sparc64: Fix huge PMD to PTE translation for sun4u in TLB miss handler.
authorDavid S. Miller <davem@davemloft.net>
Wed, 20 Feb 2013 20:38:40 +0000 (12:38 -0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 27 Feb 2013 17:21:14 +0000 (09:21 -0800)
commit53aa75aa360992e07141bbfa2c6062110e678605
treed8142e2f9892b2c7cec5a8ec24e4b3729cd50e8a
parentd13cdf91b4ccc961b496a72d80b549dc158f970e
sparc64: Fix huge PMD to PTE translation for sun4u in TLB miss handler.

[ Upstream commit 76968ad2eac6456270353de168b21f04f4b3d1d3 ]

When we set the sun4u version of the PTE execute bit, it's:

or REG, _PAGE_EXEC_4U, REG

_PAGE_EXEC_4U is 0x1000, unfortunately the immedate field of the
'or' instruction is a signed 13-bit value.  So the above actually
assembles into:

or REG, -4096, REG

completely corrupting the final PTE value.

Set it with a:

sethi %hi(_PAGE_EXEC_4U), TMP
or REG, TMP, REG

sequence instead.

This fixes "git gc" crashes on sun4u machines.

Reported-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/sparc/include/asm/tsb.h