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path: root/drivers/watchdog/watchdog_dev.c
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2023-12-17watchdog: set cdev owner before addingCurtis Klein1-2/+1
When the new watchdog character device is registered, it becomes available for opening. This creates a race where userspace may open the device before the character device's owner is set. This results in an imbalance in module_get calls as the cdev_get in cdev_open will not increment the reference count on the watchdog driver module. This causes problems when the watchdog character device is released as the module loader's reference will also be released. This makes it impossible to open the watchdog device later on as it now appears that the module is being unloaded. The open will fail with -ENXIO from chrdev_open. The legacy watchdog device will fail with -EBUSY from the try_module_get in watchdog_open because it's module owner is the watchdog core module so it can still be opened but it will fail to get a refcount on the underlying watchdog device driver. Fixes: 72139dfa2464 ("watchdog: Fix the race between the release of watchdog_core_data and cdev") Signed-off-by: Curtis Klein <curtis.klein@hpe.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20231205190522.55153-1-curtis.klein@hpe.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2023-05-04Merge tag 'linux-watchdog-6.4-rc1' of ↵Linus Torvalds1-1/+2
git://www.linux-watchdog.org/linux-watchdog Pull watchdog updates from Wim Van Sebroeck: - Add watchdog driver for StarFive JH7100 and JH7110 Soc - Add Rockchip RK3588 devices - Add Qualcom IPQ5332 APSS, QCM2290 KPSS and SM6115 SoC devices - Add Mediatke MT8365 and MT6735 devices - Watchdog-core: Always set WDOG_HW_RUNNING when starting watchdog - Convert watchdog platform drivers to return void on the remove callback - Convert to devm_clk_get_enabled() helpers - ... and other small fixes and improvements * tag 'linux-watchdog-6.4-rc1' of git://www.linux-watchdog.org/linux-watchdog: (72 commits) watchdog: dw_wdt: Simplify clk management watchdog: dw_wdt: Fix the error handling path of dw_wdt_drv_probe() watchdog: starfive: Fix the warning of starfive_wdt_match watchdog: starfive: Fix the probe return error if PM and early_enable are both disabled MAINTAINERS: Add fragment for Xilinx watchdog driver watchdog: menz069_wdt: fix timeout setting watchdog: menz069_wdt: fix watchdog initialisation dt-bindings: watchdog: alphascale-asm9260: convert to DT schema watchdog: loongson1_wdt: Implement restart handler dt-bindings: watchdog: Document Qualcomm SM6115 watchdog dt-bindings: watchdog: realtek,otto-wdt: simplify requiring interrupt-names dt-bindings: watchdog: toshiba,visconti-wdt: simplify with unevaluatedProperties dt-bindings: watchdog: fsl-imx7ulp-wdt: simplify with unevaluatedProperties dt-bindings: watchdog: arm,sp805: drop unneeded minItems dt-bindings: watchdog: drop duplicated GPIO watchdog bindings dt-bindings: reset: Add binding for MediaTek MT6735 TOPRGU/WDT drivers: watchdog: Add StarFive Watchdog driver dt-bindings: watchdog: Add watchdog for StarFive JH7100 and JH7110 dt-bindings: watchdog: indentation, quotes and white-space cleanup watchdog: ebc-c384_wdt: Mark status as orphaned ...
2023-04-22watchdog: core: Always set WDOG_HW_RUNNING when starting watchdogGuenter Roeck1-1/+2
The use of WDOG_HW_RUNNING is currently inconsistent: If set by the driver, it will remain set until the watchdog device is opened and then closed. If set by the watchdog core, it is only set if the watchdog can not be stopped when closed. Subsequenty it is always only set while the watchdog is closed and the hardware watchdog is running. This is both misleading and inconsistent: The API states that watchdog_hw_running() indicates that the hardware watchdog is running. This is currently not always the case. Set WDOG_HW_RUNNING whenever a watchdog is successfully started for consistent behavior and to accurately report its status. This means that we no longer have to check for both watchdog_active() and watchdog_hw_running() to check if the watchdog is running because watchdog_hw_running() now implies watchdog_active(). Simplify the code accordingly where warranted. Cc: Wang Wensheng <wangwensheng4@huawei.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20230304161607.1418952-1-linux@roeck-us.net Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2023-03-17drivers: remove struct module * setting from struct classGreg Kroah-Hartman1-1/+0
There is no need to manually set the owner of a struct class, as the registering function does it automatically, so remove all of the explicit settings from various drivers that did so as it is unneeded. This allows us to remove this pointer entirely from this structure going forward. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230313181843.1207845-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-18watchdog: report options in sysfsThomas Weißschuh1-0/+10
This synchronizes the information reported by ioctl and sysfs. The mismatch is confusing because "wdctl" from util-linux uses the ioctl when used with root privileges and sysfs without. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20221216-watchdog-sysfs-v2-2-6189311103a9@weissschuh.net [groeck: Fixed continuation line alignment] Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2023-02-18watchdog: report fw_version in sysfsThomas Weißschuh1-0/+10
This synchronizes the information reported by ioctl and sysfs. The mismatch is confusing because "wdctl" from util-linux uses the ioctl when used with root privileges and sysfs without. The file is called "fw_version" instead of "firmware_version" as "firmware_version" is already used as custom attribute by single drivers. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20221216-watchdog-sysfs-v2-1-6189311103a9@weissschuh.net Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2023-02-18watchdog: Fix kmemleak in watchdog_cdev_registerChen Jun1-1/+1
