1 files changed, 63 insertions, 59 deletions

diff --git a/lib/vdso/datastore.c b/lib/vdso/datastore.c
index a565c30c71a0..cf5d784a4a5a 100644
--- a/lib/vdso/datastore.c
+++ b/lib/vdso/datastore.c
@@ -1,64 +1,92 @@
 // SPDX-License-Identifier: GPL-2.0-only
 
-#include <linux/linkage.h>
-#include <linux/mmap_lock.h>
+#include <linux/gfp.h>
+#include <linux/init.h>
 #include <linux/mm.h>
 #include <linux/time_namespace.h>
 #include <linux/types.h>
 #include <linux/vdso_datastore.h>
 #include <vdso/datapage.h>
 
-/*
- * The vDSO data page.
- */
+static u8 vdso_initdata[VDSO_NR_PAGES * PAGE_SIZE] __aligned(PAGE_SIZE) __initdata = {};
+
 #ifdef CONFIG_GENERIC_GETTIMEOFDAY
-static union {
-	struct vdso_time_data	data;
-	u8			page[PAGE_SIZE];
-} vdso_time_data_store __page_aligned_data;
-struct vdso_time_data *vdso_k_time_data = &vdso_time_data_store.data;
-static_assert(sizeof(vdso_time_data_store) == PAGE_SIZE);
+struct vdso_time_data *vdso_k_time_data __refdata =
+	(void *)&vdso_initdata[VDSO_TIME_PAGE_OFFSET * PAGE_SIZE];
+
+static_assert(sizeof(struct vdso_time_data) <= PAGE_SIZE);
 #endif /* CONFIG_GENERIC_GETTIMEOFDAY */
 
 #ifdef CONFIG_VDSO_GETRANDOM
-static union {
-	struct vdso_rng_data	data;
-	u8			page[PAGE_SIZE];
-} vdso_rng_data_store __page_aligned_data;
-struct vdso_rng_data *vdso_k_rng_data = &vdso_rng_data_store.data;
-static_assert(sizeof(vdso_rng_data_store) == PAGE_SIZE);
+struct vdso_rng_data *vdso_k_rng_data __refdata =
+	(void *)&vdso_initdata[VDSO_RNG_PAGE_OFFSET * PAGE_SIZE];
+
+static_assert(sizeof(struct vdso_rng_data) <= PAGE_SIZE);
 #endif /* CONFIG_VDSO_GETRANDOM */
 
 #ifdef CONFIG_ARCH_HAS_VDSO_ARCH_DATA
-static union {
-	struct vdso_arch_data	data;
-	u8			page[VDSO_ARCH_DATA_SIZE];
-} vdso_arch_data_store __page_aligned_data;
-struct vdso_arch_data *vdso_k_arch_data = &vdso_arch_data_store.data;
+struct vdso_arch_data *vdso_k_arch_data __refdata =
+	(void *)&vdso_initdata[VDSO_ARCH_PAGES_START * PAGE_SIZE];
 #endif /* CONFIG_ARCH_HAS_VDSO_ARCH_DATA */
 
+void __init vdso_setup_data_pages(void)
+{
+	unsigned int order = get_order(VDSO_NR_PAGES * PAGE_SIZE);
+	struct page *pages;
+
+	/*
+	 * Allocate the data pages dynamically. SPARC does not support mapping
+	 * static pages to be mapped into userspace.
+	 * It is also a requirement for mlockall() support.
+	 *
+	 * Do not use folios. In time namespaces the pages are mapped in a different order
+	 * to userspace, which is not handled by the folio optimizations in finish_fault().
+	 */
+	pages = alloc_pages(GFP_KERNEL, order);
+	if (!pages)
+		panic("Unable to allocate VDSO storage pages");
+
+	/* The pages are mapped one-by-one into userspace and each one needs to be refcounted. */
+	split_page(pages, order);
+
+	/* Move the data already written by other subsystems to the new pages */
+	memcpy(page_address(pages), vdso_initdata, VDSO_NR_PAGES * PAGE_SIZE);
+
+	if (IS_ENABLED(CONFIG_GENERIC_GETTIMEOFDAY))
+		vdso_k_time_data = page_address(pages + VDSO_TIME_PAGE_OFFSET);
+
+	if (IS_ENABLED(CONFIG_VDSO_GETRANDOM))
+		vdso_k_rng_data = page_address(pages + VDSO_RNG_PAGE_OFFSET);
+
+	if (IS_ENABLED(CONFIG_ARCH_HAS_VDSO_ARCH_DATA))
+		vdso_k_arch_data = page_address(pages + VDSO_ARCH_PAGES_START);
+}
+
 static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
 			     struct vm_area_struct *vma, struct vm_fault *vmf)
 {
-	struct page *timens_page = find_timens_vvar_page(vma);
-	unsigned long addr, pfn;
-	vm_fault_t err;
+	struct page *page, *timens_page;
+
+	timens_page = find_timens_vvar_page(vma);
 
