1 files changed, 149 insertions, 19 deletions

diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index eb9ddd8efb8..1f20608d4ca 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -21,9 +21,12 @@
 # include <asm/sigcontext32.h>
 # include <asm/user32.h>
 #else
-# define save_i387_ia32         save_i387
-# define restore_i387_ia32      restore_i387
+# define save_i387_xstate_ia32          save_i387_xstate
+# define restore_i387_xstate_ia32       restore_i387_xstate
 # 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
@@ -36,6 +39,7 @@
 
 static unsigned int             mxcsr_feature_mask __read_mostly = 0xffffffffu;
 unsigned int xstate_size;
+unsigned int sig_xstate_ia32_size = sizeof(struct _fpstate_ia32);
 static struct i387_fxsave_struct fx_scratch __cpuinitdata;
 
 void __cpuinit mxcsr_feature_mask_init(void)
@@ -61,6 +65,11 @@ void __init init_thread_xstate(void)
                 return;
         }
 
+        if (cpu_has_xsave) {
+                xsave_cntxt_init();
+                return;
+        }
+
         if (cpu_has_fxsr)
                 xstate_size = sizeof(struct i387_fxsave_struct);
 #ifdef CONFIG_X86_32
@@ -83,9 +92,19 @@ 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;
+        if (cpu_has_xsave)
+                current_thread_info()->status = TS_XSAVE;
+        else
+                current_thread_info()->status = 0;
         clear_used_math();
 }
 #endif  /* CONFIG_X86_64 */
@@ -195,6 +214,13 @@ int xfpregs_set(struct task_struct *target, const struct user_regset *regset,
          */
         target->thread.xstate->fxsave.mxcsr &= mxcsr_feature_mask;
 
+        /*
+         * update the header bits in the xsave header, indicating the
+         * presence of FP and SSE state.
+         */
+        if (cpu_has_xsave)
+                target->thread.xstate->xsave.xsave_hdr.xstate_bv |= XSTATE_FPSSE;
+
         return ret;
 }
 
@@ -395,6 +421,12 @@ int fpregs_set(struct task_struct *target, const struct user_regset *regset,
         if (!ret)
                 convert_to_fxsr(target, &env);
 
+        /*
+         * update the header bit in the xsave header, indicating the
+         * presence of FP.
+         */
+        if (cpu_has_xsave)
+                target->thread.xstate->xsave.xsave_hdr.xstate_bv |= XSTATE_FP;
         return ret;
 }
 
@@ -407,7 +439,6 @@ static inline int save_i387_fsave(struct _fpstate_ia32 __user *buf)
         struct task_struct *tsk = current;
         struct i387_fsave_struct *fp = &tsk->thread.xstate->fsave;
 
-        unlazy_fpu(tsk);
         fp->status = fp->swd;
         if (__copy_to_user(buf, fp, sizeof(struct i387_fsave_struct)))
                 return -1;
@@ -421,8 +452,6 @@ static int save_i387_fxsave(struct _fpstate_ia32 __user *buf)
         struct user_i387_ia32_struct env;
         int err = 0;
 
-        unlazy_fpu(tsk);
-
         convert_from_fxsr(&env, tsk);
         if (__copy_to_user(buf, &env, sizeof(env)))
                 return -1;
@@ -432,16 +461,54 @@ 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 task_struct *tsk = current;
+        struct _fpstate_ia32 __user *fx = buf;
+        int err = 0;
+
+        /*
+         * For legacy compatible, we always set FP/SSE bits in the bit
+         * vector while saving the state to the user context.
+         * This will enable us capturing any changes(during sigreturn) to
+         * the FP/SSE bits by the legacy applications which don't touch
+         * xstate_bv in the xsave header.
+         *
+         * xsave aware applications can change the xstate_bv in the xsave
+         * header as well as change any contents in the memory layout.
+         * xrestore as part of sigreturn will capture all the changes.
+         */
+        tsk->thread.xstate->xsave.xsave_hdr.xstate_bv |= XSTATE_FPSSE;
+
+        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_ia32(struct _fpstate_ia32 __user *buf)
+int save_i387_xstate_ia32(void __user *buf)
 {
+        struct _fpstate_ia32 __user *fp = (struct _fpstate_ia32 __user *) buf;
+        struct task_struct *tsk = current;
+
         if (!used_math())
                 return 0;
+
+        if (!access_ok(VERIFY_WRITE, buf, sig_xstate_ia32_size))
+                return -EACCES;
         /*
          * This will cause a "finit" to be triggered by the next
          * attempted FPU operation by the 'current' process.
@@ -451,13 +518,17 @@ int save_i387_ia32(struct _fpstate_ia32 __user *buf)
         if (!HAVE_HWFP) {
                 return fpregs_soft_get(current, NULL,
                                        0, sizeof(struct user_i387_ia32_struct),
-                                       NULL, buf) ? -1 : 1;
+                                       NULL, fp) ? -1 : 1;
         }
 
+        unlazy_fpu(tsk);
+
+        if (cpu_has_xsave)
+                return save_i387_xsave(fp);
         if (cpu_has_fxsr)
-                return save_i387_fxsave(buf);
+                return save_i387_fxsave(fp);
         else
-                return save_i387_fsave(buf);
+                return save_i387_fsave(fp);
 }
 
 static inline int restore_i387_fsave(struct _fpstate_ia32 __user *buf)
@@ -468,14 +539,15 @@ 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)))
@@ -485,14 +557,69 @@ static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf)
         return 0;
 }
 
-int restore_i387_ia32(struct _fpstate_ia32 __user *buf)
+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;
+        u64 mask;
+        int err;
+
+        if (check_for_xstate(fx, buf, &fx_sw_user))
+                goto fx_only;
+
+        mask = fx_sw_user.xstate_bv;
+
+        err = restore_i387_fxsave(buf, fx_sw_user.xstate_size);
+
+        xsave_hdr->xstate_bv &= pcntxt_mask;
+        /*
+         * 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.
+         */
+        mask = ~(pcntxt_mask & ~mask);
+        xsave_hdr->xstate_bv &= mask;
+
+        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;
         struct task_struct *tsk = current;
+        struct _fpstate_ia32 __user *fp = (struct _fpstate_ia32 __user *) buf;
 
         if (HAVE_HWFP)
                 clear_fpu(tsk);
 
+        if (!buf) {
+                if (used_math()) {
+                        clear_fpu(tsk);
+                        clear_used_math();
+                }
+
+                return 0;
+        } else
+                if (!access_ok(VERIFY_READ, buf, sig_xstate_ia32_size))
+                        return -EACCES;
+
         if (!used_math()) {
                 err = init_fpu(tsk);
                 if (err)
@@ -500,14 +627,17 @@ int restore_i387_ia32(struct _fpstate_ia32 __user *buf)
         }
 
         if (HAVE_HWFP) {
-                if (cpu_has_fxsr)
-                        err = restore_i387_fxsave(buf);
+                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(buf);
+                        err = restore_i387_fsave(fp);
         } else {
                 err = fpregs_soft_set(current, NULL,
                                       0, sizeof(struct user_i387_ia32_struct),
-                                      NULL, buf) != 0;
+                                      NULL, fp) != 0;
         }
         set_used_math();