tree 2caf0ae3070e778d5709a34bff55916593fbc575
parent fccd6eb97dab4cf45b2cda8278d5a7582cd40d08
author Jerry Hoemann <jerry.hoemann@hp.com> 1367356555 -0600
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1368305651 -0700

x86/mm: account for PGDIR_SIZE alignment

Patch for -stable.  Function find_early_table_space removed upstream.

Fixes panic in alloc_low_page due to pgt_buf overflow during
init_memory_mapping.

find_early_table_space sizes pgt_buf based upon the size of the
memory being mapped, but it does not take into account the alignment
of the memory.  When the region being mapped spans a 512GB (PGDIR_SIZE)
alignment, a panic from alloc_low_pages occurs.

kernel_physical_mapping_init takes into account PGDIR_SIZE alignment.
This causes an extra call to alloc_low_page to be made.  This extra call
isn't accounted for by find_early_table_space and causes a kernel panic.

Change is to take into account PGDIR_SIZE alignment in find_early_table_space.

Signed-off-by: Jerry Hoemann <jerry.hoemann@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>