kmemleak reports memory leaks in watchdog_dev_register, as follows: unreferenced object 0xffff888116233000 (size 2048): comm ""modprobe"", pid 28147, jiffies 4353426116 (age 61.741s) hex dump (first 32 bytes): 80 fa b9 05 81 88 ff ff 08 30 23 16 81 88 ff ff .........0#..... 08 30 23 16 81 88 ff ff 00 00 00 00 00 00 00 00 .0#............. backtrace: [<000000007f001ffd>] __kmem_cache_alloc_node+0x157/0x220 [<000000006a389304>] kmalloc_trace+0x21/0x110 [<000000008d640eea>] watchdog_dev_register+0x4e/0x780 [watchdog] [<0000000053c9f248>] __watchdog_register_device+0x4f0/0x680 [watchdog] [<00000000b2979824>] watchdog_register_device+0xd2/0x110 [watchdog] [<000000001f730178>] 0xffffffffc10880ae [<000000007a1a8bcc>] do_one_initcall+0xcb/0x4d0 [<00000000b98be325>] do_init_module+0x1ca/0x5f0 [<0000000046d08e7c>] load_module+0x6133/0x70f0 ... unreferenced object 0xffff888105b9fa80 (size 16): comm ""modprobe"", pid 28147, jiffies 4353426116 (age 61.741s) hex dump (first 16 bytes): 77 61 74 63 68 64 6f 67 31 00 b9 05 81 88 ff ff watchdog1....... backtrace: [<000000007f001ffd>] __kmem_cache_alloc_node+0x157/0x220 [<00000000486ab89b>] __kmalloc_node_track_caller+0x44/0x1b0 [<000000005a39aab0>] kvasprintf+0xb5/0x140 [<0000000024806f85>] kvasprintf_const+0x55/0x180 [<000000009276cb7f>] kobject_set_name_vargs+0x56/0x150 [<00000000a92e820b>] dev_set_name+0xab/0xe0 [<00000000cec812c6>] watchdog_dev_register+0x285/0x780 [watchdog] [<0000000053c9f248>] __watchdog_register_device+0x4f0/0x680 [watchdog] [<00000000b2979824>] watchdog_register_device+0xd2/0x110 [watchdog] [<000000001f730178>] 0xffffffffc10880ae [<000000007a1a8bcc>] do_one_initcall+0xcb/0x4d0 [<00000000b98be325>] do_init_module+0x1ca/0x5f0 [<0000000046d08e7c>] load_module+0x6133/0x70f0 ... The reason is that put_device is not be called if cdev_device_add fails and wdd->id != 0. watchdog_cdev_register wd_data = kzalloc [1] err = dev_set_name [2] .. err = cdev_device_add if (err) { if (wdd->id == 0) { // wdd->id != 0 .. } return err; // [1],[2] would be leaked To fix it, call put_device in all wdd->id cases. Fixes: 72139dfa2464 ("watchdog: Fix the race between the release of watchdog_core_data and cdev") Signed-off-by: Chen Jun <chenjun102@huawei.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20221116012714.102066-1-chenjun102@huawei.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2023-02-18watchdog: Include <linux/kstrtox.h> when appropriateChristophe JAILLET1-0/+1
The kstrto<something>() functions have been moved from kernel.h to kstrtox.h. So, in order to eventually remove <linux/kernel.h> from <linux/watchdog.h>, include the latter directly in the appropriate files. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/08fd5512e569558231247515c04c8596a1d11004.1667646547.git.christophe.jaillet@wanadoo.fr Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2022-10-12watchdog: Add tracing events for the most usual watchdog eventsUwe Kleine-König1-2/+10
To simplify debugging which process touches a watchdog and when, add tracing events for .start(), .set_timeout(), .ping() and .stop(). Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20221008174602.3972859-1-u.kleine-koenig@pengutronix.de Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2022-10-02watchdog: Check dev_set_name() return valueBo Liu1-1/+5
It's possible that dev_set_name() returns -ENOMEM, catch and handle this. Signed-off-by: Bo Liu <liubo03@inspur.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20220920020312.2383-1-liubo03@inspur.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2022-03-27watchdog: Improve watchdog_dev function documentationDaniel Bristot de Oliveira1-119/+125
Adjust function comments to the kernel doc format. It also adjusts some variable names and adds return values. No functional change. Changes from V1: Change "Returns" to "Return:" (Randy Dunlap) Cc: Wim Van Sebroeck <wim@linux-watchdog.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: linux-watchdog@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Tested-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/30378a03e9cd9b5f6e92ec9bf512edc38bad8627.1644589712.git.bristot@kernel.org Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2021-08-22watchdog: Start watchdog in watchdog_set_last_hw_keepalive only if appropriateJan Kiszka1-1/+4
We must not pet a running watchdog when handle_boot_enabled is off because this will kick off automatic triggering before userland is running, defeating the purpose of the handle_boot_enabled control. Furthermore, don't ping in case watchdog_set_last_hw_keepalive was called incorrectly when the hardware watchdog is actually not running. Fixed: cef9572e9af3 ("watchdog: add support for adjusting last known HW keepalive time") Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/93d56386-6e37-060b-55ce-84de8cde535f@web.de Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2021-08-22watchdog: introduce watchdog_dev_suspend/resumeGrzegorz Jaszczyk1-0/+47
The watchdog drivers often disable wdog clock during suspend and then enable it again during resume. Nevertheless the ping worker is still running and can issue low-level ping while the wdog clock is disabled causing the system hang. To prevent such condition register pm notifier in the watchdog core which will call watchdog_dev_suspend/resume and actually cancel ping worker during suspend and restore it back, if needed, during resume. Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20210618195033.3209598-2-grzegorz.jaszczyk@linaro.org Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2021-08-22watchdog: Fix NULL pointer dereference when releasing cdevCurtis Klein1-1/+2
watchdog_hrtimer_pretimeout_stop needs the watchdog device to have a valid pointer to the watchdog core data to stop the pretimeout hrtimer. Therefore it needs to be called before the pointers are cleared in watchdog_cdev_unregister. Fixes: 7b7d2fdc8c3e ("watchdog: Add hrtimer-based pretimeout feature") Reported-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Curtis Klein <curtis.klein@hpe.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/1624429583-5720-1-git-send-email-curtis.klein@hpe.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2021-08-22watchdog: only run driver set_pretimeout op if device supports itCurtis Klein1-1/+1
