linux/drivers/hid/uhid.c
Kirill Smelkov c5bf68fe0c *: convert stream-like files from nonseekable_open -> stream_open
Using scripts/coccinelle/api/stream_open.cocci added in 10dce8af34
("fs: stream_open - opener for stream-like files so that read and write
can run simultaneously without deadlock"), search and convert to
stream_open all in-kernel nonseekable_open users for which read and
write actually do not depend on ppos and where there is no other methods
in file_operations which assume @offset access.

I've verified each generated change manually - that it is correct to convert -
and each other nonseekable_open instance left - that it is either not correct
to convert there, or that it is not converted due to current stream_open.cocci
limitations. The script also does not convert files that should be valid to
convert, but that currently have .llseek = noop_llseek or generic_file_llseek
for unknown reason despite file being opened with nonseekable_open (e.g.
drivers/input/mousedev.c)

Among cases converted 14 were potentially vulnerable to read vs write deadlock
(see details in 10dce8af34):

	drivers/char/pcmcia/cm4000_cs.c:1685:7-23: ERROR: cm4000_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/gnss/core.c:45:1-17: ERROR: gnss_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/hid/uhid.c:635:1-17: ERROR: uhid_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/infiniband/core/user_mad.c:988:1-17: ERROR: umad_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/input/evdev.c:527:1-17: ERROR: evdev_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/input/misc/uinput.c:401:1-17: ERROR: uinput_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/isdn/capi/capi.c:963:8-24: ERROR: capi_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/leds/uleds.c:77:1-17: ERROR: uleds_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/media/rc/lirc_dev.c:198:1-17: ERROR: lirc_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/s390/char/fs3270.c:488:1-17: ERROR: fs3270_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/usb/misc/ldusb.c:310:1-17: ERROR: ld_usb_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/xen/evtchn.c:667:8-24: ERROR: evtchn_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	net/batman-adv/icmp_socket.c:80:1-17: ERROR: batadv_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	net/rfkill/core.c:1146:8-24: ERROR: rfkill_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.

and the rest were just safe to convert to stream_open because their read and
write do not use ppos at all and corresponding file_operations do not
have methods that assume @offset file access(*):

	arch/powerpc/platforms/52xx/mpc52xx_gpt.c:631:8-24: WARNING: mpc52xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_ibox_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_ibox_stat_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_mbox_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_mbox_stat_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_wbox_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_wbox_stat_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	arch/um/drivers/harddog_kern.c:88:8-24: WARNING: harddog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	arch/x86/kernel/cpu/microcode/core.c:430:33-49: WARNING: microcode_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/char/ds1620.c:215:8-24: WARNING: ds1620_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/char/dtlk.c:301:1-17: WARNING: dtlk_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/char/ipmi/ipmi_watchdog.c:840:9-25: WARNING: ipmi_wdog_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/char/pcmcia/scr24x_cs.c:95:8-24: WARNING: scr24x_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/char/tb0219.c:246:9-25: WARNING: tb0219_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/firewire/nosy.c:306:8-24: WARNING: nosy_ops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/hwmon/fschmd.c:840:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/hwmon/w83793.c:1344:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/infiniband/core/ucma.c:1747:8-24: WARNING: ucma_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/infiniband/core/ucm.c:1178:8-24: WARNING: ucm_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/infiniband/core/uverbs_main.c:1086:8-24: WARNING: uverbs_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/input/joydev.c:282:1-17: WARNING: joydev_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/pci/switch/switchtec.c:393:1-17: WARNING: switchtec_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/platform/chrome/cros_ec_debugfs.c:135:8-24: WARNING: cros_ec_console_log_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/rtc/rtc-ds1374.c:470:9-25: WARNING: ds1374_wdt_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/rtc/rtc-m41t80.c:805:9-25: WARNING: wdt_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/s390/char/tape_char.c:293:2-18: WARNING: tape_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/s390/char/zcore.c:194:8-24: WARNING: zcore_reipl_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/s390/crypto/zcrypt_api.c:528:8-24: WARNING: zcrypt_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/spi/spidev.c:594:1-17: WARNING: spidev_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/staging/pi433/pi433_if.c:974:1-17: WARNING: pi433_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/acquirewdt.c:203:8-24: WARNING: acq_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/advantechwdt.c:202:8-24: WARNING: advwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/alim1535_wdt.c:252:8-24: WARNING: ali_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/alim7101_wdt.c:217:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/ar7_wdt.c:166:8-24: WARNING: