linux-stable/drivers/nvdimm/nd-core.h
Dan Williams a371788d4f cxl/pmem: Fix nvdimm registration races
commit f57aec443c upstream.

A loop of the form:

    while true; do modprobe cxl_pci; modprobe -r cxl_pci; done

...fails with the following crash signature:

    BUG: kernel NULL pointer dereference, address: 0000000000000040
    [..]
    RIP: 0010:cxl_internal_send_cmd+0x5/0xb0 [cxl_core]
    [..]
    Call Trace:
     <TASK>
     cxl_pmem_ctl+0x121/0x240 [cxl_pmem]
     nvdimm_get_config_data+0xd6/0x1a0 [libnvdimm]
     nd_label_data_init+0x135/0x7e0 [libnvdimm]
     nvdimm_probe+0xd6/0x1c0 [libnvdimm]
     nvdimm_bus_probe+0x7a/0x1e0 [libnvdimm]
     really_probe+0xde/0x380
     __driver_probe_device+0x78/0x170
     driver_probe_device+0x1f/0x90
     __device_attach_driver+0x85/0x110
     bus_for_each_drv+0x7d/0xc0
     __device_attach+0xb4/0x1e0
     bus_probe_device+0x9f/0xc0
     device_add+0x445/0x9c0
     nd_async_device_register+0xe/0x40 [libnvdimm]
     async_run_entry_fn+0x30/0x130

...namely that the bottom half of async nvdimm device registration runs
after the CXL has already torn down the context that cxl_pmem_ctl()
needs. Unlike the ACPI NFIT case that benefits from launching multiple
nvdimm device registrations in parallel from those listed in the table,
CXL is already marked PROBE_PREFER_ASYNCHRONOUS. So provide for a
synchronous registration path to preclude this scenario.

Fixes: 21083f5152 ("cxl/pmem: Register 'pmem' / cxl_nvdimm devices")
Cc: <stable@vger.kernel.org>
Reported-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:34:20 +01:00

