Commit Graph

50122 Commits

Author SHA1 Message Date
David S. Miller
7ab876703d [RADEON]: Fix blanking return value.
If you'll recall, over a year ago, I pointed out that the current
Radeon driver erroneously returns -EINVAL for valid blanking codes,
here is a link to that thread:

	http://lkml.org/lkml/2006/1/28/6

No other driver does this, and it confuses the X server into thinking
that the device does not support blanking properly.

I looked again and there is simply no reason for the Radeon driver to
return -EINVAL for FB_BLANK_NORMAL.  It claims it wants to do this in
order to convince fbcon to blank in software, right here:

			if (fb_blank(info, blank))
				fbcon_generic_blank(vc, info, blank);

to software blank the screen.  But it only causes that to happen
in the FB_BLANK_NORMAL case.

That makes no sense because the Radeon code does this:

		val |= CRTC_DISPLAY_DIS;

in the FB_BLANK_NORMAL case so should be blanking the hardware, and
there is therefore no reason to SW blank by returning -EINVAL.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Antonino Daplas <adaplas@gmail.com>
2007-03-02 15:22:54 -08:00
David S. Miller
c4c31fe0e2 [SPARC]: Provide 'get_property()' alias for of_get_property().
Another powerpc compatibility item, this will allow us to share
more code with them.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-03-02 15:22:53 -08:00
David S. Miller
f6d0f9ea55 [SPARC]: Provide pci_device_to_OF_node() just like powerpc.
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-03-02 15:22:51 -08:00
David S. Miller
45bcca67ed [SPARC]: Handle unresolvable resources better in of_device.c
Just leave them as zero if we couldn't calculate it.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-03-02 15:22:50 -08:00
David S. Miller
b85cdd490a [SPARC]: Fix bus handling in build_device_resources().
We mistakedly modify 'bus' in the innermost loop.  What
should happen is that at each register index iteration,
we start with the same 'bus'.

So preserve it's value at the top level, and use a loop
local variable 'dbus' for iteration.

This bug causes registers other than the first to be
decoded improperly.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-03-02 15:22:49 -08:00
Alan Cox
cc7c15ec16 pata_qdi: Fix initialisation
The QDI init code contains some bugs which mean it only works if you have
a test setup that causes both a successful and failed probe. Fix this

Found by Philip Guo

(Who found it working on code analysis tools not running VLB IDE
controllers)

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-03-02 18:18:38 -05:00
Jeff Garzik
fb9f8905a8 [libata] pata_cmd64x: fix driver description in comments
Trivial comment fix, taken out of a larger Alan Cox patch.

Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-03-02 18:17:22 -05:00
Jeff Garzik
bf7551c441 [libata] pata_{legacy,sc1200,sl82c105}: add missing hooks
Alan Cox noticed several hooks in pata_* drivers were missing, when
he authored his ->cable_detect hook patches.  This patch extracts
just those fixes from Alan's patches, adding the necessary hooks
(usually ->freeze, ->thaw, and ->post_internal_cmd) to the drivers.

Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-03-02 18:09:05 -05:00
Jeff Garzik
f31f0cc2f0 [libata] change master/slave IDENTIFY order
2.6.21-rc has horrible problems with libata and PATA cable types (and
thus speeds). This occurs because Tejun fixed a pile of other bugs and
we now do cable detect enforcement for drive side detection properly.

Unfortunately we don't do the process around cable detection right. Tejun
identified the problem and pointed to the right Annex in the spec, this patch
implements the needed changes.

The basic requirement is that we have to identify the slave before the
master.

The patch switches the identify order so that we can do the drive side
detection correctly.

[NOTE: patch and description extracted from a larger work written
and signed-off-by Alan Cox]

Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-03-02 17:47:28 -05:00
Alan
032af1ce16 libata-core: Fix simplex handling
The initial simplex handling code is fooled if you suspend and resume.
This also causes problems with some single channel controllers which
claim to be simplex.

The fix is fairly simple, instead of keeping a flag to remember if we
gave away the simplex channel we remember the actual owner. As the owner
is always part of the host_set we don't even need a refcount.

