linux-stable.git/drivers/dax, branch linux-5.6.y Linux kernel stable tree device-dax: don't leak kernel memory to user space after unloading kmem 2020-05-27T15:48:25+00:00 David Hildenbrand david@redhat.com 2020-05-23T05:22:42+00:00 513cdf8c4dc505f41573e05cb953d4603ae8b693 commit 60858c00e5f018eda711a3aa84cf62214ef62d61 upstream. Assume we have kmem configured and loaded: [root@localhost ~]# cat /proc/iomem ... 140000000-33fffffff : Persistent Memory$ 140000000-1481fffff : namespace0.0 150000000-33fffffff : dax0.0 150000000-33fffffff : System RAM Assume we try to unload kmem. This force-unloading will work, even if memory cannot get removed from the system. [root@localhost ~]# rmmod kmem [ 86.380228] removing memory fails, because memory [0x0000000150000000-0x0000000157ffffff] is onlined ... [ 86.431225] kmem dax0.0: DAX region [mem 0x150000000-0x33fffffff] cannot be hotremoved until the next reboot Now, we can reconfigure the namespace: [root@localhost ~]# ndctl create-namespace --force --reconfig=namespace0.0 --mode=devdax [ 131.409351] nd_pmem namespace0.0: could not reserve region [mem 0x140000000-0x33fffffff]dax [ 131.410147] nd_pmem: probe of namespace0.0 failed with error -16namespace0.0 --mode=devdax ... This fails as expected due to the busy memory resource, and the memory cannot be used. However, the dax0.0 device is removed, and along its name. The name of the memory resource now points at freed memory (name of the device): [root@localhost ~]# cat /proc/iomem ... 140000000-33fffffff : Persistent Memory 140000000-1481fffff : namespace0.0 150000000-33fffffff : �_�^7_��/_��wR��WQ���^��� ... 150000000-33fffffff : System RAM We have to make sure to duplicate the string. While at it, remove the superfluous setting of the name and fixup a stale comment. Fixes: 9f960da72b25 ("device-dax: "Hotremove" persistent memory that is used like normal RAM") Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: <stable@vger.kernel.org> [5.3] Link: http://lkml.kernel.org/r/20200508084217.9160-2-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 60858c00e5f018eda711a3aa84cf62214ef62d61 upstream.

Assume we have kmem configured and loaded:

  [root@localhost ~]# cat /proc/iomem
  ...
  140000000-33fffffff : Persistent Memory$
    140000000-1481fffff : namespace0.0
    150000000-33fffffff : dax0.0
      150000000-33fffffff : System RAM

Assume we try to unload kmem. This force-unloading will work, even if
memory cannot get removed from the system.

  [root@localhost ~]# rmmod kmem
  [   86.380228] removing memory fails, because memory [0x0000000150000000-0x0000000157ffffff] is onlined
  ...
  [   86.431225] kmem dax0.0: DAX region [mem 0x150000000-0x33fffffff] cannot be hotremoved until the next reboot

Now, we can reconfigure the namespace:

  [root@localhost ~]# ndctl create-namespace --force --reconfig=namespace0.0 --mode=devdax
  [  131.409351] nd_pmem namespace0.0: could not reserve region [mem 0x140000000-0x33fffffff]dax
  [  131.410147] nd_pmem: probe of namespace0.0 failed with error -16namespace0.0 --mode=devdax
  ...

This fails as expected due to the busy memory resource, and the memory
cannot be used.  However, the dax0.0 device is removed, and along its
name.

The name of the memory resource now points at freed memory (name of the
device):

  [root@localhost ~]# cat /proc/iomem
  ...
  140000000-33fffffff : Persistent Memory
    140000000-1481fffff : namespace0.0
    150000000-33fffffff : �_�^7_��/_��wR��WQ���^��� ...
    150000000-33fffffff : System RAM

We have to make sure to duplicate the string.  While at it, remove the
superfluous setting of the name and fixup a stale comment.

Fixes: 9f960da72b25 ("device-dax: "Hotremove" persistent memory that is used like normal RAM")
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@vger.kernel.org>	[5.3]
Link: http://lkml.kernel.org/r/20200508084217.9160-2-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dax: Get rid of fs_dax_get_by_host() helper 2020-01-16T17:52:27+00:00 Vivek Goyal vgoyal@redhat.com 2020-01-06T18:11:17+00:00 f01b16a85bfae2e6b4f32de0a1f37ac4050dc316 Looks like nobody is using fs_dax_get_by_host() except fs_dax_get_by_bdev() and it can easily use dax_get_by_host() instead. IIUC, fs_dax_get_by_host() was only introduced so that one could compile with CONFIG_FS_DAX=n and CONFIG_DAX=m. fs_dax_get_by_bdev() achieves the same purpose and hence it looks like fs_dax_get_by_host() is not needed anymore. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20200106181117.GA16248@redhat.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
Looks like nobody is using fs_dax_get_by_host() except fs_dax_get_by_bdev()
and it can easily use dax_get_by_host() instead.

