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@nctritech.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <20101116212442.059967454@sbsiddha-MOBL3.sc.intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@kernel.org>

diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c
index 9c253bd65e24ba3e803b044fca3ad57224a41c52..547128546cc3bd4644a189955c1b804f5c150770 100644 (file)
--- 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();