Messages in this thread Patch in this message | | | Date | Tue, 24 Aug 2010 16:46:22 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] avoiding the same resource to be inserted |
| |
On Mon, 16 Aug 2010 23:55:38 +0800 Huang Shijie <shijie8@gmail.com> wrote:
> If the same resource is inserted to the resource tree > (maybe not on purpose), a dead loop will be created. In this situation, > The kernel does not report any warning or error :( > > The command below will show a endless print. > #cat /proc/iomem
OK, we shouldn't do that.
> So, adding the check for the same resource is needed for the stability > and reliability of the kernel. > > Signed-off-by: Huang Shijie <shijie8@gmail.com> > --- > kernel/resource.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/kernel/resource.c b/kernel/resource.c > index 7b36976..60daab4 100644 > --- a/kernel/resource.c > +++ b/kernel/resource.c > @@ -451,7 +451,7 @@ static struct resource * __insert_resource(struct resource *parent, struct resou > if (!first) > return first; > > - if (first == parent) > + if (first == parent || first == new) > return first;
However, inserting the same thing twice _is_ a bug, and we shouldn't silently accept it like this. We should tell the programmer!
But we can recover from the situation so let's not kill the box. How does this look?
--- a/kernel/resource.c~kernel-resourcec-handle-reinsertion-of-an-already-inserted-resource +++ a/kernel/resource.c @@ -453,6 +453,8 @@ static struct resource * __insert_resour if (first == parent) return first; + if (WARN_ON(first == new)) /* duplicated insertion */ + return first; if ((first->start > new->start) || (first->end < new->end)) break; _
| |