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authorFenghua Yu <fenghua.yu@intel.com>2021-03-13 06:07:15 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2021-03-13 20:27:30 +0100
commit82e69a121be4b1597ce758534816a8ee04c8b761 (patch)
tree3357b2ca62c5e361ee1676c1a3081556f489e277 /kernel
parentmm/page_alloc.c: refactor initialization of struct page for holes in memory l... (diff)
downloadlinux-82e69a121be4b1597ce758534816a8ee04c8b761.tar.xz
linux-82e69a121be4b1597ce758534816a8ee04c8b761.zip
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>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/fork.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index d3171e8e88e5..54cc905e5fe0 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -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);