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![Kirill Smelkov](/assets/img/avatar_default.png)
Using scripts/coccinelle/api/stream_open.cocci added in10dce8af34
("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 in10dce8af34
): 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>
421 lines
8.3 KiB
C
421 lines
8.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* GNSS receiver core
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*
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* Copyright (C) 2018 Johan Hovold <johan@kernel.org>
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/cdev.h>
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#include <linux/errno.h>
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#include <linux/fs.h>
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#include <linux/gnss.h>
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#include <linux/idr.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/poll.h>
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#include <linux/slab.h>
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#include <linux/uaccess.h>
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#include <linux/wait.h>
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#define GNSS_FLAG_HAS_WRITE_RAW BIT(0)
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#define GNSS_MINORS 16
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static DEFINE_IDA(gnss_minors);
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static dev_t gnss_first;
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/* FIFO size must be a power of two */
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#define GNSS_READ_FIFO_SIZE 4096
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#define GNSS_WRITE_BUF_SIZE 1024
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#define to_gnss_device(d) container_of((d), struct gnss_device, dev)
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static int gnss_open(struct inode *inode, struct file *file)
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{
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struct gnss_device *gdev;
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int ret = 0;
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gdev = container_of(inode->i_cdev, struct gnss_device, cdev);
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get_device(&gdev->dev);
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stream_open(inode, file);
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file->private_data = gdev;
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down_write(&gdev->rwsem);
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|
if (gdev->disconnected) {
|
|
ret = -ENODEV;
|
|
goto unlock;
|
|
}
|
|
|
|
if (gdev->count++ == 0) {
|
|
ret = gdev->ops->open(gdev);
|
|
if (ret)
|
|
gdev->count--;
|
|
}
|
|
unlock:
|
|
up_write(&gdev->rwsem);
|
|
|
|
if (ret)
|
|
put_device(&gdev->dev);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int gnss_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct gnss_device *gdev = file->private_data;
|
|
|
|
down_write(&gdev->rwsem);
|
|
if (gdev->disconnected)
|
|
goto unlock;
|
|
|
|
if (--gdev->count == 0) {
|
|
gdev->ops->close(gdev);
|
|
kfifo_reset(&gdev->read_fifo);
|
|
}
|
|
unlock:
|
|
up_write(&gdev->rwsem);
|
|
|
|
put_device(&gdev->dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t gnss_read(struct file *file, char __user *buf,
|
|
size_t count, loff_t *pos)
|
|
{
|
|
struct gnss_device *gdev = file->private_data;
|
|
unsigned int copied;
|
|
int ret;
|
|
|
|
mutex_lock(&gdev->read_mutex);
|
|
while (kfifo_is_empty(&gdev->read_fifo)) {
|
|
mutex_unlock(&gdev->read_mutex);
|
|
|
|
if (gdev->disconnected)
|
|
return 0;
|
|
|
|
if (file->f_flags & O_NONBLOCK)
|
|
return -EAGAIN;
|
|
|
|
ret = wait_event_interruptible(gdev->read_queue,
|
|
gdev->disconnected ||
|
|
!kfifo_is_empty(&gdev->read_fifo));
|
|
if (ret)
|
|
return -ERESTARTSYS;
|
|
|
|
mutex_lock(&gdev->read_mutex);
|
|
}
|
|
|
|
ret = kfifo_to_user(&gdev->read_fifo, buf, count, &copied);
|
|
if (ret == 0)
|
|
ret = copied;
|
|
|
|
mutex_unlock(&gdev->read_mutex);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t gnss_write(struct file *file, const char __user *buf,
|
|
size_t count, loff_t *pos)
|
|
{
|
|
struct gnss_device *gdev = file->private_data;
|
|
size_t written = 0;
|
|
int ret;
|
|
|
|
if (gdev->disconnected)
|
|
return -EIO;
|
|
|
|
if (!count)
|
|
return 0;
|
|
|
|
if (!(gdev->flags & GNSS_FLAG_HAS_WRITE_RAW))
|
|
return -EIO;
|
|
|
|
/* Ignoring O_NONBLOCK, write_raw() is synchronous. */
|
|
|
|
ret = mutex_lock_interruptible(&gdev->write_mutex);
|
|
if (ret)
|
|
return -ERESTARTSYS;
|
|
|
|
for (;;) {
|
|
size_t n = count - written;
|
|
|
|
if (n > GNSS_WRITE_BUF_SIZE)
|
|
n = GNSS_WRITE_BUF_SIZE;
|
|
|
|
if (copy_from_user(gdev->write_buf, buf, n)) {
|
|
ret = -EFAULT;
|
|
goto out_unlock;
|
|
}
|
|
|
|
/*
|
|
* Assumes write_raw can always accept GNSS_WRITE_BUF_SIZE
|
|
* bytes.
