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path: root/drivers/watchdog/softdog.c (follow)
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2017-03-01watchdog: softdog: fire watchdog even if softirqs do not get to runNiklas Cassel1-17/+27
Checking for timer expiration is done from the softirq TIMER_SOFTIRQ. Since commit 4cd13c21b207 ("softirq: Let ksoftirqd do its job"), pending softirqs are no longer always handled immediately, instead, if there are pending softirqs, and ksoftirqd is in state TASK_RUNNING, the handling of the softirqs are deferred, and are instead supposed to be handled by ksoftirqd, when ksoftirqd gets scheduled. If a user space process with a real-time policy starts to misbehave by never relinquishing the CPU while ksoftirqd is in state TASK_RUNNING, what will happen is that all softirqs will get deferred, while ksoftirqd, which is supposed to handle the deferred softirqs, will never get to run. To make sure that the watchdog is able to fire even when we do not get to run softirqs, replace the timers with hrtimers. Signed-off-by: Niklas Cassel <niklas.cassel@axis.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2017-02-24watchdog: softdog: make pretimeout support a compile optionWolfram Sang1-8/+13
It occurred to me that the panic pretimeout governor will stall the softdog, because it is purely software which simply breaks when the kernel panics. Testing governors with the softdog on the other hand is really useful, so make this feature a compile time option which nees to be enabled explicitly. This also removes the overhead if pretimeout support is not used because it will now be compiled away (saving ~10% on ARM32). Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2016-10-08watchdog: softdog: implement pretimeout supportWolfram Sang1-1/+21
Give devices which do not have hardware support for pretimeout at least a software version of it. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.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>
2016-09-24watchdog: constify watchdog_ops structuresJulia Lawall1-1/+1
Check for watchdog_ops structures that are only stored in the ops field of a watchdog_device structure. This field is declared const, so watchdog_ops structures that have this property can be declared as const also. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @r disable optional_qualifier@ identifier i; position p; @@ static struct watchdog_ops i@p = { ... }; @ok@ identifier r.i; struct watchdog_device e; position p; @@ e.ops = &i@p; @bad@ position p != {r.p,ok.p}; identifier r.i; struct watchdog_ops e; @@ e@i@p @depends on !bad disable optional_qualifier@ identifier r.i; @@ static +const struct watchdog_ops i = { ... }; // </smpl> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.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>
2016-07-17watchdog: softdog: improve coding styleWolfram Sang1-3/+3
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.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>
2016-07-17watchdog: softdog: drop superfluous set_timeout callbackWolfram Sang1-7/+0
If we leave set_timeout empty, the core will do exactly what is implemented here anyway. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.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>
2016-07-17watchdog: softdog: sort includes to avoid duplicatesWolfram Sang1-5/+5
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.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>
2016-07-17watchdog: softdog: remove forward declarationWolfram Sang1-5/+3
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.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>
2016-07-17watchdog: softdog: consistently use softdog_ prefixWolfram Sang1-11/+10
And move module_init/exit to the proper place while here. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.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>
2016-07-17watchdog: softdog: use watchdog core to init timeout valueWolfram Sang1-12/+5
Error string and comment say we fall back to a default, but in reality we bailed out. Refactor the code to use the core helper which then matches the described behaviour. While updating the init message anyhow, shorten it while we are here; no need for versioning there as well and the name is already given via pr_fmt. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.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>
2016-07-17watchdog: softdog: remove obsolete commentsWolfram Sang1-33/+0
The history is obsolete, especially since we switched to watchdog framework. The section markers also don't make sense anymore given the small size of the driver. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.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>
2015-12-27watchdog: refuse to unload softdog module when its timer is runningLi RongQing1-2/+6
the softdog has static variables which are accessed if its timer is still running after the driver is unloaded. and lead to crash: $modprobe softdog $echo 1 >/dev/watchdog $modprobe -r softdog CPU 20 Unable to handle kernel paging request at virtual address Oops[#1]: CPU: 20 PID: 0 Comm: swapper/20 Not tainted 4.1.13-WR8.0.0.0_standard ... Modules linked in: [last unloaded: softdog] .... Call Trace: [<ffffffff801e142c>] cascade+0x34/0xb0 [<ffffffff801e1964>] run_timer_softirq+0x30c/0x368 [<ffffffff80181044>] __do_softirq+0x1ec/0x418 [<ffffffff801815d0>] irq_exit+0x90/0x98 [<ffffffff8010749c>] plat_irq_dispatch+0xa4/0x140 [<ffffffff80152740>] ret_from_irq+0x0/0x4 [<ffffffff801529e0>] __r4k_wait+0x20/0x40 [<ffffffff801c2278>] cpu_startup_entry+0x2a0/0x368 [<ffffffff8015fa64>] start_secondary+0x444/0x4d8 add the module ref when timer is running to avoid to unload the softdog module Signed-off-by: Li RongQing <roy.qing.li@gmail.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2015-12-13watchdog: softdog: use core reboot notifierDamien Riegel1-28/+2
