Commit a2c222be authored by Doug Berger's avatar Doug Berger Committed by Greg Kroah-Hartman

ARM: 8685/1: ensure memblock-limit is pmd-aligned

commit 9e25ebfe upstream.

The pmd containing memblock_limit is cleared by prepare_page_table()
which creates the opportunity for early_alloc() to allocate unmapped
memory if memblock_limit is not pmd aligned causing a boot-time hang.

Commit 965278dc ("ARM: 8356/1: mm: handle non-pmd-aligned end of RAM")
attempted to resolve this problem, but there is a path through the
adjust_lowmem_bounds() routine where if all memory regions start and
end on pmd-aligned addresses the memblock_limit will be set to
arm_lowmem_limit.

Since arm_lowmem_limit can be affected by the vmalloc early parameter,
the value of arm_lowmem_limit may not be pmd-aligned. This commit
corrects this oversight such that memblock_limit is always rounded
down to pmd-alignment.

Fixes: 965278dc ("ARM: 8356/1: mm: handle non-pmd-aligned end of RAM")
Signed-off-by: default avatarDoug Berger <opendmb@gmail.com>
Suggested-by: default avatarMark Rutland <mark.rutland@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 7661b196
......@@ -1211,15 +1211,15 @@ void __init adjust_lowmem_bounds(void)
high_memory = __va(arm_lowmem_limit - 1) + 1;
if (!memblock_limit)
memblock_limit = arm_lowmem_limit;
/*
* Round the memblock limit down to a pmd size. This
* helps to ensure that we will allocate memory from the
* last full pmd, which should be mapped.
*/
if (memblock_limit)
memblock_limit = round_down(memblock_limit, PMD_SIZE);
if (!memblock_limit)
memblock_limit = arm_lowmem_limit;
memblock_limit = round_down(memblock_limit, PMD_SIZE);
if (!IS_ENABLED(CONFIG_HIGHMEM) || cache_is_vipt_aliasing()) {
if (memblock_end_of_DRAM() > arm_lowmem_limit) {
......
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