Re: [PATCH V2 4/8] powerpc: Explicitly disable math features when copying thread
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From: Michael Neuling <hidden>
Date: 2016-01-15 05:42:23
On Fri, 2016-01-15 at 16:04 +1100, Cyril Bur wrote:
With threads leaving the math bits enabled in their saved MSR to indicate that the hardware is hot and a restore is not needed, children need to tu=
rn
it off as when they do get scheduled, there's no way their registers coul=
d
have been hot.
Is this a bug in the current code? Mikey
quoted hunk ↗ jump to hunk
Signed-off-by: Cyril Bur <redacted> --- arch/powerpc/kernel/process.c | 1 + 1 file changed, 1 insertion(+) =20diff --git a/arch/powerpc/kernel/process.cb/arch/powerpc/kernel/process.c index dccc87e..e0c3d2d 100644--- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c@@ -1307,6 +1307,7 @@ int copy_thread(unsigned long clone_flags,unsigned long usp, =20 f =3D ret_from_fork; } + childregs->msr &=3D ~(MSR_FP|MSR_VEC|MSR_VSX); sp -=3D STACK_FRAME_OVERHEAD; =20 /*