From: mbohan@codeaurora.org (Michael Bohan)
To: linux-arm-kernel@lists.infradead.org
Subject: MT_HIGH_VECTOR mapping set read-only creating illegal access
Date: Tue, 12 Apr 2011 17:42:24 -0700 [thread overview]
Message-ID: <4DA4F170.4020009@codeaurora.org> (raw)
Hi,
In arch/arm/kernel/traps.c:set_tls() and arch/arm/include/asm/tls.h,
some configurations allow for a assignment of address 0xffff0ff0. This
address falls within the MT_HIGH_VECTORS mapping setup in
devicemaps_init(). That mapping is explicitly made read-only. Thus, the
kernel takes a segfault when writing in set_tls().
It looks like this disparity may have been introduced in this commit:
commit 36bb94ba36f332de767cfaa3af6a5136435a3a9c
Author: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Tue Nov 16 08:40:36 2010 +0000
ARM: pgtable: provide RDONLY page table bit rather than WRITE bit
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Is there a reason this mapping must be read-only? Perhaps we could apply
write access for these special cases only?
Thanks,
Mike
--
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum
next reply other threads:[~2011-04-13 0:42 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-13 0:42 Michael Bohan [this message]
2011-04-13 3:31 ` MT_HIGH_VECTOR mapping set read-only creating illegal access Nicolas Pitre
2011-04-19 22:34 ` Michael Bohan
2011-04-20 0:21 ` Nicolas Pitre
2011-04-20 1:44 ` Michael Bohan
2011-04-20 3:01 ` Nicolas Pitre
2011-04-20 3:26 ` Colin Cross
2011-04-13 7:26 ` Russell King - ARM Linux
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