drm: Remove locking for legacy ioctls and DRM_UNLOCKED

Modern DRM drivers acquire ioctl locks by themselves. Legacy ioctls
for user-space mode setting used to acquire drm_global_mutex. After
removin

drm: Remove locking for legacy ioctls and DRM_UNLOCKED

Modern DRM drivers acquire ioctl locks by themselves. Legacy ioctls
for user-space mode setting used to acquire drm_global_mutex. After
removing the ioctl entry points, also remove the locking code. The only
legacy ioctl without global locking was VBLANK_WAIT, which has been
removed as well. Hence remove the related DRM_UNLOCKED flag.

Signed-off-by: Thomas Zimmermann <[email protected]>
Reviewed-by: David Airlie <[email protected]>
Reviewed-by: Daniel Vetter <[email protected]>
Acked-by: Alex Deucher <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

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drm: unexport drm_ioctl_permit

Since the last user of drm_ioctl_permit was removed, and it's now only
used in drm_ioctl.c, unexport the symbol.

Reported-by: Daniel Vetter <[email protected]>
S

drm: unexport drm_ioctl_permit

Since the last user of drm_ioctl_permit was removed, and it's now only
used in drm_ioctl.c, unexport the symbol.

Reported-by: Daniel Vetter <[email protected]>
Signed-off-by: Desmond Cheong Zhi Xi <[email protected]>
Signed-off-by: Daniel Vetter <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

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drm: Return -ENOTTY for non-drm ioctls

drm: Return -ENOTTY for non-drm ioctls

Return -ENOTTY from drm_ioctl() when userspace passes in a cmd number
which doesn't relate to the drm subsystem.

Glibc

drm: Return -ENOTTY for non-drm ioctls

drm: Return -ENOTTY for non-drm ioctls

Return -ENOTTY from drm_ioctl() when userspace passes in a cmd number
which doesn't relate to the drm subsystem.

Glibc uses the TCGETS ioctl to implement isatty(), and without this
change isatty() returns it incorrectly returns true for drm devices.

To test run this command:
$ if [ -t 0 ]; then echo is a tty; fi < /dev/dri/card0
which shows "is a tty" without this patch.

This may also modify memory which the userspace application is not
expecting.

Signed-off-by: Charles Baylis <[email protected]>
Cc: [email protected]
Signed-off-by: Daniel Vetter <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

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drm/ioctl: Ditch DRM_UNLOCKED except for the legacy vblank ioctl

This completes Emil's series of removing DRM_UNLOCKED from modern
drivers. It's entirely cargo-culted since we ignore it on
non-DRIVE

drm/ioctl: Ditch DRM_UNLOCKED except for the legacy vblank ioctl

This completes Emil's series of removing DRM_UNLOCKED from modern
drivers. It's entirely cargo-culted since we ignore it on
non-DRIVER_LEGACY drivers since:

commit ea487835e8876abf7ad909636e308c801a2bcda6
Author: Daniel Vetter <[email protected]>
Date: Mon Sep 28 21:42:40 2015 +0200

drm: Enforce unlocked ioctl operation for kms driver ioctls

Now justifying why we can do this for legacy drives too (and hence
close the source of all the bogus copypasting) is a bit more involved.
DRM_UNLOCKED was introduced in:

commit ed8b67040965e4fe695db333d5914e18ea5f146f
Author: Arnd Bergmann <[email protected]>
Date: Wed Dec 16 22:17:09 2009 +0000

drm: convert drm_ioctl to unlocked_ioctl

As a immediate hack to keep i810 happy, which would have deadlocked
without this trickery. The old BKL is automatically dropped in
schedule(), and hence the i810 vs. mmap_sem deadlock didn't actually
cause a real deadlock. But with a mutex it would. The solution was to
annotate these as DRM_UNLOCKED and mark i810 unsafe on SMP machines.

