1 files changed, 16 insertions, 34 deletions

diff --git a/arch/x86/um/vdso/vma.c b/arch/x86/um/vdso/vma.c
index af91901babb8..51a2b9f2eca9 100644
--- a/arch/x86/um/vdso/vma.c
+++ b/arch/x86/um/vdso/vma.c
@@ -1,73 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
  */
 
 #include <linux/slab.h>
 #include <linux/sched.h>
 #include <linux/mm.h>
 #include <asm/page.h>
+#include <asm/elf.h>
 #include <linux/init.h>
 
-unsigned int __read_mostly vdso_enabled = 1;
 unsigned long um_vdso_addr;
+static struct page *um_vdso;
 
 extern unsigned long task_size;
 extern char vdso_start[], vdso_end[];
 
-static struct page **vdsop;
-
 static int __init init_vdso(void)
 {
-	struct page *um_vdso;
-
 	BUG_ON(vdso_end - vdso_start > PAGE_SIZE);
 
 	um_vdso_addr = task_size - PAGE_SIZE;
 
-	vdsop = kmalloc(sizeof(struct page *), GFP_KERNEL);
-	if (!vdsop)
-		goto oom;
-
 	um_vdso = alloc_page(GFP_KERNEL);
-	if (!um_vdso) {
-		kfree(vdsop);
-
-		goto oom;
-	}
+	if (!um_vdso)
+		panic("Cannot allocate vdso\n");
 
 	copy_page(page_address(um_vdso), vdso_start);
-	*vdsop = um_vdso;
 
 	return 0;
-
-oom:
-	printk(KERN_ERR "Cannot allocate vdso\n");
-	vdso_enabled = 0;
-
-	return -ENOMEM;
 }
 subsys_initcall(init_vdso);
 
 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 {
-	int err;
+	struct vm_area_struct *vma;
 	struct mm_struct *mm = current->mm;
+	static struct vm_special_mapping vdso_mapping = {
+		.name = "[vdso]",
+		.pages = &um_vdso,
+	};
 
-	if (!vdso_enabled)
-		return 0;
-
-	down_write(&mm->mmap_sem);
+	if (mmap_write_lock_killable(mm))
+		return -EINTR;
 
-	err = install_special_mapping(mm, um_vdso_addr, PAGE_SIZE,
+	vma = _install_special_mapping(mm, um_vdso_addr, PAGE_SIZE,
 		VM_READ|VM_EXEC|
 		VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
-		vdsop);
+		&vdso_mapping);
 
-	up_write(&mm->mmap_sem);
+	mmap_write_unlock(mm);
 
-	return err;
+	return IS_ERR(vma) ? PTR_ERR(vma) : 0;
 }