Patch "x86/mm: account for PGDIR_SIZE alignment" has been added to the 3.4-stable tree

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This is a note to let you know that I've just added the patch titled

    x86/mm: account for PGDIR_SIZE alignment

to the 3.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     x86-mm-account-for-pgdir_size-alignment.patch
and it can be found in the queue-3.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.


>From jerry.hoemann@xxxxxx  Thu May  9 13:59:15 2013
From: Jerry Hoemann <jerry.hoemann@xxxxxx>
Date: Tue, 30 Apr 2013 15:15:55 -0600
Subject: x86/mm: account for PGDIR_SIZE alignment
To: tglx@xxxxxxxxxxxxx, mingo@xxxxxxxxxx, hpa@xxxxxxxxx
Cc: x86@xxxxxxxxxx, jacob.shin@xxxxxxx, gregkh@xxxxxxxxxxxxxxxxxxx, yinghai@xxxxxxxxxx, Jerry Hoemann <jerry.hoemann@xxxxxx>
Message-ID: <1367356555-16320-1-git-send-email-jerry.hoemann@xxxxxx>

From: Jerry Hoemann <jerry.hoemann@xxxxxx>

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@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/x86/mm/init.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -45,11 +45,15 @@ static void __init find_early_table_spac
 	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_spac
 	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 */


Patches currently in stable-queue which might be from jerry.hoemann@xxxxxx are

queue-3.4/x86-mm-account-for-pgdir_size-alignment.patch
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