Commit Graph

107309 Commits

Author SHA1 Message Date
Maxime Ripard
23d19ba06b Merge drm/drm-next into drm-misc-next
drm-next has been forwarded to 5.0-rc1, and we need it to apply the damage
helper for dirtyfb series from Noralf Trønnes.

Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
2019-01-11 16:32:10 +01:00
Daniel Vetter
7d0250ed8e drm/atomic: Add missing () to function ref in kerneldoc
Pure drive-by while reading code&docs.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181012073441.21774-1-daniel.vetter@ffwll.ch
2019-01-11 16:13:12 +01:00
Daniel Vetter
1e9080ac21 drm: Unexport drm_crtc_force_disable
It's a legacy kms only thing, good to hide it better now that all
those old drivers use the legacy crtc helpers directly.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Sean Paul <sean@poorly.run>
Cc: David Airlie <airlied@linux.ie>
Link: https://patchwork.freedesktop.org/patch/msgid/20181217194303.14397-3-daniel.vetter@ffwll.ch
2019-01-11 15:56:40 +01:00
Lyude Paul
eceae14724 drm/dp_mst: Start tracking per-port VCPI allocations
There has been a TODO waiting for quite a long time in
drm_dp_mst_topology.c:

	/* We cannot rely on port->vcpi.num_slots to update
	 * topology_state->avail_slots as the port may not exist if the parent
	 * branch device was unplugged. This should be fixed by tracking
	 * per-port slot allocation in drm_dp_mst_topology_state instead of
	 * depending on the caller to tell us how many slots to release.
	 */

That's not the only reason we should fix this: forcing the driver to
track the VCPI allocations throughout a state's atomic check is
error prone, because it means that extra care has to be taken with the
order that drm_dp_atomic_find_vcpi_slots() and
drm_dp_atomic_release_vcpi_slots() are called in in order to ensure
idempotency. Currently the only driver actually using these helpers,
i915, doesn't even do this correctly: multiple ->best_encoder() checks
with i915's current implementation would not be idempotent and would
over-allocate VCPI slots, something I learned trying to implement
fallback retraining in MST.

So: simplify this whole mess, and teach drm_dp_atomic_find_vcpi_slots()
and drm_dp_atomic_release_vcpi_slots() to track the VCPI allocations for
each port. This allows us to ensure idempotency without having to rely
on the driver as much. Additionally: the driver doesn't need to do any
kind of VCPI slot tracking anymore if it doesn't need it for it's own
internal state.

Additionally; this adds a new drm_dp_mst_atomic_check() helper which
must be used by atomic drivers to perform validity checks for the new
VCPI allocations incurred by a state.

Also: update the documentation and make it more obvious that these
/must/ be called by /all/ atomic drivers supporting MST.

Changes since v9:
* Add some missing changes that were requested by danvet that I forgot
  about after I redid all of the kref stuff:
  * Remove unnecessary state changes in intel_dp_mst_atomic_check
  * Cleanup atomic check logic for VCPI allocations - all we need to check in
    compute_config is whether or not this state disables a CRTC, then free
    VCPI based off that

Changes since v8:
 * Fix compile errors, whoops!

Changes since v7:
 - Don't check for mixed stale/valid VCPI allocations, just rely on
 connector registration to stop such erroneous modesets

Changes since v6:
 - Keep a kref to all of the ports we have allocations on. This required
   a good bit of changing to when we call drm_dp_find_vcpi_slots(),
   mainly that we need to ensure that we only redo VCPI allocations on
   actual mode or CRTC changes, not crtc_state->active changes.
   Additionally, we no longer take the registration of the DRM connector
   for each port into account because so long as we have a kref to the
   port in the new or previous atomic state, the connector will stay
   registered.
 - Use the small changes to drm_dp_put_port() to add even more error
   checking to make misusage of the helpers more obvious. I added this
   after having to chase down various use-after-free conditions that
   started popping up from the new helpers so no one else has to
   troubleshoot that.
 - Move some accidental DRM_DEBUG_KMS() calls to DRM_DEBUG_ATOMIC()
 - Update documentation again, note that find/release() should both not be
   called on the same port in a single atomic check phase (but multiple
   calls to one or the other is OK)

Changes since v4:
 - Don't skip the atomic checks for VCPI allocations if no new VCPI
   allocations happen in a state. This makes the next change I'm about
   to list here a lot easier to implement.
 - Don't ignore VCPI allocations on destroyed ports, instead ensure that
   when ports are destroyed and still have VCPI allocations in the
   topology state, the only state changes allowed are releasing said
   ports' VCPI. This prevents a state with a mix of VCPI allocations
   from destroyed ports, and allocations from valid ports.

Changes since v3:
 - Don't release VCPI allocations in the topology state immediately in
   drm_dp_atomic_release_vcpi_slots(), instead mark them as 0 and skip
   over them in drm_dp_mst_duplicate_state(). This makes it so
   drm_dp_atomic_release_vcpi_slots() is still idempotent while also
   throwing warnings if the driver messes up it's book keeping and tries
   to release VCPI slots on a port that doesn't have any pre-existing
   VCPI allocation - danvet
 - Change mst_state/state in some debugging messages to "mst state"

Changes since v2:
 - Use kmemdup() for duplicating MST state - danvet
 - Move port validation out of duplicate state callback - danvet
 - Handle looping through MST topology states in
   drm_dp_mst_atomic_check() so the driver doesn't have to do it
 - Fix documentation in drm_dp_atomic_find_vcpi_slots()
 - Move the atomic check for each individual topology state into it's
   own function, reduces indenting
 - Don't consider "stale" MST ports when calculating the bandwidth
   requirements. This is needed because originally we relied on the
   state duplication functions to prune any stale ports from the new
   state, which would prevent us from incorrectly considering their
   bandwidth requirements alongside legitimate new payloads.
 - Add function references in drm_dp_atomic_release_vcpi_slots() - danvet
 - Annotate atomic VCPI and atomic check functions with __must_check
   - danvet

Changes since v1:
 - Don't use the now-removed ->atomic_check() for private objects hook,
   just give drivers a function to call themselves

Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@redhat.com>
Cc: Jerry Zuo <Jerry.Zuo@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Juston Li <juston.li@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190111005343.17443-19-lyude@redhat.com
2019-01-10 20:42:13 -05:00
Lyude Paul
bea5c38f1e drm/dp_mst: Add some atomic state iterator macros
Changes since v6:
 - Move EXPORT_SYMBOL() for drm_dp_mst_topology_state_funcs to this
   commit
 - Document __drm_dp_mst_state_iter_get() and note that it shouldn't be
   called directly

Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Airlie <airlied@redhat.com>
Cc: Jerry Zuo <Jerry.Zuo@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Juston Li <juston.li@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190111005343.17443-18-lyude@redhat.com
2019-01-10 20:38:38 -05:00
Lyude Paul
ebcc0e6b50 drm/dp_mst: Introduce new refcounting scheme for mstbs and ports
The current way of handling refcounting in the DP MST helpers is really
confusing and probably just plain wrong because it's been hacked up many
times over the years without anyone actually going over the code and
seeing if things could be simplified.