|
|
*
|
|
* FIXME: revisit
|
|
*/
|
|
down_read(&gdev->rwsem);
|
|
if (!gdev->disconnected)
|
|
ret = gdev->ops->write_raw(gdev, gdev->write_buf, n);
|
|
else
|
|
ret = -EIO;
|
|
up_read(&gdev->rwsem);
|
|
|
|
if (ret < 0)
|
|
break;
|
|
|
|
written += ret;
|
|
buf += ret;
|
|
|
|
if (written == count)
|
|
break;
|
|
}
|
|
|
|
if (written)
|
|
ret = written;
|
|
out_unlock:
|
|
mutex_unlock(&gdev->write_mutex);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static __poll_t gnss_poll(struct file *file, poll_table *wait)
|
|
{
|
|
struct gnss_device *gdev = file->private_data;
|
|
__poll_t mask = 0;
|
|
|
|
poll_wait(file, &gdev->read_queue, wait);
|
|
|
|
if (!kfifo_is_empty(&gdev->read_fifo))
|
|
mask |= EPOLLIN | EPOLLRDNORM;
|
|
if (gdev->disconnected)
|
|
mask |= EPOLLHUP;
|
|
|
|
return mask;
|
|
}
|
|
|
|
static const struct file_operations gnss_fops = {
|
|
.owner = THIS_MODULE,
|
|
.open = gnss_open,
|
|
.release = gnss_release,
|
|
.read = gnss_read,
|
|
.write = gnss_write,
|
|
.poll = gnss_poll,
|
|
.llseek = no_llseek,
|
|
};
|
|
|
|
static struct class *gnss_class;
|
|
|
|
static void gnss_device_release(struct device *dev)
|
|
{
|
|
struct gnss_device *gdev = to_gnss_device(dev);
|
|
|
|
kfree(gdev->write_buf);
|
|
kfifo_free(&gdev->read_fifo);
|
|
ida_simple_remove(&gnss_minors, gdev->id);
|
|
kfree(gdev);
|
|
}
|
|
|
|
struct gnss_device *gnss_allocate_device(struct device *parent)
|
|
{
|
|
struct gnss_device *gdev;
|
|
struct device *dev;
|
|
int id;
|
|
int ret;
|
|
|
|
gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
|
|
if (!gdev)
|
|
return NULL;
|
|
|
|
id = ida_simple_get(&gnss_minors, 0, GNSS_MINORS, GFP_KERNEL);
|
|
if (id < 0) {
|
|
kfree(gdev);
|
|
return NULL;
|
|
}
|
|
|
|
gdev->id = id;
|
|
|
|
dev = &gdev->dev;
|
|
device_initialize(dev);
|
|
dev->devt = gnss_first + id;
|
|
dev->class = gnss_class;
|
|
dev->parent = parent;
|
|
dev->release = gnss_device_release;
|
|
dev_set_drvdata(dev, gdev);
|
|
dev_set_name(dev, "gnss%d", id);
|
|
|
|
init_rwsem(&gdev->rwsem);
|
|
mutex_init(&gdev->read_mutex);
|
|
mutex_init(&gdev->write_mutex);
|
|
init_waitqueue_head(&gdev->read_queue);
|
|
|
|
ret = kfifo_alloc(&gdev->read_fifo, GNSS_READ_FIFO_SIZE, GFP_KERNEL);
|
|
if (ret)
|
|
goto err_put_device;
|
|
|
|
gdev->write_buf = kzalloc(GNSS_WRITE_BUF_SIZE, GFP_KERNEL);
|
|
if (!gdev->write_buf)
|
|
goto err_put_device;
|
|
|
|
cdev_init(&gdev->cdev, &gnss_fops);
|
|
gdev->cdev.owner = THIS_MODULE;
|
|
|
|
return gdev;
|
|
|
|
err_put_device:
|
|
put_device(dev);
|
|
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gnss_allocate_device);
|
|
|
|
void gnss_put_device(struct gnss_device *gdev)
|
|
{
|
|
put_device(&gdev->dev);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gnss_put_device);
|
|
|
|
int gnss_register_device(struct gnss_device *gdev)
|
|
{
|
|
int ret;
|
|
|
|
/* Set a flag which can be accessed without holding the rwsem. */
|
|
if (gdev->ops->write_raw != NULL)
|
|
gdev->flags |= GNSS_FLAG_HAS_WRITE_RAW;
|
|
|
|
ret = cdev_device_add(&gdev->cdev, &gdev->dev);
|
|
if (ret) {
|
|
dev_err(&gdev->dev, "failed to add device: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gnss_register_device);
|
|
|
|
void gnss_deregister_device(struct gnss_device *gdev)
|
|
{
|
|
down_write(&gdev->rwsem);
|
|
gdev->disconnected = true;
|
|
if (gdev->count) {
|
|
wake_up_interruptible(&gdev->read_queue);
|
|
gdev->ops->close(gdev);
|
|
}
|
|
up_write(&gdev->rwsem);
|
|
|
|
cdev_device_del(&gdev->cdev, &gdev->dev);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gnss_deregister_device);
|
|
|
|
/*
|
|
* Caller guarantees serialisation.
