigphys_addr(rsrc->start, size);
*end = rsrc->start + size;
*end = rsrc->start + size - 1;
}