To the best of my understanding, the current scheme works like this:
drm_dp_mst_port and drm_dp_mst_branch both have a single refcount. When
this refcount hits 0 for either of the two, they're removed from the
topology state, but not immediately freed. Both ports and branch devices
will reinitialize their kref once it's hit 0 before actually destroying
themselves. The intended purpose behind this is so that we can avoid
problems like not being able to free a remote payload that might still
be active, due to us having removed all of the port/branch device
structures in memory, as per:

commit 91a25e4631 ("drm/dp/mst: deallocate payload on port destruction")

Which may have worked, but then it caused use-after-free errors. Being
new to MST at the time, I tried fixing it;

commit 263efde31f ("drm/dp/mst: Get validated port ref in drm_dp_update_payload_part1()")

But, that was broken: both drm_dp_mst_port and drm_dp_mst_branch structs
are validated in almost every DP MST helper function. Simply put, this
means we go through the topology and try to see if the given
drm_dp_mst_branch or drm_dp_mst_port is still attached to something
before trying to use it in order to avoid dereferencing freed memory
(something that has happened a LOT in the past with this library).
Because of this it doesn't actually matter whether or not we keep keep
the ports and branches around in memory as that's not enough, because
any function that validates the branches and ports passed to it will
still reject them anyway since they're no longer in the topology
structure. So, use-after-free errors were fixed but payload deallocation
was completely broken.

Two years later, AMD informed me about this issue and I attempted to
come up with a temporary fix, pending a long-overdue cleanup of this
library:

commit c54c7374ff ("drm/dp_mst: Skip validating ports during destruction, just ref")

But then that introduced use-after-free errors, so I quickly reverted
it:

commit 9765635b30 ("Revert "drm/dp_mst: Skip validating ports during destruction, just ref"")

And in the process, learned that there is just no simple fix for this:
the design is just broken. Unfortunately, the usage of these helpers are
quite broken as well. Some drivers like i915 have been smart enough to
avoid accessing any kind of information from MST port structures, but
others like nouveau have assumed, understandably so, that
drm_dp_mst_port structures are normal and can just be accessed at any
time without worrying about use-after-free errors.

After a lot of discussion, me and Daniel Vetter came up with a better
idea to replace all of this.

To summarize, since this is documented far more indepth in the
documentation this patch introduces, we make it so that drm_dp_mst_port
and drm_dp_mst_branch structures have two different classes of
refcounts: topology_kref, and malloc_kref. topology_kref corresponds to
the lifetime of the given drm_dp_mst_port or drm_dp_mst_branch in it's
given topology. Once it hits zero, any associated connectors are removed
and the branch or port can no longer be validated. malloc_kref
corresponds to the lifetime of the memory allocation for the actual
structure, and will always be non-zero so long as the topology_kref is
non-zero. This gives us a way to allow callers to hold onto port and
branch device structures past their topology lifetime, and dramatically
simplifies the lifetimes of both structures. This also finally fixes the
port deallocation problem, properly.

Additionally: since this now means that we can keep ports and branch
devices allocated in memory for however long we need, we no longer need
a significant amount of the port validation that we currently do.

Additionally, there is one last scenario that this fixes, which couldn't
have been fixed properly beforehand:

- CPU1 unrefs port from topology (refcount 1->0)
- CPU2 refs port in topology(refcount 0->1)

Since we now can guarantee memory safety for ports and branches
as-needed, we also can make our main reference counting functions fix
this problem by using kref_get_unless_zero() internally so that topology
refcounts can only ever reach 0 once.

Changes since v4:
* Change the kernel-figure summary for dp-mst/topology-figure-1.dot a
  bit - danvet
* Remove figure numbers - danvet

Changes since v3:
* Remove rebase detritus - danvet
* Split out purely style changes into separate patches - hwentlan

Changes since v2:
* Fix commit message - checkpatch
* s/)-1/) - 1/g - checkpatch

Changes since v1:
* Remove forward declarations - danvet
* Move "Branch device and port refcounting" section from documentation
  into kernel-doc comments - danvet
* Export internal topology lifetime functions into their own section in
  the kernel-docs - danvet
* s/@/&/g for struct references in kernel-docs - danvet
* Drop the "when they are no longer being used" bits from the kernel
  docs - danvet
* Modify diagrams to show how the DRM driver interacts with the topology
  and payloads - danvet
* Make suggested documentation changes for
  drm_dp_mst_topology_get_mstb() and drm_dp_mst_topology_get_port() -
  danvet
* Better explain the relationship between malloc refs and topology krefs
  in the documentation for drm_dp_mst_topology_get_port() and
  drm_dp_mst_topology_get_mstb() - danvet
* Fix "See also" in drm_dp_mst_topology_get_mstb() - danvet
* Rename drm_dp_mst_topology_get_(port|mstb)() ->
  drm_dp_mst_topology_try_get_(port|mstb)() and
  drm_dp_mst_topology_ref_(port|mstb)() ->
  drm_dp_mst_topology_get_(port|mstb)() - danvet
* s/should/must in docs - danvet
* WARN_ON(refcount == 0) in topology_get_(mstb|port) - danvet
* Move kdocs for mstb/port structs inline - danvet
* Split drm_dp_get_last_connected_port_and_mstb() changes into their own
  commit - danvet

Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@redhat.com>
Cc: Jerry Zuo <Jerry.Zuo@amd.com>
Cc: Juston Li <juston.li@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190111005343.17443-7-lyude@redhat.com
2019-01-10 20:12:19 -05:00
Ville Syrjälä
1581b2df4c drm/edid: Add display_info.rgb_quant_range_selectable
Move the CEA-861 QS bit handling entirely into the edid code. No
need to bother the drivers with this.

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: "David (ChunMing) Zhou" <David1.Zhou@amd.com>
Cc: amd-gfx@lists.freedesktop.org
Cc: Eric Anholt <eric@anholt.net> (supporter:DRM DRIVERS FOR VC4)
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20190108172828.15184-4-ville.syrjala@linux.intel.com
2019-01-10 19:01:06 +02:00
Ville Syrjälä
13d0add333 drm/edid: Pass connector to AVI infoframe functions
Make life easier for drivers by simply passing the connector
to drm_hdmi_avi_infoframe_from_display_mode() and
drm_hdmi_avi_infoframe_quant_range(). That way drivers don't
need to worry about is_hdmi2_sink mess.

v2: Make is_hdmi2_sink() return true for sil-sii8620
    Adapt to omap/vc4 changes

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: "David (ChunMing) Zhou" <David1.Zhou@amd.com>
Cc: Archit Taneja <architt@codeaurora.org>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Inki Dae <inki.dae@samsung.com>
Cc: Joonyoung Shim <jy0922.shim@samsung.com>
Cc: Seung-Woo Kim <sw0312.kim@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: CK Hu <ck.hu@mediatek.com>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Sandy Huang <hjc@rock-chips.com>
Cc: "Heiko Stübner" <heiko@sntech.de>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Vincent Abriou <vincent.abriou@st.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Ilia Mirkin <imirkin@alum.mit.edu>
Cc: amd-gfx@lists.freedesktop.org
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Cc: nouveau@lists.freedesktop.org
Cc: linux-tegra@vger.kernel.org
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190108172828.15184-1-ville.syrjala@linux.intel.com
2019-01-10 19:01:06 +02:00
Sam Ravnborg
785cabaae9 drm: remove drmP.h from drm_gem_cma_helper.h
With all dependencies fixed we can now remove
drmP.h from drm_gem_cma_helper.h.
It is replaced by the include files required,
or forward declarations as appropritate.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Noralf Trønnes <noralf@tronnes.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Sean Paul <sean@poorly.run>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190108192939.15255-13-sam@ravnborg.org
2019-01-09 22:54:08 +01:00
Sam Ravnborg
19126bdf96 drm: remove include of drmP.h from drm_encoder_slave.h
No further changes required.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Noralf Trønnes <noralf@tronnes.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Sean Paul <sean@poorly.run>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190108192939.15255-8-sam@ravnborg.org
2019-01-09 22:35:35 +01:00
Sam Ravnborg
428747ae5c drm: remove include of drmP.h from bridge/dw_hdmi.h
drmP.h is an relic from the days when there was a single header file.
To enable the removal of drmP.h from all users drop include
of drmP.h from bridge/dw_hdmi.h.