ar7_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/at91rm9200_wdt.c:113:8-24: WARNING: at91wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/ath79_wdt.c:135:8-24: WARNING: ath79_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/bcm63xx_wdt.c:119:8-24: WARNING: bcm63xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/cpu5wdt.c:143:8-24: WARNING: cpu5wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/cpwd.c:397:8-24: WARNING: cpwd_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/eurotechwdt.c:319:8-24: WARNING: eurwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/f71808e_wdt.c:528:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/gef_wdt.c:232:8-24: WARNING: gef_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/geodewdt.c:95:8-24: WARNING: geodewdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/ib700wdt.c:241:8-24: WARNING: ibwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/ibmasr.c:326:8-24: WARNING: asr_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/indydog.c:80:8-24: WARNING: indydog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/intel_scu_watchdog.c:307:8-24: WARNING: intel_scu_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/iop_wdt.c:104:8-24: WARNING: iop_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/it8712f_wdt.c:330:8-24: WARNING: it8712f_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/ixp4xx_wdt.c:68:8-24: WARNING: ixp4xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/ks8695_wdt.c:145:8-24: WARNING: ks8695wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/m54xx_wdt.c:88:8-24: WARNING: m54xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/machzwd.c:336:8-24: WARNING: zf_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/mixcomwd.c:153:8-24: WARNING: mixcomwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/mtx-1_wdt.c:121:8-24: WARNING: mtx1_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/mv64x60_wdt.c:136:8-24: WARNING: mv64x60_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/nuc900_wdt.c:134:8-24: WARNING: nuc900wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/nv_tco.c:164:8-24: WARNING: nv_tco_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pc87413_wdt.c:289:8-24: WARNING: pc87413_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pcwd.c:698:8-24: WARNING: pcwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pcwd.c:737:8-24: WARNING: pcwd_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pcwd_pci.c:581:8-24: WARNING: pcipcwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pcwd_pci.c:623:8-24: WARNING: pcipcwd_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pcwd_usb.c:488:8-24: WARNING: usb_pcwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pcwd_usb.c:527:8-24: WARNING: usb_pcwd_temperature_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pika_wdt.c:121:8-24: WARNING: pikawdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pnx833x_wdt.c:119:8-24: WARNING: pnx833x_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/rc32434_wdt.c:153:8-24: WARNING: rc32434_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/rdc321x_wdt.c:145:8-24: WARNING: rdc321x_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/riowd.c:79:1-17: WARNING: riowd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sa1100_wdt.c:62:8-24: WARNING: sa1100dog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sbc60xxwdt.c:211:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sbc7240_wdt.c:139:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sbc8360.c:274:8-24: WARNING: sbc8360_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sbc_epx_c3.c:81:8-24: WARNING: epx_c3_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sbc_fitpc2_wdt.c:78:8-24: WARNING: fitpc2_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sb_wdog.c:108:1-17: WARNING: sbwdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sc1200wdt.c:181:8-24: WARNING: sc1200wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sc520_wdt.c:261:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sch311x_wdt.c:319:8-24: WARNING: sch311x_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/scx200_wdt.c:105:8-24: WARNING: scx200_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/smsc37b787_wdt.c:369:8-24: WARNING: wb_smsc_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/w83877f_wdt.c:227:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/w83977f_wdt.c:301:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wafer5823wdt.c:200:8-24: WARNING: wafwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/watchdog_dev.c:828:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wdrtas.c:379:8-24: WARNING: wdrtas_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wdrtas.c:445:8-24: WARNING: wdrtas_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wdt285.c:104:1-17: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wdt977.c:276:8-24: WARNING: wdt977_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wdt.c:424:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wdt.c:484:8-24: WARNING: wdt_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wdt_pci.c:464:8-24: WARNING: wdtpci_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wdt_pci.c:527:8-24: WARNING: wdtpci_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	net/batman-adv/log.c:105:1-17: WARNING: batadv_log_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	sound/core/control.c:57:7-23: WARNING: snd_ctl_f_ops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	sound/core/rawmidi.c:385:7-23: WARNING: snd_rawmidi_f_ops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	sound/core/seq/seq_clientmgr.c:310:7-23: WARNING: snd_seq_f_ops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	sound/core/timer.c:1428:7-23: WARNING: snd_timer_f_ops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.

