x86/xsaves: Clean up code in xstate offsets computation in xsave area (8ff925e1) · Commits · 戴 / test

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>

arch/x86/kernel/xsave.c

+9 −4

Original line number	Diff line number	Diff line
		@@ -26,7 +26,7 @@ struct xsave_struct *init_xstate_buf;

		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 @@ static void __init setup_xstate_features(void)
		*/
		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++) {

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