A few files relied on the file included in drmP.h - add explicit
include statements or forward declarations to these files.
Build tested with arm and x86.

v2:
- prefer forward declarations when possible (Laurent Pinchart)
- sort include files (Laurent Pinchart)

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Archit Taneja <architt@codeaurora.org>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190108192939.15255-7-sam@ravnborg.org
2019-01-09 22:27:44 +01:00
Sam Ravnborg
2513147dce drm: make drm_framebuffer.h self contained
Add forward declaration and pull in include
file to make drm_framebuffer.h self contained.

While add it order include files alphabetically.

The use of TASK_COMM_LEN is the reason for including sched.h.
I could not see any good way to avoid this dependency,
and users of drm_framebuffer.comm already use
TASK_COMM_LEN to check for length etc.

v2:
- Added forward declaration of drm_gem_object (Noralf)
- Added ack from Noralf

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Noralf Trønnes <noralf@tronnes.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Sean Paul <sean@poorly.run>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190108192939.15255-4-sam@ravnborg.org
2019-01-09 22:11:28 +01:00
Sam Ravnborg
7af78f4061 drm: move DRM_SWITCH_POWER defines to drm_device.h
Move DRM_SWITCH_POWER out of drmP.h to allow users
to get rid of the drmP include.
Moved to drm_device.h because drm_device.switch_power_state
is the only user.

Converted to enum and added sparse kerneldoc comments.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Sean Paul <sean@poorly.run>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190108192939.15255-3-sam@ravnborg.org
2019-01-09 22:11:18 +01:00
Sam Ravnborg
ac4f24c213 drm: drm_device.h: update comments to kernel-doc style
Updated comment style to kernel-doc format in drm_device.h

In struct drm_device there are 12 struct members without doc:
- registered
- filelist_mutex
- filelist
- irq
- vbl_lock
- event_lock
- hose
- sigdata
- sigdata.context
- sigdata.lock
- agp_buffer_map
- agp_buffer_token

They all need proper documentation, a task left for someone
that knows their usage.

drm_device is not plugged into Documentation/gpu/drm-internals.rst
as this would create a new load of warnings.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Sean Paul <sean@poorly.run>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190108192939.15255-2-sam@ravnborg.org
2019-01-09 22:11:02 +01:00
Dave Airlie
8c1a765bc6 Merge tag 'drm-misc-next-2019-01-07-1' of git://anongit.freedesktop.org/drm/drm-misc into drm-next
drm-misc-next for 5.1:

UAPI Changes:

Cross-subsystem Changes:
  - Turn dma-buf fence sequence numbers into 64 bit numbers

Core Changes:
  - Move to a common helper for the DP MST hotplug for radeon, i915 and
    amdgpu
  - i2c improvements for drm_dp_mst
  - Removal of drm_syncobj_cb
  - Introduction of an helper to create and attach the TV margin properties

Driver Changes:
  - Improve cache flushes for v3d
  - Reflection support for vc4
  - HDMI overscan support for vc4
  - Add implicit fencing support for rockchip and sun4i
  - Switch to generic fbdev emulation for virtio

Signed-off-by: Dave Airlie <airlied@redhat.com>

[airlied: applied amdgpu merge fixup]
From: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190107180333.amklwycudbsub3s5@flea
2019-01-10 05:58:52 +10:00
Maxime Ripard
1c95f662fc Merge tag 'topic/drmp-cleanup-2019-01-02' of git://anongit.freedesktop.org/drm/drm-intel into drm-misc-next
Make some drm headers self-contained with includes and forward declarations

Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>

# gpg: Signature made Wed 02 Jan 2019 10:47:51 AM CET
# gpg:                using RSA key 1565A65B77B0632E1124E59CD398079D26ABEE6F
# gpg: Can't check signature: No public key
From: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/87pntfl6pa.fsf@intel.com
2019-01-07 16:43:24 +01:00
Linus Torvalds
85e1ffbd42 Merge tag 'kbuild-v4.21-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull more Kbuild updates from Masahiro Yamada:

 - improve boolinit.cocci and use_after_iter.cocci semantic patches

 - fix alignment for kallsyms

 - move 'asm goto' compiler test to Kconfig and clean up jump_label
   CONFIG option

 - generate asm-generic wrappers automatically if arch does not
   implement mandatory UAPI headers

 - remove redundant generic-y defines

 - misc cleanups

* tag 'kbuild-v4.21-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kconfig: rename generated .*conf-cfg to *conf-cfg
  kbuild: remove unnecessary stubs for archheader and archscripts
  kbuild: use assignment instead of define ... endef for filechk_* rules
  arch: remove redundant UAPI generic-y defines
  kbuild: generate asm-generic wrappers if mandatory headers are missing
  arch: remove stale comments "UAPI Header export list"
  riscv: remove redundant kernel-space generic-y
  kbuild: change filechk to surround the given command with { }
  kbuild: remove redundant target cleaning on failure
  kbuild: clean up rule_dtc_dt_yaml
  kbuild: remove UIMAGE_IN and UIMAGE_OUT
  jump_label: move 'asm goto' support test to Kconfig
  kallsyms: lower alignment on ARM
  scripts: coccinelle: boolinit: drop warnings on named constants
  scripts: coccinelle: check for redeclaration
  kconfig: remove unused "file" field of yylval union
  nds32: remove redundant kernel-space generic-y
  nios2: remove unneeded HAS_DMA define
2019-01-06 16:33:10 -08:00
Linus Torvalds
baa6707381 Merge tag 'fscrypt_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt
Pull fscrypt updates from Ted Ts'o:
 "Add Adiantum support for fscrypt"

* tag 'fscrypt_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt:
  fscrypt: add Adiantum support
2019-01-06 12:21:11 -08:00
Linus Torvalds
e2b745f469 Merge tag 'dma-mapping-4.21-1' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping fixes from Christoph Hellwig:
 "Fix various regressions introduced in this cycles:

   - fix dma-debug tracking for the map_page / map_single
     consolidatation

   - properly stub out DMA mapping symbols for !HAS_DMA builds to avoid
     link failures

   - fix AMD Gart direct mappings

   - setup the dma address for no kernel mappings using the remap
     allocator"

* tag 'dma-mapping-4.21-1' of git://git.infradead.org/users/hch/dma-mapping:
  dma-direct: fix DMA_ATTR_NO_KERNEL_MAPPING for remapped allocations
  x86/amd_gart: fix unmapping of non-GART mappings
  dma-mapping: remove a few unused exports
  dma-mapping: properly stub out the DMA API for !CONFIG_HAS_DMA
  dma-mapping: remove dmam_{declare,release}_coherent_memory
  dma-mapping: implement dmam_alloc_coherent using dmam_alloc_attrs
  dma-mapping: implement dma_map_single_attrs using dma_map_page_attrs
2019-01-06 11:47:26 -08:00
Linus Torvalds
12133258d7 Merge tag 'tag-chrome-platform-for-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/bleung/chrome-platform
Pull chrome platform updates from Benson Leung:

 - Changes for EC_MKBP_EVENT_SENSOR_FIFO handling.

