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Commit fa2b360f authored by Konstantin Khorenko's avatar Konstantin Khorenko Committed by Greg Kroah-Hartman
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tty/vt: avoid high order pages allocation on GIO_UNIMAP ioctl 



GIO_UNIMAP can easily result in a high order allocation,
seen 6th order allocation on radeondrmfb:

  fbcon: radeondrmfb (fb0) is primary device
  Console: switching to colour frame buffer device 160x64
  radeon 0000:01:05.0: fb0: radeondrmfb frame buffer device
  WARNING: CPU: 0 PID: 78661 at mm/page_alloc.c:3532
        __alloc_pages_nodemask+0x1b1/0x600
  order 6 >= 3, gfp 0x40d0

The warning is generated by a debug patch.

At the same time it's safe to use kvmalloc() for allocation in
con_get_unimap(), so let's do the substitution.

And do the same for con_set_unimap().

Signed-off-by: default avatarKonstantin Khorenko <khorenko@virtuozzo.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f692f776

drivers/tty/vt/consolemap.c

+4 −4
Original line number Diff line number Diff line
@@ -542,7 +542,7 @@ int con_set_unimap(struct vc_data *vc, ushort ct, struct unipair __user *list) 
	if (!ct)

		return 0;



	unilist = memdup_user(list, ct * sizeof(struct unipair));

	unilist = vmemdup_user(list, ct * sizeof(struct unipair));

	if (IS_ERR(unilist))

		return PTR_ERR(unilist);
@@ -641,7 +641,7 @@ int con_set_unimap(struct vc_data *vc, ushort ct, struct unipair __user *list) 


out_unlock:

	console_unlock();

	kfree(unilist);

	kvfree(unilist);

	return err;

}
@@ -743,7 +743,7 @@ int con_get_unimap(struct vc_data *vc, ushort ct, ushort __user *uct, struct uni 
	struct uni_pagedir *p;

	struct unipair *unilist;



	unilist = kmalloc_array(ct, sizeof(struct unipair), GFP_KERNEL);

	unilist = kvmalloc_array(ct, sizeof(struct unipair), GFP_KERNEL);

	if (!unilist)

		return -ENOMEM;
@@ -775,7 +775,7 @@ int con_get_unimap(struct vc_data *vc, ushort ct, ushort __user *uct, struct uni 
	if (copy_to_user(list, unilist, min(ect, ct) * sizeof(struct unipair)))

		ret = -EFAULT;

	put_user(ect, uct);

	kfree(unilist);

	kvfree(unilist);

	return ret ? ret : (ect <= ct) ? 0 : -ENOMEM;

}