Some watchdog devices might conditionally support pretimeouts (e.g. if an interrupt is exposed for the device) but some watchdog drivers might still define the set_pretimeout operation (e.g. the mtk_wdt driver) and indicate support at runtime through the WDIOF_PRETIMEOUT flag. If the kernel is compiled with CONFIG_WATCHDOG_HRTIMER_PRETIMEOUT enabled, watchdog_set_pretimeout would run the driver specific set_pretimeout even if WDIOF_PRETIMEOUT is not set which might have unintended consequences. So this change checks that the device flags and only runs the driver operation if pretimeouts are supported. Signed-off-by: Curtis Klein <curtis.klein@hpe.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/1624751265-24785-1-git-send-email-curtis.klein@hpe.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2021-06-21watchdog: Add hrtimer-based pretimeout featureCurtis Klein1-30/+17
This adds the option to use a hrtimer to generate a watchdog pretimeout event for hardware watchdogs that do not natively support watchdog pretimeouts. With this enabled, all watchdogs will appear to have pretimeout support in userspace. If no pretimeout value is set, there will be no change in the watchdog's behavior. If a pretimeout value is set for a specific watchdog that does not have built-in pretimeout support, a timer will be started that should fire at the specified time before the watchdog timeout would occur. When the watchdog is successfully pinged, the timer will be restarted. If the timer is allowed to fire it will generate a pretimeout event. However because a software timer is used, it may not be able to fire in every circumstance. If the watchdog does support a pretimeout natively, that functionality will be used instead of the hrtimer. The general design of this feaure was inspired by the software watchdog, specifically its own pretimeout implementation. However the software watchdog and this feature are completely independent. They can be used together; with or without CONFIG_SOFT_WATCHDOG_PRETIMEOUT enabled. The main advantage of using the hrtimer pretimeout with a hardware watchdog, compared to running the software watchdog with a hardware watchdog, is that if the hardware watchdog driver is unable to ping the watchdog (e.g. due to a bus or communication error), then the hrtimer pretimeout would still fire whereas the software watchdog would not. Signed-off-by: Curtis Klein <curtis.klein@hpe.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/1612383090-27110-1-git-send-email-curtis.klein@hpe.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2021-06-21watchdog: Use sysfs_emit() and sysfs_emit_at() in "show" functionsJuerg Haefliger1-9/+10
Convert sprintf() in sysfs "show" functions to sysfs_emit() and sysfs_emit_at() in order to check for buffer overruns in sysfs outputs. Signed-off-by: Juerg Haefliger <juergh@canonical.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20210511061812.480172-1-juergh@canonical.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2021-06-21watchdog: Add {min,max}_timeout sysfs nodesJuerg Haefliger1-0/+20
The valid range for the 'timeout' value is useful information so expose the min and max timeout values via sysfs. Signed-off-by: Juerg Haefliger <juergh@canonical.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20210511062953.485252-1-juergh@canonical.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2020-10-14watchdog: remove unneeded inclusion of <uapi/linux/sched/types.h>Zhen Lei1-2/+0
There has been no reference to "struct sched_param" since commit 94beddacb53c ("sched,watchdog: Convert to sched_set_fifo()"), so there's no need to include <uapi/linux/sched/types.h> any more, delete it. Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20200827062154.1847-1-thunder.leizhen@huawei.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2020-10-14watchdog: Use put_device on errorDinghao Liu1-1/+1
We should use put_device() instead of freeing device directly after device_initialize(). Fixes: cb36e29bb0e4b ("watchdog: initialize device before misc_register") Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20200824031230.31050-1-dinghao.liu@zju.edu.cn Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2020-10-14watchdog: Fix memleak in watchdog_cdev_registerDinghao Liu1-1/+3
When watchdog_kworker is NULL, we should free wd_data before the function returns to prevent memleak. Fixes: 664a39236e718 ("watchdog: Introduce hardware maximum heartbeat in watchdog core") Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20200824024001.25474-1-dinghao.liu@zju.edu.cn Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2020-08-12Merge tag 'linux-watchdog-5.9-rc1' of ↵Linus Torvalds1-20/+53
git://www.linux-watchdog.org/linux-watchdog Pull watchdog updates from Wim Van Sebroeck: - f71808e_wdt imporvements - dw_wdt improvements - mlx-wdt: support new watchdog type with longer timeout period - fallthrough pseudo-keyword replacements - overall small fixes and improvements * tag 'linux-watchdog-5.9-rc1' of git://www.linux-watchdog.org/linux-watchdog: (35 commits) watchdog: rti-wdt: balance pm runtime enable calls watchdog: rti-wdt: attach to running watchdog during probe watchdog: add support for adjusting last known HW keepalive time watchdog: use __watchdog_ping in startup watchdog: softdog: Add options 'soft_reboot_cmd' and 'soft_active_on_boot' watchdog: pcwd_usb: remove needless check before usb_free_coherent() watchdog: Replace HTTP links with HTTPS ones dt-bindings: watchdog: renesas,wdt: Document r8a774e1 support watchdog: initialize device before misc_register watchdog: booke_wdt: Add common nowayout parameter driver watchdog: scx200_wdt: Use fallthrough pseudo-keyword watchdog: Use fallthrough pseudo-keyword watchdog: f71808e_wdt: do stricter parameter validation watchdog: f71808e_wdt: clear watchdog timeout occurred flag watchdog: f71808e_wdt: remove use of wrong watchdog_info option watchdog: f71808e_wdt: indicate WDIOF_CARDRESET support in watchdog_info.options docs: watchdog: codify ident.options as superset of possible status flags dt-bindings: watchdog: Add compatible for QCS404, SC7180, SDM845, SM8150 dt-bindings: watchdog: Convert QCOM watchdog timer bindings to YAML watchdog: dw_wdt: Add DebugFS files ...
