There can only be one current master, and it's for the overall device.
Render/control minors don't support master-based auth at all.
This simplifies the master logic a lot, at least in my eyes: All these
additional pointer chases are just confusing.
While doing the conversion I spotted some locking fail:
- drm_lock/drm_auth check dev->master without holding the
master_mutex. This is fallout from
commit c996fd0b95
Author: Thomas Hellstrom <thellstrom@vmware.com>
Date: Tue Feb 25 19:57:44 2014 +0100
drm: Protect the master management with a drm_device::master_mutex v3
but I honestly don't care one bit about those old legacy drivers
using this.
- debugfs name info should just grab master_mutex.
- And the fbdev helper looked at it to figure out whether someone is
using KMS. We just need a consistent value, so READ_ONCE. Aside: We
should probably check if anyone has opened a control node too, but I
guess current userspace doesn't really do that yet.
v2: Balance locking, reported by Julia.
v3: Rebase on top of Chris' oops fixes.
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v2)
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com> (v2)
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466499262-18717-1-git-send-email-daniel.vetter@ffwll.ch
A few things:
- Rename the cleanup function from drm_master_release to
drm_legacy_lock_release. It doesn't relase any master stuff, but
just the legacy hw lock.
- Hide it in drm_lock.c, which allows us to make a few more functions
static in there. To avoid forward decl we need to shuffle the code a
bit though.
- Push the check for ->master into the function itself.
- Only call this for !DRIVER_MODESET.
End result: Another place that takes struct_mutex gone for good for
modern drivers.
v2: Remove leftover comment.
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1465930269-7883-3-git-send-email-daniel.vetter@ffwll.ch
It is hardly possible to enumerate all problems with block_all_signals()
and unblock_all_signals(). Just for example,
1. block_all_signals(SIGSTOP/etc) simply can't help if the caller is
multithreaded. Another thread can dequeue the signal and force the
group stop.
2. Even is the caller is single-threaded, it will "stop" anyway. It
will not sleep, but it will spin in kernel space until SIGCONT or
SIGKILL.
And a lot more. In short, this interface doesn't work at all, at least
the last 10+ years.
Daniel said:
Yeah the only times I played around with the DRM_LOCK stuff was when
old drivers accidentally deadlocked - my impression is that the entire
DRM_LOCK thing was never really tested properly ;-) Hence I'm all for
purging where this leaks out of the drm subsystem.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Dave Airlie <airlied@redhat.com>
Cc: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I've done some extensive history digging across libdrm, mesa and
xf86-video-{intel,nouveau,ati}. The only potential user of this with
kms drivers I could find was ttmtest, which once used drmGetLock
still. But that mistake was quickly fixed up. Even the intel xvmc
library (which otherwise was really good with using dri1 stuff in kms
mode) managed to never take the hw lock for dri2 (and hence kms).
Hence it should be save to unconditionally disallow this.
Cc: Peter Antoine <peter.antoine@intel.com>
Reviewed-by: Peter Antoine <peter.antoine@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Drivers really, really have no business even looking at this lock. And
thankfully they don't.
So unexport it and move the declaration to drm_internal.h.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Same as the other legacy APIs, most of this is internal, so prefix it with
drm_legacy_* and move into drm_legacy.h.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
The sigdata structure is only used to group two fields in drm_device.
Inline it and make it an unnamed object.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This reverts commit 48ba813701.
Thanks to Chris:
"drm_file->is_master is not synomous with having drm_file->master ==
drm_file->minor->master. This is because drm_file->master is the same
for all drm_files of the same generation and so when there is a master,
every drm_file believes itself to be the master. Confusion ensues and
things go pear shaped when one file is closed and there is no master
anymore."
Conflicts:
drivers/gpu/drm/drm_drv.c
drivers/gpu/drm/drm_stub.c
This renames all drm-context helpers to drm_legacy_*() and moves the
internal definitions into the new drm_legacy.h header. This header is
local to DRM-core and drivers shouldn't access it.
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
The drm_file->is_master field is redundant as it's equivalent to:
drm_file->master && drm_file->master == drm_file->minor->master
1) "=>"
Whenever we set drm_file->is_master, we also set:
drm_file->minor->master = drm_file->master;
Whenever we clear drm_file->is_master, we also call:
drm_master_put(&drm_file->minor->master);
which implicitly clears it to NULL.
