Patch "powerpc/mm: Correct process and partition table max size" has been added to the 4.9-stable tree

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

powerpc/mm: Correct process and partition table max size

to the 4.9-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:
powerpc-mm-correct-process-and-partition-table-max-size.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Suraj Jitindar Singh <[email protected]>
Date: Wed, 9 Nov 2016 16:36:33 +1100
Subject: powerpc/mm: Correct process and partition table max size

From: Suraj Jitindar Singh <[email protected]>

commit 555c16328ae6d75a90e234eac9b51998d68f185b upstream.

Version 3.00 of the ISA states that the PATS (partition table size) field of the PTCR (partition table control register) and the PRTS (process table size) field of the partition table entry must both be less than or equal to 24. However the actual size of the partition and process tables is equal to 2 to the power of 12 plus the PATS and PRTS fields, respectively. This means that the max allowable size of each of these tables is 2^36 or 64GB for both.

Thus when checking the size shift for each we should be checking for values of greater than 36 instead of the current check for shifts larger than 24 and 23.

---
 arch/powerpc/mm/pgtable-radix.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

@@ -159,7 +159,7 @@ redo:
 	 * Allocate Partition table and process table for the
 	 * host.
 	 */
-	BUILD_BUG_ON_MSG((PRTB_SIZE_SHIFT > 23), "Process table size too large.");
+	BUILD_BUG_ON_MSG((PRTB_SIZE_SHIFT > 36), "Process table size too large.");
 	process_tb = early_alloc_pgtable(1UL << PRTB_SIZE_SHIFT);
 	/*
 	 * Fill in the process table.

@@ -181,7 +181,7 @@ static void __init radix_init_partition_
 
 	rts_field = radix__get_tree_size();
 
-	BUILD_BUG_ON_MSG((PATB_SIZE_SHIFT > 24), "Partition table size too large.");
+	BUILD_BUG_ON_MSG((PATB_SIZE_SHIFT > 36), "Partition table size too large.");
 	partition_tb = early_alloc_pgtable(1UL << PATB_SIZE_SHIFT);
 	partition_tb->patb0 = cpu_to_be64(rts_field | __pa(init_mm.pgd) |
 					  RADIX_PGD_INDEX_SIZE | PATB_HR);

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/powerpc-mm-correct-process-and-partition-table-max-size.patch