Use mmu_notifier_put() to synchronize sgx_encl_mm deletion.
Cc: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
---
v2:
* Was not thinking clearly that we also use it for lockless
operation on the mm list. Just migrating to mmu_notifier_put().
Please ignore the previous patch!
arch/x86/kernel/cpu/sgx/encl.c | 26 ++++++++++----------------
1 file changed, 10 insertions(+), 16 deletions(-)
diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c
index d145360380d5..8cc9ea353bee 100644
--- a/arch/x86/kernel/cpu/sgx/encl.c
+++ b/arch/x86/kernel/cpu/sgx/encl.c
@@ -131,14 +131,6 @@ static struct sgx_encl_page *sgx_encl_load_page(struct sgx_encl *encl,
return entry;
}
-static void sgx_encl_mm_release_deferred(struct rcu_head *rcu)
-{
- struct sgx_encl_mm *encl_mm =
- container_of(rcu, struct sgx_encl_mm, rcu);
-
- kfree(encl_mm);
-}
-
static void sgx_mmu_notifier_release(struct mmu_notifier *mn,
struct mm_struct *mm)
{
@@ -161,19 +153,21 @@ static void sgx_mmu_notifier_release(struct mmu_notifier *mn,
if (tmp == encl_mm) {
synchronize_srcu(&encl_mm->encl->srcu);
-
- /*
- * Delay freeing encl_mm until after mmu_notifier synchronizes
- * its SRCU to ensure encl_mm cannot be dereferenced.
- */
- mmu_notifier_unregister_no_release(mn, mm);
- mmu_notifier_call_srcu(&encl_mm->rcu,
- &sgx_encl_mm_release_deferred);
+ mmu_notifier_put(mn);
}
}
+static void sgx_mmu_notifier_free(struct mmu_notifier *mn)
+{
+ struct sgx_encl_mm *encl_mm =
+ container_of(mn, struct sgx_encl_mm, mmu_notifier);
+
+ kfree(encl_mm);
+}
+
static const struct mmu_notifier_ops sgx_mmu_notifier_ops = {
.release = sgx_mmu_notifier_release,
+ .free_notifier = sgx_mmu_notifier_free,
};
static struct sgx_encl_mm *sgx_encl_find_mm(struct sgx_encl *encl,
--
2.20.1
