/*
 * Definitions for AUO-K190X framebuffer drivers
 *
 * Copyright (C) 2012 Heiko Stuebner <heiko@sntech.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#ifndef _LINUX_VIDEO_AUO_K190XFB_H_
#define _LINUX_VIDEO_AUO_K190XFB_H_

/* Controller standby command needs a param */
#define AUOK190X_QUIRK_STANDBYPARAM	(1 << 0)

/* Controller standby is completely broken */
#define AUOK190X_QUIRK_STANDBYBROKEN	(1 << 1)

/*
 * Resolutions for the displays
 */
#define AUOK190X_RESOLUTION_800_600		0
#define AUOK190X_RESOLUTION_1024_768		1
#define AUOK190X_RESOLUTION_600_800		4
#define AUOK190X_RESOLUTION_768_1024		5

/*
 * struct used by auok190x. board specific stuff comes from *board
 */
struct auok190xfb_par {
	struct fb_info *info;
	struct auok190x_board *board;

	struct regulator *regulator;

	struct mutex io_lock;
	struct delayed_work work;
	wait_queue_head_t waitq;
	int resolution;
	int rotation;
	int consecutive_threshold;
	int update_cnt;

	/* panel and controller informations */
	int epd_type;
	int panel_size_int;
	int panel_size_float;
	int panel_model;
	int tcon_version;
	int lut_version;

	/* individual controller callbacks */
	void (*update_partial)(struct auok190xfb_par *par, u16 y1, u16 y2);
	void (*update_all)(struct auok190xfb_par *par);
	bool (*need_refresh)(struct auok190xfb_par *par);
	void (*init)(struct auok190xfb_par *par);
	void (*recover)(struct auok190xfb_par *par);

	int update_mode; /* mode to use for updates */
	int last_mode; /* update mode last used */
	int flash;

	/* power management */
	int autosuspend_delay;
	bool standby;
	bool manual_standby;
};

/**
 * Board specific platform-data
 * @init:		initialize the controller interface
 * @cleanup:		cleanup the controller interface
 * @wait_for_rdy:	wait until the controller is not busy anymore
 * @set_ctl:		change an interface control
 * @set_hdb:		write a value to the data register
 * @get_hdb:		read a value from the data register
 * @setup_irq:		method to setup the irq handling on the busy gpio
 * @gpio_nsleep:	sleep gpio
 * @gpio_nrst:		reset gpio
 * @gpio_nbusy:		busy gpio
 * @resolution:		one of the AUOK190X_RESOLUTION constants
 * @rotation:		rotation of the framebuffer
 * @quirks:		controller quirks to honor
 * @fps:		frames per second for defio
 */
struct auok190x_board {
	int (*init)(struct auok190xfb_par *);
	void (*cleanup)(struct auok190xfb_par *);
	int (*wait_for_rdy)(struct auok190xfb_par *);

	void (*set_ctl)(struct auok190xfb_par *, unsigned char, u8);
	void (*set_hdb)(struct auok190xfb_par *, u16);
	u16 (*get_hdb)(struct auok190xfb_par *);

	int (*setup_irq)(struct fb_info *);

	int gpio_nsleep;
	int gpio_nrst;
	int gpio_nbusy;

	int resolution;
	int quirks;
	int fps;
};

