linux_dsm_epyc7002/drivers/gpu/drm/drm_info.c

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/**
* \file drm_info.c
* DRM info file implementations
*
* \author Ben Gamari <bgamari@gmail.com>
*/
/*
* Created: Sun Dec 21 13:09:50 2008 by bgamari@gmail.com
*
* Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
* Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
* Copyright 2008 Ben Gamari <bgamari@gmail.com>
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
#include <linux/seq_file.h>
#include <drm/drmP.h>
#include <drm/drm_gem.h>
#include "drm_internal.h"
#include "drm_legacy.h"
/**
* Called when "/proc/dri/.../name" is read.
*
* Prints the device name together with the bus id if available.
*/
int drm_name_info(struct seq_file *m, void *data)
{
struct drm_info_node *node = (struct drm_info_node *) m->private;
struct drm_minor *minor = node->minor;
struct drm_device *dev = minor->dev;
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struct drm_master *master;
mutex_lock(&dev->master_mutex);
master = dev->master;
if (!master)
goto out_unlock;
seq_printf(m, "%s", dev->driver->name);
if (dev->dev)
seq_printf(m, " dev=%s", dev_name(dev->dev));
if (master && master->unique)
seq_printf(m, " master=%s", master->unique);
if (dev->unique)
seq_printf(m, " unique=%s", dev->unique);
seq_printf(m, "\n");
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out_unlock:
mutex_unlock(&dev->master_mutex);
return 0;
}
/**
* Called when "/proc/dri/.../clients" is read.
*
*/
int drm_clients_info(struct seq_file *m, void *data)
{
struct drm_info_node *node = (struct drm_info_node *) m->private;
struct drm_device *dev = node->minor->dev;
struct drm_file *priv;
kuid_t uid;
seq_printf(m,
"%20s %5s %3s master a %5s %10s\n",
"command",
"pid",
"dev",
"uid",
"magic");
/* dev->filelist is sorted youngest first, but we want to present
* oldest first (i.e. kernel, servers, clients), so walk backwardss.
*/
mutex_lock(&dev->filelist_mutex);
list_for_each_entry_reverse(priv, &dev->filelist, lhead) {
struct task_struct *task;
rcu_read_lock(); /* locks pid_task()->comm */
task = pid_task(priv->pid, PIDTYPE_PID);
uid = task ? __task_cred(task)->euid : GLOBAL_ROOT_UID;
seq_printf(m, "%20s %5d %3d %c %c %5d %10u\n",
task ? task->comm : "<unknown>",
pid_vnr(priv->pid),
priv->minor->index,
drm_is_current_master(priv) ? 'y' : 'n',
priv->authenticated ? 'y' : 'n',
from_kuid_munged(seq_user_ns(m), uid),
priv->magic);
rcu_read_unlock();
}
mutex_unlock(&dev->filelist_mutex);
return 0;
}
static int drm_gem_one_name_info(int id, void *ptr, void *data)
{
struct drm_gem_object *obj = ptr;
struct seq_file *m = data;
seq_printf(m, "%6d %8zd %7d %8d\n",
obj->name, obj->size,
drm/gem: fix up flink name create race This is the 2nd attempt, I've always been a bit dissatisified with the tricky nature of the first one: http://lists.freedesktop.org/archives/dri-devel/2012-July/025451.html The issue is that the flink ioctl can race with calling gem_close on the last gem handle. In that case we'll end up with a zero handle count, but an flink name (and it's corresponding reference). Which results in a neat space leak. In my first attempt I've solved this by rechecking the handle count. But fundamentally the issue is that ->handle_count isn't your usual refcount - it can be resurrected from 0 among other things. For those special beasts atomic_t often suggest way more ordering that it actually guarantees. To prevent being tricked by those hairy semantics take the easy way out and simply protect the handle with the existing dev->object_name_lock. With that change implemented it's dead easy to fix the flink vs. gem close reace: When we try to create the name we simply have to check whether there's still officially a gem handle around and if not refuse to create the flink name. Since the handle count decrement and flink name destruction is now also protected by that lock the reace is gone and we can't ever leak the flink reference again. Outside of the drm core only the exynos driver looks at the handle count, and tbh I have no idea why (it's just for debug dmesg output luckily). I've considered inlining the drm_gem_object_handle_free, but I plan to add more name-like things (like the exported dma_buf) to this scheme, so it's clearer to leave the handle freeing in its own function. This is exercised by the new gem_flink_race i-g-t testcase, which on my snb leaks gem objects at a rate of roughly 1k objects/s. v2: Fix up the error path handling in handle_create and make it more robust by simply calling object_handle_unreference. v3: Fix up the handle_unreference logic bug - atomic_dec_and_test retursn 1 for 0. Oops. v4: Squash in inlining of drm_gem_object_handle_reference as suggested by Dave Airlie and add a note that we now have a testcase. Cc: Dave Airlie <airlied@gmail.com> Cc: Inki Dae <inki.dae@samsung.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Dave Airlie <airlied@redhat.com>
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obj->handle_count,
atomic_read(&obj->refcount.refcount));
return 0;
}
int drm_gem_name_info(struct seq_file *m, void *data)
{
struct drm_info_node *node = (struct drm_info_node *) m->private;
struct drm_device *dev = node->minor->dev;
seq_printf(m, " name size handles refcount\n");
mutex_lock(&dev->object_name_lock);
idr_for_each(&dev->object_name_idr, drm_gem_one_name_info, m);
mutex_unlock(&dev->object_name_lock);
return 0;
}