Messages in this thread | | | Date | Tue, 27 Mar 2012 15:51:49 -0700 | From | Andrew Morton <> | Subject | Re: suppress page allocation failure warnings from sys_listxattr |
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On Tue, 13 Mar 2012 14:22:20 -0400 Dave Jones <davej@redhat.com> wrote:
> This size is user controllable, and so it's trivial for someone to trigger a > stream of order:4 page allocation errors. > > Signed-off-by: Dave Jones <davej@redhat.com> > > --- > There's also a similar problem in setxattr, but I'm not sure how we want > to pass NOWARN down to memdup_user. Thoughts ? > > diff --git a/fs/xattr.c b/fs/xattr.c > index 82f4337..544df90 100644 > --- a/fs/xattr.c > +++ b/fs/xattr.c > @@ -496,7 +496,7 @@ listxattr(struct dentry *d, char __user *list, size_t size) > if (size) { > if (size > XATTR_LIST_MAX) > size = XATTR_LIST_MAX; > - klist = kmalloc(size, GFP_KERNEL); > + klist = kmalloc(size, __GFP_NOWARN | GFP_KERNEL); > if (!klist) > return -ENOMEM; > }
hm. The patch is good, but one would hope that it isn't "trivial" to trigger a page allocation failure for a kmalloc(65536, GFP_KERNEL) - the VM is supposed to be able to handle that.
Is it really *that* easy, or is Something Unusual happening with that machine?
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