[deliverable/linux.git] / arch / x86 / um / vdso / vma.c

/*
 * 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 <linux/init.h>

static unsigned int __read_mostly vdso_enabled = 1;
unsigned long um_vdso_addr;

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;
	}

	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 mm_struct *mm = current->mm;

	if (!vdso_enabled)
		return 0;

	down_write(&mm->mmap_sem);

	err = install_special_mapping(mm, um_vdso_addr, PAGE_SIZE,
		VM_READ|VM_EXEC|
		VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
		vdsop);

	up_write(&mm->mmap_sem);

	return err;
}
Commit	Line	Data
f1c2bb8b RW	1	/*
	2	* Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 as
	6	* published by the Free Software Foundation.
	7	*/
	8
	9	#include <linux/slab.h>
	10	#include <linux/sched.h>
	11	#include <linux/mm.h>
	12	#include <asm/page.h>
	13	#include <linux/init.h>
	14
3d7ee969	15	static unsigned int __read_mostly vdso_enabled = 1;
f1c2bb8b RW	16	unsigned long um_vdso_addr;
	17
	18	extern unsigned long task_size;
	19	extern char vdso_start[], vdso_end[];
	20
	21	static struct page **vdsop;
	22
	23	static int __init init_vdso(void)
	24	{
	25	struct page *um_vdso;
	26
	27	BUG_ON(vdso_end - vdso_start > PAGE_SIZE);
	28
	29	um_vdso_addr = task_size - PAGE_SIZE;
	30
0d65ede0	31	vdsop = kmalloc(sizeof(struct page *), GFP_KERNEL);
f1c2bb8b RW	32	if (!vdsop)
	33	goto oom;
	34
	35	um_vdso = alloc_page(GFP_KERNEL);
	36	if (!um_vdso) {
	37	kfree(vdsop);
	38
	39	goto oom;
	40	}
	41
	42	copy_page(page_address(um_vdso), vdso_start);
	43	*vdsop = um_vdso;
	44
	45	return 0;
	46
	47	oom:
	48	printk(KERN_ERR "Cannot allocate vdso\n");
	49	vdso_enabled = 0;
	50
	51	return -ENOMEM;
	52	}
	53	subsys_initcall(init_vdso);
	54
	55	int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
	56	{
	57	int err;
	58	struct mm_struct *mm = current->mm;
	59
	60	if (!vdso_enabled)
	61	return 0;
	62
	63	down_write(&mm->mmap_sem);
	64
	65	err = install_special_mapping(mm, um_vdso_addr, PAGE_SIZE,
	66	VM_READ\|VM_EXEC\|
909af768	67	VM_MAYREAD\|VM_MAYWRITE\|VM_MAYEXEC,
f1c2bb8b RW	68	vdsop);
	69
	70	up_write(&mm->mmap_sem);
	71
	72	return err;
	73	}