[tip:x86/vdso] x86-64: Pad vDSO to a page boundary

[tip-bot for Andy Lutomirski]

Commit-ID:  1bdfac19b3ecfca545281c15c7aea7ebc2eaef31
Gitweb:     http://git.kernel.org/tip/1bdfac19b3ecfca545281c15c7aea7ebc2eaef31
Author:     Andy Lutomirski <luto@xxxxxxx>
AuthorDate: Wed, 3 Aug 2011 09:31:49 -0400
Committer:  H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
CommitDate: Thu, 4 Aug 2011 16:13:34 -0700

x86-64: Pad vDSO to a page boundary

This avoids an information leak to userspace.

Signed-off-by: Andy Lutomirski <luto@xxxxxxx>
Link: http://lkml.kernel.org/r/a63380a3c58a0506a2f5a18ba1b12dbde1f25e58.1312378163.git.luto@xxxxxxx
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
---
 arch/x86/vdso/vdso.S |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/arch/x86/vdso/vdso.S b/arch/x86/vdso/vdso.S
index 1b979c1..01f5e3b 100644
--- a/arch/x86/vdso/vdso.S
+++ b/arch/x86/vdso/vdso.S
@@ -9,6 +9,7 @@ __PAGE_ALIGNED_DATA
 vdso_start:
 	.incbin "arch/x86/vdso/vdso.so"
 vdso_end:
+	.align PAGE_SIZE /* extra data here leaks to userspace. */
 
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