2020-08-05watchdog: add support for adjusting last known HW keepalive timeTero Kristo1-0/+30
Certain watchdogs require the watchdog only to be pinged within a specific time window, pinging too early or too late cause the watchdog to fire. In cases where this sort of watchdog has been started before kernel comes up, we must adjust the watchdog keepalive window to match the actually running timer, so add a new driver API for this purpose. Signed-off-by: Tero Kristo <t-kristo@ti.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20200717132958.14304-3-t-kristo@ti.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2020-08-05watchdog: use __watchdog_ping in startupTero Kristo1-8/+11
Current watchdog startup functionality does not respect the minimum hw heartbeat setup and the last watchdog ping timeframe when watchdog is already running and userspace process attaches to it. Fix this by using the __watchdog_ping from the startup also. For this code path, we can also let the __watchdog_ping handle the bookkeeping for the worker and last keepalive times. Signed-off-by: Tero Kristo <t-kristo@ti.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20200717132958.14304-2-t-kristo@ti.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2020-08-05watchdog: initialize device before misc_registerKrzysztof Sobota1-9/+9
When watchdog device is being registered, it calls misc_register that makes watchdog available for systemd to open. This is a data race scenario, because when device is open it may still have device struct not initialized - this in turn causes a crash. This patch moves device initialization before misc_register call and it solves the problem printed below. ------------[ cut here ]------------ WARNING: CPU: 3 PID: 1 at lib/kobject.c:612 kobject_get+0x50/0x54 kobject: '(null)' ((ptrval)): is not initialized, yet kobject_get() is being called. Modules linked in: k2_reset_status(O) davinci_wdt(+) sfn_platform_hwbcn(O) fsmddg_sfn(O) clk_misc_mmap(O) clk_sw_bcn(O) fsp_reset(O) cma_mod(O) slave_sup_notif(O) fpga_master(O) latency(O+) evnotify(O) enable_arm_pmu(O) xge(O) rio_mport_cdev br_netfilter bridge stp llc nvrd_checksum(O) ipv6 CPU: 3 PID: 1 Comm: systemd Tainted: G O 4.19.113-g2579778-fsm4_k2 #1 Hardware name: Keystone [<c02126c4>] (unwind_backtrace) from [<c020da94>] (show_stack+0x18/0x1c) [<c020da94>] (show_stack) from [<c07f87d8>] (dump_stack+0xb4/0xe8) [<c07f87d8>] (dump_stack) from [<c0221f70>] (__warn+0xfc/0x114) [<c0221f70>] (__warn) from [<c0221fd8>] (warn_slowpath_fmt+0x50/0x74) [<c0221fd8>] (warn_slowpath_fmt) from [<c07fd394>] (kobject_get+0x50/0x54) [<c07fd394>] (kobject_get) from [<c0602ce8>] (get_device+0x1c/0x24) [<c0602ce8>] (get_device) from [<c06961e0>] (watchdog_open+0x90/0xf0) [<c06961e0>] (watchdog_open) from [<c06001dc>] (misc_open+0x130/0x17c) [<c06001dc>] (misc_open) from [<c0388228>] (chrdev_open+0xec/0x1a8) [<c0388228>] (chrdev_open) from [<c037fa98>] (do_dentry_open+0x204/0x3cc) [<c037fa98>] (do_dentry_open) from [<c0391e2c>] (path_openat+0x330/0x1148) [<c0391e2c>] (path_openat) from [<c0394518>] (do_filp_open+0x78/0xec) [<c0394518>] (do_filp_open) from [<c0381100>] (do_sys_open+0x130/0x1f4) [<c0381100>] (do_sys_open) from [<c0201000>] (ret_fast_syscall+0x0/0x28) Exception stack(0xd2ceffa8 to 0xd2cefff0) ffa0: b6f69968 00000000 ffffff9c b6ebd210 000a0001 00000000 ffc0: b6f69968 00000000 00000000 00000142 fffffffd ffffffff 00b65530 bed7bb78 ffe0: 00000142 bed7ba70 b6cc2503 b6cc41d6 ---[ end trace 7b16eb105513974f ]--- ------------[ cut here ]------------ WARNING: CPU: 3 PID: 1 at lib/refcount.c:153 kobject_get+0x24/0x54 refcount_t: increment on 0; use-after-free. Modules linked in: k2_reset_status(O) davinci_wdt(+) sfn_platform_hwbcn(O) fsmddg_sfn(O) clk_misc_mmap(O) clk_sw_bcn(O) fsp_reset(O) cma_mod(O) slave_sup_notif(O) fpga_master(O) latency(O+) evnotify(O) enable_arm_pmu(O) xge(O) rio_mport_cdev br_netfilter bridge stp llc nvrd_checksum(O) ipv6 CPU: 3 PID: 1 Comm: systemd Tainted: G W O 4.19.113-g2579778-fsm4_k2 #1 Hardware name: Keystone [<c02126c4>] (unwind_backtrace) from [<c020da94>] (show_stack+0x18/0x1c) [<c020da94>] (show_stack) from [<c07f87d8>] (dump_stack+0xb4/0xe8) [<c07f87d8>] (dump_stack) from [<c0221f70>] (__warn+0xfc/0x114) [<c0221f70>] (__warn) from [<c0221fd8>] (warn_slowpath_fmt+0x50/0x74) [<c0221fd8>] (warn_slowpath_fmt) from [<c07fd368>] (kobject_get+0x24/0x54) [<c07fd368>] (kobject_get) from [<c0602ce8>] (get_device+0x1c/0x24) [<c0602ce8>] (get_device) from [<c06961e0>] (watchdog_open+0x90/0xf0) [<c06961e0>] (watchdog_open) from [<c06001dc>] (misc_open+0x130/0x17c) [<c06001dc>] (misc_open) from [<c0388228>] (chrdev_open+0xec/0x1a8) [<c0388228>] (chrdev_open) from [<c037fa98>] (do_dentry_open+0x204/0x3cc) [<c037fa98>] (do_dentry_open) from [<c0391e2c>] (path_openat+0x330/0x1148) [<c0391e2c>] (path_openat) from [<c0394518>] (do_filp_open+0x78/0xec) [<c0394518>] (do_filp_open) from [<c0381100>] (do_sys_open+0x130/0x1f4) [<c0381100>] (do_sys_open) from [<c0201000>] (ret_fast_syscall+0x0/0x28) Exception stack(0xd2ceffa8 to 0xd2cefff0) ffa0: b6f69968 00000000 ffffff9c b6ebd210 000a0001 00000000 ffc0: b6f69968 00000000 00000000 00000142 fffffffd ffffffff 00b65530 bed7bb78 ffe0: 00000142 bed7ba70 b6cc2503 b6cc41d6 ---[ end trace 7b16eb1055139750 ]--- Fixes: 72139dfa2464 ("watchdog: Fix the race between the release of watchdog_core_data and cdev") Reviewed-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Alexander Sverdlin <alexander.sverdlin@nokia.com> Signed-off-by: Krzysztof Sobota <krzysztof.sobota@nokia.com> Link: https://lore.kernel.org/r/20200717103109.14660-1-krzysztof.sobota@nokia.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2020-08-05watchdog: Use fallthrough pseudo-keywordGustavo A. R. Silva1-1/+1
