kwin/src/wayland/clientconnection.cpp
Martin Gräßlin 0649c8e51e [server] Use deleteLater when a ClientConnection gets destroyed
Summary:
In the situation that a wl_client gets destroyed while still
wl_resources are around it can happen that one of them calls into the
ClientConnection during the cleanup handling which gets triggered at the
same time. This can then trigger a crash.

This change uses deleteLater for the ClientConnection and sets the hold
wl_client pointer to null instead of deleting directly. So the
ClientConnection is still around while the Resources gets cleaned up.
This is similar to the cleanup of Resource where on unbind the
wl_resource pointer is set to null and the Resource gets delete later.

BUG: 370232
FIXED-IN: 5.28

Reviewers: #plasma, bshah

Subscribers: plasma-devel

Tags: #plasma_on_wayland

Differential Revision: https://phabricator.kde.org/D3004
2016-10-11 07:41:17 +02:00

174 lines
4.1 KiB
C++

/********************************************************************
Copyright 2014 Martin Gräßlin <mgraesslin@kde.org>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) version 3, or any
later version accepted by the membership of KDE e.V. (or its
successor approved by the membership of KDE e.V.), which shall
act as a proxy defined in Section 6 of version 3 of the license.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library. If not, see <http://www.gnu.org/licenses/>.
*********************************************************************/
#include "clientconnection.h"
#include "display.h"
// Qt
#include <QFileInfo>
#include <QVector>
// Wayland
#include <wayland-server.h>
namespace KWayland
{
namespace Server
{
class ClientConnection::Private
{
public:
explicit Private(wl_client *c, Display *display, ClientConnection *q);
~Private();
wl_client *client;
Display *display;
pid_t pid = 0;
uid_t user = 0;
gid_t group = 0;
QString executablePath;
private:
static void destroyListenerCallback(wl_listener *listener, void *data);
ClientConnection *q;
wl_listener listener;
static QVector<Private*> s_allClients;
};
QVector<ClientConnection::Private*> ClientConnection::Private::s_allClients;
ClientConnection::Private::Private(wl_client *c, Display *display, ClientConnection *q)
: client(c)
, display(display)
, q(q)
{
s_allClients << this;
listener.notify = destroyListenerCallback;
wl_client_add_destroy_listener(c, &listener);
wl_client_get_credentials(client, &pid, &user, &group);
executablePath = QFileInfo(QStringLiteral("/proc/%1/exe").arg(pid)).symLinkTarget();
}
ClientConnection::Private::~Private()
{
if (client) {
wl_list_remove(&listener.link);
}
s_allClients.removeAt(s_allClients.indexOf(this));
}
void ClientConnection::Private::destroyListenerCallback(wl_listener *listener, void *data)
{
Q_UNUSED(listener)
wl_client *client = reinterpret_cast<wl_client*>(data);
auto it = std::find_if(s_allClients.constBegin(), s_allClients.constEnd(),
[client](Private *c) {
return c->client == client;
}
);
Q_ASSERT(it != s_allClients.constEnd());
auto p = (*it);
auto q = p->q;
p->client = nullptr;
wl_list_remove(&p->listener.link);
emit q->disconnected(q);
q->deleteLater();
}
ClientConnection::ClientConnection(wl_client *c, Display *parent)
: QObject(parent)
, d(new Private(c, parent, this))
{
}
ClientConnection::~ClientConnection() = default;
void ClientConnection::flush()
{
if (!d->client) {
return;
}
wl_client_flush(d->client);
}
void ClientConnection::destroy()
{
if (!d->client) {
return;
}
wl_client_destroy(d->client);
}
wl_resource *ClientConnection::createResource(const wl_interface *interface, quint32 version, quint32 id)
{
if (!d->client) {
return nullptr;
}
return wl_resource_create(d->client, interface, version, id);
}
wl_resource *ClientConnection::getResource(quint32 id)
{
if (!d->client) {
return nullptr;
}
return wl_client_get_object(d->client, id);
}
wl_client *ClientConnection::client()
{
return d->client;
}
ClientConnection::operator wl_client*()
{
return d->client;
}
ClientConnection::operator wl_client*() const
{
return d->client;
}
Display *ClientConnection::display()
{
return d->display;
}
gid_t ClientConnection::groupId() const
{
return d->group;
}
pid_t ClientConnection::processId() const
{
return d->pid;
}
uid_t ClientConnection::userId() const
{
return d->user;
}
QString ClientConnection::executablePath() const
{
return d->executablePath;
}
}
}