#endif
it/commit/sound?id=191e885a2e130e639bb0c8ee350d7047294f2ce6'>sound</a>/<a href='/cgit.cgi/linux/net-next.git/commit/sound/core?id=191e885a2e130e639bb0c8ee350d7047294f2ce6'>core</a>/<a href='/cgit.cgi/linux/net-next.git/commit/sound/core/seq?id=191e885a2e130e639bb0c8ee350d7047294f2ce6'>seq</a>/<a href='/cgit.cgi/linux/net-next.git/commit/sound/core/seq/seq_virmidi.c?id=191e885a2e130e639bb0c8ee350d7047294f2ce6'>seq_virmidi.c</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='191e885a2e130e639bb0c8ee350d7047294f2ce6'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Luis R. Rodriguez &lt;mcgrof@kernel.org&gt;</td><td class='right'>2017-01-25 10:31:52 -0800</td></tr>
<tr><th>committer</th><td>Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;</td><td class='right'>2017-01-27 09:19:48 +0100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/core/seq/seq_virmidi.c?id=191e885a2e130e639bb0c8ee350d7047294f2ce6'>191e885a2e130e639bb0c8ee350d7047294f2ce6</a> (<a href='/cgit.cgi/linux/net-next.git/patch/sound/core/seq/seq_virmidi.c?id=191e885a2e130e639bb0c8ee350d7047294f2ce6'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=191e885a2e130e639bb0c8ee350d7047294f2ce6'>9bf9f9b4971df55a46e0a6750d3f6cd37bf1d9f0</a> /<a href='/cgit.cgi/linux/net-next.git/tree/sound/core/seq/seq_virmidi.c?id=191e885a2e130e639bb0c8ee350d7047294f2ce6'>sound/core/seq/seq_virmidi.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/core/seq/seq_virmidi.c?id=49def1853334396f948dcb4cedb9347abb318df5'>49def1853334396f948dcb4cedb9347abb318df5</a> (<a href='/cgit.cgi/linux/net-next.git/diff/sound/core/seq/seq_virmidi.c?id=191e885a2e130e639bb0c8ee350d7047294f2ce6&amp;id2=49def1853334396f948dcb4cedb9347abb318df5'>diff</a>)</td></tr></table>
<div class='commit-subject'>firmware: fix NULL pointer dereference in __fw_load_abort()</div><div class='commit-msg'>Since commit 5d47ec02c37ea6 ("firmware: Correct handling of
fw_state_wait() return value") fw_load_abort() could be called twice and
lead us to a kernel crash. This happens only when the firmware fallback
mechanism (regular or custom) is used. The fallback mechanism exposes a
sysfs interface for userspace to upload a file and notify the kernel
when the file is loaded and ready, or to cancel an upload by echo'ing -1
into on the loading file:

echo -n "-1" &gt; /sys/$DEVPATH/loading

This will call fw_load_abort(). Some distributions actually have a udev
rule in place to *always* immediately cancel all firmware fallback
mechanism requests (Debian), they have:

  $ cat /lib/udev/rules.d/50-firmware.rules
  # stub for immediately telling the kernel that userspace firmware loading
  # failed; necessary to avoid long timeouts with CONFIG_FW_LOADER_USER_HELPER=y
  SUBSYSTEM=="firmware", ACTION=="add", ATTR{loading}="-1

Distributions with this udev rule would run into this crash only if the
fallback mechanism is used. Since most distributions disable by default
using the fallback mechanism (CONFIG_FW_LOADER_USER_HELPER_FALLBACK),
this would typicaly mean only 2 drivers which *require* the fallback
mechanism could typically incur a crash: drivers/firmware/dell_rbu.c and
the drivers/leds/leds-lp55xx-common.c driver. Distributions enabling
CONFIG_FW_LOADER_USER_HELPER_FALLBACK by default are obviously more
exposed to this crash.

The crash happens because after commit 5b029624948d ("firmware: do not
use fw_lock for fw_state protection") and subsequent fix commit
5d47ec02c37ea6 ("firmware: Correct handling of fw_state_wait() return
value") a race can happen between this cancelation and the firmware
fw_state_wait_timeout() being woken up after a state change with which
fw_load_abort() as that calls swake_up(). Upon error
fw_state_wait_timeout() will also again call fw_load_abort() and trigger
a null reference.

At first glance we could just fix this with a !buf check on
fw_load_abort() before accessing buf-&gt;fw_st, however there is a logical
issue in having a state machine used for the fallback mechanism and
preventing access from it once we abort as its inside the buf
(buf-&gt;fw_st).

The firmware_class.c code is setting the buf to NULL to annotate an
abort has occurred. Replace this mechanism by simply using the state
check instead. All the other code in place already uses similar checks
for aborting as well so no further changes are needed.