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20200707171121.GA13472@embeddedor Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2020-08-05watchdog: Use kobj_to_dev() APIWang Qing1-1/+1
Use kobj_to_dev() API instead of container_of(). Signed-off-by: Wang Qing <wangqing@vivo.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/1591945384-14587-1-git-send-email-wangqing@vivo.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2020-08-05watchdog: test_bit() => watchdog_active()Bumsik Kim1-1/+1
Use the dedicated function watchdog_active() instead of the generic test_bit() function. It is done using the following Coccinelle script: @@ identifier wdd; @@ - test_bit(WDOG_ACTIVE, &wdd->status) + watchdog_active(wdd) Signed-off-by: Bumsik Kim <k.bumsik@gmail.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20200529012428.84684-1-k.bumsik@gmail.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2020-06-15sched,watchdog: Convert to sched_set_fifo()Peter Zijlstra1-2/+1
Because SCHED_FIFO is a broken scheduler model (see previous patches) take away the priority field, the kernel can't possibly make an informed decision. Effectively changes prio from 99 to 50. Cc: wim@linux-watchdog.org Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Ingo Molnar <mingo@kernel.org>
2020-03-18watchdog: reset last_hw_keepalive time at startTero Kristo1-0/+1
Currently the watchdog core does not initialize the last_hw_keepalive time during watchdog startup. This will cause the watchdog to be pinged immediately if enough time has passed from the system boot-up time, and some types of watchdogs like K3 RTI does not like this. To avoid the issue, setup the last_hw_keepalive time during watchdog startup. Signed-off-by: Tero Kristo <t-kristo@ti.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20200302200426.6492-3-t-kristo@ti.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2020-01-27watchdog: fix UAF in reboot notifier handling in watchdog core codeVladis Dronov1-35/+1
After the commit 44ea39420fc9 ("drivers/watchdog: make use of devm_register_reboot_notifier()") the struct notifier_block reboot_nb in the struct watchdog_device is removed from the reboot notifiers chain at the time watchdog's chardev is closed. But at least in i6300esb.c case reboot_nb is embedded in the struct esb_dev which can be freed on its device removal and before the chardev is closed, thus UAF at reboot: [ 7.728581] esb_probe: esb_dev.watchdog_device ffff91316f91ab28 ts# uname -r note the address ^^^ 5.5.0-rc5-ae6088-wdog ts# ./openwdog0 & [1] 696 ts# opened /dev/watchdog0, sleeping 10s... ts# echo 1 > /sys/devices/pci0000\:00/0000\:00\:09.0/remove [ 178.086079] devres:rel_nodes: dev ffff91317668a0b0 data ffff91316f91ab28 esb_dev.watchdog_device.reboot_nb memory is freed here ^^^ ts# ...woken up [ 181.459010] devres:rel_nodes: dev ffff913171781000 data ffff913174a1dae8 [ 181.460195] devm_unreg_reboot_notifier: res ffff913174a1dae8 nb ffff91316f91ab78 attempt to use memory already freed ^^^ [ 181.461063] devm_unreg_reboot_notifier: nb->call 6b6b6b6b6b6b6b6b [ 181.461243] devm_unreg_reboot_notifier: nb->next 6b6b6b6b6b6b6b6b freed memory is filled with a slub poison ^^^ [1]+ Done ./openwdog0 ts# reboot [ 229.921862] systemd-shutdown[1]: Rebooting. [ 229.939265] notifier_call_chain: nb ffffffff9c6c2f20 nb->next ffffffff9c6d50c0 [ 229.943080] notifier_call_chain: nb ffffffff9c6d50c0 nb->next 6b6b6b6b6b6b6b6b [ 229.946054] notifier_call_chain: nb 6b6b6b6b6b6b6b6b INVAL [ 229.957584] general protection fault: 0000 [#1] SMP [ 229.958770] CPU: 0 PID: 1 Comm: systemd-shutdow Not tainted 5.5.0-rc5-ae6088-wdog [ 229.960224] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), ... [ 229.963288] RIP: 0010:notifier_call_chain+0x66/0xd0 [ 229.969082] RSP: 0018:ffffb20dc0013d88 EFLAGS: 00010246 [ 229.970812] RAX: 000000000000002e RBX: 6b6b6b6b6b6b6b6b RCX: 00000000000008b3 [ 229.972929] RDX: 0000000000000000 RSI: 0000000000000096 RDI: ffffffff9ccc46ac [ 229.975028] RBP: 0000000000000001 R08: 0000000000000000 R09: 00000000000008b3 [ 229.977039] R10: 0000000000000001 R11: ffffffff9c26c740 R12: 0000000000000000 [ 229.979155] R13: 6b6b6b6b6b6b6b6b R14: 0000000000000000 R15: 00000000fffffffa ... slub_debug=FZP poison ^^^ [ 229.989089] Call Trace: [ 229.990157] blocking_notifier_call_chain+0x43/0x59 [ 229.991401] kernel_restart_prepare+0x14/0x30 [ 229.992607] kernel_restart+0x9/0x30 [ 229.993800] __do_sys_reboot+0x1d2/0x210 [ 230.000149] do_syscall_64+0x3d/0x130 [ 230.001277] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 230.002639] RIP: 0033:0x7f5461bdd177 [ 230.016402] Modules linked in: i6300esb [ 230.050261] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b Fix the crash by reverting 44ea39420fc9 so unregister_reboot_notifier() is called when watchdog device is removed. This also makes handling of the reboot notifier unified with the handling of the restart handler, which is freed with unregister_restart_handler() in the same place. Fixes: 44ea39420fc9 ("drivers/watchdog: make use of devm_register_reboot_notifier()") Cc: stable@vger.kernel.org # v4.15+ Signed-off-by: Vladis Dronov <vdronov@redhat.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20200108125347.6067-1-vdronov@redhat.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2019-12-01Merge tag 'linux-watchdog-5.5-rc1' of ↵Linus Torvalds1-43/+58
