Commit a3d29e82 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Borislav Petkov
Browse files

sched: Define and initialize a flag to identify valid PASID in the task 



Add a new single bit field to the task structure to track whether this task
has initialized the IA32_PASID MSR to the mm's PASID.

Initialize the field to zero when creating a new task with fork/clone.

Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
Co-developed-by: default avatarFenghua Yu <fenghua.yu@intel.com>
Signed-off-by: default avatarFenghua Yu <fenghua.yu@intel.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Reviewed-by: default avatarTony Luck <tony.luck@intel.com>
Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220207230254.3342514-8-fenghua.yu@intel.com
parent dc7507dd

include/linux/sched.h

+3 −0
Original line number Diff line number Diff line
@@ -938,6 +938,9 @@ struct task_struct { 
	/* Recursion prevention for eventfd_signal() */

	unsigned			in_eventfd_signal:1;

#endif

#ifdef CONFIG_IOMMU_SVA

	unsigned			pasid_activated:1;

#endif



	unsigned long			atomic_flags; /* Flags requiring atomic access. */

kernel/fork.c

+4 −0
Original line number Diff line number Diff line
@@ -968,6 +968,10 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node) 
	tsk->use_memdelay = 0;

#endif



#ifdef CONFIG_IOMMU_SVA

	tsk->pasid_activated = 0;

#endif



#ifdef CONFIG_MEMCG

	tsk->active_memcg = NULL;

#endif