One can also recheck/review the patch via generating it with explanation comments included via

	$ make coccicheck MODE=patch COCCI=scripts/coccinelle/api/stream_open.cocci SPFLAGS="-D explain"

(*) This second group also contains cases with read/write deadlocks that
stream_open.cocci don't yet detect, but which are still valid to convert to
stream_open since ppos is not used. For example drivers/pci/switch/switchtec.c
calls wait_for_completion_interruptible() in its .read, but stream_open.cocci
currently detects only "wait_event*" as blocking.

Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Yongzhi Pan <panyongzhi@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Tejun Heo <tj@kernel.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Nikolaus Rath <Nikolaus@rath.org>
Cc: Han-Wen Nienhuys <hanwen@google.com>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James R. Van Zandt" <jrv@vanzandt.mv.com>
Cc: Corey Minyard <minyard@acm.org>
Cc: Harald Welte <laforge@gnumonks.org>
Acked-by: Lubomir Rintel <lkundrak@v3.sk> [scr24x_cs]
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Johan Hovold <johan@kernel.org>
Cc: David Herrmann <dh.herrmann@googlemail.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: Jean Delvare <jdelvare@suse.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>	[watchdog/* hwmon/*]
Cc: Rudolf Marek <r.marek@assembler.cz>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Kurt Schwemmer <kurt.schwemmer@microsemi.com>
Acked-by: Logan Gunthorpe <logang@deltatee.com> [drivers/pci/switch/switchtec]
Acked-by: Bjorn Helgaas <bhelgaas@google.com> [drivers/pci/switch/switchtec]
Cc: Benson Leung <bleung@chromium.org>
Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> [platform/chrome]
Cc: Alessandro Zummo <a.zummo@towertech.it>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> [rtc/*]
Cc: Mark Brown <broonie@kernel.org>
Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Zwane Mwaikambo <zwanem@gmail.com>
Cc: Marek Lindner <mareklindner@neomailbox.ch>
Cc: Simon Wunderlich <sw@simonwunderlich.de>
Cc: Antonio Quartulli <a@unstable.cc>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Signed-off-by: Kirill Smelkov <kirr@nexedi.com>
2019-05-06 17:46:41 +03:00

803 lines
18 KiB
C

/*
* User-space I/O driver support for HID subsystem
* Copyright (c) 2012 David Herrmann
*/
/*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*/
#include <linux/atomic.h>
#include <linux/compat.h>
#include <linux/cred.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/hid.h>
#include <linux/input.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/poll.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/uhid.h>
#include <linux/wait.h>
#define UHID_NAME "uhid"
#define UHID_BUFSIZE 32
struct uhid_device {
struct mutex devlock;
bool running;
__u8 *rd_data;
uint rd_size;
struct hid_device *hid;
struct uhid_event input_buf;
wait_queue_head_t waitq;
spinlock_t qlock;
__u8 head;
__u8 tail;
struct uhid_event *outq[UHID_BUFSIZE];
/* blocking GET_REPORT support; state changes protected by qlock */
struct mutex report_lock;
wait_queue_head_t report_wait;
bool report_running;
u32 report_id;
u32 report_type;
struct uhid_event report_buf;
struct work_struct worker;
};
static struct miscdevice uhid_misc;
static void uhid_device_add_worker(struct work_struct *work)
{
struct uhid_device *uhid = container_of(work, struct uhid_device, worker);
int ret;
ret = hid_add_device(uhid->hid);
if (ret) {
hid_err(uhid->hid, "Cannot register HID device: error %d\n", ret);
hid_destroy_device(uhid->hid);