git://www.linux-watchdog.org/linux-watchdog Pull watchdog updates from Wim Van Sebroeck: - support for NCT6116D - several small fixes and improvements * tag 'linux-watchdog-5.5-rc1' of git://www.linux-watchdog.org/linux-watchdog: (24 commits) watchdog: jz4740: Drop dependency on MACH_JZ47xx watchdog: jz4740: Use regmap provided by TCU driver watchdog: jz4740: Use WDT clock provided by TCU driver dt-bindings: watchdog: sama5d4_wdt: add microchip,sam9x60-wdt compatible watchdog: sama5d4_wdt: cleanup the bit definitions watchdog: sprd: Fix the incorrect pointer getting from driver data watchdog: aspeed: Fix clock behaviour for ast2600 watchdog: imx7ulp: Fix reboot hang watchdog: make nowayout sysfs file writable watchdog: prevent deferral of watchdogd wakeup on RT watchdog: imx7ulp: Use definitions instead of magic values watchdog: imx7ulp: Remove inline annotations watchdog: imx7ulp: Remove unused structure member watchdog: imx7ulp: Pass the wdog instance inimx7ulp_wdt_enable() watchdog: wdat_wdt: Spelling s/configrable/configurable/ watchdog: bd70528: Trivial function documentation fix watchdog: cadence: Do not show error in case of deferred probe watchdog: Fix the race between the release of watchdog_core_data and cdev watchdog: sbc7240_wdt: Fix yet another -Wimplicit-fallthrough warning watchdog: intel-mid_wdt: Add WATCHDOG_NOWAYOUT support ...
2019-11-18watchdog: make nowayout sysfs file writableRasmus Villemoes1-1/+20
It can be useful to delay setting the nowayout feature for a watchdog device. Moreover, not every driver (notably gpio_wdt) implements a nowayout module parameter/otherwise respects CONFIG_WATCHDOG_NOWAYOUT, and modifying those drivers carries a risk of causing a regression for someone who has two watchdog devices, sets CONFIG_WATCHDOG_NOWAYOUT and somehow relies on the gpio_wdt driver being ignorant of that (i.e., allowing one to gracefully close a gpio_wdt but not the other watchdog in the system). So instead, simply make the nowayout sysfs file writable. Obviously, setting nowayout is a one-way street. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20191105205118.11359-1-linux@rasmusvillemoes.dk Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2019-11-18watchdog: prevent deferral of watchdogd wakeup on RTJulia Cartwright1-4/+6
When PREEMPT_RT is enabled, all hrtimer expiry functions are deferred for execution into the context of ksoftirqd unless otherwise annotated. Deferring the expiry of the hrtimer used by the watchdog core, however, is a waste, as the callback does nothing but queue a kthread work item and wakeup watchdogd. It's worst then that, too: the deferral through ksoftirqd also means that for correct behavior a user must adjust the scheduling parameters of both watchdogd _and_ ksoftirqd, which is unnecessary and has other side effects (like causing unrelated expiry functions to execute at potentially elevated priority). Instead, mark the hrtimer used by the watchdog core as being _HARD to allow it's execution directly from hardirq context. The work done in this expiry function is well-bounded and minimal. A user still must adjust the scheduling parameters of the watchdogd to be correct w.r.t. their application needs. Link: https://lkml.kernel.org/r/0e02d8327aeca344096c246713033887bc490dd7.1538089180.git.julia@ni.com Cc: Guenter Roeck <linux@roeck-us.net> Reported-and-tested-by: Steffen Trumtrar <s.trumtrar@pengutronix.de> Reported-by: Tim Sander <tim@krieglstein.org> Signed-off-by: Julia Cartwright <julia@ni.com> Acked-by: Guenter Roeck <linux@roeck-us.net> [bigeasy: use only HRTIMER_MODE_REL_HARD] Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20191105144506.clyadjbvnn7b7b2m@linutronix.de Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2019-11-18watchdog: Fix the race between the release of watchdog_core_data and cdevKevin Hao1-38/+32
The struct cdev is embedded in the struct watchdog_core_data. In the current code, we manage the watchdog_core_data with a kref, but the cdev is manged by a kobject. There is no any relationship between this kref and kobject. So it is possible that the watchdog_core_data is freed before the cdev is entirely released. We can easily get the following call trace with CONFIG_DEBUG_KOBJECT_RELEASE and CONFIG_DEBUG_OBJECTS_TIMERS enabled. ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x38 WARNING: CPU: 23 PID: 1028 at lib/debugobjects.c:481 debug_print_object+0xb0/0xf0 Modules linked in: softdog(-) deflate ctr twofish_generic twofish_common camellia_generic serpent_generic blowfish_generic blowfish_common cast5_generic cast_common cmac xcbc af_key sch_fq_codel openvswitch nsh nf_conncount nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 CPU: 23 PID: 1028 Comm: modprobe Not tainted 5.3.0-next-20190924-yoctodev-standard+ #180 Hardware name: Marvell OcteonTX CN96XX board (DT) pstate: 00400009 (nzcv daif +PAN -UAO) pc : debug_print_object+0xb0/0xf0 lr : debug_print_object+0xb0/0xf0 sp : ffff80001cbcfc70 x29: ffff80001cbcfc70 x28: ffff800010ea2128 x27: ffff800010bad000 x26: 0000000000000000 x25: ffff80001103c640 x24: ffff80001107b268 x23: ffff800010bad9e8 x22: ffff800010ea2128 x21: ffff000bc2c62af8 x20: ffff80001103c600 x19: ffff800010e867d8 x18: 0000000000000060 x17: 0000000000000000 x16: 0000000000000000 x15: ffff000bd7240470 x14: 6e6968207473696c x13: 5f72656d6974203a x12: 6570797420746365 x11: 6a626f2029302065 x10: 7461747320657669 x9 : 7463612820657669 x8 : 3378302f3078302b x7 : 0000000000001d7a x6 : ffff800010fd5889 x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000 x2 : ffff000bff948548 x1 : 276a1c9e1edc2300 x0 : 0000000000000000 Call trace: debug_print_object+0xb0/0xf0 debug_check_no_obj_freed+0x1e8/0x210 kfree+0x1b8/0x368 watchdog_cdev_unregister+0x88/0xc8 watchdog_dev_unregister+0x38/0x48 watchdog_unregister_device+0xa8/0x100 softdog_exit+0x18/0xfec4 [softdog] __arm64_sys_delete_module+0x174/0x200 el0_svc_handler+0xd0/0x1c8 el0_svc+0x8/0xc This is a common issue when using cdev embedded in a struct. Fortunately, we already have a mechanism to solve this kind of issue. Please see commit 233ed09d7fda ("chardev: add helper function to register char devs with a struct device") for more detail. In this patch, we choose to embed the struct device into the watchdog_core_data, and use the API provided by the commit 233ed09d7fda to make sure that the release of watchdog_core_data and cdev are in sequence. Signed-off-by: Kevin Hao <haokexin@gmail.