[PATCH] [25/139] x86, xsave: Use alloc_bootmem_align() instead of alloc_bootmem()

[Andi Kleen]

2.6.35-longterm review patch.  If anyone has any objections, please let me know.

------------------
From: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>

commit 10340ae130fb70352eae1ae8a00b7906d91bf166 upstream.

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>
Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
LKML-Reference: <20101116212442.059967454@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 arch/x86/kernel/xsave.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Index: linux-2.6.35.y/arch/x86/kernel/xsave.c
===================================================================
--- linux-2.6.35.y.orig/arch/x86/kernel/xsave.c
+++ linux-2.6.35.y/arch/x86/kernel/xsave.c
@@ -305,7 +305,8 @@ void __cpuinit xsave_init(void)
  */
 static void __init setup_xstate_init(void)
 {
-	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;
 }
 
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