 - Also, maintainership changes. Olofj out, Enric balletbo in.

* tag 'tag-chrome-platform-for-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/bleung/chrome-platform:
  MAINTAINERS: add maintainers for ChromeOS EC sub-drivers
  MAINTAINERS: platform/chrome: Add Enric as a maintainer
  MAINTAINERS: platform/chrome: remove myself as maintainer
  platform/chrome: don't report EC_MKBP_EVENT_SENSOR_FIFO as wakeup
  platform/chrome: straighten out cros_ec_get_{next,host}_event() error codes
2019-01-06 11:40:06 -08:00
Eric Biggers
8094c3ceb2 fscrypt: add Adiantum support
Add support for the Adiantum encryption mode to fscrypt.  Adiantum is a
tweakable, length-preserving encryption mode with security provably
reducible to that of XChaCha12 and AES-256, subject to a security bound.
It's also a true wide-block mode, unlike XTS.  See the paper
"Adiantum: length-preserving encryption for entry-level processors"
(https://eprint.iacr.org/2018/720.pdf) for more details.  Also see
commit 059c2a4d8e ("crypto: adiantum - add Adiantum support").

On sufficiently long messages, Adiantum's bottlenecks are XChaCha12 and
the NH hash function.  These algorithms are fast even on processors
without dedicated crypto instructions.  Adiantum makes it feasible to
enable storage encryption on low-end mobile devices that lack AES
instructions; currently such devices are unencrypted.  On ARM Cortex-A7,
on 4096-byte messages Adiantum encryption is about 4 times faster than
AES-256-XTS encryption; decryption is about 5 times faster.

In fscrypt, Adiantum is suitable for encrypting both file contents and
names.  With filenames, it fixes a known weakness: when two filenames in
a directory share a common prefix of >= 16 bytes, with CTS-CBC their
encrypted filenames share a common prefix too, leaking information.
Adiantum does not have this problem.

Since Adiantum also accepts long tweaks (IVs), it's also safe to use the
master key directly for Adiantum encryption rather than deriving
per-file keys, provided that the per-file nonce is included in the IVs
and the master key isn't used for any other encryption mode.  This
configuration saves memory and improves performance.  A new fscrypt
policy flag is added to allow users to opt-in to this configuration.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-01-06 08:36:21 -05:00
Linus Torvalds
d7252d0d36 Merge tag 'for-linus-20190104' of git://git.kernel.dk/linux-block
Pull block updates and fixes from Jens Axboe:

 - Pulled in MD changes that Shaohua had queued up for 4.21.

   Unfortunately we lost Shaohua late 2018, I'm sending these in on his
   behalf.

 - In conjunction with the above, I added a CREDITS entry for Shaoua.

 - sunvdc queue restart fix (Ming)

* tag 'for-linus-20190104' of git://git.kernel.dk/linux-block:
  Add CREDITS entry for Shaohua Li
  block: sunvdc: don't run hw queue synchronously from irq context
  md: fix raid10 hang issue caused by barrier
  raid10: refactor common wait code from regular read/write request
  md: remvoe redundant condition check
  lib/raid6: add option to skip algo benchmarking
  lib/raid6: sort algos in rough performance order
  lib/raid6: check for assembler SSSE3 support
  lib/raid6: avoid __attribute_const__ redefinition
  lib/raid6: add missing include for raid6test
  md: remove set but not used variable 'bi_rdev'
2019-01-05 18:29:13 -08:00
Linus Torvalds
a8a6b1186b Merge tag 'fbdev-v4.21' of git://github.com/bzolnier/linux
Pull fbdev updates from Bartlomiej Zolnierkiewicz:
 "This time the pull request is really small.

  The most notable changes are fixing fbcon to not cause crash on
  unregister_framebuffer() operation when there is more than one
  framebuffer, adding config option to center the bootup logo and making
  FB_BACKLIGHT config option tristate (which in turn uncovered incorrect
  FB_BACKLIGHT usage by DRM's nouveau driver).

  Summary:

   - fix fbcon to not cause crash on unregister_framebuffer() when there
     is more than one framebuffer (Noralf Trønnes)

   - improve support for small rotated displays (Peter Rosin)

   - fix probe failure handling in udlfb driver (Dan Carpenter)

   - add config option to center the bootup logo (Peter Rosin)

   - make FB_BACKLIGHT config option tristate (Rob Clark)

   - remove superfluous HAS_DMA dependency for goldfishfb driver (Geert
     Uytterhoeven)

   - misc fixes (Alexey Khoroshilov, YueHaibing, Colin Ian King, Lubomir
     Rintel)

   - misc cleanups (Yangtao Li, Wen Yang)

  also there is DRM's nouveau driver fix for wrong FB_BACKLIGHT config
  option usage (FB_BACKLIGHT is for internal fbdev subsystem use only)"

* tag 'fbdev-v4.21' of git://github.com/bzolnier/linux:
  drm/nouveau: fix incorrect FB_BACKLIGHT usage in Kconfig
  fbdev: fbcon: Fix unregister crash when more than one framebuffer
  fbdev: Remove depends on HAS_DMA in case of platform dependency
  pxa168fb: trivial typo fix
  fbdev: fsl-diu: remove redundant null check on cmap
  fbdev: omap2: omapfb: convert to DEFINE_SHOW_ATTRIBUTE
  fbdev: uvesafb: fix spelling mistake "memoery" -> "memory"
  fbdev: fbmem: add config option to center the bootup logo
  fbdev: fbmem: make fb_show_logo_line return the end instead of the height
  video: fbdev: pxafb: Fix "WARNING: invalid free of devm_ allocated data"
  fbdev: fbmem: behave better with small rotated displays and many CPUs
  video: clps711x-fb: release disp device node in probe()
  fbdev: make FB_BACKLIGHT a tristate
  udlfb: fix some inconsistent NULL checking
2019-01-05 18:15:37 -08:00
Linus Torvalds
926b02d3eb Merge tag 'pci-v4.21-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
Pull PCI updates from Bjorn Helgaas:

 - Remove unused lists from ASPM pcie_link_state (Frederick Lawler)

 - Fix Broadcom CNB20LE host bridge unintended sign extension (Colin Ian
   King)

 - Expand Kconfig "PF" acronyms (Randy Dunlap)

 - Update MAINTAINERS for arch/x86/kernel/early-quirks.c (Bjorn Helgaas)

 - Add missing include to drivers/pci.h (Alexandru Gagniuc)

 - Override Synopsys USB 3.x HAPS device class so dwc3-haps can claim it
   instead of xhci (Thinh Nguyen)

 - Clean up P2PDMA documentation (Randy Dunlap)

 - Allow runtime PM even if driver doesn't supply callbacks (Jarkko
   Nikula)

 - Remove status check after submitting Switchtec MRPC Firmware Download
   commands to avoid Completion Timeouts (Kelvin Cao)

 - Set Switchtec coherent DMA mask to allow 64-bit DMA (Boris Glimcher)

 - Fix Switchtec SWITCHTEC_IOCTL_EVENT_IDX_ALL flag overwrite issue
   (Joey Zhang)

 - Enable write combining for Switchtec MRPC Input buffers (Kelvin Cao)

