Merge branch 'x86-xsave-for-linus' of git://git.kernel.org/pub/scm/li…

…nux/kernel/git/tip/linux-2.6-tip

* 'x86-xsave-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, xsave: Make xstate_enable_boot_cpu() __init, protect on CPU 0
  x86, xsave: Add __init attribute to setup_xstate_features()
  x86, xsave: Make init_xstate_buf static
  x86, xsave: Check cpuid level for XSTATE_CPUID (0x0d)
  x86, xsave: Introduce xstate enable functions
  x86, xsave: Separate fpu and xsave initialization
  x86, xsave: Move boot cpu initialization to xsave_init()
  x86, xsave: 32/64 bit boot cpu check unification in initialization
  x86, xsave: Do not include asm/i387.h in asm/xsave.h
  x86, xsave: Use xsaveopt in context-switch path when supported
  x86, xsave: Sync xsave memory layout with its header for user handling
  x86, xsave: Track the offset, size of state in the xsave layout

arch/x86/include/asm/i387.h

@@ -31,7 +31,6 @@ extern void mxcsr_feature_mask_init(void);
 extern int init_fpu(struct task_struct *child);
 extern asmlinkage void math_state_restore(void);
 extern void __math_state_restore(void);
-extern void init_thread_xstate(void);
 extern int dump_fpu(struct pt_regs *, struct user_i387_struct *);
 
 extern user_regset_active_fn fpregs_active, xfpregs_active;
@@ -58,11 +57,25 @@ extern int restore_i387_xstate_ia32(void __user *buf);
 
 #define X87_FSW_ES (1 << 7)	/* Exception Summary */
 
+static __always_inline __pure bool use_xsaveopt(void)
+{
+	return static_cpu_has(X86_FEATURE_XSAVEOPT);
+}
+
 static __always_inline __pure bool use_xsave(void)
 {
 	return static_cpu_has(X86_FEATURE_XSAVE);
 }
 
+extern void __sanitize_i387_state(struct task_struct *);
+
+static inline void sanitize_i387_state(struct task_struct *tsk)
+{
+	if (!use_xsaveopt())
+		return;
+	__sanitize_i387_state(tsk);
+}
+
 #ifdef CONFIG_X86_64
 
 /* Ignore delayed exceptions from user space */

arch/x86/include/asm/xsave.h

@@ -3,7 +3,8 @@
 
 #include <linux/types.h>
 #include <asm/processor.h>
-#include <asm/i387.h>
+
+#define XSTATE_CPUID		0x0000000d
 
 #define XSTATE_FP	0x1
 #define XSTATE_SSE	0x2
@@ -32,10 +33,8 @@
 
 extern unsigned int xstate_size;
 extern u64 pcntxt_mask;
-extern struct xsave_struct *init_xstate_buf;
 extern u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
 
-extern void xsave_cntxt_init(void);
 extern void xsave_init(void);
 extern void update_regset_xstate_info(unsigned int size, u64 xstate_mask);
 extern int init_fpu(struct task_struct *child);
@@ -127,12 +126,25 @@ static inline void xrstor_state(struct xsave_struct *fx, u64 mask)
 		     :   "memory");
 }
 
+static inline void xsave_state(struct xsave_struct *fx, u64 mask)
+{
+	u32 lmask = mask;
+	u32 hmask = mask >> 32;
+
+	asm volatile(".byte " REX_PREFIX "0x0f,0xae,0x27\n\t"
+		     : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
+		     :   "memory");
+}
+
 static inline void fpu_xsave(struct fpu *fpu)
 {
 	/* This, however, we can work around by forcing the compiler to select
 	   an addressing mode that doesn't require extended registers. */
-	__asm__ __volatile__(".byte " REX_PREFIX "0x0f,0xae,0x27"
-			     : : "D" (&(fpu->state->xsave)),
-				 "a" (-1), "d"(-1) : "memory");
+	alternative_input(
+		".byte " REX_PREFIX "0x0f,0xae,0x27",
+		".byte " REX_PREFIX "0x0f,0xae,0x37",
+		X86_FEATURE_XSAVEOPT,
+		[fx] "D" (&fpu->state->xsave), "a" (-1), "d" (-1) :
+		"memory");
 }
 #endif

arch/x86/kernel/cpu/common.c

@@ -140,10 +140,18 @@ EXPORT_PER_CPU_SYMBOL_GPL(gdt_page);
 static int __init x86_xsave_setup(char *s)
 {
 	setup_clear_cpu_cap(X86_FEATURE_XSAVE);
+	setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT);
 	return 1;
 }
 __setup("noxsave", x86_xsave_setup);
 
