stack_erasing

file: /proc/sys/kernel/stack_erasing
variable: kernel.stack_erasing
Official reference

This parameter can be used to control kernel stack erasing at the end of syscalls for kernels built with CONFIG_KSTACK_ERASE.

That erasing reduces the information which kernel stack leak bugs can reveal and blocks some uninitialized stack variable attacks. The tradeoff is the performance impact: on a single CPU system kernel compilation sees a 1% slowdown, other systems and workloads may vary.

= ====================================================================
0 Kernel stack erasing is disabled, KSTACK_ERASE_METRICS are not updated.
1 Kernel stack erasing is enabled (default), it is performed before
  returning to the userspace at the end of syscalls.
= ====================================================================