 - Add Switchtec MRPC DMA mode support (Wesley Sheng)

 - Skip VF scanning on powerpc, which does this in firmware (Sebastian
   Ott)

 - Add Amlogic Meson PCIe controller driver and DT bindings (Yue Wang)

 - Constify histb dw_pcie_host_ops structure (Julia Lawall)

 - Support multiple power domains for imx6 (Leonard Crestez)

 - Constify layerscape driver data (Stefan Agner)

 - Update imx6 Kconfig to allow imx6 PCIe in imx7 kernel (Trent Piepho)

 - Support armada8k GPIO reset (Baruch Siach)

 - Support suspend/resume support on imx6 (Leonard Crestez)

 - Don't hard-code DesignWare DBI/ATU offst (Stephen Warren)

 - Skip i.MX6 PHY setup on i.MX7D (Andrey Smirnov)

 - Remove Jianguo Sun from HiSilicon STB maintainers (Lorenzo Pieralisi)

 - Mask DesignWare interrupts instead of disabling them to avoid lost
   interrupts (Marc Zyngier)

 - Add locking when acking DesignWare interrupts (Marc Zyngier)

 - Ack DesignWare interrupts in the proper callbacks (Marc Zyngier)

 - Use devm resource parser in mediatek (Honghui Zhang)

 - Remove unused mediatek "num-lanes" DT property (Honghui Zhang)

 - Add UniPhier PCIe controller driver and DT bindings (Kunihiko
   Hayashi)

 - Enable MSI for imx6 downstream components (Richard Zhu)

* tag 'pci-v4.21-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (40 commits)
  PCI: imx: Enable MSI from downstream components
  s390/pci: skip VF scanning
  PCI/IOV: Add flag so platforms can skip VF scanning
  PCI/IOV: Factor out sriov_add_vfs()
  PCI: uniphier: Add UniPhier PCIe host controller support
  dt-bindings: PCI: Add UniPhier PCIe host controller description
  PCI: amlogic: Add the Amlogic Meson PCIe controller driver
  dt-bindings: PCI: meson: add DT bindings for Amlogic Meson PCIe controller
  arm64: dts: mt7622: Remove un-used property for PCIe
  arm: dts: mt7623: Remove un-used property for PCIe
  dt-bindings: PCI: MediaTek: Remove un-used property
  PCI: mediatek: Remove un-used variant in struct mtk_pcie_port
  MAINTAINERS: Remove Jianguo Sun from HiSilicon STB DWC entry
  PCI: dwc: Don't hard-code DBI/ATU offset
  PCI: imx: Add imx6sx suspend/resume support
  PCI: armada8k: Add support for gpio controlled reset signal
  PCI: dwc: Adjust Kconfig to allow IMX6 PCIe host on IMX7
  PCI: dwc: layerscape: Constify driver data
  PCI: imx: Add multi-pd support
  PCI: Override Synopsys USB 3.x HAPS device class
  ...
2019-01-05 17:57:34 -08:00
Linus Torvalds
cf26057a94 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid
Pull HID updates from Jiri Kosina:

 - high-resolution scrolling support that gracefully handles differences
   between MS and Logitech implementations in HW, from Peter Hutterer
   and Harry Cutts

 - MSI IRQ support for intel-ish driver, from Song Hongyan

 - support for new hardware (Cougar 700K, Odys Winbook 13, ASUS FX503VD,
   ASUS T101HA) from Daniel M. Lambea, Hans de Goede and Aleix Roca
   Nonell

 - other small assorted fixups

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid: (22 commits)
  HID: i2c-hid: Add Odys Winbook 13 to descriptor override
  HID: lenovo: Add checks to fix of_led_classdev_register
  HID: intel-ish-hid: add MSI interrupt support
  HID: debug: Change to use DEFINE_SHOW_ATTRIBUTE macro
  HID: doc: fix wrong data structure reference for UHID_OUTPUT
  HID: intel-ish-hid: fixes incorrect error handling
  HID: asus: Add support for the ASUS T101HA keyboard dock
  HID: logitech: Use LDJ_DEVICE macro for existing Logitech mice
  HID: logitech: Enable high-resolution scrolling on Logitech mice
  HID: logitech: Add function to enable HID++ 1.0 "scrolling acceleration"
  HID: logitech-hidpp: fix typo, hiddpp to hidpp
  HID: input: use the Resolution Multiplier for high-resolution scrolling
  HID: core: process the Resolution Multiplier
  HID: core: store the collections as a basic tree
  Input: add `REL_WHEEL_HI_RES` and `REL_HWHEEL_HI_RES`
  HID: input: support Microsoft wireless radio control hotkey
  HID: use macros in IS_INPUT_APPLICATION
  HID: asus: Add support for the ASUS FX503VD laptop
  HID: asus: Add event handler to catch unmapped Asus Vendor UsagePage codes
  HID: cougar: Add support for Cougar 700K Gaming Keyboard
  ...
2019-01-05 17:53:40 -08:00
Masahiro Yamada
d4ce5458ea arch: remove stale comments "UAPI Header export list"
These comments are leftovers of commit fcc8487d47 ("uapi: export all
headers under uapi directories").

Prior to that commit, exported headers must be explicitly added to
header-y. Now, all headers under the uapi/ directories are exported.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-01-06 09:46:51 +09:00
Masahiro Yamada
e9666d10a5 jump_label: move 'asm goto' support test to Kconfig
Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label".

The jump label is controlled by HAVE_JUMP_LABEL, which is defined
like this:

  #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
  # define HAVE_JUMP_LABEL
  #endif

We can improve this by testing 'asm goto' support in Kconfig, then
make JUMP_LABEL depend on CC_HAS_ASM_GOTO.

Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will
match to the real kernel capability.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
2019-01-06 09:46:51 +09:00
Linus Torvalds
505b050fdf Merge branch 'mount.part1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs mount API prep from Al Viro:
 "Mount API prereqs.

  Mostly that's LSM mount options cleanups. There are several minor
  fixes in there, but nothing earth-shattering (leaks on failure exits,
  mostly)"

* 'mount.part1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (27 commits)
  mount_fs: suppress MAC on MS_SUBMOUNT as well as MS_KERNMOUNT
  smack: rewrite smack_sb_eat_lsm_opts()
  smack: get rid of match_token()
  smack: take the guts of smack_parse_opts_str() into a new helper
  LSM: new method: ->sb_add_mnt_opt()
  selinux: rewrite selinux_sb_eat_lsm_opts()
  selinux: regularize Opt_... names a bit
  selinux: switch away from match_token()
  selinux: new helper - selinux_add_opt()
  LSM: bury struct security_mnt_opts
  smack: switch to private smack_mnt_opts
  selinux: switch to private struct selinux_mnt_opts
  LSM: hide struct security_mnt_opts from any generic code
  selinux: kill selinux_sb_get_mnt_opts()
  LSM: turn sb_eat_lsm_opts() into a method
  nfs_remount(): don't leak, don't ignore LSM options quietly
  btrfs: sanitize security_mnt_opts use
  selinux; don't open-code a loop in sb_finish_set_opts()
  LSM: split ->sb_set_mnt_opts() out of ->sb_kern_mount()
  new helper: security_sb_eat_lsm_opts()
  ...
2019-01-05 13:25:58 -08:00
Linus Torvalds
9b286efeb5 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull trivial vfs updates from Al Viro:
 "A few cleanups + Neil's namespace_unlock() optimization"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  exec: make prepare_bprm_creds static
  genheaders: %-<width>s had been there since v6; %-*s - since v7
  VFS: use synchronize_rcu_expedited() in namespace_unlock()
  iov_iter: reduce code duplication
2019-01-05 13:18:59 -08:00
Linus Torvalds
b23b0ea370 Merge tag 'armsoc-late' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull more ARM SoC updates from Olof Johansson:
 "A few updates that we merged late but are low risk for regressions for
  other platforms (and a few other straggling patches):

   - I mis-tagged the 'drivers' branch, and missed 3 patches. Merged in
     here. They're for a driver for the PL353 SRAM controller and a
     build fix for the qualcomm scm driver.