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20191008112934.29669-1-haokexin@gmail.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2019-10-23compat_ioctl: move WDIOC handling into wdt driversArnd Bergmann1-0/+1
All watchdog drivers implement the same set of ioctl commands, and fortunately all of them are compatible between 32-bit and 64-bit architectures. Modern drivers always go through drivers/watchdog/wdt.c as an abstraction layer, but older ones implement their own file_operations on a character device for this. Move the handling from fs/compat_ioctl.c into the individual drivers. Note that most of the legacy drivers will never be used on 64-bit hardware, because they are for an old 32-bit SoC implementation, but doing them all at once is safer than trying to guess which ones do or do not need the compat_ioctl handling. Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-07-08watchdog: convert remaining drivers to use SPDX license identifierGuenter Roeck1-5/+1
This gets rid of the unnecessary license boilerplate, and avoids having to deal with individual patches one by one. No functional changes. Reviewed-by: Jerry Hoemann <jerry.hoemann@hpe.com> Acked-by: Sylvain Lemieux <slemieux.tyco@gmail.com> Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com> Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2019-07-08watchdog: make the device time out at open_deadline when open_timeout is usedRasmus Villemoes1-5/+6
When the watchdog device is not open by userspace, the kernel takes care of pinging it. When the open_timeout feature is in use, we should ensure that the hardware fires close to open_timeout seconds after the kernel has assumed responsibility for the device. To do this, simply reuse the logic that is already in place for ensuring the same thing when userspace is responsible for regularly pinging the device: - When watchdog_active(wdd), this patch doesn't change anything. - When !watchdog_active(wdd), the "virtual timeout" should be taken to be ->open_deadline". When the open_timeout feature is not used or the device has been opened at least once, ->open_deadline is KTIME_MAX, and the arithmetic ends up returning keepalive_interval as we used to. This has been tested on a Wandboard with various combinations of open_timeout and timeout-sec properties for the on-board watchdog by booting with 'init=/bin/sh', timestamping the lines on the serial console, and comparing the timestamp of the 'imx2-wdt 20bc000.wdog: timeout nnn sec' line with the timestamp of the 'U-Boot SPL ...' line (which appears just after reset). Suggested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2019-07-08watchdog: introduce CONFIG_WATCHDOG_OPEN_TIMEOUTRasmus Villemoes1-2/+3
This allows setting a default value for the watchdog.open_timeout commandline parameter via Kconfig. Some BSPs allow remote updating of the kernel image and root file system, but updating the bootloader requires physical access. Hence, if one has a firmware update that requires relaxing the watchdog.open_timeout a little, the value used must be baked into the kernel image itself and cannot come from the u-boot environment via the kernel command line. Being able to set the initial value in .config doesn't change the fact that the value on the command line, if present, takes precedence, and is of course immensely useful for development purposes while one has console acccess, as well as usable in the cases where one can make a permanent update of the kernel command line. Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2019-07-08watchdog: introduce watchdog.open_timeout commandline parameterRasmus Villemoes1-1/+35
The watchdog framework takes care of feeding a hardware watchdog until userspace opens /dev/watchdogN. If that never happens for some reason (buggy init script, corrupt root filesystem or whatnot) but the kernel itself is fine, the machine stays up indefinitely. This patch allows setting an upper limit for how long the kernel will take care of the watchdog, thus ensuring that the watchdog will eventually reset the machine. A value of 0 (the default) means infinite timeout, preserving the current behaviour. This is particularly useful for embedded devices where some fallback logic is implemented in the bootloader (e.g., use a different root partition, boot from network, ...). There is already handle_boot_enabled serving a similar purpose. However, such a binary choice is unsuitable if the hardware watchdog cannot be programmed by the bootloader to provide a timeout long enough for userspace to get up and running. Many of the embedded devices we see use external (gpio-triggered) watchdogs with a fixed timeout of the order of 1-2 seconds. The open timeout only applies for the first open from userspace. Should userspace need to close the watchdog device, with the intention of re-opening it shortly, the application can emulate the open timeout feature by combining the nowayout feature with an appropriate WDIOC_SETTIMEOUT immediately prior to closing the device. Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2019-05-06*: convert stream-like files from nonseekable_open -> stream_openKirill Smelkov1-1/+1
