History log of /drivers/gpu/drm/drm_fops.c
Revision Date Author Comments
4e47e02d1ac47b6eb591b2a632a6c059ce3e5002 14-Apr-2012 Prathyush <prathyush.k@samsung.com> drm: Releasing FBs before releasing GEM objects during drm_release

During DRM release, all the FBs and gem objects are released. If
a gem object is being used as a FB and set to a crtc, it must not
be freed before releasing the framebuffer first.

If FBs are released first, the crtc using the FB is disabled first
so now the GEM object can be freed safely. The CRTC will be enabled
again when the driver restores fbdev mode.

Signed-off-by: Prathyush K <prathyush.k@samsung.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
3248877ea1796915419fba7c89315fdbf00cb56a 25-Nov-2011 Dave Airlie <airlied@redhat.com> drm: base prime/dma-buf support (v5)

This adds the basic drm dma-buf interface layer, called PRIME. This
commit doesn't add any driver support, it is simply and agreed upon starting
point so we can work towards merging driver support for the next merge window.

Current drivers with work done are nouveau, i915, udl, exynos and omap.

The main APIs exposed to userspace allow translating a 32-bit object handle
to a file descriptor, and a file descriptor to a 32-bit object handle.

The flags value is currently limited to O_CLOEXEC.

Acknowledgements:
Daniel Vetter: lots of review
Rob Clark: cleaned up lots of the internals and did lifetime review.

v2: rename some functions after Chris preferred a green shed
fix IS_ERR_OR_NULL -> IS_ERR
v3: Fix Ville pointed out using buffer + kmalloc
v4: add locking as per ickle review
v5: allow re-exporting the original dma-buf (Daniel)

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Rob Clark <rob.clark@linaro.org>
Reviewed-by: Sumit Semwal <sumit.semwal@linaro.org>
Reviewed-by: Inki Dae <inki.dae@samsung.com>
Acked-by: Ben Widawsky <benjamin.widawsky@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2c07a21d6fb0be47fda696a618b726ea258ed1dd 20-Feb-2012 Dave Airlie <airlied@redhat.com> drm: add core support for unplugging a device (v2)

Two parts to this, one is simple unplug from sysfs for the device node.

The second adds an unplugged state, if we have device opens, we
just set the unplugged state and return, if we have no device
opens we drop the drm device.

If after a lastclose we discover we are unplugged we then
drop the drm device.

v2: use an atomic for unplugged and wrap it for users,
add checks on open + mmap + ioctl entry points.

Signed-off-by: Dave Airlie <airlied@redhat.com>
598781d71119827b454fd75d46f84755bca6f0c6 24-Jan-2012 Thomas Hellstrom <thellstrom@vmware.com> drm: Fix authentication kernel crash

If the master tries to authenticate a client using drm_authmagic and
that client has already closed its drm file descriptor,
either wilfully or because it was terminated, the
call to drm_authmagic will dereference a stale pointer into kmalloc'ed memory
and corrupt it.

Typically this results in a hard system hang.

This patch fixes that problem by removing any authentication tokens
(struct drm_magic_entry) open for a file descriptor when that file
descriptor is closed.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
e08e96de986ceb2c6b683df0bd0c4ddd4f91dcfd 31-Oct-2011 Arjan van de Ven <arjan@infradead.org> drm: Make the per-driver file_operations struct const

From fdf1fdebaa00f81de18c227f32f8074c8b352d50 Mon Sep 17 00:00:00 2001
From: Arjan van de Ven <arjan@linux.intel.com>
Date: Sun, 30 Oct 2011 19:06:07 -0700
Subject: [PATCH] drm: Make the per-driver file_operations struct const

The DRM layer keeps a copy of struct file_operations inside its
big driver struct... which prevents it from being consistent and static.
For consistency (and the general security objective of having such things
static), it's desirable to get this fixed.

This patch splits out the file_operations field to its own struct,
which is then "static const", and just stick a pointer to this into
the driver struct, making it more consistent with how the rest of the
kernel does this.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
e0cd3608135b2ed8eddbe3fdf048d22e0593d836 30-Aug-2011 Paul Gortmaker <paul.gortmaker@windriver.com> gpu: add module.h to drivers/gpu files as required.

So that we don't get build failures once the implicit module.h
presence is removed.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
5bcf719b7db0f9366cedaf102b081f99b1c325ae 07-Dec-2010 Dave Airlie <airlied@redhat.com> drm/switcheroo: track state of switch in drivers.

