Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[sfrench/cifs-2.6.git] / arch / x86 / kernel / i387.c

diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index 45723f1fe198bec671ba5f7001b1d61ef5e671be..1f20608d4ca8b6e274518715ef487933e8489c59 100644 (file)
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -468,9 +468,23 @@ static int save_i387_fxsave(struct _fpstate_ia32 __user *buf)
 
 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;