Using scripts/coccinelle/api/stream_open.cocci added in 10dce8af3422 ("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 10dce8af3422): 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>
2018-10-02watchdog: core: fix null pointer dereference when releasing cdevWolfram Sang1-5/+5
watchdog_stop() calls watchdog_update_worker() which needs a valid wdd->wd_data pointer. So, when unregistering the cdev, clear the pointers after we call watchdog_stop(), not before. Fixes: bb292ac1c602 ("watchdog: Introduce watchdog_stop_on_unregister helper") Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2018-01-21watchdog: core: make sure the watchdog_worker is not deferredChristophe Leroy1-34/+52
commit 4cd13c21b207e ("softirq: Let ksoftirqd do its job") has the effect of deferring timer handling in case of high CPU load, hence delaying the delayed work allthought the worker is running which high realtime priority. As hrtimers are not managed by softirqs, this patch replaces the delayed work by a plain work and uses an hrtimer to schedule that work. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Guenter Roeck <Linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2017-12-28watchdog: core: make sure the watchdog worker always worksChristophe Leroy1-21/+27
When running a command like 'chrt -f 50 dd if=/dev/zero of=/dev/null', the watchdog_worker fails to service the HW watchdog and the HW watchdog fires long before the watchdog soft timeout. At the moment, the watchdog_worker is invoked as a delayed work. Delayed works are handled by non realtime kernel threads. The WQ_HIGHPRI flag only increases the niceness of that threads. This patch replaces the delayed work logic by kthread delayed work, and sets the associated kernel task to SCHED_FIFO with the highest priority, in order to ensure that the watchdog worker will run as soon as possible. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2017-12-28watchdog: watchdog_dev: mark expected switch fall-throughGustavo A. R. Silva1-1/+1
In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. Notice that in this particular case I replaced "Fall" with a proper "fall through" comment, which is what GCC is expecting to find. Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2017-12-17watchdog: Fix kref imbalance seen if handle_boot_enabled=0Guenter Roeck1-6/+5
If handle_boot_enabled is set to 0, the watchdog driver module use counter will not be increased and kref_get() will not be called when registering the watchdog. Subsequently, on open, this does not happen either because the code believes that it was already done because the hardware watchdog is marked as running. We could introduce a state variable to indicate this state, but let's just increase the module use counter and call kref_get() unconditionally if the hardware watchdog is running when a driver is registering itself to keep the code simple. Fixes: 2501b015313fe ("watchdog: core: add option to avoid early ...") Cc: Sebastian Reichel <sebastian.reichel@collabora.co.uk> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2017-12-17watchdog: Fix potential kref imbalance when opening watchdogGuenter Roeck1-2/+4
If a watchdog driver's open function sets WDOG_HW_RUNNING with the expectation that the watchdog can not be stopped, but then stops the watchdog anyway in its stop function, kref_get() wil not be called in watchdog_open(). If the watchdog then stops on close, WDOG_HW_RUNNING will be cleared and kref_put() will be called, causing a kref imbalance. As result the character device data structure will be released, which in turn will cause the system to crash on the next call to watchdog_open(). Fixes: ee142889e32f5 ("watchdog: Introduce WDOG_HW_RUNNING flag") Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2017-11-17drivers/watchdog: make use of devm_register_reboot_notifier()Andrey Smirnov1-0/+32
Save a bit of cleanup code by leveraging newly added devm_register_reboot_notifier(). [akpm@linux-foundation.org: small cleanup: avoid 80-col tricks] Link: http://lkml.kernel.org/r/20170411160615.9784-1-andrew.smirnov@gmail.com Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Acked-by: Guenter Roeck <linux@roeck-us.net> Cc: Chris Healy <cphealy@gmail.com> Cc: Wim Van Sebroeck <wim@iguana.be> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-03watchdog: introduce watchdog_worker_should_ping helperRasmus Villemoes1-4/+9
This will be useful when the condition becomes slightly more complicated in the next patch. Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk> Reviewed-by: Esben Haabendal <esben@haabendal.dk> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2017-06-05watchdog: core: add option to avoid early handling of watchdogSebastian Reichel1-3/+16
On some systems its desirable to have watchdog reboot the system when it does not come up fast enough. This adds a kernel parameter to disable the auto-update of watchdog before userspace takes over and a kernel option to set the default. The info messages were added to shorten error searching on misconfigured systems. Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
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