uhid->hid = NULL;
uhid->running = false;
}
}
static void uhid_queue(struct uhid_device *uhid, struct uhid_event *ev)
{
__u8 newhead;
newhead = (uhid->head + 1) % UHID_BUFSIZE;
if (newhead != uhid->tail) {
uhid->outq[uhid->head] = ev;
uhid->head = newhead;
wake_up_interruptible(&uhid->waitq);
} else {
hid_warn(uhid->hid, "Output queue is full\n");
kfree(ev);
}
}
static int uhid_queue_event(struct uhid_device *uhid, __u32 event)
{
unsigned long flags;
struct uhid_event *ev;
ev = kzalloc(sizeof(*ev), GFP_KERNEL);
if (!ev)
return -ENOMEM;
ev->type = event;
spin_lock_irqsave(&uhid->qlock, flags);
uhid_queue(uhid, ev);
spin_unlock_irqrestore(&uhid->qlock, flags);
return 0;
}
static int uhid_hid_start(struct hid_device *hid)
{
struct uhid_device *uhid = hid->driver_data;
struct uhid_event *ev;
unsigned long flags;
ev = kzalloc(sizeof(*ev), GFP_KERNEL);
if (!ev)
return -ENOMEM;
ev->type = UHID_START;
if (hid->report_enum[HID_FEATURE_REPORT].numbered)
ev->u.start.dev_flags |= UHID_DEV_NUMBERED_FEATURE_REPORTS;
if (hid->report_enum[HID_OUTPUT_REPORT].numbered)
ev->u.start.dev_flags |= UHID_DEV_NUMBERED_OUTPUT_REPORTS;
if (hid->report_enum[HID_INPUT_REPORT].numbered)
ev->u.start.dev_flags |= UHID_DEV_NUMBERED_INPUT_REPORTS;
spin_lock_irqsave(&uhid->qlock, flags);
uhid_queue(uhid, ev);
spin_unlock_irqrestore(&uhid->qlock, flags);
return 0;
}
static void uhid_hid_stop(struct hid_device *hid)
{
struct uhid_device *uhid = hid->driver_data;
hid->claimed = 0;
uhid_queue_event(uhid, UHID_STOP);
}
static int uhid_hid_open(struct hid_device *hid)
{
struct uhid_device *uhid = hid->driver_data;
return uhid_queue_event(uhid, UHID_OPEN);
}
static void uhid_hid_close(struct hid_device *hid)
{
struct uhid_device *uhid = hid->driver_data;
uhid_queue_event(uhid, UHID_CLOSE);
}
static int uhid_hid_parse(struct hid_device *hid)
{
struct uhid_device *uhid = hid->driver_data;
return hid_parse_report(hid, uhid->rd_data, uhid->rd_size);
}
/* must be called with report_lock held */
static int __uhid_report_queue_and_wait(struct uhid_device *uhid,
struct uhid_event *ev,
__u32 *report_id)
{
unsigned long flags;
int ret;
spin_lock_irqsave(&uhid->qlock, flags);
*report_id = ++uhid->report_id;
uhid->report_type = ev->type + 1;
uhid->report_running = true;
uhid_queue(uhid, ev);
spin_unlock_irqrestore(&uhid->qlock, flags);
ret = wait_event_interruptible_timeout(uhid->report_wait,
!uhid->report_running || !uhid->running,
5 * HZ);
if (!ret || !uhid->running || uhid->report_running)
ret = -EIO;
else if (ret < 0)
ret = -ERESTARTSYS;
else
ret = 0;
uhid->report_running = false;
return ret;
}
static void uhid_report_wake_up(struct uhid_device *uhid, u32 id,
const struct uhid_event *ev)
{
unsigned long flags;
spin_lock_irqsave(&uhid->qlock, flags);
/* id for old report; drop it silently */
if (uhid->report_type != ev->type || uhid->report_id != id)
goto unlock;
if (!uhid->report_running)
goto unlock;
memcpy(&uhid->report_buf, ev, sizeof(*ev));
uhid->report_running = false;
wake_up_interruptible(&uhid->report_wait);
unlock:
spin_unlock_irqrestore(&uhid->qlock, flags);
}
static int uhid_hid_get_report(struct hid_device *hid, unsigned char rnum,
u8 *buf, size_t count, u8 rtype)
{
struct uhid_device *uhid = hid->driver_data;
struct uhid_get_report_reply_req *req;
struct uhid_event *ev;
int ret;
if (!uhid->running)
return -EIO;
ev = kzalloc(sizeof(*ev), GFP_KERNEL);
if (!ev)
return -ENOMEM;
ev->type = UHID_GET_REPORT;
ev->u.get_report.rnum = rnum;
ev->u.get_report.rtype = rtype;
ret = mutex_lock_interruptible(&uhid->report_lock);