   - A new platform, RDA Micro RDA8810PL (Cortex-A5 w/ integrated
     Vivante GPU, 256MB RAM, Wifi). This includes some acked
     platform-specific drivers (serial, etc). This also include DTs for
     two boards with this SoC, OrangePi 2G and OrangePi i86.

   - i.MX8 is another new platform (NXP, 4x Cortex-A53 + Cortex-M4, 4K
     video playback offload). This is the first i.MX 64-bit SoC.

   - Some minor updates to Samsung boards (adding a few peripherals in
     DTs).

   - Small rework for SMP bootup on STi platforms.

   - A couple of TEE driver fixes.

   - A couple of new config options (bcm2835 thermal, Uniphier MDMAC)
     enabled in defconfigs"

* tag 'armsoc-late' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (27 commits)
  ARM: multi_v7_defconfig: enable CONFIG_UNIPHIER_MDMAC
  arm64: defconfig: Re-enable bcm2835-thermal driver
  MAINTAINERS: Add entry for RDA Micro SoC architecture
  tty: serial: Add RDA8810PL UART driver
  ARM: dts: rda8810pl: Add interrupt support for UART
  dt-bindings: serial: Document RDA Micro UART
  ARM: dts: rda8810pl: Add timer support
  ARM: dts: Add devicetree for OrangePi i96 board
  ARM: dts: Add devicetree for OrangePi 2G IoT board
  ARM: dts: Add devicetree for RDA8810PL SoC
  ARM: Prepare RDA8810PL SoC
  dt-bindings: arm: Document RDA8810PL and reference boards
  dt-bindings: Add RDA Micro vendor prefix
  ARM: sti: remove pen_release and boot_lock
  arm64: dts: exynos: Add Bluetooth chip to TM2(e) boards
  arm64: dts: imx8mq-evk: enable watchdog
  arm64: dts: imx8mq: add watchdog devices
  MAINTAINERS: add i.MX8 DT path to i.MX architecture
  arm64: add support for i.MX8M EVK board
  arm64: add basic DTS for i.MX8MQ
  ...
2019-01-05 11:30:37 -08:00
Linus Torvalds
9ee3b3f4a5 Merge tag 'csky-for-linus-4.21' of git://github.com/c-sky/csky-linux
Pull arch/csky updates from Guo Ren:
 "Here are three main features (cpu_hotplug, basic ftrace, basic perf)
  and some bugfixes:

  Features:
   - Add CPU-hotplug support for SMP
   - Add ftrace with function trace and function graph trace
   - Add Perf support
   - Add EM_CSKY_OLD 39
   - optimize kernel panic print.
   - remove syscall_exit_work

  Bugfixes:
   - fix abiv2 mmap(... O_SYNC) failure
   - fix gdb coredump error
   - remove vdsp implement for kernel
   - fix qemu failure to bootup sometimes
   - fix ftrace call-graph panic
   - fix device tree node reference leak
   - remove meaningless header-y
   - fix save hi,lo,dspcr regs in switch_stack
   - remove unused members in processor.h"

* tag 'csky-for-linus-4.21' of git://github.com/c-sky/csky-linux:
  csky: Add perf support for C-SKY
  csky: Add EM_CSKY_OLD 39
  clocksource/drivers/c-sky: fixup ftrace call-graph panic
  csky: ftrace call graph supported.
  csky: basic ftrace supported
  csky: remove unused members in processor.h
  csky: optimize kernel panic print.
  csky: stacktrace supported.
  csky: CPU-hotplug supported for SMP
  clocksource/drivers/c-sky: fixup qemu fail to bootup sometimes.
  csky: fixup save hi,lo,dspcr regs in switch_stack.
  csky: remove syscall_exit_work
  csky: fixup remove vdsp implement for kernel.
  csky: bugfix gdb coredump error.
  csky: fixup abiv2 mmap(... O_SYNC) failed.
  csky: define syscall_get_arch()
  elf-em.h: add EM_CSKY
  csky: remove meaningless header-y
  csky: Don't leak device tree node reference
2019-01-05 09:50:07 -08:00
Linus Torvalds
a65981109f Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:

 - procfs updates

 - various misc bits

 - lib/ updates

 - epoll updates

 - autofs

 - fatfs

 - a few more MM bits

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (58 commits)
  mm/page_io.c: fix polled swap page in
  checkpatch: add Co-developed-by to signature tags
  docs: fix Co-Developed-by docs
  drivers/base/platform.c: kmemleak ignore a known leak
  fs: don't open code lru_to_page()
  fs/: remove caller signal_pending branch predictions
  mm/: remove caller signal_pending branch predictions
  arch/arc/mm/fault.c: remove caller signal_pending_branch predictions
  kernel/sched/: remove caller signal_pending branch predictions
  kernel/locking/mutex.c: remove caller signal_pending branch predictions
  mm: select HAVE_MOVE_PMD on x86 for faster mremap
  mm: speed up mremap by 20x on large regions
  mm: treewide: remove unused address argument from pte_alloc functions
  initramfs: cleanup incomplete rootfs
  scripts/gdb: fix lx-version string output
  kernel/kcov.c: mark write_comp_data() as notrace
  kernel/sysctl: add panic_print into sysctl
  panic: add options to print system info when panic happens
  bfs: extra sanity checking and static inode bitmap
  exec: separate MM_ANONPAGES and RLIMIT_STACK accounting
  ...
2019-01-05 09:16:18 -08:00
Olof Johansson
00f8ccd0c9 Merge branch 'next/drivers' into next/late
Merge in a few missing patches from the pull request (my copy of the
branch was behind the staged version in linux-next).

* next/drivers:
  memory: pl353: Add driver for arm pl353 static memory controller
  dt-bindings: memory: Add pl353 smc controller devicetree binding information
  firmware: qcom: scm: fix compilation error when disabled

Signed-off-by: Olof Johansson <olof@lixom.net>
2019-01-04 14:31:38 -08:00
Nikolay Borisov
f86196ea87 fs: don't open code lru_to_page()
Multiple filesystems open code lru_to_page().  Rectify this by moving
the macro from mm_inline (which is specific to lru stuff) to the more
generic mm.h header and start using the macro where appropriate.

No functional changes.

Link: http://lkml.kernel.org/r/20181129104810.23361-1-nborisov@suse.com
Link: https://lkml.kernel.org/r/20181129075301.29087-1-nborisov@suse.com
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Pankaj gupta <pagupta@redhat.com>
Acked-by: "Yan, Zheng" <zyan@redhat.com>		[ceph]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 13:13:48 -08:00
Joel Fernandes (Google)
4cf5892495 mm: treewide: remove unused address argument from pte_alloc functions
Patch series "Add support for fast mremap".

