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authorJerry Hoemann <jerry.hoemann@hp.com>2013-04-30 15:15:55 -0600
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-05-11 13:48:15 -0700
commit94544e2e6ef40c33b760f0c8649904db262dfd64 (patch)
tree808d75bf9fa91db463c5ae4a705a235e9b032145
parente4727b26cd5c972a1688e23c877538ccdd5513be (diff)
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>
-rw-r--r--arch/x86/mm/init.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index fae70904ed0..71d37f527c6 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -45,11 +45,15 @@ static void __init find_early_table_space(struct map_range *mr, int nr_range)
int i;
unsigned long puds = 0, pmds = 0, ptes = 0, tables;
unsigned long start = 0, good_end;
+ unsigned long pgd_extra = 0;
phys_addr_t base;
for (i = 0; i < nr_range; i++) {
unsigned long range, extra;
+ if ((mr[i].end >> PGDIR_SHIFT) - (mr[i].start >> PGDIR_SHIFT))
+ pgd_extra++;
+
range = mr[i].end - mr[i].start;
puds += (range + PUD_SIZE - 1) >> PUD_SHIFT;
@@ -74,6 +78,7 @@ static void __init find_early_table_space(struct map_range *mr, int nr_range)
tables = roundup(puds * sizeof(pud_t), PAGE_SIZE);
tables += roundup(pmds * sizeof(pmd_t), PAGE_SIZE);
tables += roundup(ptes * sizeof(pte_t), PAGE_SIZE);
+ tables += (pgd_extra * PAGE_SIZE);
#ifdef CONFIG_X86_32
/* for fixmap */