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From: Ralf Baechle <ralf@linux-mips.org>
To: linux-mips@linux-mips.org,
	David Daney <ddaney@caviumnetworks.com>,
	Markos Chandras <Markos.Chandras@imgtec.com>,
	James Hogan <james.hogan@imgtec.com>
Subject: [PATCH 0/2] RIXI fixes.
Date: Thu, 23 Jul 2015 11:34:22 +0200	[thread overview]
Message-ID: <cover.1437644062.git.ralf@linux-mips.org> (raw)

As part of unrelated work I ran into issus with RIXI support which allows
the creation of pages that are executable but not readable.  Problems
arise with instruction emulation on such pages, for example when a load
or store instruction is taking an unaligned exception, is an FPU
instruction that requires emulation, a trap or break instruction of
which the break code needs to bread and more.

A better solution would be to create a temporary mapping using
kmap_coherent() but that's more complex so left for a later stage.

These patches have been sitting in a shady git tree for years but seem to
work for me.  Nevertheless Comments appreciated.

Cheers,

  Ralf

Ralf Baechle (2):
  MIPS: Handle page faults of executable but unreadable pages correctly.
  MIPS: Partially disable RIXI support.

 arch/mips/mm/cache.c | 8 ++++----
 arch/mips/mm/fault.c | 3 ++-
 2 files changed, 6 insertions(+), 5 deletions(-)

-- 
2.4.3

             reply	other threads:[~2015-07-23  9:52 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-07-23  9:34 Ralf Baechle [this message]
2015-07-23  9:10 ` [PATCH 1/2] MIPS: Handle page faults of executable but unreadable pages correctly Ralf Baechle
2015-07-23 10:15   ` James Hogan
2015-07-23 10:15     ` James Hogan
2015-07-23 12:35     ` Ralf Baechle
2015-07-23  9:10 ` [PATCH 2/2] MIPS: Partially disable RIXI support Ralf Baechle
2015-07-23 10:06   ` James Hogan
2015-07-23 10:06     ` James Hogan

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