x86, xsave: save/restore the extended state context in sigframe

[linux-2.6-omap-h63xx.git] / arch / x86 / kernel / i387.c

diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index 7daf3a011dd94dda358e3abd68f9038e8fbe1d16..cbb9dc474a21f95305b0d0d12b951c84716dd573 100644 (file)
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -26,6 +26,7 @@
 # define _fpstate_ia32         _fpstate
 # define _xstate_ia32          _xstate
 # define sig_xstate_ia32_size   sig_xstate_size
+# define fx_sw_reserved_ia32   fx_sw_reserved
 # define user_i387_ia32_struct user_i387_struct
 # define user32_fxsr_struct    user_fxsr_struct
 #endif
@@ -447,12 +448,30 @@ static int save_i387_fxsave(struct _fpstate_ia32 __user *buf)
        if (err)
                return -1;
 
-       if (__copy_to_user(&buf->_fxsr_env[0], fx,
-                          sizeof(struct i387_fxsave_struct)))
+       if (__copy_to_user(&buf->_fxsr_env[0], fx, xstate_size))
                return -1;
        return 1;
 }
 
+static int save_i387_xsave(void __user *buf)
+{
+       struct _fpstate_ia32 __user *fx = buf;
+       int err = 0;
+
+       if (save_i387_fxsave(fx) < 0)
+               return -1;
+
+       err = __copy_to_user(&fx->sw_reserved, &fx_sw_reserved_ia32,
+                            sizeof(struct _fpx_sw_bytes));
+       err |= __put_user(FP_XSTATE_MAGIC2,
+                         (__u32 __user *) (buf + sig_xstate_ia32_size
+                                           - FP_XSTATE_MAGIC2_SIZE));
+       if (err)
+               return -1;
+
+       return 1;
+}
+
 int save_i387_xstate_ia32(void __user *buf)
 {
        struct _fpstate_ia32 __user *fp = (struct _fpstate_ia32 __user *) buf;
@@ -477,6 +496,8 @@ int save_i387_xstate_ia32(void __user *buf)
 
        unlazy_fpu(tsk);
 
+       if (cpu_has_xsave)
+               return save_i387_xsave(fp);
        if (cpu_has_fxsr)
                return save_i387_fxsave(fp);
        else
@@ -491,14 +512,15 @@ static inline int restore_i387_fsave(struct _fpstate_ia32 __user *buf)
                                sizeof(struct i387_fsave_struct));
 }
 
-static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf)
+static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf,
+                              unsigned int size)
 {
        struct task_struct *tsk = current;
        struct user_i387_ia32_struct env;
        int err;
 
        err = __copy_from_user(&tsk->thread.xstate->fxsave, &buf->_fxsr_env[0],
-                              sizeof(struct i387_fxsave_struct));
+                              size);
        /* mxcsr reserved bits must be masked to zero for security reasons */
        tsk->thread.xstate->fxsave.mxcsr &= mxcsr_feature_mask;
        if (err || __copy_from_user(&env, buf, sizeof(env)))
@@ -508,6 +530,51 @@ static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf)
        return 0;
 }
 
+static int restore_i387_xsave(void __user *buf)
+{
+       struct _fpx_sw_bytes fx_sw_user;
+       struct _fpstate_ia32 __user *fx_user =
+                       ((struct _fpstate_ia32 __user *) buf);
+       struct i387_fxsave_struct __user *fx =
+               (struct i387_fxsave_struct __user *) &fx_user->_fxsr_env[0];
+       struct xsave_hdr_struct *xsave_hdr =
+                               &current->thread.xstate->xsave.xsave_hdr;
+       unsigned int lmask, hmask;
+       int err;
+
+       if (check_for_xstate(fx, buf, &fx_sw_user))
+               goto fx_only;
+
+       lmask = fx_sw_user.xstate_bv;
+       hmask = fx_sw_user.xstate_bv >> 32;
+
+       err = restore_i387_fxsave(buf, fx_sw_user.xstate_size);
+
+       xsave_hdr->xstate_bv &=  (pcntxt_lmask | (((u64) pcntxt_hmask) << 32));
+       /*
+        * These bits must be zero.
+        */
+       xsave_hdr->reserved1[0] = xsave_hdr->reserved1[1] = 0;
+
+       /*
+        * Init the state that is not present in the memory layout
+        * and enabled by the OS.
+        */
+       lmask = ~(pcntxt_lmask & ~lmask);
+       hmask = ~(pcntxt_hmask & ~hmask);
+       xsave_hdr->xstate_bv &=  (lmask | (((u64) hmask) << 32));
+
+       return err;
+fx_only:
+       /*
+        * Couldn't find the extended state information in the memory
+        * layout. Restore the FP/SSE and init the other extended state
+        * enabled by the OS.
+        */
+       xsave_hdr->xstate_bv = XSTATE_FPSSE;
+       return restore_i387_fxsave(buf, sizeof(struct i387_fxsave_struct));
+}
+
 int restore_i387_xstate_ia32(void __user *buf)
 {
        int err;
@@ -535,8 +602,11 @@ int restore_i387_xstate_ia32(void __user *buf)
        }
 
        if (HAVE_HWFP) {
-               if (cpu_has_fxsr)
-                       err = restore_i387_fxsave(fp);
+               if (cpu_has_xsave)
+                       err = restore_i387_xsave(buf);
+               else if (cpu_has_fxsr)
+                       err = restore_i387_fxsave(fp, sizeof(struct
+                                                          i387_fxsave_struct));
                else
                        err = restore_i387_fsave(fp);
        } else {