x86/xsaves: Clean up code in xstate offsets computation in xsave area
This patch cleans up some code in xstate offsets computation in xsave
area:
1. It changes xstate_comp_offsets as an array. This avoids possible NULL pointer
caused by possible kmalloc() failure during boot time.
2. It changes the global variable xstate_comp_sizes to a local variable because
it is used only in setup_xstate_comp().
3. It adds missing offsets for FP and SSE in xsave area.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1401387164-43416-17-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c
index a6cb823..940b142 100644
--- a/arch/x86/kernel/xsave.c
+++ b/arch/x86/kernel/xsave.c
@@ -26,7 +26,7 @@
static struct _fpx_sw_bytes fx_sw_reserved, fx_sw_reserved_ia32;
static unsigned int *xstate_offsets, *xstate_sizes;
-static unsigned int *xstate_comp_offsets, *xstate_comp_sizes;
+static unsigned int xstate_comp_offsets[sizeof(pcntxt_mask)*8];
static unsigned int xstate_features;
/*
@@ -491,11 +491,16 @@
*/
void setup_xstate_comp(void)
{
+ unsigned int xstate_comp_sizes[sizeof(pcntxt_mask)*8];
int i;
- xstate_comp_offsets = kmalloc(xstate_features * sizeof(int),
- GFP_KERNEL);
- xstate_comp_sizes = kmalloc(xstate_features * sizeof(int), GFP_KERNEL);
+ /*
+ * The FP xstates and SSE xstates are legacy states. They are always
+ * in the fixed offsets in the xsave area in either compacted form
+ * or standard form.
+ */
+ xstate_comp_offsets[0] = 0;
+ xstate_comp_offsets[1] = offsetof(struct i387_fxsave_struct, xmm_space);
if (!cpu_has_xsaves) {
for (i = 2; i < xstate_features; i++) {