Zeroing the forked task's FPU register buffer to avoid leaking init optimized stale data into the clone is a pointless exercise for the case where the current task has TIF_NEED_FPU_LOAD set. In that case the FPU register state is copied from current's FPU register buffer which can contain stale init optimized data as well. The alledged information leak is non-existant because this stale init optimized data is nowhere used and cannot leak anywhere. Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> --- arch/x86/kernel/fpu/core.c | 6 ------ 1 file changed, 6 deletions(-) --- diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 7ada7bd03a32..191269edac97 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -260,12 +260,6 @@ int fpu_clone(struct task_struct *dst) return 0; /* - * Don't let 'init optimized' areas of the XSAVE area - * leak into the child task: - */ - memset(&dst_fpu->state.xsave, 0, fpu_kernel_xstate_size); - - /* * If the FPU registers are not owned by current just memcpy() the * state. Otherwise save the FPU registers directly into the * child's FPU context, without any memory-to-memory copying.
