linux/drivers/platform/chrome/cros_ec_debugfs.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

505 lines
12 KiB
C

// SPDX-License-Identifier: GPL-2.0+
// Debug logs for the ChromeOS EC
//
// Copyright (C) 2015 Google, Inc.
#include <linux/circ_buf.h>
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/mfd/cros_ec.h>
#include <linux/mfd/cros_ec_commands.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/poll.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/wait.h>
#define DRV_NAME "cros-ec-debugfs"
#define LOG_SHIFT 14
#define LOG_SIZE (1 << LOG_SHIFT)
#define LOG_POLL_SEC 10
#define CIRC_ADD(idx, size, value) (((idx) + (value)) & ((size) - 1))
/* struct cros_ec_debugfs - ChromeOS EC debugging information
*
* @ec: EC device this debugfs information belongs to
* @dir: dentry for debugfs files
* @log_buffer: circular buffer for console log information
* @read_msg: preallocated EC command and buffer to read console log
* @log_mutex: mutex to protect circular buffer
* @log_wq: waitqueue for log readers
* @log_poll_work: recurring task to poll EC for new console log data
* @panicinfo_blob: panicinfo debugfs blob
*/
struct cros_ec_debugfs {
struct cros_ec_dev *ec;
struct dentry *dir;
/* EC log */
struct circ_buf log_buffer;
struct cros_ec_command *read_msg;
struct mutex log_mutex;
wait_queue_head_t log_wq;
struct delayed_work log_poll_work;
/* EC panicinfo */
struct debugfs_blob_wrapper panicinfo_blob;
};
/*
* We need to make sure that the EC log buffer on the UART is large enough,
* so that it is unlikely enough to overlow within LOG_POLL_SEC.
*/
static void cros_ec_console_log_work(struct work_struct *__work)
{
struct cros_ec_debugfs *debug_info =
container_of(to_delayed_work(__work),
struct cros_ec_debugfs,
log_poll_work);
struct cros_ec_dev *ec = debug_info->ec;
struct circ_buf *cb = &debug_info->log_buffer;
struct cros_ec_command snapshot_msg = {
.command = EC_CMD_CONSOLE_SNAPSHOT + ec->cmd_offset,
};
struct ec_params_console_read_v1 *read_params =
(struct ec_params_console_read_v1 *)debug_info->read_msg->data;
uint8_t *ec_buffer = (uint8_t *)debug_info->read_msg->data;
int idx;
int buf_space;
int ret;
ret = cros_ec_cmd_xfer(ec->ec_dev, &snapshot_msg);
if (ret < 0) {
dev_err(ec->dev, "EC communication failed\n");
goto resched;
}
if (snapshot_msg.result != EC_RES_SUCCESS) {
dev_err(ec->dev, "EC failed to snapshot the console log\n");
goto resched;
}
/* Loop until we have read everything, or there's an error. */
mutex_lock(&debug_info->log_mutex);
buf_space = CIRC_SPACE(cb->head, cb->tail, LOG_SIZE);
while (1) {
if (!buf_space) {
dev_info_once(ec->dev,
"Some logs may have been dropped...\n");
break;
}
memset(read_params, '\0', sizeof(*read_params));
read_params->subcmd = CONSOLE_READ_RECENT;
ret = cros_ec_cmd_xfer(ec->ec_dev, debug_info->read_msg);
if (ret < 0) {
dev_err(ec->dev, "EC communication failed\n");
break;
}
if (debug_info->read_msg->result != EC_RES_SUCCESS) {
dev_err(ec->dev,
