1 files changed, 37 insertions, 35 deletions

diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index c1b8496b5606..311eae30e089 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -38,6 +38,8 @@ struct vdso_data *arch_get_vdso_data(void *vvar_page)
 }
 #undef EMIT_VVAR
 
+unsigned int vclocks_used __read_mostly;
+
 #if defined(CONFIG_X86_64)
 unsigned int __read_mostly vdso64_enabled = 1;
 #endif
@@ -87,30 +89,14 @@ static void vdso_fix_landing(const struct vdso_image *image,
 static int vdso_mremap(const struct vm_special_mapping *sm,
 		struct vm_area_struct *new_vma)
 {
-	unsigned long new_size = new_vma->vm_end - new_vma->vm_start;
 	const struct vdso_image *image = current->mm->context.vdso_image;
 
-	if (image->size != new_size)
-		return -EINVAL;
-
 	vdso_fix_landing(image, new_vma);
 	current->mm->context.vdso = (void __user *)new_vma->vm_start;
 
 	return 0;
 }
 
-static int vvar_mremap(const struct vm_special_mapping *sm,
-		struct vm_area_struct *new_vma)
-{
-	const struct vdso_image *image = new_vma->vm_mm->context.vdso_image;
-	unsigned long new_size = new_vma->vm_end - new_vma->vm_start;
-
-	if (new_size != -image->sym_vvar_start)
-		return -EINVAL;
-
-	return 0;
-}
-
 #ifdef CONFIG_TIME_NS
 static struct page *find_timens_vvar_page(struct vm_area_struct *vma)
 {
@@ -141,18 +127,17 @@ 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);
 
-	if (down_write_killable(&mm->mmap_sem))
-		return -EINTR;
-
-	for (vma = mm->mmap; vma; vma = vma->vm_next) {
+	mmap_read_lock(mm);
+	for_each_vma(vmi, vma) {
 		unsigned long size = vma->vm_end - vma->vm_start;
 
 		if (vma_is_special_mapping(vma, &vvar_mapping))
 			zap_page_range(vma, vma->vm_start, size);
 	}
+	mmap_read_unlock(mm);
 
-	up_write(&mm->mmap_sem);
 	return 0;
 }
 #else
@@ -219,7 +204,7 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
 	} else if (sym_offset == image->sym_pvclock_page) {
 		struct pvclock_vsyscall_time_info *pvti =
 			pvclock_get_pvti_cpu0_va();
-		if (pvti && vclock_was_used(VCLOCK_PVCLOCK)) {
+		if (pvti && vclock_was_used(VDSO_CLOCKMODE_PVCLOCK)) {
 			return vmf_insert_pfn_prot(vma, vmf->address,
 					__pa(pvti) >> PAGE_SHIFT,
 					pgprot_decrypted(vma->vm_page_prot));
@@ -227,7 +212,7 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
 	} else if (sym_offset == image->sym_hvclock_page) {
 		struct ms_hyperv_tsc_page *tsc_pg = hv_get_tsc_page();
 
-		if (tsc_pg && vclock_was_used(VCLOCK_HVCLOCK))
+		if (tsc_pg && vclock_was_used(VDSO_CLOCKMODE_HVCLOCK))
 			return vmf_insert_pfn(vma, vmf->address,
 					virt_to_phys(tsc_pg) >> PAGE_SHIFT);
 	} else if (sym_offset == image->sym_timens_page) {
@@ -251,7 +236,6 @@ static const struct vm_special_mapping vdso_mapping = {
 static const struct vm_special_mapping vvar_mapping = {
 	.name = "[vvar]",
 	.fault = vvar_fault,
-	.mremap = vvar_mremap,
 };
 
 /*
@@ -266,7 +250,7 @@ static int map_vdso(const struct vdso_image *image, unsigned long addr)
 	unsigned long text_start;
 	int ret = 0;
 
-	if (down_write_killable(&mm->mmap_sem))
+	if (mmap_write_lock_killable(mm))
 		return -EINTR;
 
 	addr = get_unmapped_area(NULL, addr,
@@ -309,7 +293,7 @@ static int map_vdso(const struct vdso_image *image, unsigned long addr)
 	}
 
 up_fail:
-	up_write(&mm->mmap_sem);
+	mmap_write_unlock(mm);
 	return ret;
 }
 
@@ -343,7 +327,7 @@ static unsigned long vdso_addr(unsigned long start, unsigned len)
 	end -= len;
 
 	if (end > start) {
-		offset = get_random_int() % (((end - start) >> PAGE_SHIFT) + 1);
+		offset = prandom_u32_max(((end - start) >> PAGE_SHIFT) + 1);
 		addr = start + (offset << PAGE_SHIFT);
 	} else {
 		addr = start;
@@ -370,23 +354,24 @@ int map_vdso_once(const struct vdso_image *image, unsigned long addr)
 {
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma;
+	VMA_ITERATOR(vmi, mm, 0);
 
-	down_write(&mm->mmap_sem);
+	mmap_write_lock(mm);
 	/*
 	 * Check if we have already mapped vdso blob - fail to prevent
-	 * abusing from userspace install_speciall_mapping, which may
+	 * abusing from userspace install_special_mapping, which may
 	 * not do accounting and rlimit right.
 	 * We could search vma near context.vdso, but it's a slowpath,
 	 * so let's explicitly check all VMAs to be completely sure.
 	 */
-	for (vma = mm->mmap; vma; vma = vma->vm_next) {
+	for_each_vma(vmi, vma) {
 		if (vma_is_special_mapping(vma, &vdso_mapping) ||
 				vma_is_special_mapping(vma, &vvar_mapping)) {
-			up_write(&mm->mmap_sem);
+			mmap_write_unlock(mm);
 			return -EEXIST;
 		}
 	}
-	up_write(&mm->mmap_sem);
+	mmap_write_unlock(mm);
 
 	return map_vdso(image, addr);
 }
@@ -412,10 +397,10 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 
 #ifdef CONFIG_COMPAT
 int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
-				       int uses_interp)
+				       int uses_interp, bool x32)
 {
 #ifdef CONFIG_X86_X32_ABI
-	if (test_thread_flag(TIF_X32)) {
+	if (x32) {
 		if (!vdso64_enabled)
 			return 0;
 		return map_vdso_randomized(&vdso_image_x32);
@@ -435,16 +420,33 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 }
 #endif
 
+bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)
+{
+#if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION)
+	const struct vdso_image *image = current->mm->context.vdso_image;
+	unsigned long vdso = (unsigned long) current->mm->context.vdso;
+
+	if (in_ia32_syscall() && image == &vdso_image_32) {
+		if (regs->ip == vdso + image->sym_vdso32_sigreturn_landing_pad ||
+		    regs->ip == vdso + image->sym_vdso32_rt_sigreturn_landing_pad)
+			return true;
+	}
+#endif
+	return false;
+}
+
 #ifdef CONFIG_X86_64
 static __init int vdso_setup(char *s)
 {
 	vdso64_enabled = simple_strtoul(s, NULL, 0);
-	return 0;
+	return 1;
 }
 __setup("vdso=", vdso_setup);
 
 static int __init init_vdso(void)
 {
+	BUILD_BUG_ON(VDSO_CLOCKMODE_MAX >= 32);
+
 	init_vdso_image(&vdso_image_64);
 
 #ifdef CONFIG_X86_X32_ABI