 	switch (vmf->pgoff) {
 	case VDSO_TIME_PAGE_OFFSET:
 		if (!IS_ENABLED(CONFIG_GENERIC_GETTIMEOFDAY))
 			return VM_FAULT_SIGBUS;
-		pfn = __phys_to_pfn(__pa_symbol(vdso_k_time_data));
+		page = virt_to_page(vdso_k_time_data);
 		if (timens_page) {
 			/*
 			 * Fault in VVAR page too, since it will be accessed
 			 * to get clock data anyway.
 			 */
+			unsigned long addr;
+			vm_fault_t err;
+
 			addr = vmf->address + VDSO_TIMENS_PAGE_OFFSET * PAGE_SIZE;
-			err = vmf_insert_pfn(vma, addr, pfn);
+			err = vmf_insert_page(vma, addr, page);
 			if (unlikely(err & VM_FAULT_ERROR))
 				return err;
-			pfn = page_to_pfn(timens_page);
+			page = timens_page;
 		}
 		break;
 	case VDSO_TIMENS_PAGE_OFFSET:
@@ -71,24 +99,25 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
 		 */
 		if (!IS_ENABLED(CONFIG_TIME_NS) || !timens_page)
 			return VM_FAULT_SIGBUS;
-		pfn = __phys_to_pfn(__pa_symbol(vdso_k_time_data));
+		page = virt_to_page(vdso_k_time_data);
 		break;
 	case VDSO_RNG_PAGE_OFFSET:
 		if (!IS_ENABLED(CONFIG_VDSO_GETRANDOM))
 			return VM_FAULT_SIGBUS;
-		pfn = __phys_to_pfn(__pa_symbol(vdso_k_rng_data));
+		page = virt_to_page(vdso_k_rng_data);
 		break;
 	case VDSO_ARCH_PAGES_START ... VDSO_ARCH_PAGES_END:
 		if (!IS_ENABLED(CONFIG_ARCH_HAS_VDSO_ARCH_DATA))
 			return VM_FAULT_SIGBUS;
-		pfn = __phys_to_pfn(__pa_symbol(vdso_k_arch_data)) +
-			vmf->pgoff - VDSO_ARCH_PAGES_START;
+		page = virt_to_page(vdso_k_arch_data) + vmf->pgoff - VDSO_ARCH_PAGES_START;
 		break;
 	default:
 		return VM_FAULT_SIGBUS;
 	}
 
-	return vmf_insert_pfn(vma, vmf->address, pfn);
+	get_page(page);
+	vmf->page = page;
+	return 0;
 }
 
 const struct vm_special_mapping vdso_vvar_mapping = {
@@ -100,31 +129,6 @@ struct vm_area_struct *vdso_install_vvar_mapping(struct mm_struct *mm, unsigned
 {
 	return _install_special_mapping(mm, addr, VDSO_NR_PAGES * PAGE_SIZE,
 					VM_READ | VM_MAYREAD | VM_IO | VM_DONTDUMP |
-					VM_PFNMAP | VM_SEALED_SYSMAP,
+					VM_MIXEDMAP | VM_SEALED_SYSMAP,
 					&vdso_vvar_mapping);
 }
-
-#ifdef CONFIG_TIME_NS
-/*
- * The vvar page layout depends on whether a task belongs to the root or
- * non-root time namespace. Whenever a task changes its namespace, the VVAR
- * page tables are cleared and then they will be re-faulted with a
- * corresponding layout.
- * See also the comment near timens_setup_vdso_clock_data() for details.
- */
-int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
-{
-	struct mm_struct *mm = task->mm;
-	struct vm_area_struct *vma;
-	VMA_ITERATOR(vmi, mm, 0);
-
-	mmap_read_lock(mm);
-	for_each_vma(vmi, vma) {
-		if (vma_is_special_mapping(vma, &vdso_vvar_mapping))
-			zap_vma_pages(vma);
-	}
-	mmap_read_unlock(mm);
-
-	return 0;
-}
-#endif