2) "<="
minor->master cannot be set if it is non-NULL. Therefore, it stays as
is unless a file drops it.
If minor->master is NULL, it is only set by places that also adjust
drm_file->is_master.
Therefore, we can safely drop is_master and replace it by an inline helper
that matches:
drm_file->master && drm_file->master == drm_file->minor->master
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
The user of these counters was killed in
commit d79cdc8312
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Thu Aug 8 15:41:32 2013 +0200
drm: no-op out GET_STATS ioctl
so clean up the leftovers as well.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Convert #include "..." to #include <path/...> in drivers/gpu/.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
Only one driver (i810) even sets that flag. Now the actual locking
code uncoditionally promotes lock->context to an unsigned int.
Closer inspection of the userspace reveals that the drm lock context
is defined as an unsigned int (at least on linux). I suspect we just
have a strange case of signedness confusion going on.
Tested on my i815, doesn't seem to break anything.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
I've accidently killed a little bit too much in
commit 1da3f87ebb
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Mon Aug 23 22:53:24 2010 +0200
drm: kill kernel_context_switch callbacks
Note to self: Next time also test with AIGLX disabled.
Reported-and-Tested-by: Andy Furniss <lists@andyfurniss.entadsl.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=30374
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This locking path needs proper auditing but probably too late for changes at this point for 2.6.36, so lets go with the quick fix, which is to drop the lock around schedule.
Reported-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This is done by
1) Wake up lock waiters when we close the master file descriptor.
Not when the master structure is removed, since the latter
requires the waiters themselves to release the refcount on the
master structure -> Deadlock.
2) Send a SIGTERM to all clients waiting for the lock.
Normally these clients will get a SIGPIPE when the X server dies,
but clients may also spin trying to grab the DRM lock, without
getting any sort of notification.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@linux.ie>
That return code is for in-kernel use only.
Use EINTR instead.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@linux.ie>
This is step one towards having multiple masters sharing a drm
device in order to get fast-user-switching to work.
It splits out the information associated with the drm master
into a separate kref counted structure, and allocates this when
a master opens the device node. It also allows the current master
to abdicate (say while VT switched), and a new master to take over
the hardware.
It moves the Intel and radeon drivers to using the sarea from
within the new master structures.
Signed-off-by: Dave Airlie <airlied@redhat.com>
It's not used in any other drivers, and doesn't look like it will be from
drm.git master.
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@linux.ie>
To synchronize clip lists with the X server, the DRM lock must be held while
looking at drawable clip lists. To synchronize with other ring access, the
ring mutex must be held while inserting commands into the ring. Failure to
do the first resulted in easy visual corruption when moving windows, and the
second could have corrupted the ring with DRI2.
Grabbing the DRM lock involves using the DRM tasklet mechanism, grabbing the
ring mutex means potentially sleeping. Deal with both of these by always
running the tasklet from a work handler.
Also, protect from clip list changes since the vblank request was queued by
making sure the window has at least one rectangle while looking inside,
preventing oopses .
Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
There is a problem with debugging the X server and gdb crashes in
the xkb startup code.
This avoids the problem by allowing the master process to get signals.
It should be safe as the signal blocker is mainly so that you can
Ctrl-Z a 3D application without locking up the whole box. Ctrl-Z the
X server isn't something many people do.
Signed-off-by: Dave Airlie <airlied@redhat.com>
If a specific tasklet shares data with irq context,
it needs to take a private irq-blocking spinlock within
the tasklet itself.
Signed-off-by: Dave Airlie <airlied@redhat.com>
With the coming of kernel based modesetting and the memory manager stuff,
the everything in one directory approach was getting very ugly and
starting to be unmanageable.
This restructures the drm along the lines of other kernel components.
It creates a drivers/gpu/drm directory and moves the hw drivers into
subdirectores. It moves the includes into an include/drm, and
sets up the unifdef for the userspace headers we should be exporting.
Signed-off-by: Dave Airlie <airlied@redhat.com>
Daniel Vetter