IIUC, fs_dax_get_by_host() was only introduced so that one could compile
with CONFIG_FS_DAX=n and CONFIG_DAX=m. fs_dax_get_by_bdev() achieves
the same purpose and hence it looks like fs_dax_get_by_host() is not
needed anymore.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20200106181117.GA16248@redhat.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Merge tag 'libnvdimm-for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm 2019-12-02T02:43:25+00:00 Linus Torvalds torvalds@linux-foundation.org 2019-12-02T02:43:25+00:00 d10032dd539c93dbff016f5667e5627c6c2a4467 Pull libnvdimm updates from Dan Williams: "The highlight this cycle is continuing integration fixes for PowerPC and some resulting optimizations. Summary: - Updates to better support vmalloc space restrictions on PowerPC platforms. - Cleanups to move common sysfs attributes to core 'struct device_type' objects. - Export the 'target_node' attribute (the effective numa node if pmem is marked online) for regions and namespaces. - Miscellaneous fixups and optimizations" * tag 'libnvdimm-for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (21 commits) MAINTAINERS: Remove Keith from NVDIMM maintainers libnvdimm: Export the target_node attribute for regions and namespaces dax: Add numa_node to the default device-dax attributes libnvdimm: Simplify root read-only definition for the 'resource' attribute dax: Simplify root read-only definition for the 'resource' attribute dax: Create a dax device_type libnvdimm: Move nvdimm_bus_attribute_group to device_type libnvdimm: Move nvdimm_attribute_group to device_type libnvdimm: Move nd_mapping_attribute_group to device_type libnvdimm: Move nd_region_attribute_group to device_type libnvdimm: Move nd_numa_attribute_group to device_type libnvdimm: Move nd_device_attribute_group to device_type libnvdimm: Move region attribute group definition libnvdimm: Move attribute groups to device type libnvdimm: Remove prototypes for nonexistent functions libnvdimm/btt: fix variable 'rc' set but not used libnvdimm/pmem: Delete include of nd-core.h libnvdimm/namespace: Differentiate between probe mapping and runtime mapping libnvdimm/pfn_dev: Don't clear device memmap area during generic namespace probe libnvdimm: Trivial comment fix ... 
Pull libnvdimm updates from Dan Williams:
 "The highlight this cycle is continuing integration fixes for PowerPC
  and some resulting optimizations.

  Summary:

   - Updates to better support vmalloc space restrictions on PowerPC
     platforms.

   - Cleanups to move common sysfs attributes to core 'struct
     device_type' objects.

   - Export the 'target_node' attribute (the effective numa node if pmem
     is marked online) for regions and namespaces.

   - Miscellaneous fixups and optimizations"

* tag 'libnvdimm-for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (21 commits)
  MAINTAINERS: Remove Keith from NVDIMM maintainers
  libnvdimm: Export the target_node attribute for regions and namespaces
  dax: Add numa_node to the default device-dax attributes
  libnvdimm: Simplify root read-only definition for the 'resource' attribute
  dax: Simplify root read-only definition for the 'resource' attribute
  dax: Create a dax device_type
  libnvdimm: Move nvdimm_bus_attribute_group to device_type
  libnvdimm: Move nvdimm_attribute_group to device_type
  libnvdimm: Move nd_mapping_attribute_group to device_type
  libnvdimm: Move nd_region_attribute_group to device_type
  libnvdimm: Move nd_numa_attribute_group to device_type
  libnvdimm: Move nd_device_attribute_group to device_type
  libnvdimm: Move region attribute group definition
  libnvdimm: Move attribute groups to device type
  libnvdimm: Remove prototypes for nonexistent functions
  libnvdimm/btt: fix variable 'rc' set but not used
  libnvdimm/pmem: Delete include of nd-core.h
  libnvdimm/namespace: Differentiate between probe mapping and runtime mapping
  libnvdimm/pfn_dev: Don't clear device memmap area during generic namespace probe
  libnvdimm: Trivial comment fix
  ...
dax: Add numa_node to the default device-dax attributes 2019-11-19T17:52:12+00:00 Dan Williams dan.j.williams@intel.com 2019-11-13T01:13:31+00:00 cb4dd729ee6ccc67ad604b1750990eb8c18783fa It is confusing that device-dax instances publish a 'target_node' attribute, but not a 'numa_node'. The 'numa_node' information is available elsewhere in the sysfs device hierarchy, but it is not obvious and not reliable from one device-dax instance-type (e.g. child devices of nvdimm namespaces) to the next (e.g. 'hmem' devices defined by EFI Specific Purpose Memory and the ACPI HMAT). Cc: Ira Weiny <ira.weiny@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Link: https://lore.kernel.org/r/157309906102.1582359.4262088001244476001.stgit@dwillia2-desk3.amr.corp.intel.com 
It is confusing that device-dax instances publish a 'target_node'
attribute, but not a 'numa_node'. The 'numa_node' information is
available elsewhere in the sysfs device hierarchy, but it is not obvious
and not reliable from one device-dax instance-type (e.g. child devices
of nvdimm namespaces) to the next (e.g. 'hmem' devices defined by EFI
Specific Purpose Memory and the ACPI HMAT).

Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/157309906102.1582359.4262088001244476001.stgit@dwillia2-desk3.amr.corp.intel.com
 dax: Simplify root read-only definition for the 'resource' attribute 2019-11-19T17:52:12+00:00 Dan Williams dan.j.williams@intel.com 2019-11-13T01:12:38+00:00 153dd28647d63086dc6e1df5ee06fd0a5d6435a5 Rather than update the permission in ->is_visible() set the permission directly at declaration time. Cc: Ira Weiny <ira.weiny@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Link: https://lore.kernel.org/r/157309904959.1582359.7281180042781955506.stgit@dwillia2-desk3.amr.corp.intel.com 
Rather than update the permission in ->is_visible() set the permission
directly at declaration time.

Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/157309904959.1582359.7281180042781955506.stgit@dwillia2-desk3.amr.corp.intel.com
 dax: Create a dax device_type 2019-11-19T17:52:12+00:00 Dan Williams dan.j.williams@intel.com 2019-11-13T01:12:23+00:00 770619a95106340230a72a725c958c037284ec1f Move the open coded release method and attribute groups to a 'struct device_type' instance. Cc: Ira Weiny <ira.weiny@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Link: https://lore.kernel.org/r/157309904365.1582359.5451327195246651379.stgit@dwillia2-desk3.amr.corp.intel.com 
Move the open coded release method and attribute groups to a 'struct
device_type' instance.

Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/157309904365.1582359.5451327195246651379.stgit@dwillia2-desk3.amr.corp.intel.com
 libnvdimm/namespace: Differentiate between probe mapping and runtime mapping 2019-11-15T03:08:47+00:00 Aneesh Kumar K.V aneesh.kumar@linux.ibm.com 2019-10-31T10:57:41+00:00 8f4b01fcded2dc821349cc0edfa5311c05abe293 The nvdimm core currently maps the full namespace to an ioremap range while probing the namespace mode. This can result in probe failures on architectures that have limited ioremap space. For example, with a large btt namespace that consumes most of I/O remap range, depending on the sequence of namespace initialization, the user can find a pfn namespace initialization failure due to unavailable I/O remap space which nvdimm core uses for temporary mapping. nvdimm core can avoid this failure by only mapping the reserved info block area to check for pfn superblock type and map the full namespace resource only before using the namespace. Given that personalities like BTT can be layered on top of any namespace type create a generic form of devm_nsio_enable (devm_namespace_enable) and use it inside the per-personality attach routines. Now devm_namespace_enable() is always paired with disable unless the mapping is going to be used for long term runtime access. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Link: https://lore.kernel.org/r/20191017073308.32645-1-aneesh.kumar@linux.ibm.com [djbw: reworks to move devm_namespace_{en,dis}able into *attach helpers] Reported-by: kbuild test robot <lkp@intel.com> Link: https://lore.kernel.org/r/20191031105741.102793-2-aneesh.kumar@linux.ibm.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
The nvdimm core currently maps the full namespace to an ioremap range
while probing the namespace mode. This can result in probe failures on
architectures that have limited ioremap space.

For example, with a large btt namespace that consumes most of I/O remap
range, depending on the sequence of namespace initialization, the user
can find a pfn namespace initialization failure due to unavailable I/O
remap space which nvdimm core uses for temporary mapping.

nvdimm core can avoid this failure by only mapping the reserved info
block area to check for pfn superblock type and map the full namespace
resource only before using the namespace.

