Linux-libre 4.8.2-gnupck-4.8.2-gnu

1 files changed, 37 insertions, 15 deletions

diff --git a/arch/x86/kernel/fpu/regset.c b/arch/x86/kernel/fpu/regset.c
index 81422dfb1..c114b132d 100644
--- a/arch/x86/kernel/fpu/regset.c
+++ b/arch/x86/kernel/fpu/regset.c
@@ -4,6 +4,7 @@
 #include <asm/fpu/internal.h>
 #include <asm/fpu/signal.h>
 #include <asm/fpu/regset.h>
+#include <asm/fpu/xstate.h>
 
 /*
  * The xstateregs_active() routine is the same as the regset_fpregs_active() routine,
@@ -85,21 +86,26 @@ int xstateregs_get(struct task_struct *target, const struct user_regset *regset,
 	if (!boot_cpu_has(X86_FEATURE_XSAVE))
 		return -ENODEV;
 
-	fpu__activate_fpstate_read(fpu);
-
 	xsave = &fpu->state.xsave;
 
-	/*
-	 * Copy the 48bytes defined by the software first into the xstate
-	 * memory layout in the thread struct, so that we can copy the entire
-	 * xstateregs to the user using one user_regset_copyout().
-	 */
-	memcpy(&xsave->i387.sw_reserved,
-		xstate_fx_sw_bytes, sizeof(xstate_fx_sw_bytes));
-	/*
-	 * Copy the xstate memory layout.
-	 */
-	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, xsave, 0, -1);
+	fpu__activate_fpstate_read(fpu);
+
+	if (using_compacted_format()) {
+		ret = copyout_from_xsaves(pos, count, kbuf, ubuf, xsave);
+	} else {
+		fpstate_sanitize_xstate(fpu);
+		/*
+		 * Copy the 48 bytes defined by the software into the xsave
+		 * area in the thread struct, so that we can copy the whole
+		 * area to user using one user_regset_copyout().
+		 */
+		memcpy(&xsave->i387.sw_reserved, xstate_fx_sw_bytes, sizeof(xstate_fx_sw_bytes));
+
+		/*
+		 * Copy the xstate memory layout.
+		 */
+		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, xsave, 0, -1);
+	}
 	return ret;
 }
 
@@ -114,11 +120,27 @@ int xstateregs_set(struct task_struct *target, const struct user_regset *regset,
 	if (!boot_cpu_has(X86_FEATURE_XSAVE))
 		return -ENODEV;
 
-	fpu__activate_fpstate_write(fpu);
+	/*
+	 * A whole standard-format XSAVE buffer is needed:
+	 */
+	if ((pos != 0) || (count < fpu_user_xstate_size))
+		return -EFAULT;
 
 	xsave = &fpu->state.xsave;
 
-	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, xsave, 0, -1);
+	fpu__activate_fpstate_write(fpu);
+
+	if (boot_cpu_has(X86_FEATURE_XSAVES))
+		ret = copyin_to_xsaves(kbuf, ubuf, xsave);
+	else
+		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, xsave, 0, -1);
+
+	/*
+	 * In case of failure, mark all states as init:
+	 */
+	if (ret)
+		fpstate_init(&fpu->state);
+
 	/*
 	 * mxcsr reserved bits must be masked to zero for security reasons.
 	 */