ExternalVendorCode/genode
1
0
Fork 0
mirror of https://github.com/genodelabs/genode.git synced 2025-04-10 12:51:34 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

base: safeguard entrypoint against double manage

Browse Source 
This patch adds sanity checks to the RPC entrypoint that detect attempts
to manage or dissolve the same RPC object twice. This is not always a
bug. I.e., if RPC objects are implemented in the modern way where the
object manages/dissolves itself. As the generic framework code (in
particular root/component.h) cannot rely on this pattern, it has to
call manage/dissolve for session objects anyway. For modern session
objects, this double attempt would result in a serious error (double
insertion into the object pool's AVL tree).

Issue #2398
This commit is contained in:
Norman Feske 2017-05-08 12:52:23 +02:00 committed by Christian Helmuth
parent 843dd179d7
commit eea493a8ca
4 changed files with 26 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
repos/base-nova/src/lib/base/rpc_entrypoint.cc
View File

@ -36,6 +36,12 @@ Untyped_capability Rpc_entrypoint::_manage(Rpc_object_base *obj)
{
using namespace Nova;
/* don't manage RPC object twice */
if (obj->cap().valid()) {
warning("attempt to manage RPC object twice");
return obj->cap();
}
Untyped_capability ec_cap;
/* _ec_sel is invalid until thread gets started */
@ -60,6 +66,10 @@ Untyped_capability Rpc_entrypoint::_manage(Rpc_object_base *obj)
void Rpc_entrypoint::_dissolve(Rpc_object_base *obj)
{
/* don't dissolve RPC object twice */
if (!obj->cap().valid())
return;
/* de-announce object from cap_session */
_free_rpc_cap(_pd_session, obj->cap());

7
repos/base/include/root/component.h
View File

@ -169,7 +169,12 @@ class Genode::Root_component : public Rpc_object<Typed_root<SESSION_TYPE> >,
throw Root::Unavailable();
}
_ep->manage(s);
/*
* Consider that the session-object constructor may already have
* called 'manage'.
*/
if (!s->cap().valid())
_ep->manage(s);
aquire_guard.ack = true;
return *s;

6
repos/base/src/lib/base/rpc_dispatch_loop.cc
View File

@ -27,6 +27,12 @@ using namespace Genode;
Untyped_capability Rpc_entrypoint::_manage(Rpc_object_base *obj)
{
/* don't manage RPC object twice */
if (obj->cap().valid()) {
warning("attempt to manage RPC object twice");
return obj->cap();
}
Untyped_capability new_obj_cap = _alloc_rpc_cap(_pd_session, _cap);
/* add server object to object pool */

4
repos/base/src/lib/base/rpc_entrypoint.cc
View File

@ -26,6 +26,10 @@ using namespace Genode;
void Rpc_entrypoint::_dissolve(Rpc_object_base *obj)
{
/* don't dissolve RPC object twice */
if (!obj->cap().valid())
return;
/* make sure nobody is able to find this object */
remove(obj);