From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: Date: Thu, 13 Sep 2018 14:02:14 +0100 From: Will Deacon To: Andrew Murray Subject: Re: [PATCH] asm-generic: io: Fix ioport_map() for !CONFIG_GENERIC_IOMAP && CONFIG_INDIRECT_PIO Message-ID: <20180913130214.GA13242@arm.com> References: <1536842907-51732-1-git-send-email-andrew.murray@arm.com> MIME-Version: 1.0 In-Reply-To: <1536842907-51732-1-git-send-email-andrew.murray@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Arnd Bergmann , gabriele.paoloni@huawei.com, suzuki.poulose@arm.com, jean-philippe.brucker@arm.com, dann.frazier@canonical.com, linux-kernel@vger.kernel.org, yuanzhichang@hisilicon.com, andy.shevchenko@gmail.com, linux-pci@vger.kernel.org, bhelgaas@google.com, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+bjorn=helgaas.com@lists.infradead.org List-ID: On Thu, Sep 13, 2018 at 01:48:27PM +0100, Andrew Murray wrote: > The !CONFIG_GENERIC_IOMAP version of ioport_map uses MMIO_UPPER_LIMIT to > prevent users from making I/O accesses outside the expected I/O range - > however it erroneously treats MMIO_UPPER_LIMIT as a mask which is > contradictory to its other users. > > The introduction of CONFIG_INDIRECT_PIO, which subtracts an arbitrary > amount from IO_SPACE_LIMIT to form MMIO_UPPER_LIMIT, results in ioport_map > mangling the given port rather than capping it. > > We address this by aligning more closely with the CONFIG_GENERIC_IOMAP > implementation of ioport_map by using the comparison operator and > returning NULL where the port exceeds MMIO_UPPER_LIMIT. Though note that > we preserve the existing behavior of masking with IO_SPACE_LIMIT such that > we don't break existing buggy drivers that somehow rely on this masking. > > Fixes: 5745392e0c2b ("PCI: Apply the new generic I/O management on PCI IO hosts") > Reported-by: Will Deacon > Signed-off-by: Andrew Murray > --- > include/asm-generic/io.h | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h > index 66d1d45..d356f80 100644 > --- a/include/asm-generic/io.h > +++ b/include/asm-generic/io.h > @@ -1026,7 +1026,8 @@ static inline void __iomem *ioremap_wt(phys_addr_t offset, size_t size) > #define ioport_map ioport_map > static inline void __iomem *ioport_map(unsigned long port, unsigned int nr) > { > - return PCI_IOBASE + (port & MMIO_UPPER_LIMIT); > + port &= IO_SPACE_LIMIT; > + return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port; > } > #endif Thanks, that fixes legacy virtio PCI devices under kvmtool, so: Tested-by: Will Deacon Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel