linux-stable.git/drivers/tty, branch v4.7.2

tty/serial: atmel: fix RS485 half duplex with DMA

2016-08-20T16:10:49+00:00

commit 0058f0871efe7b01c6f2b3046c68196ab73e96da upstream.

When using DMA, half duplex doesn't work properly because rx is not stopped
before starting tx. Ensure we call atmel_stop_rx() in the DMA case.

Signed-off-by: Alexandre Belloni 
Acked-by: Nicolas Ferre 
Signed-off-by: Greg Kroah-Hartman

serial: samsung: Fix ERR pointer dereference on deferred probe

2016-08-20T16:10:49+00:00

commit e51e4d8a185de90424b03f30181b35f29c46a25a upstream.

When the clk_get() of "uart" clock returns EPROBE_DEFER, the next re-probe
finishes with success but uses invalid (ERR_PTR) values.  This leads to
dereferencing of ERR_PTR stored under ourport->clk:

	12c30000.serial: Controller clock not found
	(...)
	12c30000.serial: ttySAC3 at MMIO 0x12c30000 (irq = 61, base_baud = 0) is a S3C6400/10
	Unable to handle kernel paging request at virtual address fffffdfb

	(clk_prepare) from [] (s3c24xx_serial_pm+0x20/0x128)
	(s3c24xx_serial_pm) from [] (uart_change_pm+0x38/0x40)
	(uart_change_pm) from [] (uart_add_one_port+0x31c/0x44c)
	(uart_add_one_port) from [] (s3c24xx_serial_probe+0x2a8/0x418)
	(s3c24xx_serial_probe) from [] (platform_drv_probe+0x50/0xb0)
	(platform_drv_probe) from [] (driver_probe_device+0x1f4/0x2b0)
	(driver_probe_device) from [] (bus_for_each_drv+0x44/0x8c)
	(bus_for_each_drv) from [] (__device_attach+0x9c/0x100)
	(__device_attach) from [] (bus_probe_device+0x84/0x8c)
	(bus_probe_device) from [] (deferred_probe_work_func+0x60/0x8c)
	(deferred_probe_work_func) from [] (process_one_work+0x120/0x328)
	(process_one_work) from [] (worker_thread+0x2c/0x4ac)
	(worker_thread) from [] (kthread+0xd8/0xf4)
	(kthread) from [] (ret_from_fork+0x14/0x3c)

The first unsuccessful clk_get() causes s3c24xx_serial_init_port() to
exit with failure but the s3c24xx_uart_port is left half-configured
(e.g. port->mapbase is set, clk contains ERR_PTR).  On next re-probe,
the function s3c24xx_serial_init_port() will exit early with success
because of configured port->mapbase and driver will use old values,
including the ERR_PTR as clock.

Fix this by cleaning the port->mapbase on error path so each re-probe
will initialize all of the port settings.

Fixes: 60e93575476f ("serial: samsung: enable clock before clearing pending interrupts during init")
Signed-off-by: Krzysztof Kozlowski 
Reviewed-by: Javier Martinez Canillas 
Tested-by: Javier Martinez Canillas 
Tested-by: Kevin Hilman 
Signed-off-by: Greg Kroah-Hartman

tty: serial: msm: Don't read off end of tx fifo

2016-08-20T16:10:49+00:00

commit 30acf549ca1e81859a67590ab9ecfce3d1050a0b upstream.

For dm uarts in pio mode tx data is transferred to the fifo register 4
bytes at a time, but care is not taken when these 4 bytes spans the end
of the xmit buffer so the loop might read up to 3 bytes past the buffer
and then skip the actual data at the beginning of the buffer.

Fix this by, analogous to the DMA case, make sure the chunk doesn't
wrap the xmit buffer.

Fixes: 3a878c430fd6 ("tty: serial: msm: Add TX DMA support")
Cc: Ivan Ivanov 
Reported-by: Frank Rowand 
Reported-by: Nicolas Dechesne 
Signed-off-by: Bjorn Andersson 
Acked-by: Andy Gross 
Tested-by: Frank Rowand 
Reviewed-by: Stephen Boyd 
Signed-off-by: Greg Kroah-Hartman

serial: mvebu-uart: free the IRQ in ->shutdown()

2016-08-16T07:35:00+00:00

commit c2c1659b4f8f9e19fe82a4fd06cca4b3d59090ce upstream.

As suggested by the serial port infrastructure documentation, the IRQ is
requested in ->startup(). However, it is never freed in the ->shutdown()
hook.

With simple systems that open the serial port once for all and always
have at least one process that keep the serial port opened, there was no
problem. But with a more complicated system (*cough* systemd *cough*),
the serial port is opened/closed many times, which at some point no
processes having the serial port open at all. Due to this ->startup()
gets called again, tries to request_irq() again, which fails.

Fixes: 30530791a7a0 ("serial: mvebu-uart: initial support for Armada-3700 serial port")
Cc: Ofer Heifetz 
Signed-off-by: Thomas Petazzoni 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input

2016-07-23T03:10:48+00:00

Pull input fixes from Dmitry Torokhov:
 "A few more fixes for the input subsystem:

   - restore naming for tsc2005 touchscreens as some userspace match on it
   - fix out of bound access in legacy keyboard driver
   - fixup in RMI4 driver

  Everything is tagged for stable as well"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: tsc200x - report proper input_dev name
  tty/vt/keyboard: fix OOB access in do_compute_shiftstate()
  Input: synaptics-rmi4 - fix maximum size check for F12 control register 8

tty/vt/keyboard: fix OOB access in do_compute_shiftstate()

2016-07-21T00:50:23+00:00

The size of individual keymap in drivers/tty/vt/keyboard.c is NR_KEYS,
which is currently 256, whereas number of keys/buttons in input device (and
therefor in key_down) is much larger - KEY_CNT - 768, and that can cause
out-of-bound access when we do

	sym = U(key_maps[0][k]);

with large 'k'.

To fix it we should not attempt iterating beyond smaller of NR_KEYS and
KEY_CNT.

Also while at it let's switch to for_each_set_bit() instead of open-coding
it.

Reported-by: Sasha Levin 
Reviewed-by: Guenter Roeck 
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov

devpts: fix null pointer dereference on failed memory allocation

2016-06-26T18:39:00+00:00

An ENOMEM when creating a pair tty in tty_ldisc_setup causes a null
pointer dereference in devpts_kill_index because tty->link->driver_data
is NULL.  The oops was triggered with the pty stressor in stress-ng when
in a low memory condition.

tty_init_dev tries to clean up a tty_ldisc_setup ENOMEM error by calling
release_tty, however, this ultimately tries to clean up the NULL pair'd
tty in pty_unix98_remove, triggering the Oops.

Add check to pty_unix98_remove to only clean up fsi if it is not NULL.

Ooops:

[   23.020961] Oops: 0000 [#1] SMP
[   23.020976] Modules linked in: ppdev snd_hda_codec_generic snd_hda_intel snd_hda_codec parport_pc snd_hda_core snd_hwdep parport snd_pcm input_leds joydev snd_timer serio_raw snd soundcore i2c_piix4 mac_hid ib_iser rdma_cm iw_cm ib_cm ib_core configfs iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi autofs4 btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel qxl aes_x86_64 ttm lrw gf128mul glue_helper ablk_helper drm_kms_helper cryptd syscopyarea sysfillrect psmouse sysimgblt floppy fb_sys_fops drm pata_acpi jitterentropy_rng drbg ansi_cprng
[   23.020978] CPU: 0 PID: 1452 Comm: stress-ng-pty Not tainted 4.7.0-rc4+ #2
[   23.020978] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[   23.020979] task: ffff88007ba30000 ti: ffff880078ea8000 task.ti: ffff880078ea8000
[   23.020981] RIP: 0010:[]  [] ida_remove+0x1f/0x120
[   23.020981] RSP: 0018:ffff880078eabb60  EFLAGS: 00010a03
[   23.020982] RAX: 4444444444444567 RBX: 0000000000000000 RCX: 000000000000001f
[   23.020982] RDX: 000000000000014c RSI: 000000000000026f RDI: 0000000000000000
[   23.020982] RBP: ffff880078eabb70 R08: 0000000000000004 R09: 0000000000000036
[   23.020983] R10: 000000000000026f R11: 0000000000000000 R12: 000000000000026f
[   23.020983] R13: 000000000000026f R14: ffff88007c944b40 R15: 000000000000026f
[   23.020984] FS:  00007f9a2f3cc700(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000
[   23.020984] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   23.020985] CR2: 0000000000000010 CR3: 000000006c81b000 CR4: 00000000001406f0
[   23.020988] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   23.020988] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   23.020988] Stack:
[   23.020989]  0000000000000000 000000000000026f ffff880078eabb90 ffffffff812a5a99
[   23.020990]  0000000000000000 00000000fffffff4 ffff880078eabba8 ffffffff814f9cbe
[   23.020991]  ffff88007965c800 ffff880078eabbc8 ffffffff814eef43 fffffffffffffff4
[   23.020991] Call Trace:
[   23.021000]  [] devpts_kill_index+0x29/0x50
[   23.021002]  [] pty_unix98_remove+0x2e/0x50
[   23.021006]  [] release_tty+0xb3/0x1b0
[   23.021007]  [] tty_init_dev+0xd4/0x1c0
[   23.021011]  [] ptmx_open+0xae/0x190
[   23.021013]  [] chrdev_open+0xbf/0x1b0
[   23.021015]  [] do_dentry_open+0x203/0x310
[   23.021016]  [] ? cdev_put+0x30/0x30
[   23.021017]  [] vfs_open+0x54/0x80
[   23.021018]  [] ? may_open+0x8c/0x100
[   23.021019]  [] path_openat+0x2eb/0x1440
[   23.021020]  [] ? putname+0x54/0x60
[   23.021022]  [] ? n_tty_ioctl_helper+0x27/0x100
[   23.021023]  [] do_filp_open+0x91/0x100
[   23.021024]  [] ? getname_flags+0x56/0x1f0
[   23.021026]  [] ? __alloc_fd+0x46/0x190
[   23.021027]  [] do_sys_open+0x124/0x210
[   23.021028]  [] SyS_open+0x1e/0x20
[   23.021035]  [] entry_SYSCALL_64_fastpath+0x1e/0xa8
[   23.021044] Code: 63 28 45 31 e4 eb dd 0f 1f 44 00 00 55 4c 63 d6 48 ba 89 88 88 88 88 88 88 88 4c 89 d0 b9 1f 00 00 00 48 f7 e2 48 89 e5 41 54 53 <8b> 47 10 48 89 fb 8d 3c c5 00 00 00 00 48 c1 ea 09 b8 01 00 00
[   23.021045] RIP  [] ida_remove+0x1f/0x120
[   23.021045]  RSP 
[   23.021046] CR2: 0000000000000010

Signed-off-by: Colin Ian King 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

tty: vt: Fix soft lockup in fbcon cursor blink timer.

2016-06-25T17:41:13+00:00

We are getting somewhat random soft lockups with this signature:

[   86.992215] [] el1_irq+0xa0/0x10c
[   86.997082] [] cursor_timer_handler+0x30/0x54
[   87.002991] [] call_timer_fn+0x54/0x1a8
[   87.008378] [] run_timer_softirq+0x1c4/0x2bc
[   87.014200] [] __do_softirq+0x114/0x344
[   87.019590] [] irq_exit+0x74/0x98
[   87.024458] [] __handle_domain_irq+0x98/0xfc
[   87.030278] [] gic_handle_irq+0x94/0x190

This is caused by the vt visual_init() function calling into
fbcon_init() with a vc_cur_blink_ms value of zero.  This is a
transient condition, as it is later set to a non-zero value.  But, if
the timer happens to expire while the blink rate is zero, it goes into
an endless loop, and we get soft lockup.

The fix is to initialize vc_cur_blink_ms before calling the con_init()
function.

Signed-off-by: David Daney 
Cc: stable@vger.kernel.org
Acked-by: Pavel Machek 
Tested-by: Ming Lei 
Acked-by: Scot Doyle 
Tested-by: Henrique de Moraes Holschuh 
Signed-off-by: Greg Kroah-Hartman

devpts: Make each mount of devpts an independent filesystem.

2016-06-05T17:36:01+00:00

The /dev/ptmx device node is changed to lookup the directory entry "pts"
in the same directory as the /dev/ptmx device node was opened in.  If
there is a "pts" entry and that entry is a devpts filesystem /dev/ptmx
uses that filesystem.  Otherwise the open of /dev/ptmx fails.

The DEVPTS_MULTIPLE_INSTANCES configuration option is removed, so that
userspace can now safely depend on each mount of devpts creating a new
instance of the filesystem.

Each mount of devpts is now a separate and equal filesystem.

Reserved ttys are now available to all instances of devpts where the
mounter is in the initial mount namespace.