Knowing the owner also means we can reassign simplex DMA channels in
future hotplug code etc if we need to

Signed-off-by: Alan Cox <alan@redhat.com>
(and a signed-off for the patch I sent before while I remember)
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-03-02 17:42:48 -05:00
Russell King
6139dbbb77 Merge branch 'omap-fixes' of master.kernel.org:/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6 2007-03-02 12:04:16 +00:00
Catalin Marinas
9623b3732d [ARM] 4241/1: Define mb() as compiler barrier on a uniprocessor system
Currently, the mb() is defined as a DMB operation on ARMv6, even for
UP systems. This patch defines mb() as a compiler barrier only. For
the SMP case, the smp_* variants should be used anyway and the patch
defines them as DMB.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-03-02 11:59:00 +00:00
Ben Dooks
5bfe8cb621 [ARM] 4239/1: S3C24XX: Update kconfig entries for PM
Update help text with location of documentation
and duplicate the note on the speed of CRC

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-03-02 11:58:58 +00:00
Ben Dooks
540988eb67 [ARM] 4238/1: S3C24XX: docs: update suspend and resume
Remove some of the explicit use of S3C2410 where
it is generic to all the S3C24XX series. Add more
info on the CRC code, and add an example of using
IRQ_EINT0 to resume from suspend

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-03-02 11:58:58 +00:00
Richard Purdie
1b7b56982f [ARM] 4237/2: oprofile: Always allow backtraces on ARM
Always allow backtrace when using oprofile on ARM, even if a PMU
isn't present.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-03-02 11:58:58 +00:00
Russell King
14fca61a98 [ARM] Yet more asm/apm-emulation.h stuff
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-03-02 11:58:57 +00:00
Tony Lindgren
1f4d177413 ARM: OMAP: Add missing get_irqnr_preamble and arch_ret_to_user for omap2
Only entries for omap1 were added earlier.

Signed-off-by: Tony Lindgren <tony@atomide.com>
2007-03-02 01:47:13 -08:00
Tony Lindgren
04fbf6a291 ARM: OMAP: Use linux/delay.h not asm/delay.h
Use linux/delay.h not asm/delay.h

Signed-off-by: Tony Lindgren <tony@atomide.com>
2007-03-02 01:47:13 -08:00
Tony Lindgren
2f4ff76499 ARM: OMAP: Remove obsolete alsa typedefs
Remove obsolete alsa typedefs

Signed-off-by: Tony Lindgren <tony@atomide.com>
2007-03-02 01:47:12 -08:00
Vladimir Ananiev
99c658a6c0 ARM: OMAP: omap1510->15xx conversions needed for sx1
Convert 1510->15xx in generic omap code, so that sx1 can work.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2007-03-02 01:47:12 -08:00
Dirk Behme
193506106d ARM: OMAP: Add missing includes to board-nokia770
Add missing includes to board-nokia770 to make it
compile again.

Signed-off-by: Dirk Behme <dirk.behme_at_gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2007-03-02 01:47:12 -08:00
Dirk Behme
060ebf97b4 ARM: OMAP: Workqueue changes for board-h4.c
Workqueue changes for board-h4.c

Signed-off-by: Dirk Behme <dirk.behme_at_gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2007-03-02 01:47:12 -08:00
Matthew Percival
53037f4c10 ARM: OMAP: dmtimer.c omap1 register fix
When I went to use dmtimer7 it did not seem to work.  I noticed that
the base addresses for dmtimers 7 and 8 were set wrong.  A simple patch
to correct a small error.  Confirmed to fix the problem on an OSK.

Signed-off-by: Matthew Percival <matthew@capgo.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2007-03-02 01:47:11 -08:00
Arnaud Patard
e016a40cab ARM: OMAP: board-nokia770: correct lcd name
Some time ago, the 'lcd_lph8923' device was renamed to 'lcd_mipid' but
the board-nokia770.c file was not updated accordingly, leading to not
working lcd.

