1 files changed, 112 insertions, 0 deletions

diff --git a/recipes-kernel/linux/linux-ti33x-psp-3.2/3.2.6/0028-mm-compaction-check-pfn_valid-when-entering-a-new-MA.patch b/recipes-kernel/linux/linux-ti33x-psp-3.2/3.2.6/0028-mm-compaction-check-pfn_valid-when-entering-a-new-MA.patch
new file mode 100644
index 00000000..8862a782
--- /dev/null
+++ b/recipes-kernel/linux/linux-ti33x-psp-3.2/3.2.6/0028-mm-compaction-check-pfn_valid-when-entering-a-new-MA.patch
@@ -0,0 +1,112 @@
+From 9da11afefb6f8ccc0f7731831f7ad73106fc87f3 Mon Sep 17 00:00:00 2001
+From: Mel Gorman <mgorman@suse.de>
+Date: Fri, 3 Feb 2012 15:37:18 -0800
+Subject: [PATCH 28/87] mm: compaction: check pfn_valid when entering a new
+ MAX_ORDER_NR_PAGES block during isolation for
+ migration
+
+commit 0bf380bc70ecba68cb4d74dc656cc2fa8c4d801a upstream.
+
+When isolating for migration, migration starts at the start of a zone
+which is not necessarily pageblock aligned.  Further, it stops isolating
+when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
+not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
+an invalid PFN which can result in a crash.  This was originally reported
+against a 3.0-based kernel with the following trace in a crash dump.
+
+PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
+ #0 [d72d3ad0] crash_kexec at c028cfdb
+ #1 [d72d3b24] oops_end at c05c5322
+ #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
+ #3 [d72d3bec] bad_area at c0227fb6
+ #4 [d72d3c00] do_page_fault at c05c72ec
+ #5 [d72d3c80] error_code (via page_fault) at c05c47a4
+    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
+    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
+    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
+ #6 [d72d3cb4] isolate_migratepages at c030b15a
+ #7 [d72d3d14] zone_watermark_ok at c02d26cb
+ #8 [d72d3d2c] compact_zone at c030b8de
+ #9 [d72d3d68] compact_zone_order at c030bba1
+#10 [d72d3db4] try_to_compact_pages at c030bc84
+#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
+#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
+#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
+#14 [d72d3eb8] alloc_pages_vma at c030a845
+#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
+#16 [d72d3f00] handle_mm_fault at c02f36c6
+#17 [d72d3f30] do_page_fault at c05c70ed
+#18 [d72d3fb0] error_code (via page_fault) at c05c47a4
+    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
+    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
+    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
+    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202
+
+It was also reported by Herbert van den Bergh against 3.1-based kernel
+with the following snippet from the console log.
+
+BUG: unable to handle kernel paging request at 01c00008
+IP: [<c0522399>] isolate_migratepages+0x119/0x390
+*pdpt = 000000002f7ce001 *pde = 0000000000000000
+
+It is expected that it also affects 3.2.x and current mainline.
+
+The problem is that pfn_valid is only called on the first PFN being
+checked and that PFN is not necessarily aligned.  Lets say we have a case
+like this
+
+H = MAX_ORDER_NR_PAGES boundary
+| = pageblock boundary
+m = cc->migrate_pfn
+f = cc->free_pfn
+o = memory hole
+
+H------|------H------|----m-Hoooooo|ooooooH-f----|------H
+
+The migrate_pfn is just below a memory hole and the free scanner is beyond
+the hole.  When isolate_migratepages started, it scans from migrate_pfn to
+migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
+pfn_valid() on the first PFN but then scans into the hole where there are
+not necessarily valid struct pages.
+
+This patch ensures that isolate_migratepages calls pfn_valid when
+necessary.
+
+Reported-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com>
+Tested-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com>
+Signed-off-by: Mel Gorman <mgorman@suse.de>
+Acked-by: Michal Nazarewicz <mina86@mina86.com>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ mm/compaction.c |   13 +++++++++++++
+ 1 files changed, 13 insertions(+), 0 deletions(-)
+
+diff --git a/mm/compaction.c b/mm/compaction.c
+index 899d956..edc1e26 100644
+--- a/mm/compaction.c
++++ b/mm/compaction.c
+@@ -313,6 +313,19 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone,
+                } else if (!locked)
+                        spin_lock_irq(&zone->lru_lock);
+ 
++               /*
++                * migrate_pfn does not necessarily start aligned to a
++                * pageblock. Ensure that pfn_valid is called when moving
++                * into a new MAX_ORDER_NR_PAGES range in case of large
++                * memory holes within the zone
++                */
++               if ((low_pfn & (MAX_ORDER_NR_PAGES - 1)) == 0) {
++                       if (!pfn_valid(low_pfn)) {
++                               low_pfn += MAX_ORDER_NR_PAGES - 1;
++                               continue;
++                       }
++               }
++
+                if (!pfn_valid_within(low_pfn))
+                        continue;
+                nr_scanned++;
+-- 
+1.7.7.4
+