kernel_optimize_test/drivers/gpu/drm/drm_debugfs.c
Marcin Slusarz b3e067c0b2 drm: serialize access to list of debugfs files
Nouveau, when configured with debugfs, creates debugfs files for every
channel, so structure holding list of files needs to be protected from
simultaneous changes by multiple threads.

Without this patch it's possible to hit kernel oops in
drm_debugfs_remove_files just by running a couple of xterms with
looped glxinfo.

Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-11-11 11:05:19 +00:00

243 lines
6.3 KiB
C

/**
* \file drm_debugfs.c
* debugfs support for DRM
*
* \author Ben Gamari <bgamari@gmail.com>
*/
/*
* Created: Sun Dec 21 13:08:50 2008 by bgamari@gmail.com
*
* Copyright 2008 Ben Gamari <bgamari@gmail.com>
*
* 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/debugfs.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/export.h>
#include "drmP.h"
#if defined(CONFIG_DEBUG_FS)
/***************************************************
* Initialization, etc.
**************************************************/
static struct drm_info_list drm_debugfs_list[] = {
{"name", drm_name_info, 0},
{"vm", drm_vm_info, 0},
{"clients", drm_clients_info, 0},
{"queues", drm_queues_info, 0},
{"bufs", drm_bufs_info, 0},
{"gem_names", drm_gem_name_info, DRIVER_GEM},
#if DRM_DEBUG_CODE
{"vma", drm_vma_info, 0},
#endif
};
#define DRM_DEBUGFS_ENTRIES ARRAY_SIZE(drm_debugfs_list)
static int drm_debugfs_open(struct inode *inode, struct file *file)
{
struct drm_info_node *node = inode->i_private;
return single_open(file, node->info_ent->show, node);
}
static const struct file_operations drm_debugfs_fops = {
.owner = THIS_MODULE,
.open = drm_debugfs_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
/**
* Initialize a given set of debugfs files for a device
*
* \param files The array of files to create
* \param count The number of files given
* \param root DRI debugfs dir entry.
* \param minor device minor number
* \return Zero on success, non-zero on failure
*
* Create a given set of debugfs files represented by an array of
* gdm_debugfs_lists in the given root directory.
*/
int drm_debugfs_create_files(struct drm_info_list *files, int count,
struct dentry *root, struct drm_minor *minor)
{
struct drm_device *dev = minor->dev;
struct dentry *ent;
struct drm_info_node *tmp;
int i, ret;
for (i = 0; i < count; i++) {
u32 features = files[i].driver_features;
if (features != 0 &&
(dev->driver->driver_features & features) != features)
continue;
tmp = kmalloc(sizeof(struct drm_info_node), GFP_KERNEL);
if (tmp == NULL) {
ret = -1;
goto fail;
}
ent = debugfs_create_file(files[i].name, S_IFREG | S_IRUGO,
root, tmp, &drm_debugfs_fops);
if (!ent) {
DRM_ERROR("Cannot create /sys/kernel/debug/dri/%s/%s\n",
root->d_name.name, files[i].name);
kfree(tmp);
ret = -1;
goto fail;
}
tmp->minor = minor;
tmp->dent = ent;
tmp->info_ent = &files[i];
mutex_lock(&minor->debugfs_lock);
list_add(&tmp->list, &minor->debugfs_list);
mutex_unlock(&minor->debugfs_lock);
}
return 0;
fail:
drm_debugfs_remove_files(files, count, minor);
return ret;
}
EXPORT_SYMBOL(drm_debugfs_create_files);
/**
* Initialize the DRI debugfs filesystem for a device
*
* \param dev DRM device
* \param minor device minor number
* \param root DRI debugfs dir entry.
*
* Create the DRI debugfs root entry "/sys/kernel/debug/dri", the device debugfs root entry
* "/sys/kernel/debug/dri/%minor%/", and each entry in debugfs_list as
* "/sys/kernel/debug/dri/%minor%/%name%".
*/
int drm_debugfs_init(struct drm_minor *minor, int minor_id,
struct dentry *root)
{
struct drm_device *dev = minor->dev;
char name[64];
int ret;
INIT_LIST_HEAD(&minor->debugfs_list);
mutex_init(&minor->debugfs_lock);
sprintf(name, "%d", minor_id);
minor->debugfs_root = debugfs_create_dir(name, root);
if (!minor->debugfs_root) {
DRM_ERROR("Cannot create /sys/kernel/debug/dri/%s\n", name);
return -1;
}
ret = drm_debugfs_create_files(drm_debugfs_list, DRM_DEBUGFS_ENTRIES,
minor->debugfs_root, minor);
if (ret) {
debugfs_remove(minor->debugfs_root);
minor->debugfs_root = NULL;
DRM_ERROR("Failed to create core drm debugfs files\n");
return ret;
}
if (dev->driver->debugfs_init) {
ret = dev->driver->debugfs_init(minor);
if (ret) {
DRM_ERROR("DRM: Driver failed to initialize "
"/sys/kernel/debug/dri.\n");
return ret;
}
}
return 0;
}
/**
* Remove a list of debugfs files
*
* \param files The list of files
* \param count The number of files
* \param minor The minor of which we should remove the files
* \return always zero.
*
* Remove all debugfs entries created by debugfs_init().
*/
int drm_debugfs_remove_files(struct drm_info_list *files, int count,
struct drm_minor *minor)
{
struct list_head *pos, *q;
struct drm_info_node *tmp;
int i;
mutex_lock(&minor->debugfs_lock);
for (i = 0; i < count; i++) {
list_for_each_safe(pos, q, &minor->debugfs_list) {
tmp = list_entry(pos, struct drm_info_node, list);
if (tmp->info_ent == &files[i]) {
debugfs_remove(tmp->dent);
list_del(pos);
kfree(tmp);
}
}
}
mutex_unlock(&minor->debugfs_lock);
return 0;
}
EXPORT_SYMBOL(drm_debugfs_remove_files);
/**
* Cleanup the debugfs filesystem resources.
*
* \param minor device minor number.
* \return always zero.
*
* Remove all debugfs entries created by debugfs_init().
*/
int drm_debugfs_cleanup(struct drm_minor *minor)
{
struct drm_device *dev = minor->dev;
if (!minor->debugfs_root)
return 0;
if (dev->driver->debugfs_cleanup)
dev->driver->debugfs_cleanup(minor);
drm_debugfs_remove_files(drm_debugfs_list, DRM_DEBUGFS_ENTRIES, minor);
debugfs_remove(minor->debugfs_root);
minor->debugfs_root = NULL;
return 0;
}
#endif /* CONFIG_DEBUG_FS */