This one-liner fixe the trouble.

Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2007-03-02 01:47:10 -08:00
David Brownell
b097f494cc ARM: OMAP: omap GP timer: HZ != 100
Teach OMAP2 gp timer that HZ isn't always 100.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2007-03-02 01:47:10 -08:00
Dirk Behme
2f5c4b6f1c ARM: OMAP: Fix warning in mach-omap1
Fix warning

arch/arm/mach-omap1/pm.c: In function 'omap_pm_init':
arch/arm/mach-omap1/pm.c:765: warning: ignoring return value
of 'subsys_create_file', declared with attribute
warn_unused_result

Signed-off-by: Dirk Behme <dirk.behme_at_gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2007-03-02 01:47:10 -08:00
Dirk Behme
ef772f2ee3 ARM: OMAP: Fix CONFIG_DEBUG_LL
Fix broken CONFIG_DEBUG_LL. In case of low level debugging
reconfigure some clocks early.

See

http://source.mvista.com/git/gitweb.cgi?p=linux-omap-2.6.git;a=commitdiff;h=3bfb289ccc6c4624fd5ff0381546935e105f4093

too.

Signed-off-by: Dirk Behme <dirk.behme_at_gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2007-03-02 01:47:09 -08:00
Dirk Behme
e6687290ae ARM: OMAP: Fix warning in mach-omap2
Fix warning

arch/arm/mach-omap2/timer-gp.c: In function
'omap2_gp_timer_init':
arch/arm/mach-omap2/timer-gp.c:70: warning: implicit
declaration of function 'setup_irq'

Signed-off-by: Dirk Behme <dirk.behme_at_gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2007-03-02 01:47:09 -08:00
Dirk Behme
2121880e88 ARM: OMAP: Fix warnings in plat-omap
Fix warnings

arch/arm/plat-omap/dmtimer.c: In function
'omap_dm_timer_modify_idlect_mask':
arch/arm/plat-omap/dmtimer.c:317: warning: no return
statement in function returning non-void

arch/arm/plat-omap/mailbox.c: In function 'omap_mbox_init':
arch/arm/plat-omap/mailbox.c:231: warning: ignoring return
value of 'class_device_create_file', declared with attribute
warn_unused_result

Signed-off-by: Dirk Behme <dirk.behme_at_gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2007-03-02 01:47:09 -08:00
Dirk Behme
b286f7ba30 ARM: OMAP: No IRQF_TRIGGER set_type function for IRQ 353 (MPUIO)
No IRQF_TRIGGER set_type function for IRQ 353 (MPUIO)

Signed-off-by: Dirk Behme <dirk.behme_at_gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2007-03-02 01:47:09 -08:00
Marek Vašut
65d873caab ARM: OMAP: OMAP310 Serial
This makes serial usable also on omap310, not only 1510.
(changing 1510->15xx)

Signed-off-by: Marek Vašut <marek.vasut@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2007-03-02 01:47:09 -08:00
Timo Teras
681e9940da ARM: OMAP: Proper handling of DMA4_IRQSTATUS_L0
The register bits are reset by writing one. Remove the unneeded reads and
fix writes to not clear too many bits.

Signed-off-by: Timo Teras <timo.teras@solidboot.com>
Signed-off-by: Juha Yrjola <juha.yrjola@solidboot.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2007-03-02 01:47:09 -08:00
Dirk Behme
6f9c92f1b9 ARM: OMAP: Fix warning in clock.c
Fix warning:

arch/arm/mach-omap1/clock.c: In function
'omap1_clk_enable_generic':
arch/arm/mach-omap1/clock.c:499: warning: 'return' with no
value, in function returning non-void

