1 files changed, 108 insertions, 17 deletions

diff --git a/include/asm-x86/i387.h b/include/asm-x86/i387.h
index 96fa8449ff11..9ba862a4eac0 100644
--- a/include/asm-x86/i387.h
+++ b/include/asm-x86/i387.h
@@ -7,34 +7,44 @@
  * x86-64 work by Andi Kleen 2002
  */
 
-#ifndef _ASM_X86_I387_H
-#define _ASM_X86_I387_H
+#ifndef ASM_X86__I387_H
+#define ASM_X86__I387_H
 
 #include <linux/sched.h>
 #include <linux/kernel_stat.h>
 #include <linux/regset.h>
+#include <linux/hardirq.h>
 #include <asm/asm.h>
 #include <asm/processor.h>
 #include <asm/sigcontext.h>
 #include <asm/user.h>
 #include <asm/uaccess.h>
+#include <asm/xsave.h>
 
+extern unsigned int sig_xstate_size;
 extern void fpu_init(void);
 extern void mxcsr_feature_mask_init(void);
 extern int init_fpu(struct task_struct *child);
 extern asmlinkage 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;
 extern user_regset_get_fn fpregs_get, xfpregs_get, fpregs_soft_get;
 extern user_regset_set_fn fpregs_set, xfpregs_set, fpregs_soft_set;
 
+extern struct _fpx_sw_bytes fx_sw_reserved;
 #ifdef CONFIG_IA32_EMULATION
+extern unsigned int sig_xstate_ia32_size;
+extern struct _fpx_sw_bytes fx_sw_reserved_ia32;
 struct _fpstate_ia32;
-extern int save_i387_ia32(struct _fpstate_ia32 __user *buf);
-extern int restore_i387_ia32(struct _fpstate_ia32 __user *buf);
+struct _xstate_ia32;
+extern int save_i387_xstate_ia32(void __user *buf);
+extern int restore_i387_xstate_ia32(void __user *buf);
 #endif
 
+#define X87_FSW_ES (1 << 7)     /* Exception Summary */
+
 #ifdef CONFIG_X86_64
 
 /* Ignore delayed exceptions from user space */
@@ -45,7 +55,7 @@ static inline void tolerant_fwait(void)
                      _ASM_EXTABLE(1b, 2b));
 }
 
-static inline int restore_fpu_checking(struct i387_fxsave_struct *fx)
+static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
 {
         int err;
 
@@ -62,20 +72,34 @@ static inline int restore_fpu_checking(struct i387_fxsave_struct *fx)
 #else
                      : [fx] "cdaSDb" (fx), "m" (*fx), "0" (0));
 #endif
-        if (unlikely(err))
-                init_fpu(current);
         return err;
 }
 
-#define X87_FSW_ES (1 << 7)     /* Exception Summary */
+static inline int restore_fpu_checking(struct task_struct *tsk)
+{
+        if (task_thread_info(tsk)->status & TS_XSAVE)
+                return xrstor_checking(&tsk->thread.xstate->xsave);
+        else
+                return fxrstor_checking(&tsk->thread.xstate->fxsave);
+}
 
 /* AMD CPUs don't save/restore FDP/FIP/FOP unless an exception
    is pending. Clear the x87 state here by setting it to fixed
    values. The kernel data segment can be sometimes 0 and sometimes
    new user value. Both should be ok.
    Use the PDA as safe address because it should be already in L1. */
-static inline void clear_fpu_state(struct i387_fxsave_struct *fx)
+static inline void clear_fpu_state(struct task_struct *tsk)
 {
+        struct xsave_struct *xstate = &tsk->thread.xstate->xsave;
+        struct i387_fxsave_struct *fx = &tsk->thread.xstate->fxsave;
+
+        /*
+         * xsave header may indicate the init state of the FP.
+         */
+        if ((task_thread_info(tsk)->status & TS_XSAVE) &&
+            !(xstate->xsave_hdr.xstate_bv & XSTATE_FP))
+                return;
+
         if (unlikely(fx->swd & X87_FSW_ES))
                 asm volatile("fnclex");
         alternative_input(ASM_NOP8 ASM_NOP2,
@@ -84,7 +108,7 @@ static inline void clear_fpu_state(struct i387_fxsave_struct *fx)
                           X86_FEATURE_FXSAVE_LEAK);
 }
 
-static inline int save_i387_checking(struct i387_fxsave_struct __user *fx)
+static inline int fxsave_user(struct i387_fxsave_struct __user *fx)
 {
         int err;
 
@@ -108,7 +132,7 @@ static inline int save_i387_checking(struct i387_fxsave_struct __user *fx)
         return err;
 }
 