An oops can be reproduced with the new fw_fallback.sh fallback mechanism
cancellation test. Either cancelling the fallback mechanism or the
custom fallback mechanism triggers a crash.

mcgrof@piggy ~/linux-next/tools/testing/selftests/firmware
(git::20170111-fw-fixes)$ sudo ./fw_fallback.sh

./fw_fallback.sh: timeout works
./fw_fallback.sh: firmware comparison works
./fw_fallback.sh: fallback mechanism works

[ this then sits here when it is trying the cancellation test ]

Kernel log:

test_firmware: loading 'nope-test-firmware.bin'
misc test_firmware: Direct firmware load for nope-test-firmware.bin failed with error -2
misc test_firmware: Falling back to user helper
BUG: unable to handle kernel NULL pointer dereference at 0000000000000038
IP: _request_firmware+0xa27/0xad0
PGD 0

Oops: 0000 [#1] SMP
Modules linked in: test_firmware(E) ... etc ...
CPU: 1 PID: 1396 Comm: fw_fallback.sh Tainted: G        W E   4.10.0-rc3-next-20170111+ #30
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.1-0-g8891697-prebuilt.qemu-project.org 04/01/2014
task: ffff9740b27f4340 task.stack: ffffbb15c0bc8000
RIP: 0010:_request_firmware+0xa27/0xad0
RSP: 0018:ffffbb15c0bcbd10 EFLAGS: 00010246
RAX: 00000000fffffffe RBX: ffff9740afe5aa80 RCX: 0000000000000000
RDX: ffff9740b27f4340 RSI: 0000000000000283 RDI: 0000000000000000
RBP: ffffbb15c0bcbd90 R08: ffffbb15c0bcbcd8 R09: 0000000000000000
R10: 0000000894a0d4b1 R11: 000000000000008c R12: ffffffffc0312480
R13: 0000000000000005 R14: ffff9740b1c32400 R15: 00000000000003e8
FS:  00007f8604422700(0000) GS:ffff9740bfc80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000038 CR3: 000000012164c000 CR4: 00000000000006e0
Call Trace:
 request_firmware+0x37/0x50
 trigger_request_store+0x79/0xd0 [test_firmware]
 dev_attr_store+0x18/0x30
 sysfs_kf_write+0x37/0x40
 kernfs_fop_write+0x110/0x1a0
 __vfs_write+0x37/0x160
 ? _cond_resched+0x1a/0x50
 vfs_write+0xb5/0x1a0
 SyS_write+0x55/0xc0
 ? trace_do_page_fault+0x37/0xd0
 entry_SYSCALL_64_fastpath+0x1e/0xad
RIP: 0033:0x7f8603f49620
RSP: 002b:00007fff6287b788 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000055c307b110a0 RCX: 00007f8603f49620
RDX: 0000000000000016 RSI: 000055c3084d8a90 RDI: 0000000000000001
RBP: 0000000000000016 R08: 000000000000c0ff R09: 000055c3084d6336
R10: 000055c307b108b0 R11: 0000000000000246 R12: 000055c307b13c80
R13: 000055c3084d6320 R14: 0000000000000000 R15: 00007fff6287b950
Code: 9f 64 84 e8 9c 61 fe ff b8 f4 ff ff ff e9 6b f9 ff
ff 48 c7 c7 40 6b 8d 84 89 45 a8 e8 43 84 18 00 49 8b be 00 03 00 00 8b
45 a8 &lt;83&gt; 7f 38 02 74 08 e8 6e ec ff ff 8b 45 a8 49 c7 86 00 03 00 00
RIP: _request_firmware+0xa27/0xad0 RSP: ffffbb15c0bcbd10
CR2: 0000000000000038
---[ end trace 6d94ac339c133e6f ]---

Fixes: 5d47ec02c37e ("firmware: Correct handling of fw_state_wait() return value")
Reported-and-Tested-by: Jakub Kicinski &lt;jakub.kicinski@netronome.com&gt;
Reported-and-Tested-by: Patrick Bruenn &lt;p.bruenn@beckhoff.com&gt;
Reported-by: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
CC: &lt;stable@vger.kernel.org&gt;    [3.10+]
Signed-off-by: Luis R. Rodriguez &lt;mcgrof@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=191e885a2e130e639bb0c8ee350d7047294f2ce6'>Diffstat</a> (limited to 'sound/core/seq/seq_virmidi.c')</div><table summary='diffstat' class='diffstat'>