A new vfs helper path_pts is introduced that finds a directory entry
named "pts" in the directory of the passed in path, and changes the
passed in path to point to it.  The helper path_pts uses a function
path_parent_directory that was factored out of follow_dotdot.

In the implementation of devpts:
 - devpts_mnt is killed as it is no longer meaningful if all mounts of
   devpts are equal.
 - pts_sb_from_inode is replaced by just inode->i_sb as all cached
   inodes in the tty layer are now from the devpts filesystem.
 - devpts_add_ref is rolled into the new function devpts_ptmx.  And the
   unnecessary inode hold is removed.
 - devpts_del_ref is renamed devpts_release and reduced to just a
   deacrivate_super.
 - The newinstance mount option continues to be accepted but is now
   ignored.

In devpts_fs.h definitions for when !CONFIG_UNIX98_PTYS are removed as
they are never used.

Documentation/filesystems/devices.txt is updated to describe the current
situation.

This has been verified to work properly on openwrt-15.05, centos5,
centos6, centos7, debian-6.0.2, debian-7.9, debian-8.2, ubuntu-14.04.3,
ubuntu-15.10, fedora23, magia-5, mint-17.3, opensuse-42.1,
slackware-14.1, gentoo-20151225 (13.0?), archlinux-2015-12-01.  With the
caveat that on centos6 and on slackware-14.1 that there wind up being
two instances of the devpts filesystem mounted on /dev/pts, the lower
copy does not end up getting used.

Signed-off-by: "Eric W. Biederman" 
Cc: Greg KH 
Cc: Peter Hurley 
Cc: Peter Anvin 
Cc: Andy Lutomirski 
Cc: Al Viro 
Cc: Serge Hallyn 
Cc: Willy Tarreau 
Cc: Aurelien Jarno 
Cc: One Thousand Gnomes 
Cc: Jann Horn 
Cc: Jiri Slaby 
Cc: Florian Weimer 
Cc: Konstantin Khlebnikov 
Signed-off-by: Linus Torvalds

remove lots of IS_ERR_VALUE abuses

2016-05-27T22:26:11+00:00

Most users of IS_ERR_VALUE() in the kernel are wrong, as they
pass an 'int' into a function that takes an 'unsigned long'
argument. This happens to work because the type is sign-extended
on 64-bit architectures before it gets converted into an
unsigned type.

However, anything that passes an 'unsigned short' or 'unsigned int'
argument into IS_ERR_VALUE() is guaranteed to be broken, as are
8-bit integers and types that are wider than 'unsigned long'.

Andrzej Hajda has already fixed a lot of the worst abusers that
were causing actual bugs, but it would be nice to prevent any
users that are not passing 'unsigned long' arguments.

This patch changes all users of IS_ERR_VALUE() that I could find
on 32-bit ARM randconfig builds and x86 allmodconfig. For the
moment, this doesn't change the definition of IS_ERR_VALUE()
because there are probably still architecture specific users
elsewhere.

Almost all the warnings I got are for files that are better off
using 'if (err)' or 'if (err < 0)'.
The only legitimate user I could find that we get a warning for
is the (32-bit only) freescale fman driver, so I did not remove
the IS_ERR_VALUE() there but changed the type to 'unsigned long'.
For 9pfs, I just worked around one user whose calling conventions
are so obscure that I did not dare change the behavior.

I was using this definition for testing:

 #define IS_ERR_VALUE(x) ((unsigned long*)NULL == (typeof (x)*)NULL && \
       unlikely((unsigned long long)(x) >= (unsigned long long)(typeof(x))-MAX_ERRNO))

which ends up making all 16-bit or wider types work correctly with
the most plausible interpretation of what IS_ERR_VALUE() was supposed
to return according to its users, but also causes a compile-time
warning for any users that do not pass an 'unsigned long' argument.

I suggested this approach earlier this year, but back then we ended
up deciding to just fix the users that are obviously broken. After
the initial warning that caused me to get involved in the discussion
(fs/gfs2/dir.c) showed up again in the mainline kernel, Linus
asked me to send the whole thing again.

[ Updated the 9p parts as per Al Viro  - Linus ]

Signed-off-by: Arnd Bergmann 
Cc: Andrzej Hajda 
Cc: Andrew Morton 
Link: https://lkml.org/lkml/2016/1/7/363
Link: https://lkml.org/lkml/2016/5/27/486
Acked-by: Srinivas Kandagatla  # For nvmem part
Signed-off-by: Linus Torvalds