From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Wed, 22 Jan 2014 21:00:53 +0000 (-0800)
Subject: 3.10-stable patches
X-Git-Tag: v3.10.28~9
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=fc5d0de9d590bb10c0359d5b8d64f5446e1a8f7f;p=thirdparty%2Fkernel%2Fstable-queue.git

3.10-stable patches

added patches:
	thp-fix-copy_page_rep-gpf-by-testing-is_huge_zero_pmd-once-only.patch
---

diff --git a/queue-3.10/series b/queue-3.10/series
index fc9ea4dbf06..c4c6659eb60 100644
--- a/queue-3.10/series
+++ b/queue-3.10/series
@@ -10,3 +10,4 @@ hwmon-coretemp-fix-truncated-name-of-alarm-attributes.patch
 writeback-fix-data-corruption-on-nfs.patch
 selinux-fix-possible-null-pointer-dereference-in-selinux_inode_permission.patch
 ftrace-x86-load-ftrace_ops-in-parameter-not-the-variable-holding-it.patch
+thp-fix-copy_page_rep-gpf-by-testing-is_huge_zero_pmd-once-only.patch
diff --git a/queue-3.10/thp-fix-copy_page_rep-gpf-by-testing-is_huge_zero_pmd-once-only.patch b/queue-3.10/thp-fix-copy_page_rep-gpf-by-testing-is_huge_zero_pmd-once-only.patch
new file mode 100644
index 00000000000..eb451ad24f6
--- /dev/null
+++ b/queue-3.10/thp-fix-copy_page_rep-gpf-by-testing-is_huge_zero_pmd-once-only.patch
@@ -0,0 +1,83 @@
+From eecc1e426d681351a6026a7d3e7d225f38955b6c Mon Sep 17 00:00:00 2001
+From: Hugh Dickins <hughd@google.com>
+Date: Sun, 12 Jan 2014 01:25:21 -0800
+Subject: thp: fix copy_page_rep GPF by testing is_huge_zero_pmd once only
+
+From: Hugh Dickins <hughd@google.com>
+
+commit eecc1e426d681351a6026a7d3e7d225f38955b6c upstream.
+
+We see General Protection Fault on RSI in copy_page_rep: that RSI is
+what you get from a NULL struct page pointer.
+
+  RIP: 0010:[<ffffffff81154955>]  [<ffffffff81154955>] copy_page_rep+0x5/0x10
+  RSP: 0000:ffff880136e15c00  EFLAGS: 00010286
+  RAX: ffff880000000000 RBX: ffff880136e14000 RCX: 0000000000000200
+  RDX: 6db6db6db6db6db7 RSI: db73880000000000 RDI: ffff880dd0c00000
+  RBP: ffff880136e15c18 R08: 0000000000000200 R09: 000000000005987c
+  R10: 000000000005987c R11: 0000000000000200 R12: 0000000000000001
+  R13: ffffea00305aa000 R14: 0000000000000000 R15: 0000000000000000
+  FS:  00007f195752f700(0000) GS:ffff880c7fc20000(0000) knlGS:0000000000000000
+  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
+  CR2: 0000000093010000 CR3: 00000001458e1000 CR4: 00000000000027e0
+  Call Trace:
+    copy_user_huge_page+0x93/0xab
+    do_huge_pmd_wp_page+0x710/0x815
+    handle_mm_fault+0x15d8/0x1d70
+    __do_page_fault+0x14d/0x840
+    do_page_fault+0x2f/0x90
+    page_fault+0x22/0x30
+
+do_huge_pmd_wp_page() tests is_huge_zero_pmd(orig_pmd) four times: but
+since shrink_huge_zero_page() can free the huge_zero_page, and we have
+no hold of our own on it here (except where the fourth test holds
+page_table_lock and has checked pmd_same), it's possible for it to
+answer yes the first time, but no to the second or third test.  Change
+all those last three to tests for NULL page.
+
+(Note: this is not the same issue as trinity's DEBUG_PAGEALLOC BUG
+in copy_page_rep with RSI: ffff88009c422000, reported by Sasha Levin
+in https://lkml.org/lkml/2013/3/29/103.  I believe that one is due
+to the source page being split, and a tail page freed, while copy
+is in progress; and not a problem without DEBUG_PAGEALLOC, since
+the pmd_same check will prevent a miscopy from being made visible.)
+
+Fixes: 97ae17497e99 ("thp: implement refcounting for huge zero page")
+Signed-off-by: Hugh Dickins <hughd@google.com>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+
+---
+ mm/huge_memory.c |    6 +++---
+ 1 file changed, 3 insertions(+), 3 deletions(-)
+
+--- a/mm/huge_memory.c
++++ b/mm/huge_memory.c
+@@ -1166,7 +1166,7 @@ alloc:
+ 
+ 	if (unlikely(!new_page)) {
+ 		count_vm_event(THP_FAULT_FALLBACK);
+-		if (is_huge_zero_pmd(orig_pmd)) {
++		if (!page) {
+ 			ret = do_huge_pmd_wp_zero_page_fallback(mm, vma,
+ 					address, pmd, orig_pmd, haddr);
+ 		} else {
+@@ -1190,7 +1190,7 @@ alloc:
+ 		goto out;
+ 	}
+ 
+-	if (is_huge_zero_pmd(orig_pmd))
++	if (!page)
+ 		clear_huge_page(new_page, haddr, HPAGE_PMD_NR);
+ 	else
+ 		copy_user_huge_page(new_page, page, haddr, vma, HPAGE_PMD_NR);
+@@ -1215,7 +1215,7 @@ alloc:
+ 		page_add_new_anon_rmap(new_page, vma, haddr);
+ 		set_pmd_at(mm, haddr, pmd, entry);
+ 		update_mmu_cache_pmd(vma, address, pmd);
+-		if (is_huge_zero_pmd(orig_pmd)) {
++		if (!page) {
+ 			add_mm_counter(mm, MM_ANONPAGES, HPAGE_PMD_NR);
+ 			put_huge_zero_page();
+ 		} else {