linux/drivers/edac/debugfs.c
Tan Xiaojun 30f84a891b EDAC: Use edac_debugfs_remove_recursive()
debugfs_remove() is used to remove a file or a directory from the
debugfs filesystem, but mci->debugfs might not empty.

This can be triggered by the following sequence:

1) Enable CONFIG_EDAC_DEBUG
2) insmod an EDAC module (like i3000_edac or similar)
3) rmmod this module
4) we can see files remaining under <debugfs_mountpoint>/edac/ like
   "fake_inject", for example.

Removing edac_core then, causes a NULL pointer dereference.

Reported-by: Yun Wu (Abel) <wuyun.wu@huawei.com>
Signed-off-by: Tan Xiaojun <tanxiaojun@huawei.com>
Cc: Doug Thompson <dougthompson@xmission.com>
Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1444787364-104353-1-git-send-email-tanxiaojun@huawei.com
Signed-off-by: Borislav Petkov <bp@suse.de>
2015-10-14 18:50:32 +02:00

163 lines
4 KiB
C

#include "edac_module.h"
static struct dentry *edac_debugfs;
static ssize_t edac_fake_inject_write(struct file *file,
const char __user *data,
size_t count, loff_t *ppos)
{
struct device *dev = file->private_data;
struct mem_ctl_info *mci = to_mci(dev);
static enum hw_event_mc_err_type type;
u16 errcount = mci->fake_inject_count;
if (!errcount)
errcount = 1;
type = mci->fake_inject_ue ? HW_EVENT_ERR_UNCORRECTED
: HW_EVENT_ERR_CORRECTED;
printk(KERN_DEBUG
"Generating %d %s fake error%s to %d.%d.%d to test core handling. NOTE: this won't test the driver-specific decoding logic.\n",
errcount,
(type == HW_EVENT_ERR_UNCORRECTED) ? "UE" : "CE",
errcount > 1 ? "s" : "",
mci->fake_inject_layer[0],
mci->fake_inject_layer[1],
mci->fake_inject_layer[2]
);
edac_mc_handle_error(type, mci, errcount, 0, 0, 0,
mci->fake_inject_layer[0],
mci->fake_inject_layer[1],
mci->fake_inject_layer[2],
"FAKE ERROR", "for EDAC testing only");
return count;
}
static const struct file_operations debug_fake_inject_fops = {
.open = simple_open,
.write = edac_fake_inject_write,
.llseek = generic_file_llseek,
};
int __init edac_debugfs_init(void)
{
edac_debugfs = debugfs_create_dir("edac", NULL);
if (IS_ERR(edac_debugfs)) {
edac_debugfs = NULL;
return -ENOMEM;
}
return 0;
}
void edac_debugfs_exit(void)
{
debugfs_remove(edac_debugfs);
}
int edac_create_debugfs_nodes(struct mem_ctl_info *mci)
{
struct dentry *d, *parent;
char name[80];
int i;
if (!edac_debugfs)
return -ENODEV;
d = debugfs_create_dir(mci->dev.kobj.name, edac_debugfs);
if (!d)
return -ENOMEM;
parent = d;
for (i = 0; i < mci->n_layers; i++) {
sprintf(name, "fake_inject_%s",
edac_layer_name[mci->layers[i].type]);
d = debugfs_create_u8(name, S_IRUGO | S_IWUSR, parent,
&mci->fake_inject_layer[i]);
if (!d)
goto nomem;
}
d = debugfs_create_bool("fake_inject_ue", S_IRUGO | S_IWUSR, parent,
&mci->fake_inject_ue);
if (!d)
goto nomem;
d = debugfs_create_u16("fake_inject_count", S_IRUGO | S_IWUSR, parent,
&mci->fake_inject_count);
if (!d)
goto nomem;
d = debugfs_create_file("fake_inject", S_IWUSR, parent,
&mci->dev,
&debug_fake_inject_fops);
if (!d)
goto nomem;
mci->debugfs = parent;
return 0;
nomem:
edac_debugfs_remove_recursive(mci->debugfs);
return -ENOMEM;
}
/* Create a toplevel dir under EDAC's debugfs hierarchy */
struct dentry *edac_debugfs_create_dir(const char *dirname)
{
if (!edac_debugfs)
return NULL;
return debugfs_create_dir(dirname, edac_debugfs);
}
EXPORT_SYMBOL_GPL(edac_debugfs_create_dir);
/* Create a toplevel dir under EDAC's debugfs hierarchy with parent @parent */
struct dentry *
edac_debugfs_create_dir_at(const char *dirname, struct dentry *parent)
{
return debugfs_create_dir(dirname, parent);
}
EXPORT_SYMBOL_GPL(edac_debugfs_create_dir_at);
/*
* Create a file under EDAC's hierarchy or a sub-hierarchy:
*
* @name: file name
* @mode: file permissions
* @parent: parent dentry. If NULL, it becomes the toplevel EDAC dir
* @data: private data of caller
* @fops: file operations of this file
*/
struct dentry *
edac_debugfs_create_file(const char *name, umode_t mode, struct dentry *parent,
void *data, const struct file_operations *fops)
{
if (!parent)
parent = edac_debugfs;
return debugfs_create_file(name, mode, parent, data, fops);
}
EXPORT_SYMBOL_GPL(edac_debugfs_create_file);
/* Wrapper for debugfs_create_x8() */
struct dentry *edac_debugfs_create_x8(const char *name, umode_t mode,
struct dentry *parent, u8 *value)
{
if (!parent)
parent = edac_debugfs;
return debugfs_create_x8(name, mode, parent, value);
}
EXPORT_SYMBOL_GPL(edac_debugfs_create_x8);
/* Wrapper for debugfs_create_x16() */
struct dentry *edac_debugfs_create_x16(const char *name, umode_t mode,
struct dentry *parent, u16 *value)
{
if (!parent)
parent = edac_debugfs;
return debugfs_create_x16(name, mode, parent, value);
}
EXPORT_SYMBOL_GPL(edac_debugfs_create_x16);