-static inline void __save_init_fpu(struct task_struct *tsk)
+static inline void fxsave(struct task_struct *tsk)
 {
         /* Using "rex64; fxsave %0" is broken because, if the memory operand
            uses any extended registers for addressing, a second REX prefix
@@ -133,7 +157,16 @@ static inline void __save_init_fpu(struct task_struct *tsk)
                              : "=m" (tsk->thread.xstate->fxsave)
                              : "cdaSDb" (&tsk->thread.xstate->fxsave));
 #endif
-        clear_fpu_state(&tsk->thread.xstate->fxsave);
+}
+
+static inline void __save_init_fpu(struct task_struct *tsk)
+{
+        if (task_thread_info(tsk)->status & TS_XSAVE)
+                xsave(tsk);
+        else
+                fxsave(tsk);
+
+        clear_fpu_state(tsk);
         task_thread_info(tsk)->status &= ~TS_USEDFPU;
 }
 
@@ -148,6 +181,10 @@ static inline void tolerant_fwait(void)
 
 static inline void restore_fpu(struct task_struct *tsk)
 {
+        if (task_thread_info(tsk)->status & TS_XSAVE) {
+                xrstor_checking(&tsk->thread.xstate->xsave);
+                return;
+        }
         /*
          * The "nop" is needed to make the instructions the same
          * length.
@@ -173,6 +210,27 @@ static inline void restore_fpu(struct task_struct *tsk)
  */
 static inline void __save_init_fpu(struct task_struct *tsk)
 {
+        if (task_thread_info(tsk)->status & TS_XSAVE) {
+                struct xsave_struct *xstate = &tsk->thread.xstate->xsave;
+                struct i387_fxsave_struct *fx = &tsk->thread.xstate->fxsave;
+
+                xsave(tsk);
+
+                /*
+                 * xsave header may indicate the init state of the FP.
+                 */
+                if (!(xstate->xsave_hdr.xstate_bv & XSTATE_FP))
+                        goto end;
+
+                if (unlikely(fx->swd & X87_FSW_ES))
+                        asm volatile("fnclex");
+
+                /*
+                 * we can do a simple return here or be paranoid :)
+                 */
+                goto clear_state;
+        }
+
         /* Use more nops than strictly needed in case the compiler
            varies code */
         alternative_input(
@@ -182,6 +240,7 @@ static inline void __save_init_fpu(struct task_struct *tsk)
                 X86_FEATURE_FXSR,
                 [fx] "m" (tsk->thread.xstate->fxsave),
                 [fsw] "m" (tsk->thread.xstate->fxsave.swd) : "memory");
+clear_state:
         /* AMD K7/K8 CPUs don't save/restore FDP/FIP/FOP unless an exception
            is pending.  Clear the x87 state here by setting it to fixed
            values. safe_address is a random variable that should be in L1 */
@@ -191,16 +250,17 @@ static inline void __save_init_fpu(struct task_struct *tsk)
                 "fildl %[addr]",        /* set F?P to defined value */
                 X86_FEATURE_FXSAVE_LEAK,
                 [addr] "m" (safe_address));
+end:
         task_thread_info(tsk)->status &= ~TS_USEDFPU;
 }
 
+#endif  /* CONFIG_X86_64 */
+
 /*
  * Signal frame handlers...
  */
-extern int save_i387(struct _fpstate __user *buf);
-extern int restore_i387(struct _fpstate __user *buf);
-
-#endif  /* CONFIG_X86_64 */
+extern int save_i387_xstate(void __user *buf);
+extern int restore_i387_xstate(void __user *buf);
 
 static inline void __unlazy_fpu(struct task_struct *tsk)
 {
@@ -236,6 +296,37 @@ static inline void kernel_fpu_end(void)
         preempt_enable();
 }
 
+/*
+ * Some instructions like VIA's padlock instructions generate a spurious
+ * DNA fault but don't modify SSE registers. And these instructions
+ * get used from interrupt context aswell. To prevent these kernel instructions
+ * in interrupt context interact wrongly with other user/kernel fpu usage, we
+ * should use them only in the context of irq_ts_save/restore()
+ */
+static inline int irq_ts_save(void)
+{
+        /*
+         * If we are in process context, we are ok to take a spurious DNA fault.
+         * Otherwise, doing clts() in process context require pre-emption to
+         * be disabled or some heavy lifting like kernel_fpu_begin()
+         */
+        if (!in_interrupt())
+                return 0;
+
+        if (read_cr0() & X86_CR0_TS) {
+                clts();
+                return 1;
+        }
+
+        return 0;
+}
+
+static inline void irq_ts_restore(int TS_state)
+{
+        if (TS_state)
+                stts();
+}
+
 #ifdef CONFIG_X86_64
 
 static inline void save_init_fpu(struct task_struct *tsk)
@@ -306,4 +397,4 @@ static inline unsigned short get_fpu_mxcsr(struct task_struct *tsk)
         }
 }
 
-#endif  /* _ASM_X86_I387_H */
+#endif /* ASM_X86__I387_H */