The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 38c0a74fe06da3be133cae3fb7bde6a9438e698b Mon Sep 17 00:00:00 2001 From: Paul Burton <paul.burton@xxxxxxxx> Date: Thu, 12 Jul 2018 09:33:04 -0700 Subject: [PATCH] MIPS: Fix off-by-one in pci_resource_to_user() 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@xxxxxxxx> Reported-by: Rui Wang <rui.wang@xxxxxxxxxxxxx> Fixes: 4c2924b725fb ("MIPS: PCI: Use pci_resource_to_user to map pci memory space properly") Cc: James Hogan <jhogan@xxxxxxxxxx> Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx> Cc: Wolfgang Grandegger <wg@xxxxxxxxxxxxxx> Cc: linux-mips@xxxxxxxxxxxxxx Cc: stable@xxxxxxxxxxxxxxx # v3.12+ Patchwork: https://patchwork.linux-mips.org/patch/19829/ diff --git a/arch/mips/pci/pci.c b/arch/mips/pci/pci.c index 9632436d74d7..c2e94cf5ecda 100644 --- a/arch/mips/pci/pci.c +++ b/arch/mips/pci/pci.c @@ -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; }