The SIGSTKSZ constant may not represent enough stack size in some
architectures as the hardware state size grows.

Use getauxval(AT_MINSIGSTKSZ) to increase the stack size.
Signed-off-by: NChang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NLen Brown <len.brown@intel.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20210518200320.17239-5-chang.seok.bae@intel.com