Messages in this thread Patch in this message | | | From | Andrew Murray <> | Subject | [PATCH] asm-generic: io: Fix ioport_map() for !CONFIG_GENERIC_IOMAP && CONFIG_INDIRECT_PIO | Date | Thu, 13 Sep 2018 13:48:27 +0100 |
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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 <will.deacon@arm.com> Signed-off-by: Andrew Murray <andrew.murray@arm.com> --- 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 -- 2.7.4
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