if (ret) {
kfree(ev);
return ret;
}
/* this _always_ takes ownership of @ev */
ret = __uhid_report_queue_and_wait(uhid, ev, &ev->u.get_report.id);
if (ret)
goto unlock;
req = &uhid->report_buf.u.get_report_reply;
if (req->err) {
ret = -EIO;
} else {
ret = min3(count, (size_t)req->size, (size_t)UHID_DATA_MAX);
memcpy(buf, req->data, ret);
}
unlock:
mutex_unlock(&uhid->report_lock);
return ret;
}
static int uhid_hid_set_report(struct hid_device *hid, unsigned char rnum,
const u8 *buf, size_t count, u8 rtype)
{
struct uhid_device *uhid = hid->driver_data;
struct uhid_event *ev;
int ret;
if (!uhid->running || count > UHID_DATA_MAX)
return -EIO;
ev = kzalloc(sizeof(*ev), GFP_KERNEL);
if (!ev)
return -ENOMEM;
ev->type = UHID_SET_REPORT;
ev->u.set_report.rnum = rnum;
ev->u.set_report.rtype = rtype;
ev->u.set_report.size = count;
memcpy(ev->u.set_report.data, buf, count);
ret = mutex_lock_interruptible(&uhid->report_lock);
if (ret) {
kfree(ev);
return ret;
}
/* this _always_ takes ownership of @ev */
ret = __uhid_report_queue_and_wait(uhid, ev, &ev->u.set_report.id);
if (ret)
goto unlock;
if (uhid->report_buf.u.set_report_reply.err)
ret = -EIO;
else
ret = count;
unlock:
mutex_unlock(&uhid->report_lock);
return ret;
}
static int uhid_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
__u8 *buf, size_t len, unsigned char rtype,
int reqtype)
{
u8 u_rtype;
switch (rtype) {
case HID_FEATURE_REPORT:
u_rtype = UHID_FEATURE_REPORT;
break;
case HID_OUTPUT_REPORT:
u_rtype = UHID_OUTPUT_REPORT;
break;
case HID_INPUT_REPORT:
u_rtype = UHID_INPUT_REPORT;
break;
default:
return -EINVAL;
}
switch (reqtype) {
case HID_REQ_GET_REPORT:
return uhid_hid_get_report(hid, reportnum, buf, len, u_rtype);
case HID_REQ_SET_REPORT:
return uhid_hid_set_report(hid, reportnum, buf, len, u_rtype);
default:
return -EIO;
}
}
static int uhid_hid_output_raw(struct hid_device *hid, __u8 *buf, size_t count,
unsigned char report_type)
{
struct uhid_device *uhid = hid->driver_data;
__u8 rtype;
unsigned long flags;
struct uhid_event *ev;
switch (report_type) {
case HID_FEATURE_REPORT:
rtype = UHID_FEATURE_REPORT;
break;
case HID_OUTPUT_REPORT:
rtype = UHID_OUTPUT_REPORT;
break;
default:
return -EINVAL;
}
if (count < 1 || count > UHID_DATA_MAX)
return -EINVAL;
ev = kzalloc(sizeof(*ev), GFP_KERNEL);
if (!ev)
return -ENOMEM;
ev->type = UHID_OUTPUT;
ev->u.output.size = count;
ev->u.output.rtype = rtype;
memcpy(ev->u.output.data, buf, count);
spin_lock_irqsave(&uhid->qlock, flags);
uhid_queue(uhid, ev);
spin_unlock_irqrestore(&uhid->qlock, flags);
return count;
}
static int uhid_hid_output_report(struct hid_device *hid, __u8 *buf,
size_t count)
{
return uhid_hid_output_raw(hid, buf, count, HID_OUTPUT_REPORT);
}
struct hid_ll_driver uhid_hid_driver = {
.start = uhid_hid_start,
.stop = uhid_hid_stop,
.open = uhid_hid_open,
.close = uhid_hid_close,
.parse = uhid_hid_parse,
.raw_request = uhid_hid_raw_request,
.output_report = uhid_hid_output_report,
};
EXPORT_SYMBOL_GPL(uhid_hid_driver);
#ifdef CONFIG_COMPAT
/* Apparently we haven't stepped on these rakes enough times yet. */
struct uhid_create_req_compat {
__u8 name[128];
__u8 phys[64];
__u8 uniq[64];
compat_uptr_t rd_data;
__u16 rd_size;
__u16 bus;
__u32 vendor;
__u32 product;
__u32 version;
__u32 country;
} __attribute__((__packed__));
static int uhid_event_from_user(const char __user *buffer, size_t len,
struct uhid_event *event)
{
if (in_compat_syscall()) {
u32 type;
if (get_user(type, buffer))
return -EFAULT;
if (type == UHID_CREATE) {
/*
* This is our messed up request with compat pointer.
