[PATCH 1/1] x86, xsave: clear pre-allocated xsave area

[Hans Rosenfeld]

Bogus data in the xsave area can cause xrstor to panic, so make sure
that the pre-allocated xsave area is all nice and clean before being
used.

Signed-off-by: Hans Rosenfeld <hans.rosenfeld@xxxxxxx>
---
 arch/x86/kernel/process.c |   11 +++++++++--
 1 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index c5ae256..03c5ded 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -28,8 +28,15 @@ EXPORT_SYMBOL_GPL(task_xstate_cachep);
 
 int arch_prealloc_fpu(struct task_struct *tsk)
 {
-	if (!fpu_allocated(&tsk->thread.fpu))
-		return fpu_alloc(&tsk->thread.fpu);
+	if (!fpu_allocated(&tsk->thread.fpu)) {
+		int err = fpu_alloc(&tsk->thread.fpu);
+
+		if (err)
+			return err;
+
+		fpu_clear(&tsk->thread.fpu);
+	}
+
 	return 0;
 }
 
-- 
1.5.6.5


--qDbXVdCdHGoSgWSk--
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