1 files changed, 90 insertions, 21 deletions

diff --git a/arch/loongarch/kernel/vdso.c b/arch/loongarch/kernel/vdso.c
index e20c8ca87473..90dfccb41c14 100644
--- a/arch/loongarch/kernel/vdso.c
+++ b/arch/loongarch/kernel/vdso.c
@@ -14,23 +14,29 @@
 #include <linux/random.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
+#include <linux/time_namespace.h>
 #include <linux/timekeeper_internal.h>
 
 #include <asm/page.h>
 #include <asm/vdso.h>
 #include <vdso/helpers.h>
 #include <vdso/vsyscall.h>
+#include <vdso/datapage.h>
 #include <generated/vdso-offsets.h>
 
 extern char vdso_start[], vdso_end[];
 
 /* Kernel-provided data used by the VDSO. */
-static union loongarch_vdso_data {
-	u8 page[PAGE_SIZE];
-	struct vdso_data data[CS_BASES];
+static union vdso_data_store generic_vdso_data __page_aligned_data;
+
+static union {
+	u8 page[LOONGARCH_VDSO_DATA_SIZE];
+	struct loongarch_vdso_data vdata;
 } loongarch_vdso_data __page_aligned_data;
-struct vdso_data *vdso_data = loongarch_vdso_data.data;
+
 static struct page *vdso_pages[] = { NULL };
+struct vdso_data *vdso_data = generic_vdso_data.data;
+struct vdso_pcpu_data *vdso_pdata = loongarch_vdso_data.vdata.pdata;
 
 static int vdso_mremap(const struct vm_special_mapping *sm, struct vm_area_struct *new_vma)
 {
@@ -39,6 +45,43 @@ static int vdso_mremap(const struct vm_special_mapping *sm, struct vm_area_struc
 	return 0;
 }
 
+static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
+			     struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+	unsigned long pfn;
+	struct page *timens_page = find_timens_vvar_page(vma);
+
+	switch (vmf->pgoff) {
+	case VVAR_GENERIC_PAGE_OFFSET:
+		if (!timens_page)
+			pfn = sym_to_pfn(vdso_data);
+		else
+			pfn = page_to_pfn(timens_page);
+		break;
+#ifdef CONFIG_TIME_NS
+	case VVAR_TIMENS_PAGE_OFFSET:
+		/*
+		 * If a task belongs to a time namespace then a namespace specific
+		 * VVAR is mapped with the VVAR_GENERIC_PAGE_OFFSET and the real
+		 * VVAR page is mapped with the VVAR_TIMENS_PAGE_OFFSET offset.
+		 * See also the comment near timens_setup_vdso_data().
+		 */
+		if (!timens_page)
+			return VM_FAULT_SIGBUS;
+		else
+			pfn = sym_to_pfn(vdso_data);
+		break;
+#endif /* CONFIG_TIME_NS */
+	case VVAR_LOONGARCH_PAGES_START ... VVAR_LOONGARCH_PAGES_END:
+		pfn = sym_to_pfn(&loongarch_vdso_data) + vmf->pgoff - VVAR_LOONGARCH_PAGES_START;
+		break;
+	default:
+		return VM_FAULT_SIGBUS;
+	}
+
+	return vmf_insert_pfn(vma, vmf->address, pfn);
+}
+
 struct loongarch_vdso_info vdso_info = {
 	.vdso = vdso_start,
 	.size = PAGE_SIZE,
@@ -49,17 +92,21 @@ struct loongarch_vdso_info vdso_info = {
 	},
 	.data_mapping = {
 		.name = "[vvar]",
+		.fault = vvar_fault,
 	},
 	.offset_sigreturn = vdso_offset_sigreturn,
 };
 
 static int __init init_vdso(void)
 {
-	unsigned long i, pfn;
+	unsigned long i, cpu, pfn;
 
 	BUG_ON(!PAGE_ALIGNED(vdso_info.vdso));
 	BUG_ON(!PAGE_ALIGNED(vdso_info.size));
 
+	for_each_possible_cpu(cpu)
+		vdso_pdata[cpu].node = cpu_to_node(cpu);
+
 	pfn = __phys_to_pfn(__pa_symbol(vdso_info.vdso));
 	for (i = 0; i < vdso_info.size / PAGE_SIZE; i++)
 		vdso_info.code_mapping.pages[i] = pfn_to_page(pfn + i);
@@ -68,12 +115,43 @@ static int __init init_vdso(void)
 }
 subsys_initcall(init_vdso);
 
+#ifdef CONFIG_TIME_NS
+struct vdso_data *arch_get_vdso_data(void *vvar_page)
+{
+	return (struct vdso_data *)(vvar_page);
+}
+
+/*
+ * The vvar mapping contains data for a specific time namespace, so when a
+ * task changes namespace we must unmap its vvar data for the old namespace.
+ * Subsequent faults will map in data for the new namespace.
+ *
+ * For more details see timens_setup_vdso_data().
+ */
+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_info.data_mapping))
+			zap_vma_pages(vma);
+	}
+	mmap_read_unlock(mm);
+
+	return 0;
+}
+#endif
+
 static unsigned long vdso_base(void)
 {
 	unsigned long base = STACK_TOP;
 
 	if (current->flags & PF_RANDOMIZE) {
-		base += get_random_int() & (VDSO_RANDOMIZE_SIZE - 1);
+		base += get_random_u32_below(VDSO_RANDOMIZE_SIZE);
 		base = PAGE_ALIGN(base);
 	}
 
@@ -83,7 +161,7 @@ static unsigned long vdso_base(void)
 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 {
 	int ret;
-	unsigned long vvar_size, size, data_addr, vdso_addr;
+	unsigned long size, data_addr, vdso_addr;
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma;
 	struct loongarch_vdso_info *info = current->thread.vdso;
@@ -93,34 +171,25 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 
 	/*
 	 * Determine total area size. This includes the VDSO data itself
-	 * and the data page.
+	 * and the data pages.
 	 */
-	vvar_size = PAGE_SIZE;
-	size = vvar_size + info->size;
+	size = VVAR_SIZE + info->size;
 
 	data_addr = get_unmapped_area(NULL, vdso_base(), size, 0, 0);
 	if (IS_ERR_VALUE(data_addr)) {
 		ret = data_addr;
 		goto out;
 	}
-	vdso_addr = data_addr + PAGE_SIZE;
 
-	vma = _install_special_mapping(mm, data_addr, vvar_size,
-				       VM_READ | VM_MAYREAD,
+	vma = _install_special_mapping(mm, data_addr, VVAR_SIZE,
+				       VM_READ | VM_MAYREAD | VM_PFNMAP,
 				       &info->data_mapping);
 	if (IS_ERR(vma)) {
 		ret = PTR_ERR(vma);
 		goto out;
 	}
 
-	/* Map VDSO data page. */
-	ret = remap_pfn_range(vma, data_addr,
-			      virt_to_phys(vdso_data) >> PAGE_SHIFT,
-			      PAGE_SIZE, PAGE_READONLY);
-	if (ret)
-		goto out;
-
-	/* Map VDSO code page. */
+	vdso_addr = data_addr + VVAR_SIZE;
 	vma = _install_special_mapping(mm, vdso_addr, info->size,
 				       VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
 				       &info->code_mapping);