This series speeds up the mremap(2) syscall by copying page tables at
the PMD level even for non-THP systems.  There is concern that the extra
'address' argument that mremap passes to pte_alloc may do something
subtle architecture related in the future that may make the scheme not
work.  Also we find that there is no point in passing the 'address' to
pte_alloc since its unused.  This patch therefore removes this argument
tree-wide resulting in a nice negative diff as well.  Also ensuring
along the way that the enabled architectures do not do anything funky
with the 'address' argument that goes unnoticed by the optimization.

Build and boot tested on x86-64.  Build tested on arm64.  The config
enablement patch for arm64 will be posted in the future after more
testing.

The changes were obtained by applying the following Coccinelle script.
(thanks Julia for answering all Coccinelle questions!).
Following fix ups were done manually:
* Removal of address argument from  pte_fragment_alloc
* Removal of pte_alloc_one_fast definitions from m68k and microblaze.

// Options: --include-headers --no-includes
// Note: I split the 'identifier fn' line, so if you are manually
// running it, please unsplit it so it runs for you.

virtual patch

@pte_alloc_func_def depends on patch exists@
identifier E2;
identifier fn =~
"^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
type T2;
@@

 fn(...
- , T2 E2
 )
 { ... }

@pte_alloc_func_proto_noarg depends on patch exists@
type T1, T2, T3, T4;
identifier fn =~ "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
@@

(
- T3 fn(T1, T2);
+ T3 fn(T1);
|
- T3 fn(T1, T2, T4);
+ T3 fn(T1, T2);
)

@pte_alloc_func_proto depends on patch exists@
identifier E1, E2, E4;
type T1, T2, T3, T4;
identifier fn =~
"^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
@@

(
- T3 fn(T1 E1, T2 E2);
+ T3 fn(T1 E1);
|
- T3 fn(T1 E1, T2 E2, T4 E4);
+ T3 fn(T1 E1, T2 E2);
)

@pte_alloc_func_call depends on patch exists@
expression E2;
identifier fn =~
"^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
@@

 fn(...
-,  E2
 )

@pte_alloc_macro depends on patch exists@
identifier fn =~
"^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
identifier a, b, c;
expression e;
position p;
@@

(
- #define fn(a, b, c) e
+ #define fn(a, b) e
|
- #define fn(a, b) e
+ #define fn(a) e
)

Link: http://lkml.kernel.org/r/20181108181201.88826-2-joelaf@google.com
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Suggested-by: Kirill A. Shutemov <kirill@shutemov.name>
Acked-by: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 13:13:47 -08:00
Feng Tang
81c9d43f94 kernel/sysctl: add panic_print into sysctl
So that we can also runtime chose to print out the needed system info
for panic, other than setting the kernel cmdline.

Link: http://lkml.kernel.org/r/1543398842-19295-3-git-send-email-feng.tang@intel.com
Signed-off-by: Feng Tang <feng.tang@intel.com>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 13:13:47 -08:00
Tigran Aivazian
d187715589 bfs: extra sanity checking and static inode bitmap
Strengthen validation of BFS superblock against corruption.  Make
in-core inode bitmap static part of superblock info structure.  Print a
warning when mounting a BFS filesystem created with "-N 512" option as
only 510 files can be created in the root directory.  Make the kernel
messages more uniform.  Update the 'prefix' passed to bfs_dump_imap() to
match the current naming of operations.  White space and comments
cleanup.

Link: http://lkml.kernel.org/r/CAK+_RLkFZMduoQF36wZFd3zLi-6ZutWKsydjeHFNdtRvZZEb4w@mail.gmail.com
Signed-off-by: Tigran Aivazian <aivazian.tigran@gmail.com>
Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 13:13:47 -08:00
Oleg Nesterov
655c16a8ce exec: separate MM_ANONPAGES and RLIMIT_STACK accounting
get_arg_page() checks bprm->rlim_stack.rlim_cur and re-calculates the
"extra" size for argv/envp pointers every time, this is a bit ugly and
even not strictly correct: acct_arg_size() must not account this size.

Remove all the rlimit code in get_arg_page().  Instead, add bprm->argmin
calculated once at the start of __do_execve_file() and change
copy_strings to check bprm->p >= bprm->argmin.

The patch adds the new helper, prepare_arg_pages() which initializes
bprm->argc/envc and bprm->argmin.

[oleg@redhat.com: fix !CONFIG_MMU version of get_arg_page()]
  Link: http://lkml.kernel.org/r/20181126122307.GA1660@redhat.com
[akpm@linux-foundation.org: use max_t]
Link: http://lkml.kernel.org/r/20181112160910.GA28440@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 13:13:47 -08:00
Yi Wang
fb5bf31722 fork: fix some -Wmissing-prototypes warnings
We get a warning when building kernel with W=1:

  kernel/fork.c:167:13: warning: no previous prototype for `arch_release_thread_stack' [-Wmissing-prototypes]
  kernel/fork.c:779:13: warning: no previous prototype for `fork_init' [-Wmissing-prototypes]

Add the missing declaration in head file to fix this.

Also, remove arch_release_thread_stack() completely because no arch
seems to implement it since bb9d81264 (arch: remove tile port).

Link: http://lkml.kernel.org/r/1542170087-23645-1-git-send-email-wang.yi59@zte.com.cn
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 13:13:47 -08:00
Carmeli Tamir
d19dc01618 fat: move MAX_FAT to fat.h and change it to inline function
MAX_FAT is useless in msdos_fs.h, since it uses the MSDOS_SB function
that is defined in fat.h.  So really, this macro can be only called from
code that already includes fat.h.

Hence, this patch moves it to fat.h, right after MSDOS_SB is defined.  I
also changed it to an inline function in order to save the double call
to MSDOS_SB.  This was suggested by joe@perches.com in the previous
version.

This patch is required for the next in the series, in which the variant
(whether this is FAT12, FAT16 or FAT32) checks are replaced with new
macros.

Link: http://lkml.kernel.org/r/1544990640-11604-3-git-send-email-carmeli.tamir@gmail.com
Signed-off-by: Carmeli Tamir <carmeli.tamir@gmail.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 13:13:47 -08:00
Carmeli Tamir
b553337a57 fat: remove FAT_FIRST_ENT macro
The comment edited in this patch was the only reference to the
FAT_FIRST_ENT macro, which is not used anymore.  Moreover, the commented
line of code does not compile with the current code.

Since the FAT_FIRST_ENT macro checks the FAT variant in a way that the
patch series changes, I removed it, and instead wrote a clear
explanation of what was checked.

I verified that the changed comment is correct according to Microsoft
FAT spec, search for "BPB_Media" in the following references:

1. Microsoft FAT specification 2005
(http://read.pudn.com/downloads77/ebook/294884/FAT32%20Spec%20%28SDA%20Contribution%29.pdf).
Search for 'volume label'.
2. Microsoft Extensible Firmware Initiative, FAT32 File System Specification
(https://staff.washington.edu/dittrich/misc/fatgen103.pdf).
Search for 'volume label'.

Link: http://lkml.kernel.org/r/1544990640-11604-2-git-send-email-carmeli.tamir@gmail.com
Signed-off-by: Carmeli Tamir <carmeli.tamir@gmail.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 13:13:47 -08:00
Carmeli Tamir
9da2285476 include/uapi/linux/msdos_fs.h: use MSDOS_NAME for volume label size
The FAT file system volume label file stored in the root directory
should match the volume label field in the FAT boot sector.  As
consequence, the max length of these fields ought to be the same.  This
patch replaces the magic '11' usef in the struct fat_boot_sector with
MSDOS_NAME, which is used in struct msdos_dir_entry.

