mm/fork: clear PASID for new mm

When a new mm is created, its PASID should be cleared, i.e.  the PASID is
initialized to its init state 0 on both ARM and X86.

This patch was part of the series introducing mm->pasid, but got lost
along the way [1].  It still makes sense to have it, because each address
space has a different PASID.  And the IOMMU code in
iommu_sva_alloc_pasid() expects the pasid field of a new mm struct to be
cleared.

[1] https://lore.kernel.org/linux-iommu/YDgh53AcQHT+T3L0@otcwcpicx3.sc.intel.com/

Link: https://lkml.kernel.org/r/20210302103837.2562625-1-jean-philippe@linaro.org
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Cc: Jacob Pan <jacob.jun.pan@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Fenghua Yu 2021-03-12 21:07:15 -08:00 committed by Linus Torvalds
parent 0740a50b9b
commit 82e69a121b
2 changed files with 9 additions and 0 deletions

View File

@ -23,6 +23,7 @@
#endif
#define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1))
#define INIT_PASID 0
struct address_space;
struct mem_cgroup;

View File

@ -994,6 +994,13 @@ static void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
#endif
}
static void mm_init_pasid(struct mm_struct *mm)
{
#ifdef CONFIG_IOMMU_SUPPORT
mm->pasid = INIT_PASID;
#endif
}
static void mm_init_uprobes_state(struct mm_struct *mm)
{
#ifdef CONFIG_UPROBES
@ -1024,6 +1031,7 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p,
mm_init_cpumask(mm);
mm_init_aio(mm);
mm_init_owner(mm, p);
mm_init_pasid(mm);
RCU_INIT_POINTER(mm->exe_file, NULL);
mmu_notifier_subscriptions_init(mm);
init_tlb_flush_pending(mm);