"EC failed to read the console log\n");
break;
}
/* If the buffer is empty, we're done here. */
if (ret == 0 || ec_buffer[0] == '\0')
break;
idx = 0;
while (idx < ret && ec_buffer[idx] != '\0' && buf_space > 0) {
cb->buf[cb->head] = ec_buffer[idx];
cb->head = CIRC_ADD(cb->head, LOG_SIZE, 1);
idx++;
buf_space--;
}
wake_up(&debug_info->log_wq);
}
mutex_unlock(&debug_info->log_mutex);
resched:
schedule_delayed_work(&debug_info->log_poll_work,
msecs_to_jiffies(LOG_POLL_SEC * 1000));
}
static int cros_ec_console_log_open(struct inode *inode, struct file *file)
{
file->private_data = inode->i_private;
return stream_open(inode, file);
}
static ssize_t cros_ec_console_log_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
struct cros_ec_debugfs *debug_info = file->private_data;
struct circ_buf *cb = &debug_info->log_buffer;
ssize_t ret;
mutex_lock(&debug_info->log_mutex);
while (!CIRC_CNT(cb->head, cb->tail, LOG_SIZE)) {
if (file->f_flags & O_NONBLOCK) {
ret = -EAGAIN;
goto error;
}
mutex_unlock(&debug_info->log_mutex);
ret = wait_event_interruptible(debug_info->log_wq,
CIRC_CNT(cb->head, cb->tail, LOG_SIZE));
if (ret < 0)
return ret;
mutex_lock(&debug_info->log_mutex);
}
/* Only copy until the end of the circular buffer, and let userspace
* retry to get the rest of the data.
*/
ret = min_t(size_t, CIRC_CNT_TO_END(cb->head, cb->tail, LOG_SIZE),
count);
if (copy_to_user(buf, cb->buf + cb->tail, ret)) {
ret = -EFAULT;
goto error;
}
cb->tail = CIRC_ADD(cb->tail, LOG_SIZE, ret);
error:
mutex_unlock(&debug_info->log_mutex);
return ret;
}
static __poll_t cros_ec_console_log_poll(struct file *file,
poll_table *wait)
{
struct cros_ec_debugfs *debug_info = file->private_data;
__poll_t mask = 0;
poll_wait(file, &debug_info->log_wq, wait);
mutex_lock(&debug_info->log_mutex);
if (CIRC_CNT(debug_info->log_buffer.head,
debug_info->log_buffer.tail,
LOG_SIZE))
mask |= EPOLLIN | EPOLLRDNORM;
mutex_unlock(&debug_info->log_mutex);
return mask;
}
static int cros_ec_console_log_release(struct inode *inode, struct file *file)
{
return 0;
}
static ssize_t cros_ec_pdinfo_read(struct file *file,
char __user *user_buf,
size_t count,
loff_t *ppos)
{
char read_buf[EC_USB_PD_MAX_PORTS * 40], *p = read_buf;
struct cros_ec_debugfs *debug_info = file->private_data;
struct cros_ec_device *ec_dev = debug_info->ec->ec_dev;
struct {
struct cros_ec_command msg;
union {
struct ec_response_usb_pd_control_v1 resp;
struct ec_params_usb_pd_control params;
};
} __packed ec_buf;
struct cros_ec_command *msg;
struct ec_response_usb_pd_control_v1 *resp;
struct ec_params_usb_pd_control *params;
int i;
msg = &ec_buf.msg;
params = (struct ec_params_usb_pd_control *)msg->data;
resp = (struct ec_response_usb_pd_control_v1 *)msg->data;
msg->command = EC_CMD_USB_PD_CONTROL;
msg->version = 1;
msg->insize = sizeof(*resp);
msg->outsize = sizeof(*params);
/*
* Read status from all PD ports until failure, typically caused
* by attempting to read status on a port that doesn't exist.