|
|
*
|
|
* Must not be called for a closed device.
|
|
*/
|
|
int gnss_insert_raw(struct gnss_device *gdev, const unsigned char *buf,
|
|
size_t count)
|
|
{
|
|
int ret;
|
|
|
|
ret = kfifo_in(&gdev->read_fifo, buf, count);
|
|
|
|
wake_up_interruptible(&gdev->read_queue);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gnss_insert_raw);
|
|
|
|
static const char * const gnss_type_names[GNSS_TYPE_COUNT] = {
|
|
[GNSS_TYPE_NMEA] = "NMEA",
|
|
[GNSS_TYPE_SIRF] = "SiRF",
|
|
[GNSS_TYPE_UBX] = "UBX",
|
|
[GNSS_TYPE_MTK] = "MTK",
|
|
};
|
|
|
|
static const char *gnss_type_name(struct gnss_device *gdev)
|
|
{
|
|
const char *name = NULL;
|
|
|
|
if (gdev->type < GNSS_TYPE_COUNT)
|
|
name = gnss_type_names[gdev->type];
|
|
|
|
if (!name)
|
|
dev_WARN(&gdev->dev, "type name not defined\n");
|
|
|
|
return name;
|
|
}
|
|
|
|
static ssize_t type_show(struct device *dev, struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
struct gnss_device *gdev = to_gnss_device(dev);
|
|
|
|
return sprintf(buf, "%s\n", gnss_type_name(gdev));
|
|
}
|
|
static DEVICE_ATTR_RO(type);
|
|
|
|
static struct attribute *gnss_attrs[] = {
|
|
&dev_attr_type.attr,
|
|
NULL,
|
|
};
|
|
ATTRIBUTE_GROUPS(gnss);
|
|
|
|
static int gnss_uevent(struct device *dev, struct kobj_uevent_env *env)
|
|
{
|
|
struct gnss_device *gdev = to_gnss_device(dev);
|
|
int ret;
|
|
|
|
ret = add_uevent_var(env, "GNSS_TYPE=%s", gnss_type_name(gdev));
|
|
if (ret)
|
|
return ret;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __init gnss_module_init(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = alloc_chrdev_region(&gnss_first, 0, GNSS_MINORS, "gnss");
|
|
if (ret < 0) {
|
|
pr_err("failed to allocate device numbers: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
gnss_class = class_create(THIS_MODULE, "gnss");
|
|
if (IS_ERR(gnss_class)) {
|
|
ret = PTR_ERR(gnss_class);
|
|
pr_err("failed to create class: %d\n", ret);
|
|
goto err_unregister_chrdev;
|
|
}
|
|
|
|
gnss_class->dev_groups = gnss_groups;
|
|
gnss_class->dev_uevent = gnss_uevent;
|
|
|
|
pr_info("GNSS driver registered with major %d\n", MAJOR(gnss_first));
|
|
|
|
return 0;
|
|
|
|
err_unregister_chrdev:
|
|
unregister_chrdev_region(gnss_first, GNSS_MINORS);
|
|
|
|
return ret;
|
|
}
|
|
module_init(gnss_module_init);
|
|
|
|
static void __exit gnss_module_exit(void)
|
|
{
|
|
class_destroy(gnss_class);
|
|
unregister_chrdev_region(gnss_first, GNSS_MINORS);
|
|
ida_destroy(&gnss_minors);
|
|
}
|
|
module_exit(gnss_module_exit);
|
|
|
|
MODULE_AUTHOR("Johan Hovold <johan@kernel.org>");
|
|
MODULE_DESCRIPTION("GNSS receiver core");
|
|
MODULE_LICENSE("GPL v2");
|