From: Andrew Murray <andrew.murray@arm.com>
To: Arnd Bergmann <arnd@arndb.de>, Will Deacon <will.deacon@arm.com>,
yuanzhichang@hisilicon.com, dann.frazier@canonical.com,
gabriele.paoloni@huawei.com, bhelgaas@google.com,
andy.shevchenko@gmail.com
Cc: jean-philippe.brucker@arm.com, linux-pci@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, suzuki.poulose@arm.com
Subject: [PATCH] asm-generic: io: Fix ioport_map() for !CONFIG_GENERIC_IOMAP && CONFIG_INDIRECT_PIO
Date: Thu, 13 Sep 2018 13:48:27 +0100 [thread overview]
Message-ID: <1536842907-51732-1-git-send-email-andrew.murray@arm.com> (raw)
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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next reply other threads:[~2018-09-13 12:48 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-13 12:48 Andrew Murray [this message]
2018-09-13 13:02 ` [PATCH] asm-generic: io: Fix ioport_map() for !CONFIG_GENERIC_IOMAP && CONFIG_INDIRECT_PIO Will Deacon
2018-09-13 14:00 ` Arnd Bergmann
2018-09-13 17:38 ` Will Deacon
2018-09-17 14:42 ` John Garry
2018-09-17 14:42 ` John Garry
2018-09-17 15:19 ` Andrew Murray
2018-09-17 15:19 ` Andrew Murray
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