Given that personalities like BTT can be layered on top of any namespace
type create a generic form of devm_nsio_enable (devm_namespace_enable)
and use it inside the per-personality attach routines. Now
devm_namespace_enable() is always paired with disable unless the mapping
is going to be used for long term runtime access.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/20191017073308.32645-1-aneesh.kumar@linux.ibm.com
[djbw: reworks to move devm_namespace_{en,dis}able into *attach helpers]
Reported-by: kbuild test robot <lkp@intel.com>
Link: https://lore.kernel.org/r/20191031105741.102793-2-aneesh.kumar@linux.ibm.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
device-dax: Add a driver for "hmem" devices 2019-11-07T14:45:00+00:00 Dan Williams dan.j.williams@intel.com 2019-11-07T01:43:43+00:00 a6c7f4c6aea5f4ca6056b06cec7ebd79f8c23e33 Platform firmware like EFI/ACPI may publish "hmem" platform devices. Such a device is a performance differentiated memory range likely reserved for an application specific use case. The driver gives access to 100% of the capacity via a device-dax mmap instance by default. However, if over-subscription and other kernel memory management is desired the resulting dax device can be assigned to the core-mm via the kmem driver. This consumes "hmem" devices the producer of "hmem" devices is saved for a follow-on patch so that it can reference the new CONFIG_DEV_DAX_HMEM symbol to gate performing the enumeration work. Reported-by: kbuild test robot <lkp@intel.com> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Platform firmware like EFI/ACPI may publish "hmem" platform devices.
Such a device is a performance differentiated memory range likely
reserved for an application specific use case. The driver gives access
to 100% of the capacity via a device-dax mmap instance by default.

However, if over-subscription and other kernel memory management is
desired the resulting dax device can be assigned to the core-mm via the
kmem driver.

This consumes "hmem" devices the producer of "hmem" devices is saved for
a follow-on patch so that it can reference the new CONFIG_DEV_DAX_HMEM
symbol to gate performing the enumeration work.

Reported-by: kbuild test robot <lkp@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
dax: Fix alloc_dax_region() compile warning 2019-11-07T14:44:47+00:00 Dan Williams dan.j.williams@intel.com 2019-11-07T01:43:37+00:00 460370ab20b6cc174256e46e192adf01e730faf6 PFN flags are (unsigned long long), fix the alloc_dax_region() calling convention to fix warnings of the form: >> include/linux/pfn_t.h:18:17: warning: large integer implicitly truncated to unsigned type [-Woverflow] #define PFN_DEV (1ULL << (BITS_PER_LONG_LONG - 3)) Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
PFN flags are (unsigned long long), fix the alloc_dax_region() calling
convention to fix warnings of the form:

>> include/linux/pfn_t.h:18:17: warning: large integer implicitly truncated to unsigned type [-Woverflow]
    #define PFN_DEV (1ULL << (BITS_PER_LONG_LONG - 3))

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19T17:42:02+00:00 Linus Torvalds torvalds@linux-foundation.org 2019-07-19T17:42:02+00:00 933a90bf4f3505f8ec83bda21a3c7d70d7c2b426 Pull vfs mount updates from Al Viro: "The first part of mount updates. Convert filesystems to use the new mount API" * 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) mnt_init(): call shmem_init() unconditionally constify ksys_mount() string arguments don't bother with registering rootfs init_rootfs(): don't bother with init_ramfs_fs() vfs: Convert smackfs to use the new mount API vfs: Convert selinuxfs to use the new mount API vfs: Convert securityfs to use the new mount API vfs: Convert apparmorfs to use the new mount API vfs: Convert openpromfs to use the new mount API vfs: Convert xenfs to use the new mount API vfs: Convert gadgetfs to use the new mount API vfs: Convert oprofilefs to use the new mount API vfs: Convert ibmasmfs to use the new mount API vfs: Convert qib_fs/ipathfs to use the new mount API vfs: Convert efivarfs to use the new mount API vfs: Convert configfs to use the new mount API vfs: Convert binfmt_misc to use the new mount API convenience helper: get_tree_single() convenience helper get_tree_nodev() vfs: Kill sget_userns() ... 
Pull vfs mount updates from Al Viro:
 "The first part of mount updates.

  Convert filesystems to use the new mount API"

* 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  mnt_init(): call shmem_init() unconditionally
  constify ksys_mount() string arguments
  don't bother with registering rootfs
  init_rootfs(): don't bother with init_ramfs_fs()
  vfs: Convert smackfs to use the new mount API
  vfs: Convert selinuxfs to use the new mount API
  vfs: Convert securityfs to use the new mount API
  vfs: Convert apparmorfs to use the new mount API
  vfs: Convert openpromfs to use the new mount API
  vfs: Convert xenfs to use the new mount API
  vfs: Convert gadgetfs to use the new mount API
  vfs: Convert oprofilefs to use the new mount API
  vfs: Convert ibmasmfs to use the new mount API
  vfs: Convert qib_fs/ipathfs to use the new mount API
  vfs: Convert efivarfs to use the new mount API
  vfs: Convert configfs to use the new mount API
  vfs: Convert binfmt_misc to use the new mount API
  convenience helper: get_tree_single()
  convenience helper get_tree_nodev()
  vfs: Kill sget_userns()
  ...