This conversion caused a regression, because unlike the BKL a mutex
isn't dropped over schedule (that thing again), which caused a vblank
wait in one thread to block the entire desktop and all its apps. Back
then we did vblank scheduling by blocking in the client, awesome isn't
it. This was fixed quickly in (ok not so quickly, took 2 years):

commit 8f4ff2b06afcd6f151868474a432c603057eaf56
Author: Ilija Hadzic <[email protected]>
Date: Mon Oct 31 17:46:18 2011 -0400

drm: do not sleep on vblank while holding a mutex

All the other DRM_UNLOCKED annotations for all the core ioctls was
work to reach finer-grained locking for modern drivers. This took
years, and culminated in:

commit fdd5b877e9ebc2029e1373b4a3cd057329a9ab7a
Author: Daniel Vetter <[email protected]>
Date: Sat Dec 10 22:52:54 2016 +0100

drm: Enforce BKL-less ioctls for modern drivers

DRM_UNLOCKED was never required by any legacy drivers, except for the
vblank_wait IOCTL. Therefore we will not regress these old drivers by
going back to where we've been in 2011. For all modern drivers nothing
will change.

To make this perfectly clear, also add a comment to DRM_UNLOCKED.

v2: Don't forget about drm_ioc32.c (Michel).

Cc: Michel Dänzer <[email protected]>
Cc: Emil Velikov <[email protected]>
Acked-by: Emil Velikov <[email protected]>
Acked-by: Michel Dänzer <[email protected]>
Signed-off-by: Daniel Vetter <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

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drm: remove all control node code

With the ioctl and driver prep done, we can remove everything else.

Reviewed-by: Sean Paul <[email protected]>
Signed-off-by: Daniel Vetter <daniel.vetter@inte

drm: remove all control node code

With the ioctl and driver prep done, we can remove everything else.

Reviewed-by: Sean Paul <[email protected]>
Signed-off-by: Daniel Vetter <[email protected]>
Cc: Gustavo Padovan <[email protected]>
Cc: Maarten Lankhorst <[email protected]>
Cc: Sean Paul <[email protected]>
Cc: David Airlie <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

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new helper: drm_ioctl_kernel()

drm_ioctl() guts sans copying the structure to/from userland
and parsing the ioctl cmd.

Signed-off-by: Al Viro <[email protected]>

drm: document drm_ioctl.[hc]

Also unify/merge with the existing stuff.

I was a bit torn where to put this, but in the end I decided to put
all the ioctl/sysfs/debugfs stuff into drm-uapi.rst. That

drm: document drm_ioctl.[hc]

Also unify/merge with the existing stuff.

I was a bit torn where to put this, but in the end I decided to put
all the ioctl/sysfs/debugfs stuff into drm-uapi.rst. That means we
have a bit a split with the other uapi related stuff used internally,
like drm_file.[hc], but I think overall this makes more sense.

If it's too confusing we can always add more cross-links to make it
more discoverable. But the auto-sprinkling of links kernel-doc already
does seems sufficient.

Also for prettier docs and more cross-links, switch the internal
defines over to an enum, as usual.

v2: Update kerneldoc fro drm_compat_ioctl too (caught by 0day), plus a
bit more drive-by polish.

v3: Fix typo, spotted by xerpi on irc (Sergi).

v4: Add missing space in comment (Neil).

Cc: Sergi Granell <[email protected]>
Reviewed-by: Neil Armstrong <[email protected]>
Signed-off-by: Daniel Vetter <[email protected]>
Link: http://patchwork.freedesktop.org/patch/msgid/[email protected]

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drm: Extract drm_ioctl.h

To match the drm_ioctl.c we already have.

v2: Remove spurious space (Ville).

Cc: Ville Syrjälä <[email protected]>
Reviewed-by: Ville Syrjälä <ville.syrjala@li

drm: Extract drm_ioctl.h

To match the drm_ioctl.c we already have.

v2: Remove spurious space (Ville).

Cc: Ville Syrjälä <[email protected]>
Reviewed-by: Ville Syrjälä <[email protected]>
Signed-off-by: Daniel Vetter <[email protected]>

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