* It is largish (more than 256 bytes) so we better
* allocate it from the heap.
*/
struct uhid_create_req_compat *compat;
compat = kzalloc(sizeof(*compat), GFP_KERNEL);
if (!compat)
return -ENOMEM;
buffer += sizeof(type);
len -= sizeof(type);
if (copy_from_user(compat, buffer,
min(len, sizeof(*compat)))) {
kfree(compat);
return -EFAULT;
}
/* Shuffle the data over to proper structure */
event->type = type;
memcpy(event->u.create.name, compat->name,
sizeof(compat->name));
memcpy(event->u.create.phys, compat->phys,
sizeof(compat->phys));
memcpy(event->u.create.uniq, compat->uniq,
sizeof(compat->uniq));
event->u.create.rd_data = compat_ptr(compat->rd_data);
event->u.create.rd_size = compat->rd_size;
event->u.create.bus = compat->bus;
event->u.create.vendor = compat->vendor;
event->u.create.product = compat->product;
event->u.create.version = compat->version;
event->u.create.country = compat->country;
kfree(compat);
return 0;
}
/* All others can be copied directly */
}
if (copy_from_user(event, buffer, min(len, sizeof(*event))))
return -EFAULT;
return 0;
}
#else
static int uhid_event_from_user(const char __user *buffer, size_t len,
struct uhid_event *event)
{
if (copy_from_user(event, buffer, min(len, sizeof(*event))))
return -EFAULT;
return 0;
}
#endif
static int uhid_dev_create2(struct uhid_device *uhid,
const struct uhid_event *ev)
{
struct hid_device *hid;
size_t rd_size, len;
void *rd_data;
int ret;
if (uhid->running)
return -EALREADY;
rd_size = ev->u.create2.rd_size;
if (rd_size <= 0 || rd_size > HID_MAX_DESCRIPTOR_SIZE)
return -EINVAL;
rd_data = kmemdup(ev->u.create2.rd_data, rd_size, GFP_KERNEL);
if (!rd_data)
return -ENOMEM;
uhid->rd_size = rd_size;
uhid->rd_data = rd_data;
hid = hid_allocate_device();
if (IS_ERR(hid)) {
ret = PTR_ERR(hid);
goto err_free;
}
/* @hid is zero-initialized, strncpy() is correct, strlcpy() not */
len = min(sizeof(hid->name), sizeof(ev->u.create2.name)) - 1;
strncpy(hid->name, ev->u.create2.name, len);
len = min(sizeof(hid->phys), sizeof(ev->u.create2.phys)) - 1;
strncpy(hid->phys, ev->u.create2.phys, len);
len = min(sizeof(hid->uniq), sizeof(ev->u.create2.uniq)) - 1;
strncpy(hid->uniq, ev->u.create2.uniq, len);
hid->ll_driver = &uhid_hid_driver;
hid->bus = ev->u.create2.bus;
hid->vendor = ev->u.create2.vendor;
hid->product = ev->u.create2.product;
hid->version = ev->u.create2.version;
hid->country = ev->u.create2.country;
hid->driver_data = uhid;
hid->dev.parent = uhid_misc.this_device;
uhid->hid = hid;
uhid->running = true;
/* Adding of a HID device is done through a worker, to allow HID drivers
* which use feature requests during .probe to work, without they would
* be blocked on devlock, which is held by uhid_char_write.
