[tip:x86/urgent] x86, xsave: Use alloc_bootmem_align() instead of alloc_bootmem()

[tip-bot for Suresh Siddha]

Commit-ID:  10340ae130fb70352eae1ae8a00b7906d91bf166
Gitweb:     http://git.kernel.org/tip/10340ae130fb70352eae1ae8a00b7906d91bf166
Author:     Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
AuthorDate: Tue, 16 Nov 2010 13:23:51 -0800
Committer:  H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
CommitDate: Mon, 13 Dec 2010 16:13:11 -0800

x86, xsave: Use alloc_bootmem_align() instead of alloc_bootmem()

Alignment of alloc_bootmem() depends on the value of
L1_CACHE_SHIFT. What we need here, however, is 64 byte alignment.  Use
alloc_bootmem_align() and explicitly specify the alignment instead.

This fixes a kernel boot crash reported by Jody when the cpu in .config
is set to MPENTIUMII but the kernel is booted on a xsave-capable CPU.

Reported-by: Jody Bruchon <jody@xxxxxxxxxxxxx>
Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
LKML-Reference: <20101116212442.059967454@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxx>
---
 arch/x86/kernel/xsave.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c
index 9c253bd..5471285 100644
--- a/arch/x86/kernel/xsave.c
+++ b/arch/x86/kernel/xsave.c
@@ -394,7 +394,8 @@ static void __init setup_xstate_init(void)
 	 * Setup init_xstate_buf to represent the init state of
 	 * all the features managed by the xsave
 	 */
-	init_xstate_buf = alloc_bootmem(xstate_size);
+	init_xstate_buf = alloc_bootmem_align(xstate_size,
+					      __alignof__(struct xsave_struct));
 	init_xstate_buf->i387.mxcsr = MXCSR_DEFAULT;
 
 	clts();
--
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