Merge tag 'x86-urgent-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip (d717180e) · Commits · EulixOS / Software / Kernel

arch/x86/kernel/cpu/sgx/encl.c

+103 −2

Original line number	Diff line number	Diff line
		@@ -152,7 +152,7 @@ static int __sgx_encl_eldu(struct sgx_encl_page *encl_page,

		page_pcmd_off = sgx_encl_get_backing_page_pcmd_offset(encl, page_index);

		ret = sgx_encl_get_backing(encl, page_index, &b);
		ret = sgx_encl_lookup_backing(encl, page_index, &b);
		if (ret)
		return ret;

		@@ -718,7 +718,7 @@ static struct page sgx_encl_get_backing_page(struct sgx_encl encl,
		* 0 on success,
		* -errno otherwise.
		*/
		int sgx_encl_get_backing(struct sgx_encl *encl, unsigned long page_index,
		static int sgx_encl_get_backing(struct sgx_encl *encl, unsigned long page_index,
		struct sgx_backing *backing)
		{
		pgoff_t page_pcmd_off = sgx_encl_get_backing_page_pcmd_offset(encl, page_index);
		@@ -743,6 +743,107 @@ int sgx_encl_get_backing(struct sgx_encl *encl, unsigned long page_index,
		return 0;
		}

		/*
		* When called from ksgxd, returns the mem_cgroup of a struct mm stored
		* in the enclave's mm_list. When not called from ksgxd, just returns
		* the mem_cgroup of the current task.
		*/
		static struct mem_cgroup sgx_encl_get_mem_cgroup(struct sgx_encl encl)
		{
		struct mem_cgroup *memcg = NULL;
		struct sgx_encl_mm *encl_mm;
		int idx;

		/*
		* If called from normal task context, return the mem_cgroup
		* of the current task's mm. The remainder of the handling is for
		* ksgxd.
		*/
		if (!current_is_ksgxd())
		return get_mem_cgroup_from_mm(current->mm);

		/*
		* Search the enclave's mm_list to find an mm associated with
		* this enclave to charge the allocation to.
		*/
		idx = srcu_read_lock(&encl->srcu);

		list_for_each_entry_rcu(encl_mm, &encl->mm_list, list) {
		if (!mmget_not_zero(encl_mm->mm))
		continue;

		memcg = get_mem_cgroup_from_mm(encl_mm->mm);

		mmput_async(encl_mm->mm);

		break;
		}

		srcu_read_unlock(&encl->srcu, idx);

		/*
		* In the rare case that there isn't an mm associated with
		* the enclave, set memcg to the current active mem_cgroup.
		* This will be the root mem_cgroup if there is no active
		* mem_cgroup.
		*/
		if (!memcg)
		return get_mem_cgroup_from_mm(NULL);

		return memcg;
		}

		/**
		* sgx_encl_alloc_backing() - allocate a new backing storage page
		* @encl: an enclave pointer
		* @page_index: enclave page index
		* @backing: data for accessing backing storage for the page
		*
		* When called from ksgxd, sets the active memcg from one of the
		* mms in the enclave's mm_list prior to any backing page allocation,
		* in order to ensure that shmem page allocations are charged to the
		* enclave.
		*
		* Return:
		* 0 on success,
		* -errno otherwise.
		*/
		int sgx_encl_alloc_backing(struct sgx_encl *encl, unsigned long page_index,
		struct sgx_backing *backing)
		{
		struct mem_cgroup *encl_memcg = sgx_encl_get_mem_cgroup(encl);
		struct mem_cgroup *memcg = set_active_memcg(encl_memcg);
		int ret;

		ret = sgx_encl_get_backing(encl, page_index, backing);

		set_active_memcg(memcg);
		mem_cgroup_put(encl_memcg);

		return ret;
		}

		/**
		* sgx_encl_lookup_backing() - retrieve an existing backing storage page
		* @encl: an enclave pointer
		* @page_index: enclave page index
		* @backing: data for accessing backing storage for the page
		*
		* Retrieve a backing page for loading data back into an EPC page with ELDU.
		* It is the caller's responsibility to ensure that it is appropriate to use
		* sgx_encl_lookup_backing() rather than sgx_encl_alloc_backing(). If lookup is
		* not used correctly, this will cause an allocation which is not accounted for.
		*
		* Return:
		* 0 on success,
		* -errno otherwise.
		*/
		int sgx_encl_lookup_backing(struct sgx_encl *encl, unsigned long page_index,
		struct sgx_backing *backing)
		{
		return sgx_encl_get_backing(encl, page_index, backing);
		}

		/**
		* sgx_encl_put_backing() - Unpin the backing storage
		* @backing: data for accessing backing storage for the page

arch/x86/kernel/cpu/sgx/encl.h

+5 −2

Original line number	Diff line number	Diff line
		@@ -103,9 +103,12 @@ static inline int sgx_encl_find(struct mm_struct *mm, unsigned long addr,
		int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start,
		unsigned long end, unsigned long vm_flags);

		bool current_is_ksgxd(void);
		void sgx_encl_release(struct kref *ref);
		int sgx_encl_mm_add(struct sgx_encl encl, struct mm_struct mm);
		int sgx_encl_get_backing(struct sgx_encl *encl, unsigned long page_index,
		int sgx_encl_lookup_backing(struct sgx_encl *encl, unsigned long page_index,
		struct sgx_backing *backing);
		int sgx_encl_alloc_backing(struct sgx_encl *encl, unsigned long page_index,
		struct sgx_backing *backing);
		void sgx_encl_put_backing(struct sgx_backing *backing);
		int sgx_encl_test_and_clear_young(struct mm_struct *mm,

arch/x86/kernel/cpu/sgx/main.c

+7 −2

Original line number	Diff line number	Diff line
		@@ -313,7 +313,7 @@ static void sgx_reclaimer_write(struct sgx_epc_page *epc_page,
		sgx_encl_put_backing(backing);

		if (!encl->secs_child_cnt && test_bit(SGX_ENCL_INITIALIZED, &encl->flags)) {
		ret = sgx_encl_get_backing(encl, PFN_DOWN(encl->size),
		ret = sgx_encl_alloc_backing(encl, PFN_DOWN(encl->size),
		&secs_backing);
		if (ret)
		goto out;
		@@ -384,7 +384,7 @@ static void sgx_reclaim_pages(void)
		page_index = PFN_DOWN(encl_page->desc - encl_page->encl->base);

		mutex_lock(&encl_page->encl->lock);
		ret = sgx_encl_get_backing(encl_page->encl, page_index, &backing[i]);
		ret = sgx_encl_alloc_backing(encl_page->encl, page_index, &backing[i]);
		if (ret) {
		mutex_unlock(&encl_page->encl->lock);
		goto skip;
		@@ -475,6 +475,11 @@ static bool __init sgx_page_reclaimer_init(void)
		return true;
		}

		bool current_is_ksgxd(void)
		{
		return current == ksgxd_tsk;
		}

		static struct sgx_epc_page *__sgx_alloc_epc_page_from_node(int nid)
		{
		struct sgx_numa_node *node = &sgx_numa_nodes[nid];