powerpc/fadump: re-register firmware-assisted dump if already registered

[Michael Ellerman]

On Fri, 2018-09-14 at 14:06:02 UTC, Hari Bathini wrote:
> Firmware-Assisted Dump (FADump) needs to be registered again after any
> memory hot add/remove operation to update the crash memory ranges. But
> currently, the kernel returns '-EEXIST' if we try to register without
> uregistering it first. This could expose the system to racing issues
> while unregistering and registering FADump from userspace during udev
> events. Spare the userspace of this and let it be taken care of in the
> kernel space for a simpler interface.
> 
> Since this change, running 'echo 1 > /sys/kernel/fadump_registered'
> would result in re-regisering (unregistering and registering) FADump,
> if it was already registered.
> 
> Signed-off-by: Hari Bathini <hbathini at linux.ibm.com>
> Acked-by: Mahesh Salgaonkar <mahesh at linux.vnet.ibm.com>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/0823c68b054bca9dc321adea829af5

cheers