linux/drivers/nvdimm/dimm.c
Dan Williams 1cd7386549 libnvdimm/security: Require nvdimm_security_setup_events() to succeed
The following warning:

    ACPI0012:00: security event setup failed: -19

...is meant to capture exceptional failures of sysfs_get_dirent(),
however it will also fail in the common case when security support is
disabled. A few issues:

1/ A dev_warn() report for a common case is too chatty
2/ The setup of this notifier is generic, no need for it to be driven
   from the nfit driver, it can exist completely in the core.
3/ If it fails for any reason besides security support being disabled,
   that's fatal and should abort DIMM activation. Userspace may hang if
   it never gets overwrite notifications.
4/ The dirent needs to be released.

Move the call to the core 'dimm' driver, make it conditional on security
support being active, make it fatal for the exceptional case, add the
missing sysfs_put() at device disable time.

Fixes: 7d988097c5 ("...Add security DSM overwrite support")
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-01-21 09:57:43 -08:00

159 lines
3.5 KiB
C

/*
* Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program 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
* General Public License for more details.
*/
#include <linux/vmalloc.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/sizes.h>
#include <linux/ndctl.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/nd.h>
#include "label.h"
#include "nd.h"
static int nvdimm_probe(struct device *dev)
{
struct nvdimm_drvdata *ndd;
int rc;
rc = nvdimm_security_setup_events(dev);
if (rc < 0) {
dev_err(dev, "security event setup failed: %d\n", rc);
return rc;
}
rc = nvdimm_check_config_data(dev);
if (rc) {
/* not required for non-aliased nvdimm, ex. NVDIMM-N */
if (rc == -ENOTTY)
rc = 0;
return rc;
}
/*
* The locked status bit reflects explicit status codes from the
* label reading commands, revalidate it each time the driver is
* activated and re-reads the label area.
*/
nvdimm_clear_locked(dev);
ndd = kzalloc(sizeof(*ndd), GFP_KERNEL);
if (!ndd)
return -ENOMEM;
dev_set_drvdata(dev, ndd);
ndd->dpa.name = dev_name(dev);
ndd->ns_current = -1;
ndd->ns_next = -1;
ndd->dpa.start = 0;
ndd->dpa.end = -1;
ndd->dev = dev;
get_device(dev);
kref_init(&ndd->kref);
/*
* Attempt to unlock, if the DIMM supports security commands,
* otherwise the locked indication is determined by explicit
* status codes from the label reading commands.
*/
rc = nvdimm_security_unlock(dev);
if (rc < 0)
dev_dbg(dev, "failed to unlock dimm: %d\n", rc);
/*
* EACCES failures reading the namespace label-area-properties
* are interpreted as the DIMM capacity being locked but the
* namespace labels themselves being accessible.
*/
rc = nvdimm_init_nsarea(ndd);
if (rc == -EACCES) {
/*
* See nvdimm_namespace_common_probe() where we fail to
* allow namespaces to probe while the DIMM is locked,
* but we do allow for namespace enumeration.
*/
nvdimm_set_locked(dev);
rc = 0;
}
if (rc)
goto err;
/*
* EACCES failures reading the namespace label-data are
* interpreted as the label area being locked in addition to the
* DIMM capacity. We fail the dimm probe to prevent regions from
* attempting to parse the label area.
*/
rc = nd_label_data_init(ndd);
if (rc == -EACCES)
nvdimm_set_locked(dev);
if (rc)
goto err;
dev_dbg(dev, "config data size: %d\n", ndd->nsarea.config_size);
nvdimm_bus_lock(dev);
if (ndd->ns_current >= 0) {
rc = nd_label_reserve_dpa(ndd);
if (rc == 0)
nvdimm_set_aliasing(dev);
}
nvdimm_bus_unlock(dev);
if (rc)
goto err;
return 0;
err:
put_ndd(ndd);
return rc;
}
static int nvdimm_remove(struct device *dev)
{
struct nvdimm_drvdata *ndd = dev_get_drvdata(dev);
if (!ndd)
return 0;
nvdimm_bus_lock(dev);
dev_set_drvdata(dev, NULL);
nvdimm_bus_unlock(dev);
put_ndd(ndd);
return 0;
}
static struct nd_device_driver nvdimm_driver = {
.probe = nvdimm_probe,
.remove = nvdimm_remove,
.drv = {
.name = "nvdimm",
},
.type = ND_DRIVER_DIMM,
};
int __init nvdimm_init(void)
{
return nd_driver_register(&nvdimm_driver);
}
void nvdimm_exit(void)
{
driver_unregister(&nvdimm_driver.drv);
}
MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DIMM);