+static int __init x86_xsaveopt_setup(char *s)
+{
+	setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT);
+	return 1;
+}
+__setup("noxsaveopt", x86_xsaveopt_setup);
+
 #ifdef CONFIG_X86_32
 static int cachesize_override __cpuinitdata = -1;
 static int disable_x86_serial_nr __cpuinitdata = 1;
@@ -1202,6 +1210,7 @@ void __cpuinit cpu_init(void)
 	dbg_restore_debug_regs();
 
 	fpu_init();
+	xsave_init();
 
 	raw_local_save_flags(kernel_eflags);
 
@@ -1262,12 +1271,7 @@ void __cpuinit cpu_init(void)
 	clear_used_math();
 	mxcsr_feature_mask_init();
 
-	/*
-	 * Boot processor to setup the FP and extended state context info.
-	 */
-	if (smp_processor_id() == boot_cpu_id)
-		init_thread_xstate();
-
+	fpu_init();
 	xsave_init();
 }
 #endif

arch/x86/kernel/i387.c

@@ -59,18 +59,18 @@ void __cpuinit mxcsr_feature_mask_init(void)
 	stts();
 }
 
-void __cpuinit init_thread_xstate(void)
+static void __cpuinit init_thread_xstate(void)
 {
+	/*
+	 * Note that xstate_size might be overwriten later during
+	 * xsave_init().
+	 */
+
 	if (!HAVE_HWFP) {
 		xstate_size = sizeof(struct i387_soft_struct);
 		return;
 	}
 
-	if (cpu_has_xsave) {
-		xsave_cntxt_init();
-		return;
-	}
-
 	if (cpu_has_fxsr)
 		xstate_size = sizeof(struct i387_fxsave_struct);
 #ifdef CONFIG_X86_32
@@ -84,6 +84,7 @@ void __cpuinit init_thread_xstate(void)
  * Called at bootup to set up the initial FPU state that is later cloned
  * into all processes.
  */
+
 void __cpuinit fpu_init(void)
 {
 	unsigned long oldcr0 = read_cr0();
@@ -93,19 +94,24 @@ void __cpuinit fpu_init(void)
 
 	write_cr0(oldcr0 & ~(X86_CR0_TS|X86_CR0_EM)); /* clear TS and EM */
 
-	/*
-	 * Boot processor to setup the FP and extended state context info.
-	 */
 	if (!smp_processor_id())
 		init_thread_xstate();
-	xsave_init();
 
 	mxcsr_feature_mask_init();
 	/* clean state in init */
 	current_thread_info()->status = 0;
 	clear_used_math();
 }
-#endif	/* CONFIG_X86_64 */
+
+#else	/* CONFIG_X86_64 */
+
+void __cpuinit fpu_init(void)
+{
+	if (!smp_processor_id())
+		init_thread_xstate();
+}
+
+#endif	/* CONFIG_X86_32 */
 
 void fpu_finit(struct fpu *fpu)
 {
@@ -191,6 +197,8 @@ int xfpregs_get(struct task_struct *target, const struct user_regset *regset,
 	if (ret)
 		return ret;
 
+	sanitize_i387_state(target);
+
 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 				   &target->thread.fpu.state->fxsave, 0, -1);
 }
@@ -208,6 +216,8 @@ int xfpregs_set(struct task_struct *target, const struct user_regset *regset,
 	if (ret)
 		return ret;
 
+	sanitize_i387_state(target);
+
 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 				 &target->thread.fpu.state->fxsave, 0, -1);
 
@@ -447,6 +457,8 @@ int fpregs_get(struct task_struct *target, const struct user_regset *regset,
 					   -1);
 	}
 
+	sanitize_i387_state(target);
+
 	if (kbuf && pos == 0 && count == sizeof(env)) {
 		convert_from_fxsr(kbuf, target);
 		return 0;
@@ -468,6 +480,8 @@ int fpregs_set(struct task_struct *target, const struct user_regset *regset,
 	if (ret)
 		return ret;
 
+	sanitize_i387_state(target);
+
 	if (!HAVE_HWFP)
 		return fpregs_soft_set(target, regset, pos, count, kbuf, ubuf);
 
@@ -534,6 +548,9 @@ static int save_i387_xsave(void __user *buf)
 	struct _fpstate_ia32 __user *fx = buf;
 	int err = 0;
 
+
+	sanitize_i387_state(tsk);
+
 	/*
 	 * For legacy compatible, we always set FP/SSE bits in the bit
 	 * vector while saving the state to the user context.