We need to track the state of the switch in drivers, so that after s/r
we don't resume the card we've explicitly switched off before. Also
don't allow a userspace open to occur if we've switched the gpu off.

Signed-off-by: Dave Airlie <airlied@redhat.com>
451a3c24b0135bce54542009b5fde43846c7cf67 17-Nov-2010 Arnd Bergmann <arnd@arndb.de> BKL: remove extraneous #include <smp_lock.h>

The big kernel lock has been removed from all these files at some point,
leaving only the #include.

Remove this too as a cleanup.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
e3461a2bc0d67ce60a915e0f26e2a6eb4a4d4b99 26-Aug-2010 Ben Skeggs <bskeggs@redhat.com> drm: export drm_global_mutex for drivers to use

Nouveau needs to be able to drop the mutex before sleeping to prevent a
deadlock from occuring.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
1a72d65d6291ec248cbc5f05df2487edd714aba6 11-Aug-2010 Chris Wilson <chris@chris-wilson.co.uk> drm: Remove count_lock for calling lastclose() after 58474713 (v2)

When removing of the BKL the locking around lastclose() was rearranged
and resulted in the holding of the open_count spinlock over the call
into drm_lastclose(). The drivers were not ready for this path to be
atomic - it may indeed involve long waits to release old objects and
cleanup the GPU - and so we ended up scheduling whilst atomic.

[ 54.625598] BUG: scheduling while atomic: X/3546/0x00000002
[ 54.625600] Modules linked in: sco bridge stp llc input_polldev rfcomm bnep l2cap crc16 sch_sfq ipv6 md_mod acpi_cpufreq mperf cryptd aes_x86_64 aes_generic xts gf128mul dm_crypt dm_mod btusb bluetooth usbhid hid zaurus cdc_ether usbnet mii cdc_wdm cdc_acm uvcvideo videodev v4l1_compat v4l2_compat_ioctl32 snd_hda_codec_conexant arc4 pcmcia ecb snd_hda_intel joydev sdhci_pci sdhci snd_hda_codec tpm_tis firewire_ohci mmc_core e1000e uhci_hcd thinkpad_acpi nvram yenta_socket pcmcia_rsrc pcmcia_core tpm wmi sr_mod firewire_core iwlagn ehci_hcd snd_hwdep snd_pcm usbcore tpm_bios thermal led_class snd_timer iwlcore snd soundcore ac snd_page_alloc pcspkr psmouse serio_raw battery sg mac80211 evdev cfg80211 i2c_i801 iTCO_wdt iTCO_vendor_support cdrom processor crc_itu_t rfkill xfs exportfs sd_mod crc_t10dif ahci libahci libata scsi_mod [last unloaded: scsi_wait_scan]
[ 54.625663] Pid: 3546, comm: X Not tainted 2.6.35-04771-g1787985 #301
[ 54.625665] Call Trace:
[ 54.625671] [<ffffffff8102d599>] __schedule_bug+0x57/0x5c
[ 54.625675] [<ffffffff81384141>] schedule+0xe5/0x832
[ 54.625679] [<ffffffff81163e77>] ? put_dec+0x20/0x3c
[ 54.625682] [<ffffffff81384dd4>] schedule_timeout+0x275/0x29f
[ 54.625686] [<ffffffff810455e1>] ? process_timeout+0x0/0xb
[ 54.625688] [<ffffffff81384e17>] schedule_timeout_uninterruptible+0x19/0x1b
[ 54.625691] [<ffffffff81045893>] msleep+0x16/0x1d
[ 54.625695] [<ffffffff812a2e53>] i9xx_crtc_dpms+0x273/0x2ae
[ 54.625698] [<ffffffff812a18be>] intel_crtc_dpms+0x28/0xe7
[ 54.625702] [<ffffffff811ec0fa>] drm_helper_disable_unused_functions+0xf0/0x118
[ 54.625705] [<ffffffff811ecde3>] drm_crtc_helper_set_config+0x644/0x7c8
[ 54.625708] [<ffffffff811f12dd>] ? drm_copy_field+0x40/0x50
[ 54.625711] [<ffffffff811ebca2>] drm_fb_helper_force_kernel_mode+0x3e/0x85
[ 54.625713] [<ffffffff811ebcf2>] drm_fb_helper_restore+0x9/0x24
[ 54.625717] [<ffffffff81290a41>] i915_driver_lastclose+0x2b/0x5c
[ 54.625720] [<ffffffff811f14a7>] drm_lastclose+0x44/0x2ad
[ 54.625722] [<ffffffff811f1ed2>] drm_release+0x5c6/0x609
[ 54.625726] [<ffffffff810d1275>] fput+0x109/0x1c7
[ 54.625728] [<ffffffff810ce5e4>] filp_close+0x61/0x6b
[ 54.625731] [<ffffffff810ce680>] sys_close+0x92/0xd4
[ 54.625734] [<ffffffff81002a2b>] system_call_fastpath+0x16/0x1b