Signed-off-by: Dirk Behme <dirk.behme_at_gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2007-03-02 01:47:09 -08:00
Andrzej Zaborowski
ef557d76df ARM: OMAP: correct misc 15xx and non-15xx platform code
Disable accesses to SOFT_REQ_REG2 and ULPD_SOFT_DISABLE_REQ_REG
registers for 15xx processors that don't have these registers. Enable
level 2 interrupt handler for processors that identify as OMAP 15xx
(e.g 310) and not 1510 specifically. Also fix the following compiler
warning (only visible with CONFIG_OMAP_RESET_CLOCKS):

arch/arm/mach-omap1/clock.c: In function 'omap1_clk_disable_unused':
arch/arm/mach-omap1/clock.c:634: warning: 'return' with a value, in
function returning void

Signed-off-by: Andrzej Zaborowski <balrog@zabor.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2007-03-02 01:47:08 -08:00
Linus Torvalds
562aa1d4c6 Merge branch 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/libata-dev
* 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  ahci: improve spurious SDB FIS handling
  ahci/pata_jmicron: match class not function number
  jmicron ATA: reimplement jmicron ATA quirk
  pata_jmicron: drop unnecessary device programming in [re]init
  libata: blacklist FUJITSU MHT2060BH for NCQ
  sata_sil24: kill unused local variable idx in sil24_fill_sg()
  libata: clear drvdata in ata_host_release(), take#2
2007-03-01 19:48:21 -08:00
Linus Torvalds
b4350861dd Merge branch 'for-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jikos/hid
* 'for-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jikos/hid:
  HID: fix Logitech DiNovo Edge touchwheel and Logic3 /SpectraVideo middle button
  HID: add git tree information to MAINTAINERS
  HID: fix broken Logitech S510 keyboard report descriptor; make extra keys work
  HID: fix possible double-free on error path in hid parser
  HID: hid-debug.c should #include <linux/hid-debug.h>
  HID: fix bug in zeroing the last field byte in output reports
  USB HID: use CONFIG_HID_DEBUG for outputting report descriptor
  USB HID: Fix USB vendor and product IDs endianness for USB HID devices
2007-03-01 17:30:51 -08:00
Linus Torvalds
132a69c6cc Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6
* master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6:
  [SPARC64]: Fix parport_pc build.
  [SPARC64]: Update defconfig.
2007-03-01 17:28:31 -08:00
Linus Torvalds
fb7d404566 Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
* master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6:
  [TCP]: Fix minisock tcp_create_openreq_child() typo.
  [TCP]: Document several sysctls.
  [NET]: Fix kfree(skb)
  [NET]: Handle disabled preemption in gfp_any()
  [BRIDGE]: Fix locking of set path cost.
  [IPV6]: /proc/net/anycast6 unbalanced inet6_dev refcnt
  [IPX]: Remove ancient changelog
  [IPX]: Remove outdated information from Kconfig
  [NET]: Revert socket.h/stat.h ifdef hacks.
  [IPV6]: anycast refcnt fix
  [XFRM] xfrm_user: Fix return values of xfrm_add_sa_expire.
2007-03-01 17:27:01 -08:00
Linus Torvalds
100b425480 Merge master.kernel.org:/pub/scm/linux/kernel/git/mchehab/v4l-dvb
* master.kernel.org:/pub/scm/linux/kernel/git/mchehab/v4l-dvb:
  V4L/DVB (5305): Mark VIDIOC_DBG_S/G_REGISTER as experimental
  V4L/DVB (5271): Add VIDIOC_TRY_ENCODER_CMD and VIDIOC_ENCODER_CMD ioctls.
  V4L/DVB (5270): Add VIDIOC_G_ENC_INDEX ioctl
  V4L/DVB (5276): Cxusb: fix firmware patch for big endian systems
  V4L/DVB (5258): Cafe_ccic: fix compiler warning
  V4L/DVB (5295): Digitv: open nxt6000 i2c_gate for TDED4 tuner handling
  V4L/DVB (5304): Improve chip matching in v4l2_register
  V4L/DVB (5255): Fix cx25840 firmware loading.
2007-03-01 17:25:23 -08:00
Ralf Baechle
d701d8a3bc [PATCH] Fix sysfs build breakage if !CONFIG_SYSFS
B0rkage introduced by dfa87c824a.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-01 17:22:04 -08:00
Tejun Heo
afb2d552bc ahci: improve spurious SDB FIS handling
Spurious SDB FIS during NCQ might not contain spurious completions.
It could be spurious TF update or invalid async notification.  Treat
as HSM violation iff a spurious SDB FIS contains spurious completions;
otherwise, just whine once about it.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-03-01 20:19:45 -05:00
Tejun Heo
e34bb370de ahci/pata_jmicron: match class not function number
Make jmiron_ata quirk update pdev->class after programming the device
and update ahci and pata_jmicron such that they match class code
instead of checking function number manually.  For ahci, it matches
for vendor and class.  For pata_jmicron, it matches vendor, device and
class as IDE class isn't as well defined as AHCI class.

