From: Jean-Philippe Brucker <jean-philippe@linaro.org>
To: akpm@linux-foundation.org
Cc: linux-kernel@vger.kernel.org, zhangfei.gao@foxmail.com,
linux-mm@kvack.org, iommu@lists.linux-foundation.org,
jacob.jun.pan@intel.com, fenghua.yu@intel.com,
Tony Luck <tony.luck@intel.com>,
Jean-Philippe Brucker <jean-philippe@linaro.org>
Subject: [PATCH] mm/fork: Clear PASID for new mm
Date: Tue, 2 Mar 2021 11:38:40 +0100 [thread overview]
Message-ID: <20210302103837.2562625-1-jean-philippe@linaro.org> (raw)
From: Fenghua Yu <fenghua.yu@intel.com>
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.
Reviewed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
---
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/
---
include/linux/mm_types.h | 1 +
kernel/fork.c | 8 ++++++++
2 files changed, 9 insertions(+)
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 0974ad501a47..6613b26a8894 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -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;
diff --git a/kernel/fork.c b/kernel/fork.c
index d66cd1014211..808af2cc8ab6 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);
--
2.30.1
reply other threads:[~2021-03-02 11:02 UTC|newest]
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