On Tue, Jul 31, 2012 at 12:08:22PM +0200, richard -rw- weinberger wrote:

On Tue, Jul 31, 2012 at 11:54 AM, Pavel Emelyanov [off-list ref] wrote:

quoted

quoted

Yeah, but I fear it's not that easy.
We'd have to change crtools to work without ptrace().

Well, this is hard. Using ptrace saved us from having many special-purpose
APIs for dumping various stuff (there will be an article about it). Thus I
don't know which way is simpler -- stop using ptrace or teach ptrece to allow
several tracers to attach to one task %)

Allowing multiple tracers in a safe way is IMHO even more harder.

BTW:  While reading prctl_set_mm() I noticed two things.
1.  Why isn't the return value of find_vma() verified?

prctl_set_mm
	vma = find_vma(mm, addr);
	...
	if (!vma) {
		error = -EFAULT;
		goto out;
	}

these values are used in procfs statistics only. So I don't get
which verify you mean here.

It looks like one can set an addr which does not belong to any vma.
2. What will happen if addr is not page aligned?

you'll have a bit weird output in procfs stat (probably I should add
page alignment check here).

	Cyrill