This makes jmicron device matching more conventional and script
friendly.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-03-01 20:19:45 -05:00
Tejun Heo
5ee2ae7fb2 jmicron ATA: reimplement jmicron ATA quirk
Reimplement jmicron ATA quirk.

* renamed to quirk_jmicron_ata()
* quirk is invoked only for the affected controllers
* programming is stricter.  e.g. conf5 bit24 is cleared if
  unnecessary.
* code factored for readability
* JMB360 and JMB368 are programmed into proper mode

Verified on JMB360, 363 and 368.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-03-01 20:19:45 -05:00
Tejun Heo
960627b7ad pata_jmicron: drop unnecessary device programming in [re]init
Channel redirect and AHCI mode enable programmings are done via PCI
quirk for both probe and resume paths.  Drop duplicate and possibly
unsafe device programming from pata_jmicron().

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-03-01 20:19:45 -05:00
Adam Litke
516dffdcd8 [PATCH] Fix get_unmapped_area and fsync for hugetlb shm segments
This patch provides the following hugetlb-related fixes to the recent stacked
shm files changes:
 - Update is_file_hugepages() so it will reconize hugetlb shm segments.
 - get_unmapped_area must be called with the nested file struct to handle
   the sfd->file->f_ops->get_unmapped_area == NULL case.
 - The fsync f_op must be wrapped since it is specified in the hugetlbfs
   f_ops.

This is based on proposed fixes from Eric Biederman that were debugged and
tested by me.  Without it, attempting to use hugetlb shared memory segments
on powerpc (and likely ia64) will kill your box.

Signed-off-by: Adam Litke <agl@us.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: William Irwin <bill.irwin@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-01 17:18:39 -08:00
Tejun Heo
09125ea617 libata: blacklist FUJITSU MHT2060BH for NCQ
Blacklist FUJITSU MHT2060BH for NCQ.  On this drive, NCQ works iff
queue depth is equal to or less than 4.  Just turn it off.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Mike Accetta <maccetta@laurelnetworks.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-03-01 20:16:29 -05:00
Tejun Heo
4fc00cb4d5 sata_sil24: kill unused local variable idx in sil24_fill_sg()
Kill unused local variable idx in sil24_fill_sg().

Spotted by Jeff Garzik.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-03-01 20:16:29 -05:00
Tejun Heo
1aa56cca5b libata: clear drvdata in ata_host_release(), take#2
Clearing drvdata in ->remove_one causes NULL pointer deference.  Clear
drvdata only in ata_host_release() after all resources are freed.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-03-01 20:16:28 -05:00
Trond Myklebust
7b965e0884 [PATCH] VM: invalidate_inode_pages2_range() should not exit early
Fix invalidate_inode_pages2_range() so that it does not immediately exit
just because a single page in the specified range could not be removed.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-01 14:53:39 -08:00
Aristeu Sergio Rozanski Filho
5a39e8c6d6 [PATCH] tty_io: fix race in master pty close/slave pty close path
This patch fixes a possible race that leads to double freeing an idr index.
 When the master begin to close, release_dev() is called and then
pty_close() is called:

        if (tty->driver->close)
                tty->driver->close(tty, filp);

This is done without helding any locks other than BKL.  Inside pty_close(),
being a master close, the devpts entry will be removed:

#ifdef CONFIG_UNIX98_PTYS
                if (tty->driver == ptm_driver)
                        devpts_pty_kill(tty->index);
#endif

But devpts_pty_kill() will call get_node() that may sleep while waiting for
&devpts_root->d_inode->i_sem.  When this happens and the slave is being
opened, tty_open() just found the driver and index:

        driver = get_tty_driver(device, &index);
        if (!driver) {
                mutex_unlock(&tty_mutex);
                return -ENODEV;
        }

This part of the code is already protected under tty_mute.  The problem is
that the slave close already got an index.  Then init_dev() is called and
blocks waiting for the same &devpts_root->d_inode->i_sem.