*/
schedule_work(&uhid->worker);
return 0;
err_free:
kfree(uhid->rd_data);
uhid->rd_data = NULL;
uhid->rd_size = 0;
return ret;
}
static int uhid_dev_create(struct uhid_device *uhid,
struct uhid_event *ev)
{
struct uhid_create_req orig;
orig = ev->u.create;
if (orig.rd_size <= 0 || orig.rd_size > HID_MAX_DESCRIPTOR_SIZE)
return -EINVAL;
if (copy_from_user(&ev->u.create2.rd_data, orig.rd_data, orig.rd_size))
return -EFAULT;
memcpy(ev->u.create2.name, orig.name, sizeof(orig.name));
memcpy(ev->u.create2.phys, orig.phys, sizeof(orig.phys));
memcpy(ev->u.create2.uniq, orig.uniq, sizeof(orig.uniq));
ev->u.create2.rd_size = orig.rd_size;
ev->u.create2.bus = orig.bus;
ev->u.create2.vendor = orig.vendor;
ev->u.create2.product = orig.product;
ev->u.create2.version = orig.version;
ev->u.create2.country = orig.country;
return uhid_dev_create2(uhid, ev);
}
static int uhid_dev_destroy(struct uhid_device *uhid)
{
if (!uhid->running)
return -EINVAL;
uhid->running = false;
wake_up_interruptible(&uhid->report_wait);
cancel_work_sync(&uhid->worker);
hid_destroy_device(uhid->hid);
kfree(uhid->rd_data);
return 0;
}
static int uhid_dev_input(struct uhid_device *uhid, struct uhid_event *ev)
{
if (!uhid->running)
return -EINVAL;
hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input.data,
min_t(size_t, ev->u.input.size, UHID_DATA_MAX), 0);
return 0;
}
static int uhid_dev_input2(struct uhid_device *uhid, struct uhid_event *ev)
{
if (!uhid->running)
return -EINVAL;
hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input2.data,
min_t(size_t, ev->u.input2.size, UHID_DATA_MAX), 0);
return 0;
}
static int uhid_dev_get_report_reply(struct uhid_device *uhid,
struct uhid_event *ev)
{
if (!uhid->running)
return -EINVAL;
uhid_report_wake_up(uhid, ev->u.get_report_reply.id, ev);
return 0;
}
static int uhid_dev_set_report_reply(struct uhid_device *uhid,
struct uhid_event *ev)
{
if (!uhid->running)
return -EINVAL;
uhid_report_wake_up(uhid, ev->u.set_report_reply.id, ev);
return 0;
}
static int uhid_char_open(struct inode *inode, struct file *file)
{
struct uhid_device *uhid;
uhid = kzalloc(sizeof(*uhid), GFP_KERNEL);
if (!uhid)
return -ENOMEM;
mutex_init(&uhid->devlock);
mutex_init(&uhid->report_lock);
spin_lock_init(&uhid->qlock);
init_waitqueue_head(&uhid->waitq);
init_waitqueue_head(&uhid->report_wait);
uhid->running = false;
INIT_WORK(&uhid->worker, uhid_device_add_worker);
file->private_data = uhid;
stream_open(inode, file);
return 0;
}
static int uhid_char_release(struct inode *inode, struct file *file)
{
struct uhid_device *uhid = file->private_data;
unsigned int i;
uhid_dev_destroy(uhid);
for (i = 0; i < UHID_BUFSIZE; ++i)
kfree(uhid->outq[i]);
kfree(uhid);
return 0;
}
static ssize_t uhid_char_read(struct file *file, char __user *buffer,
size_t count, loff_t *ppos)
{
struct uhid_device *uhid = file->private_data;
int ret;
unsigned long flags;
size_t len;
/* they need at least the "type" member of uhid_event */
if (count < sizeof(__u32))
return -EINVAL;
try_again:
if (file->f_flags & O_NONBLOCK) {
if (uhid->head == uhid->tail)
return -EAGAIN;
} else {