*/
for (i = 0; i < EC_USB_PD_MAX_PORTS; ++i) {
params->port = i;
params->role = 0;
params->mux = 0;
params->swap = 0;
if (cros_ec_cmd_xfer_status(ec_dev, msg) < 0)
break;
p += scnprintf(p, sizeof(read_buf) + read_buf - p,
"p%d: %s en:%.2x role:%.2x pol:%.2x\n", i,
resp->state, resp->enabled, resp->role,
resp->polarity);
}
return simple_read_from_buffer(user_buf, count, ppos,
read_buf, p - read_buf);
}
const struct file_operations cros_ec_console_log_fops = {
.owner = THIS_MODULE,
.open = cros_ec_console_log_open,
.read = cros_ec_console_log_read,
.llseek = no_llseek,
.poll = cros_ec_console_log_poll,
.release = cros_ec_console_log_release,
};
const struct file_operations cros_ec_pdinfo_fops = {
.owner = THIS_MODULE,
.open = simple_open,
.read = cros_ec_pdinfo_read,
.llseek = default_llseek,
};
static int ec_read_version_supported(struct cros_ec_dev *ec)
{
struct ec_params_get_cmd_versions_v1 *params;
struct ec_response_get_cmd_versions *response;
int ret;
struct cros_ec_command *msg;
msg = kzalloc(sizeof(*msg) + max(sizeof(*params), sizeof(*response)),
GFP_KERNEL);
if (!msg)
return 0;
msg->command = EC_CMD_GET_CMD_VERSIONS + ec->cmd_offset;
msg->outsize = sizeof(*params);
msg->insize = sizeof(*response);
params = (struct ec_params_get_cmd_versions_v1 *)msg->data;
params->cmd = EC_CMD_CONSOLE_READ;
response = (struct ec_response_get_cmd_versions *)msg->data;
ret = cros_ec_cmd_xfer(ec->ec_dev, msg) >= 0 &&
msg->result == EC_RES_SUCCESS &&
(response->version_mask & EC_VER_MASK(1));
kfree(msg);
return ret;
}
static int cros_ec_create_console_log(struct cros_ec_debugfs *debug_info)
{
struct cros_ec_dev *ec = debug_info->ec;
char *buf;
int read_params_size;
int read_response_size;
if (!ec_read_version_supported(ec)) {
dev_warn(ec->dev,
"device does not support reading the console log\n");
return 0;
}
buf = devm_kzalloc(ec->dev, LOG_SIZE, GFP_KERNEL);
if (!buf)
return -ENOMEM;
read_params_size = sizeof(struct ec_params_console_read_v1);
read_response_size = ec->ec_dev->max_response;
debug_info->read_msg = devm_kzalloc(ec->dev,
sizeof(*debug_info->read_msg) +
max(read_params_size, read_response_size), GFP_KERNEL);
if (!debug_info->read_msg)
return -ENOMEM;
debug_info->read_msg->version = 1;
debug_info->read_msg->command = EC_CMD_CONSOLE_READ + ec->cmd_offset;
debug_info->read_msg->outsize = read_params_size;
debug_info->read_msg->insize = read_response_size;
debug_info->log_buffer.buf = buf;
debug_info->log_buffer.head = 0;
debug_info->log_buffer.tail = 0;
mutex_init(&debug_info->log_mutex);
init_waitqueue_head(&debug_info->log_wq);
if (!debugfs_create_file("console_log",
S_IFREG | 0444,
debug_info->dir,
debug_info,
&cros_ec_console_log_fops))
return -ENOMEM;
INIT_DELAYED_WORK(&debug_info->log_poll_work,
cros_ec_console_log_work);
schedule_delayed_work(&debug_info->log_poll_work, 0);
return 0;
}
static void cros_ec_cleanup_console_log(struct cros_ec_debugfs *debug_info)
{
if (debug_info->log_buffer.buf) {
cancel_delayed_work_sync(&debug_info->log_poll_work);
mutex_destroy(&debug_info->log_mutex);
}
}