Please check the following references:
1. Microsoft FAT specification 2005
(http://read.pudn.com/downloads77/ebook/294884/FAT32%20Spec%20%28SDA%20Contribution%29.pdf).
Search for 'volume label'.
2. Microsoft Extensible Firmware Initiative, FAT32 File System Specification
(https://staff.washington.edu/dittrich/misc/fatgen103.pdf).
Search for 'volume label'.
3. User space code that creates FAT filesystem
sometimes uses MSDOS_NAME for the label, sometimes not.
Search for 'if (memcmp(label, NO_NAME, MSDOS_NAME))'.
I consider to make the same patch there as well.
https://github.com/dosfstools/dosfstools/blob/master/src/mkfs.fat.c

Link: http://lkml.kernel.org/r/1543096879-82837-1-git-send-email-carmeli.tamir@gmail.com
Signed-off-by: Carmeli Tamir <carmeli.tamir@gmail.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 13:13:47 -08:00
Ian Kent
f5162216b7 autofs: add strictexpire mount option
Commit 092a53452b ("autofs: take more care to not update last_used on
path walk") helped to (partially) resolve a problem where automounts
were not expiring due to aggressive accesses from user space.

This patch was later reverted because, for very large environments, it
meant more mount requests from clients and when there are a lot of
clients this caused a fairly significant increase in server load.

But there is a need for both types of expire check, depending on use
case, so add a mount option to allow for strict update of last use of
autofs dentrys (which just means not updating the last use on path walk
access).

Link: http://lkml.kernel.org/r/154296973880.9889.14085372741514507967.stgit@pluto-themaw-net
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 13:13:47 -08:00
Alexey Skidanov
52fbf1134d lib/genalloc.c: fix allocation of aligned buffer from non-aligned chunk
gen_pool_alloc_algo() uses different allocation functions implementing
different allocation algorithms.  With gen_pool_first_fit_align()
allocation function, the returned address should be aligned on the
requested boundary.

If chunk start address isn't aligned on the requested boundary, the
returned address isn't aligned too.  The only way to get properly
aligned address is to initialize the pool with chunks aligned on the
requested boundary.  If want to have an ability to allocate buffers
aligned on different boundaries (for example, 4K, 1MB, ...), the chunk
start address should be aligned on the max possible alignment.

This happens because gen_pool_first_fit_align() looks for properly
aligned memory block without taking into account the chunk start address
alignment.

To fix this, we provide chunk start address to
gen_pool_first_fit_align() and change its implementation such that it
starts looking for properly aligned block with appropriate offset
(exactly as is done in CMA).

Link: https://lkml.kernel.org/lkml/a170cf65-6884-3592-1de9-4c235888cc8a@intel.com
Link: http://lkml.kernel.org/r/1541690953-4623-1-git-send-email-alexey.skidanov@intel.com
Signed-off-by: Alexey Skidanov <alexey.skidanov@intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Daniel Mentz <danielmentz@google.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Laura Abbott <labbott@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 13:13:46 -08:00
Matthew Wilcox
3fc2579e6f fls: change parameter to unsigned int
When testing in userspace, UBSAN pointed out that shifting into the sign
bit is undefined behaviour.  It doesn't really make sense to ask for the
highest set bit of a negative value, so just turn the argument type into
an unsigned int.

Some architectures (eg ppc) already had it declared as an unsigned int,
so I don't expect too many problems.

Link: http://lkml.kernel.org/r/20181105221117.31828-1-willy@infradead.org
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 13:13:46 -08:00
Alexey Dobriyan
e6310f0fb5 include/linux/printk.h: drop silly "static inline asmlinkage" from dump_stack()
Empty function will be inlined so asmlinkage doesn't do anything.

Link: http://lkml.kernel.org/r/20181124093530.GE10969@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Joey Pabalinas <joeypabalinas@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 13:13:46 -08:00
Masahiro Yamada
527edbc18a build_bug.h: remove most of dummy BUILD_BUG_ON stubs for Sparse
The introduction of these dummy BUILD_BUG_ON stubs dates back to commmit
903c0c7cdc ("sparse: define dummy BUILD_BUG_ON definition for
sparse").

At that time, BUILD_BUG_ON() was implemented with the negative array
trick *and* the link-time trick, like this:

  extern int __build_bug_on_failed;
  #define BUILD_BUG_ON(condition)                                \
          do {                                                   \
                  ((void)sizeof(char[1 - 2*!!(condition)]));     \
                  if (condition) __build_bug_on_failed = 1;      \
          } while(0)

Sparse is more strict about the negative array trick than GCC because
Sparse requires the array length to be really constant.

Here is the simple test code for the macro above:

  static const int x = 0;
  BUILD_BUG_ON(x);

GCC is absolutely fine with it (-Wvla was enabled only very recently),
but Sparse warns like this:

  error: bad constant expression
  error: cannot size expression

(If you are using a newer version of Sparse, you will see a different
warning message, "warning: Variable length array is used".)

Anyway, Sparse was producing many false positives, and noisier than it
should be at that time.

With the previous commit, the leftover negative array trick is gone.
Sparse is fine with the current BUILD_BUG_ON(), which is implemented by
using the 'error' attribute.

I am keeping the stub for BUILD_BUG_ON_ZERO().  Otherwise, Sparse would
complain about the following code, which GCC is fine with:

  static const int x = 0;
  int y = BUILD_BUG_ON_ZERO(x);

Link: http://lkml.kernel.org/r/1542856462-18836-3-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 13:13:45 -08:00
Masahiro Yamada
c60d3b7942 build_bug.h: remove negative-array fallback for BUILD_BUG_ON()
The kernel can only be compiled with an optimization option (-O2, -Os,
or the currently proposed -Og).  Hence, __OPTIMIZE__ is always defined
in the kernel source.

The fallback for the -O0 case is just hypothetical and pointless.
Moreover, commit 0bb95f80a3 ("Makefile: Globally enable VLA warning")
enabled -Wvla warning.  The use of variable length arrays is banned.

Link: http://lkml.kernel.org/r/1542856462-18836-2-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 13:13:45 -08:00
Linus Torvalds
594cc251fd make 'user_access_begin()' do 'access_ok()'
Originally, the rule used to be that you'd have to do access_ok()
separately, and then user_access_begin() before actually doing the
direct (optimized) user access.

But experience has shown that people then decide not to do access_ok()
at all, and instead rely on it being implied by other operations or
similar.  Which makes it very hard to verify that the access has
actually been range-checked.

If you use the unsafe direct user accesses, hardware features (either
SMAP - Supervisor Mode Access Protection - on x86, or PAN - Privileged
Access Never - on ARM) do force you to use user_access_begin().  But
nothing really forces the range check.

By putting the range check into user_access_begin(), we actually force
people to do the right thing (tm), and the range check vill be visible
near the actual accesses.  We have way too long a history of people
trying to avoid them.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 12:56:09 -08:00
Christoph Hellwig
ed6ccf10f2 dma-mapping: properly stub out the DMA API for !CONFIG_HAS_DMA
This avoids link failures in drivers using the DMA API, when they
are compiled for user mode Linux with CONFIG_COMPILE_TEST=y.

Fixes: 356da6d0cd ("dma-mapping: bypass indirect calls for dma-direct")
Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-01-04 09:03:17 +01:00