When the master close resumes, it removes the devpts entry, and the
relation between idr index and the tty is gone.  The master then sleeps
waiting for the tty_mutex on release_dev().

Slave open resumes and found no tty for that index.  As result, a NULL tty
is returned and init_dev() doesn't flow to fast_track:

        /* check whether we're reopening an existing tty */
        if (driver->flags & TTY_DRIVER_DEVPTS_MEM) {
                tty = devpts_get_tty(idx);
                if (tty && driver->subtype == PTY_TYPE_MASTER)
                        tty = tty->link;
        } else {
                tty = driver->ttys[idx];
        }
        if (tty) goto fast_track;

The result of this, is that a new tty will be created and init_dev() returns
sucessfull. After returning, tty_mutex is dropped and master close may resume.

Master close finds it's the only use and both sides are closing, then releases
the tty and the index. At this point, the idr index is free, but slave still
has it.

Slave open then calls pty_open() and finds that tty->link->count is 0,
because there's no master and returns error.  Then tty_open() calls
release_dev() which executes without any warning, as it was a case of last
slave close when the master is already closed (master->count == 0,
slave->count == 1).  The tty is then released with the already released idr
index.

This normally would only issue a warning on idr_remove() but in case of a
customer's critical application, it's never too simple:

thread1: opens master, gets index X
thread1: begin closing master
thread2: begin opening slave with index X
thread1: finishes closing master, index X released
thread3: opens master, gets index X, just released
thread2: fails opening slave, releases index X         <----
thread4: opens master, gets index X, init_dev() then find an already in use
	 and healthy tty and fails

If no more indexes are released, ptmx_open() will keep failing, as the
first free index available is X, and it will make init_dev() fail because
you're trying to "reopen a master" which isn't valid.

The patch notices when this race happens and make init_dev() fail
imediately.  The init_dev() function is called with tty_mutex held, so it's
safe to continue with tty till the end of function because release_dev()
won't make any further changes without grabbing the tty_mutex.

Without the patch, on some machines it's possible get easily idr warnings
like this one:

idr_remove called for id=15 which is not allocated.
 [<c02555b9>] idr_remove+0x139/0x170
 [<c02a1b62>] release_mem+0x182/0x230
 [<c02a28e7>] release_dev+0x4b7/0x700
 [<c02a0ea7>] tty_ldisc_enable+0x27/0x30
 [<c02a1e64>] init_dev+0x254/0x580
 [<c02a0d64>] check_tty_count+0x14/0xb0
 [<c02a4f05>] tty_open+0x1c5/0x340
 [<c02a4d40>] tty_open+0x0/0x340
 [<c017388f>] chrdev_open+0xaf/0x180
 [<c017c2ac>] open_namei+0x8c/0x760
 [<c01737e0>] chrdev_open+0x0/0x180
 [<c0167bc9>] __dentry_open+0xc9/0x210
 [<c0167e2c>] do_filp_open+0x5c/0x70
 [<c0167a91>] get_unused_fd+0x61/0xd0
 [<c0167e93>] do_sys_open+0x53/0x100
 [<c0167f97>] sys_open+0x27/0x30
 [<c010303b>] syscall_call+0x7/0xb

using this test application available on:
 http://www.ruivo.org/~aris/pty_sodomizer.c

Signed-off-by: Aristeu Sergio Rozanski Filho <aris@ruivo.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Chuck Ebbert <cebbert@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-01 14:53:39 -08:00