static int cros_ec_create_panicinfo(struct cros_ec_debugfs *debug_info)
{
struct cros_ec_device *ec_dev = debug_info->ec->ec_dev;
int ret;
struct cros_ec_command *msg;
int insize;
insize = ec_dev->max_response;
msg = devm_kzalloc(debug_info->ec->dev,
sizeof(*msg) + insize, GFP_KERNEL);
if (!msg)
return -ENOMEM;
msg->command = EC_CMD_GET_PANIC_INFO;
msg->insize = insize;
ret = cros_ec_cmd_xfer(ec_dev, msg);
if (ret < 0) {
dev_warn(debug_info->ec->dev, "Cannot read panicinfo.\n");
ret = 0;
goto free;
}
/* No panic data */
if (ret == 0)
goto free;
debug_info->panicinfo_blob.data = msg->data;
debug_info->panicinfo_blob.size = ret;
if (!debugfs_create_blob("panicinfo",
S_IFREG | 0444,
debug_info->dir,
&debug_info->panicinfo_blob)) {
ret = -ENOMEM;
goto free;
}
return 0;
free:
devm_kfree(debug_info->ec->dev, msg);
return ret;
}
static int cros_ec_create_pdinfo(struct cros_ec_debugfs *debug_info)
{
if (!debugfs_create_file("pdinfo", 0444, debug_info->dir, debug_info,
&cros_ec_pdinfo_fops))
return -ENOMEM;
return 0;
}
static int cros_ec_debugfs_probe(struct platform_device *pd)
{
struct cros_ec_dev *ec = dev_get_drvdata(pd->dev.parent);
struct cros_ec_platform *ec_platform = dev_get_platdata(ec->dev);
const char *name = ec_platform->ec_name;
struct cros_ec_debugfs *debug_info;
int ret;
debug_info = devm_kzalloc(ec->dev, sizeof(*debug_info), GFP_KERNEL);
if (!debug_info)
return -ENOMEM;
debug_info->ec = ec;
debug_info->dir = debugfs_create_dir(name, NULL);
if (!debug_info->dir)
return -ENOMEM;
ret = cros_ec_create_panicinfo(debug_info);
if (ret)
goto remove_debugfs;
ret = cros_ec_create_console_log(debug_info);
if (ret)
goto remove_debugfs;
ret = cros_ec_create_pdinfo(debug_info);
if (ret)
goto remove_log;
ec->debug_info = debug_info;
dev_set_drvdata(&pd->dev, ec);
return 0;
remove_log:
cros_ec_cleanup_console_log(debug_info);
remove_debugfs:
debugfs_remove_recursive(debug_info->dir);
return ret;
}
static int cros_ec_debugfs_remove(struct platform_device *pd)
{
struct cros_ec_dev *ec = dev_get_drvdata(pd->dev.parent);
debugfs_remove_recursive(ec->debug_info->dir);
cros_ec_cleanup_console_log(ec->debug_info);
return 0;
}
static int __maybe_unused cros_ec_debugfs_suspend(struct device *dev)
{
struct cros_ec_dev *ec = dev_get_drvdata(dev);
if (ec->debug_info->log_buffer.buf)
cancel_delayed_work_sync(&ec->debug_info->log_poll_work);
return 0;
}
static int __maybe_unused cros_ec_debugfs_resume(struct device *dev)
{
struct cros_ec_dev *ec = dev_get_drvdata(dev);
if (ec->debug_info->log_buffer.buf)
schedule_delayed_work(&ec->debug_info->log_poll_work, 0);
return 0;
}
static SIMPLE_DEV_PM_OPS(cros_ec_debugfs_pm_ops,
cros_ec_debugfs_suspend, cros_ec_debugfs_resume);
static struct platform_driver cros_ec_debugfs_driver = {
.driver = {
.name = DRV_NAME,
.pm = &cros_ec_debugfs_pm_ops,
},
.probe = cros_ec_debugfs_probe,
.remove = cros_ec_debugfs_remove,
};
module_platform_driver(cros_ec_debugfs_driver);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Debug logs for ChromeOS EC");
MODULE_ALIAS("platform:" DRV_NAME);