v2: The spinlock is actually superfluous as access to open_count is
entirely serialised by drm_global_mutex and so can be dropped. The
count_lock spinlock instead appears to be used to protect access to
dev->buf_alloc and dev->buf_use.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>
58374713c9dfb4d231f8c56cac089f6fbdedc2ec 10-Jul-2010 Arnd Bergmann <arnd@arndb.de> drm: kill BKL from common code

This restricts the use of the big kernel lock to the i830 and i810
device drivers. The three remaining users in common code (open, ioctl
and release) get converted to a new mutex, the drm_global_mutex,
making the locking stricter than the big kernel lock.

This may have a performance impact, but only in those cases that
currently don't use DRM_UNLOCKED flag in the ioctl list and would
benefit from that anyway.

The reason why i810 and i830 cannot use drm_global_mutex in their
mmap functions is a lock-order inversion problem between the current
use of the BKL and mmap_sem in these drivers. Since the BKL has
release-on-sleep semantics, it's harmless but it would cause trouble
if we replace the BKL with a mutex.

Instead, these drivers get their own ioctl wrappers that take the
BKL around every ioctl call and then set their own handlers as
DRM_UNLOCKED.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: David Airlie <airlied@linux.ie>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
6ebc22e6d06760466859b79d7b3b3edad264a230 13-May-2010 Julia Lawall <julia@diku.dk> drivers/gpu/drm: Use kzalloc

Use kzalloc rather than the combination of kmalloc and memset.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression x,size,flags;
statement S;
@@

-x = kmalloc(size,flags);
+x = kzalloc(size,flags);
if (x == NULL) S
-memset(x, 0, size);
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Reviewed-by: Corbin Simpson <MostAwesomeDude@gmail.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
da58405860b992d2bb21ebae5d685fe3204dd3f0 18-Mar-2010 Chris Wilson <chris@chris-wilson.co.uk> drm: Return ENODEV if the inode mapping changes

Replace a BUG_ON with an error code in the event that the inode mapping
changes between calls to drm_open. This may happen for instance if udev
is loaded subsequent to the original opening of the device:

[ 644.291870] kernel BUG at drivers/gpu/drm/drm_fops.c:146!
[ 644.291876] invalid opcode: 0000 [#1] SMP
[ 644.291882] last sysfs file: /sys/kernel/uevent_seqnum
[ 644.291888]
[ 644.291895] Pid: 7276, comm: lt-cairo-test-s Not tainted 2.6.34-rc1 #2 N150/N210/N220 /N150/N210/N220
[ 644.291903] EIP: 0060:[<c11c70e3>] EFLAGS: 00210283 CPU: 0
[ 644.291912] EIP is at drm_open+0x4b1/0x4e2
[ 644.291918] EAX: f72d8d18 EBX: f790a400 ECX: f73176b8 EDX: 00000000
[ 644.291923] ESI: f790a414 EDI: f790a414 EBP: f647ae20 ESP: f647adfc
[ 644.291929] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
[ 644.291937] Process lt-cairo-test-s (pid: 7276, ti=f647a000 task=f73f5c80 task.ti=f647a000)
[ 644.291941] Stack:
[ 644.291945] 00000000 f7bb7400 00000080 f6451100 f73176b8 f6479214 f6451100 f73176b8
[ 644.291957] <0> c1297ce0 f647ae34 c11c6c04 f73176b8 f7949800 00000000 f647ae54 c1080ac5
[ 644.291969] <0> f7949800 f6451100 00000000 f6451100 f73176b8 f6452780 f647ae70 c107d1e6
[ 644.291982] Call Trace:
[ 644.291991] [<c11c6c04>] ? drm_stub_open+0x8a/0xb8
[ 644.292000] [<c1080ac5>] ? chrdev_open+0xef/0x106
[ 644.292008] [<c107d1e6>] ? __dentry_open+0xd4/0x1a6
[ 644.292015] [<c107d35b>] ? nameidata_to_filp+0x31/0x45
[ 644.292022] [<c10809d6>] ? chrdev_open+0x0/0x106
[ 644.292030] [<c10864e2>] ? do_last+0x346/0x423
[ 644.292037] [<c108789f>] ? do_filp_open+0x190/0x415
[ 644.292046] [<c1071eb5>] ? handle_mm_fault+0x214/0x710
[ 644.292053] [<c107d008>] ? do_sys_open+0x4d/0xe9
[ 644.292061] [<c1016462>] ? do_page_fault+0x211/0x23f
[ 644.292068] [<c107d0f0>] ? sys_open+0x23/0x2b
[ 644.292075] [<c1002650>] ? sysenter_do_call+0x12/0x26
[ 644.292079] Code: 89 f0 89 55 dc e8 8d 96 0a 00 8b 45 e0 8b 55 dc 83 78 04 01 75 28 8b 83 18 02 00 00 85 c0 74 0f 8b 4d ec 3b 81 ac 00 00 00 74 13 <0f> 0b eb fe 8b 4d ec 8b 81 ac 00 00 00 89 83 18 02 00 00 89 f0
[ 644.292143] EIP: [<c11c70e3>] drm_open+0x4b1/0x4e2 SS:ESP 0068:f647adfc
[ 644.292175] ---[ end trace 2ddd476af89a60fa ]---

