Provide a trap for the CONFIG_IO_STRICT_DEVMEM issue about nvme-cli HOT 2 CLOSED

From /libs/Kconfig.debug

config IO_STRICT_DEVMEM
bool "Filter I/O access to /dev/mem"
depends on STRICT_DEVMEM
---help---
If this option is disabled, you allow userspace (root) access to all
io-memory regardless of whether a driver is actively using that
range. Accidental access to this is obviously disastrous, but
specific access can be used by people debugging kernel drivers.

      If this option is switched on, the /dev/mem file only allows
      userspace access to *idle* io-memory ranges (see /proc/iomem) This
      may break traditional users of /dev/mem (dosemu, legacy X, etc...)
      if the driver using a given range cannot be disabled.

      If in doubt, say Y.

from nvme-cli.

We've got the one command (show-regs) that relies on this being disabled, but it's not a super critical command. Even with the config enabled, it should be possible to use it with a user space driver like SPDK.

from nvme-cli.