ret = wait_event_interruptible(uhid->waitq,
uhid->head != uhid->tail);
if (ret)
return ret;
}
ret = mutex_lock_interruptible(&uhid->devlock);
if (ret)
return ret;
if (uhid->head == uhid->tail) {
mutex_unlock(&uhid->devlock);
goto try_again;
} else {
len = min(count, sizeof(**uhid->outq));
if (copy_to_user(buffer, uhid->outq[uhid->tail], len)) {
ret = -EFAULT;
} else {
kfree(uhid->outq[uhid->tail]);
uhid->outq[uhid->tail] = NULL;
spin_lock_irqsave(&uhid->qlock, flags);
uhid->tail = (uhid->tail + 1) % UHID_BUFSIZE;
spin_unlock_irqrestore(&uhid->qlock, flags);
}
}
mutex_unlock(&uhid->devlock);
return ret ? ret : len;
}
static ssize_t uhid_char_write(struct file *file, const char __user *buffer,
size_t count, loff_t *ppos)
{
struct uhid_device *uhid = file->private_data;
int ret;
size_t len;
/* we need at least the "type" member of uhid_event */
if (count < sizeof(__u32))
return -EINVAL;
ret = mutex_lock_interruptible(&uhid->devlock);
if (ret)
return ret;
memset(&uhid->input_buf, 0, sizeof(uhid->input_buf));
len = min(count, sizeof(uhid->input_buf));
ret = uhid_event_from_user(buffer, len, &uhid->input_buf);
if (ret)
goto unlock;
switch (uhid->input_buf.type) {
case UHID_CREATE:
/*
* 'struct uhid_create_req' contains a __user pointer which is
* copied from, so it's unsafe to allow this with elevated
* privileges (e.g. from a setuid binary) or via kernel_write().
*/
if (file->f_cred != current_cred() || uaccess_kernel()) {
pr_err_once("UHID_CREATE from different security context by process %d (%s), this is not allowed.\n",
task_tgid_vnr(current), current->comm);
ret = -EACCES;
goto unlock;
}
ret = uhid_dev_create(uhid, &uhid->input_buf);
break;
case UHID_CREATE2:
ret = uhid_dev_create2(uhid, &uhid->input_buf);
break;
case UHID_DESTROY:
ret = uhid_dev_destroy(uhid);
break;
case UHID_INPUT:
ret = uhid_dev_input(uhid, &uhid->input_buf);
break;
case UHID_INPUT2:
ret = uhid_dev_input2(uhid, &uhid->input_buf);
break;
case UHID_GET_REPORT_REPLY:
ret = uhid_dev_get_report_reply(uhid, &uhid->input_buf);
break;
case UHID_SET_REPORT_REPLY:
ret = uhid_dev_set_report_reply(uhid, &uhid->input_buf);
break;
default:
ret = -EOPNOTSUPP;
}
unlock:
mutex_unlock(&uhid->devlock);
/* return "count" not "len" to not confuse the caller */
return ret ? ret : count;
}
static __poll_t uhid_char_poll(struct file *file, poll_table *wait)
{
struct uhid_device *uhid = file->private_data;
poll_wait(file, &uhid->waitq, wait);
if (uhid->head != uhid->tail)
return EPOLLIN | EPOLLRDNORM;
return 0;
}
static const struct file_operations uhid_fops = {
.owner = THIS_MODULE,
.open = uhid_char_open,
.release = uhid_char_release,
.read = uhid_char_read,
.write = uhid_char_write,
.poll = uhid_char_poll,
.llseek = no_llseek,
};
static struct miscdevice uhid_misc = {
.fops = &uhid_fops,
.minor = UHID_MINOR,
.name = UHID_NAME,
};
module_misc_device(uhid_misc);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Herrmann <dh.herrmann@gmail.com>");
MODULE_DESCRIPTION("User-space I/O driver support for HID subsystem");
MODULE_ALIAS_MISCDEV(UHID_MINOR);
MODULE_ALIAS("devname:" UHID_NAME);