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
5a0e3ad6af8660be21ca98a971cd00f331318c05 24-Mar-2010 Tejun Heo <tj@kernel.org> include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
862302ffe422378a5213f558fc5cdf62c37050a9 02-Dec-2009 Thomas Hellstrom <thellstrom@vmware.com> drm: Add support for drm master_[set|drop] callbacks.

The vmwgfx driver has a per master rw lock around TTM, to guarantee
mutual exclusion when needed.

This is typically when all evictable buffers are evicted due to

1) vt switch
2) master switch
3) suspend / resume.

In the multi-master case, on master switch the new master takes the
previously active master lock in write mode, and then evicts all
buffers. Any clients to previous masters will then block on that lock
when trying to validate a buffer. fbdev also acts as a virtual master
wrt this.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Jakob Bornecrantz <jakob@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
c9a9c5e02aedc1a2815877b0268f886d2640b771 11-Sep-2009 Kristian Høgsberg <krh@bitplanet.net> drm: Add async event synchronization for drmWaitVblank

This patch adds a new flag to the drmWaitVblank ioctl, which asks the drm
to return immediately and notify userspace when the specified vblank sequence
happens by sending an event back on the drm fd.

The event mechanism works with the other flags supported by the ioctls,
specifically, the vblank sequence can be specified relatively or absolutely,
and works for primary and seconday crtc.

The signal field of the vblank request is used to provide user data,
which will be sent back to user space in the vblank event.

Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
c182be37ed7cb04c344501b88b8fdb747016e6cf 11-Sep-2009 Kristian Høgsberg <krh@bitplanet.net> drm: Add async event synchronization for drmWaitVblank

This patch adds a new flag to the drmWaitVblank ioctl, which asks the drm
to return immediately and notify userspace when the specified vblank sequence
happens by sending an event back on the drm fd.

The event mechanism works with the other flags supported by the ioctls,
specifically, the vblank sequence can be specified relatively or absolutely,
and works for primary and seconday crtc.

The signal field of the vblank request is used to provide user data,
which will be sent back to user space in the vblank event.

Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
9a298b2acd771d8a5c0004d8f8e4156c65b11f6b 24-Mar-2009 Eric Anholt <eric@anholt.net> drm: Remove memory debugging infrastructure.

It hasn't been used in ages, and having the user tell your how much
memory is being freed at free time is a recipe for disaster even if it
was ever used.

Signed-off-by: Eric Anholt <eric@anholt.net>
dba5ed0cd12d8db5c0d2e1c869c2a50c5bcf6743 27-Mar-2009 Dan Carpenter <error27@gmail.com> drm: drm_fops.c unlock missing on error path

drm_open_helper() from drm_fops.c had a missing mutex_unlock in a error
path.

This was caught by smatch (http://repo.or.cz/w/smatch.git/). Compile
tested.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
60aa49243d09afc873f082567d2e3c16634ced84 01-Feb-2009 Jonathan Corbet <corbet@lwn.net> Rationalize fasync return values

Most fasync implementations do something like:

return fasync_helper(...);

But fasync_helper() will return a positive value at times - a feature used
in at least one place. Thus, a number of other drivers do:

err = fasync_helper(...);
if (err < 0)
return err;
return 0;

In the interests of consistency and more concise code, it makes sense to
map positive return values onto zero where ->fasync() is called.

Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
fda714c29cdf360464059044b221450decb4b913 02-Mar-2009 Thomas Hellstrom <thellstrom@vmware.com> drm: Avoid client deadlocks when the master disappears.

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>
ea39f835168f60b01e59d0f348da25d297e7cf94 12-Feb-2009 Kristian Høgsberg <krh@redhat.com> drm: Release user fbs in drm_release

Avoids leaking fbs and associated buffers on release.

Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Tested-by: Tested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@linux.ie>
f41ced8f108cc80f16509b907cd7ac93944459bc 06-Jan-2009 Laurent Pinchart <laurent.pinchart@skynet.be> Check fops_get() return value

Several subsystem open handlers dereference the fops_get() return value
without checking it for nullness. This opens a race condition between the
open handler and module unloading.

A module can be marked as being unloaded (MODULE_STATE_GOING) before its
exit function is called and gets the chance to unregister the driver.
During that window open handlers can still be called, and fops_get() will
fail in try_module_get() and return a NULL pointer.

This change checks the fops_get() return value and returns -ENODEV if NULL.

Reported-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Acked-by: Takashi Iwai <tiwai@suse.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Airlie <airlied@linux.ie>
Acked-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
f453ba0460742ad027ae0c4c7d61e62817b3e7ef 07-Nov-2008 Dave Airlie <airlied@redhat.com> DRM: add mode setting support

Add mode setting support to the DRM layer.

This is a fairly big chunk of work that allows DRM drivers to provide
full output control and configuration capabilities to userspace. It was
motivated by several factors:
- the fb layer's APIs aren't suited for anything but simple
configurations
- coordination between the fb layer, DRM layer, and various userspace
drivers is poor to non-existent (radeonfb excepted)
- user level mode setting drivers makes displaying panic & oops
messages more difficult
- suspend/resume of graphics state is possible in many more
configurations with kernel level support

This commit just adds the core DRM part of the mode setting APIs.
Driver specific commits using these new structure and APIs will follow.

Co-authors: Jesse Barnes <jbarnes@virtuousgeek.org>, Jakob Bornecrantz <jakob@tungstengraphics.com>
Contributors: Alan Hourihane <alanh@tungstengraphics.com>, Maarten Maathuis <madman2003@gmail.com>

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
a2c0a97b784f837300f7b0869c82ab712c600952 05-Nov-2008 Jesse Barnes <jbarnes@virtuousgeek.org> drm: GEM mmap support

Add core support for mapping of GEM objects. Drivers should provide a
vm_operations_struct if they want to support page faulting of objects.
The code for handling GEM object offsets was taken from TTM, which was
written by Thomas Hellström.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
7c1c2871a6a3a114853ec6836e9035ac1c0c7f7a 28-Nov-2008 Dave Airlie <airlied@redhat.com> drm: move to kref per-master structures.

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>
233e70f4228e78eb2f80dc6650f65d3ae3dbf17c 01-Nov-2008 Al Viro <viro@ZenIV.linux.org.uk> saner FASYNC handling on file close

As it is, all instances of ->release() for files that have ->fasync()
need to remember to evict file from fasync lists; forgetting that
creates a hole and we actually have a bunch that *does* forget.

So let's keep our lives simple - let __fput() check FASYNC in
file->f_flags and call ->fasync() there if it's been set. And lose that
crap in ->release() instances - leaving it there is still valid, but we
don't have to bother anymore.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
673a394b1e3b69be886ff24abfd6df97c52e8d08 30-Jul-2008 Eric Anholt <eric@anholt.net> drm: Add GEM ("graphics execution manager") to i915 driver.

GEM allows the creation of persistent buffer objects accessible by the
graphics device through new ioctls for managing execution of commands on the
device. The userland API is almost entirely driver-specific to ensure that
any driver building on this model can easily map the interface to individual
driver requirements.

GEM is used by the 2d driver for managing its internal state allocations and
will be used for pixmap storage to reduce memory consumption and enable
zero-copy GLX_EXT_texture_from_pixmap, and in the 3d driver is used to enable
GL_EXT_framebuffer_object and GL_ARB_pixel_buffer_object.

Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2df68b439fcb97a4c55f81516206ef4ee325e28d 02-Sep-2008 David Howells <dhowells@redhat.com> drm/cred: wrap task credential accesses in the drm driver.

Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.

Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().

Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: David Airlie <airlied@redhat.com>
c0e09200dc0813972442e550a5905a132768e56c 29-May-2008 Dave Airlie <airlied@redhat.com> drm: reorganise drm tree to be more future proof.

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>