tree f482405c40d75a886b0322f84512f1333d5fcd5b
parent abd89aaa1cd4142834192d7cece972b67d2332aa
author Nicolas Pitre <nicolas.pitre@linaro.org> 1340814537 +0100
committer Laura Abbott <lauraa@codeaurora.org> 1341667310 -0700

ARM: 7438/1: fill possible PMD empty section gaps

On ARM with the 2-level page table format, a PMD entry is represented by
two consecutive section entries covering 2MB of virtual space.

However, static mappings always were allowed to use separate 1MB section
entries.  This means in practice that a static mapping may create half
populated PMDs via create_mapping().

Since commit 0536bdf33f (ARM: move iotable mappings within the vmalloc
region) those static mappings are located in the vmalloc area. We must
ensure no such half populated PMDs are accessible once vmalloc() or
ioremap() start looking at the vmalloc area for nearby free virtual
address ranges, or various things leading to a kernel crash will happen.

Change-Id: Icff38652afbd6c2da1211fad110d1abb1621dc86
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reported-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: "R, Sricharan" <r.sricharan@ti.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>