Avoid IPI-ing a task in certain cases and prevent load/store tearing
when accessing a task's resctrl fields concurrently.
x86/resctrl: Apply READ_ONCE/WRITE_ONCE to task_struct.{rmid,closid}
A CPU's current task can have its {closid, rmid} fields read locally
while they are being concurrently written to from another CPU.
This can happen anytime __resctrl_sched_in() races with either
__rdtgroup_move_task() or rdt_move_group_tasks().
Prevent load / store tearing for those accesses by giving them the
READ_ONCE() / WRITE_ONCE() treatment.
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/9921fda88ad81afb9885b517fbe864a2bc7c35a9.1608243147.git.reinette.chatre@intel.com
2 files changed
