linux-kernel - [PATCH v3 08/10] thp: setup huge zero page on non-write page fault

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1349191172-28855-9-git-send-email-kirill.shutemov@linux.intel.com>
Date:	Tue,  2 Oct 2012 18:19:30 +0300
From:	"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
To:	Andrew Morton <akpm@...ux-foundation.org>, linux-mm@...ck.org
Cc:	Andrea Arcangeli <aarcange@...hat.com>,
	Andi Kleen <ak@...ux.intel.com>,
	"H. Peter Anvin" <hpa@...ux.intel.com>,
	linux-kernel@...r.kernel.org,
	"Kirill A. Shutemov" <kirill@...temov.name>,
	"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
Subject: [PATCH v3 08/10] thp: setup huge zero page on non-write page fault

From: "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>

All code paths seems covered. Now we can map huge zero page on read page
fault.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com>
Reviewed-by: Andrea Arcangeli <aarcange@...hat.com>
---
 mm/huge_memory.c |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 3f1c59c..a5b9282 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -751,6 +751,16 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
 			return VM_FAULT_OOM;
 		if (unlikely(khugepaged_enter(vma)))
 			return VM_FAULT_OOM;
+		if (!(flags & FAULT_FLAG_WRITE)) {
+			pgtable_t pgtable;
+			pgtable = pte_alloc_one(mm, haddr);
+			if (unlikely(!pgtable))
+				goto out;
+			spin_lock(&mm->page_table_lock);
+			set_huge_zero_page(pgtable, mm, vma, haddr, pmd);
+			spin_unlock(&mm->page_table_lock);
+			return 0;
+		}
 		page = alloc_hugepage_vma(transparent_hugepage_defrag(vma),
 					  vma, haddr, numa_node_id(), 0);
 		if (unlikely(!page)) {
-- 
1.7.7.6

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/