165 lines
5.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
*/
#ifndef __ND_CORE_H__
#define __ND_CORE_H__
#include <linux/libnvdimm.h>
#include <linux/device.h>
#include <linux/sizes.h>
#include <linux/mutex.h>
#include <linux/nd.h>
#include "nd.h"
extern struct list_head nvdimm_bus_list;
extern struct mutex nvdimm_bus_list_mutex;
extern int nvdimm_major;
extern struct workqueue_struct *nvdimm_wq;
struct nvdimm_bus {
struct nvdimm_bus_descriptor *nd_desc;
wait_queue_head_t wait;
struct list_head list;
struct device dev;
int id, probe_active;
atomic_t ioctl_active;
struct list_head mapping_list;
struct mutex reconfig_mutex;
struct badrange badrange;
};
struct nvdimm {
unsigned long flags;
void *provider_data;
unsigned long cmd_mask;
struct device dev;
atomic_t busy;
int id, num_flush;
struct resource *flush_wpq;
const char *dimm_id;
struct {
const struct nvdimm_security_ops *ops;
unsigned long flags;
unsigned long ext_flags;
unsigned int overwrite_tmo;
struct kernfs_node *overwrite_state;
} sec;
struct delayed_work dwork;
const struct nvdimm_fw_ops *fw_ops;
};
static inline unsigned long nvdimm_security_flags(
struct nvdimm *nvdimm, enum nvdimm_passphrase_type ptype)
{
u64 flags;
const u64 state_flags = 1UL << NVDIMM_SECURITY_DISABLED
| 1UL << NVDIMM_SECURITY_LOCKED
| 1UL << NVDIMM_SECURITY_UNLOCKED
| 1UL << NVDIMM_SECURITY_OVERWRITE;
if (!nvdimm->sec.ops)
return 0;
flags = nvdimm->sec.ops->get_flags(nvdimm, ptype);
/* disabled, locked, unlocked, and overwrite are mutually exclusive */
dev_WARN_ONCE(&nvdimm->dev, hweight64(flags & state_flags) > 1,
"reported invalid security state: %#llx\n",
(unsigned long long) flags);
return flags;
}
int nvdimm_security_freeze(struct nvdimm *nvdimm);
#if IS_ENABLED(CONFIG_NVDIMM_KEYS)
ssize_t nvdimm_security_store(struct device *dev, const char *buf, size_t len);
void nvdimm_security_overwrite_query(struct work_struct *work);
#else
static inline ssize_t nvdimm_security_store(struct device *dev,
const char *buf, size_t len)
{
return -EOPNOTSUPP;
}
static inline void nvdimm_security_overwrite_query(struct work_struct *work)
{
}
#endif
bool is_nvdimm(struct device *dev);
bool is_nd_pmem(struct device *dev);
bool is_nd_volatile(struct device *dev);
static inline bool is_nd_region(struct device *dev)
{
return is_nd_pmem(dev) || is_nd_volatile(dev);
}
static inline bool is_memory(struct device *dev)
{
return is_nd_pmem(dev) || is_nd_volatile(dev);
}
struct nvdimm_bus *walk_to_nvdimm_bus(struct device *nd_dev);
int __init nvdimm_bus_init(void);
void nvdimm_bus_exit(void);
void nvdimm_devs_exit(void);
struct nd_region;
void nd_region_advance_seeds(struct nd_region *nd_region, struct device *dev);
void nd_region_create_ns_seed(struct nd_region *nd_region);
void nd_region_create_btt_seed(struct nd_region *nd_region);
void nd_region_create_pfn_seed(struct nd_region *nd_region);
void nd_region_create_dax_seed(struct nd_region *nd_region);
int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus);
void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus);
void nd_synchronize(void);
void nd_device_register(struct device *dev);
void nd_device_register_sync(struct device *dev);
struct nd_label_id;
char *nd_label_gen_id(struct nd_label_id *label_id, const uuid_t *uuid,
u32 flags);
bool nd_is_uuid_unique(struct device *dev, uuid_t *uuid);
struct nd_region;
struct nvdimm_drvdata;
struct nd_mapping;
void nd_mapping_free_labels(struct nd_mapping *nd_mapping);
int __reserve_free_pmem(struct device *dev, void *data);
void release_free_pmem(struct nvdimm_bus *nvdimm_bus,
struct nd_mapping *nd_mapping);
resource_size_t nd_pmem_max_contiguous_dpa(struct nd_region *nd_region,
struct nd_mapping *nd_mapping);
resource_size_t nd_region_allocatable_dpa(struct nd_region *nd_region);
resource_size_t nd_pmem_available_dpa(struct nd_region *nd_region,
struct nd_mapping *nd_mapping);
resource_size_t nd_region_available_dpa(struct nd_region *nd_region);
int nd_region_conflict(struct nd_region *nd_region, resource_size_t start,
resource_size_t size);
resource_size_t nvdimm_allocated_dpa(struct nvdimm_drvdata *ndd,
struct nd_label_id *label_id);
int nvdimm_num_label_slots(struct nvdimm_drvdata *ndd);
void get_ndd(struct nvdimm_drvdata *ndd);
resource_size_t __nvdimm_namespace_capacity(struct nd_namespace_common *ndns);
void nd_detach_ndns(struct device *dev, struct nd_namespace_common **_ndns);
void __nd_detach_ndns(struct device *dev, struct nd_namespace_common **_ndns);
bool nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
struct nd_namespace_common **_ndns);
bool __nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
struct nd_namespace_common **_ndns);
ssize_t nd_namespace_store(struct device *dev,
struct nd_namespace_common **_ndns, const char *buf,
size_t len);
struct nd_pfn *to_nd_pfn_safe(struct device *dev);
bool is_nvdimm_bus(struct device *dev);
#if IS_ENABLED(CONFIG_ND_CLAIM)
int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio,
resource_size_t size);
void devm_nsio_disable(struct device *dev, struct nd_namespace_io *nsio);
#else
static inline int devm_nsio_enable(struct device *dev,
struct nd_namespace_io *nsio, resource_size_t size)
{
return -ENXIO;
}
static inline void devm_nsio_disable(struct device *dev,
struct nd_namespace_io *nsio)
{
}
#endif
#endif /* __ND_CORE_H__ */