Get rid of the custom reboot notifier block registration and use the one provided by the watchdog core. Signed-off-by: Damien Riegel <damien.riegel@savoirfairelinux.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Vivien Didelot <vivien.didelot@savoirlinux.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2014-03-31watchdog: fix checkpatch warnings and errorJingoo Han1-1/+1
Fix the following checkpatch warnings and error: WARNING: quoted string split across lines WARNING: braces {} are not necessary for single statement blocks WARNING: __initdata should be placed after ibmasr_id_table[] WARNING: please, no space before tabs ERROR: do not initialise statics to 0 or NULL Signed-off-by: Jingoo Han <jg1.han@samsung.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2013-12-10watchdog: Drop unnecessary include of miscdevice.hGuenter Roeck1-1/+0
After commit 487722cf2 (watchdog: Get rid of MODULE_ALIAS_MISCDEV statements) the affected drivers no longer need to include miscdevice.h. Only exception is rt2880_wdt.c which never needed it. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2013-11-17watchdog: Get rid of MODULE_ALIAS_MISCDEV statementsJean Delvare1-1/+0
I just can't find any value in MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR) and MODULE_ALIAS_MISCDEV(TEMP_MINOR) statements. Either the device is enumerated and the driver already has a module alias (e.g. PCI, USB etc.) that will get the right driver loaded automatically. Or the device is not enumerated and loading its driver will lead to more or less intrusive hardware poking. Such hardware poking should be limited to a bare minimum, so the user should really decide which drivers should be tried and in what order. Trying them all in arbitrary order can't do any good. On top of that, loading that many drivers at once bloats the kernel log. Also many drivers will stay loaded afterward, bloating the output of "lsmod" and wasting memory. Some modules (cs5535_mfgpt which gets loaded as a dependency) can't even be unloaded! If defining char-major-10-130 is needed then it should happen in user-space. Signed-off-by: Jean Delvare <jdelvare@suse.de> Acked-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Mike Frysinger <vapier.adi@gmail.com> Cc: Wan ZongShun <mcuos.com@gmail.com> Cc: Ben Dooks <ben-linux@fluff.org> Cc: Kukjin Kim <kgene.kim@samsung.com> Cc: Zwane Mwaikambo <zwane@arm.linux.org.uk> Cc: Jim Cromie <jim.cromie@gmail.com>
2013-07-11watchdog: softdog: remove replaceable ping operationKim, Milo1-1/+0
In watchdog_ping(), 'start' is called automatically when 'ping' function call is not configured. Softdog driver has same handling in both cases - start and ping, so 'ping' OPS can be removed. Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-03-27watchdog: softdog: convert to watchdog coreAlan Cox1-146/+36
Convert softdog.c to the new watchdog API. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-03-27watchdog: nowayout is boolWim Van Sebroeck1-2/+2
nowayout is actually a boolean value. So make it bool for all watchdog device drivers. Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-03-27watchdog: Use pr_<fmt> and pr_<level>Joe Perches1-21/+14
Use the current logging styles. Make sure all output has a prefix. Add missing newlines. Remove now unnecessary PFX, NAME, and miscellaneous other #defines. Coalesce formats. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2011-03-29watchdog: softdog.c: enhancement to optionally invoke panic instead of reboot on timer expiryAnithra P Janakiraman1-3/+13
This is needed for determining the reason for failure when a softdog timeout occurs. We use softdog to watch for critical application failures and at the minimum a snapshot of the system would help to determine the cause. In such a scenario the application could fail but there isn't a softlockup as such, hence the detect softlockup feature does not help. The patch adds a module parameter soft_panic which when set to 1 causes softdog to invoke panic instead of reboot when the softdog timer expires. By invoking panic we execute kdump if it is configured and the vmcore generated by kdump should provide atleast a minimal idea of the reason for failure. Based on an original patch by Ken Sugawara <sugaken.r3@gmail.com> Signed-off-by: Anithra P J <anithra@linux.vnet.ibm.com> Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2011-03-15watchdog: cleanup spaces before tabsWim Van Sebroeck1-1/+1
cleanup spaces before tabs in drivers/watchdog/ Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2009-06-18[WATCHDOG] Some more general cleanupWim Van Sebroeck1-2/+5
Clean-up the watchdog drivers so that checkpatch.pl get's happy... Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2009-03-25[WATCHDOG] More coding-style and trivial clean-upWim Van Sebroeck1-2/+3
Some more cleaning-up of the watchdog drivers. Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2008-10-28[PATCH] Switch all my contributions stuff to a single common addressAlan Cox1-2/+1
Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2008-08-06[WATCHDOG] Coding style - Indentation - part 2Wim Van Sebroeck1-2/+2
This brings the watchdog drivers into line with coding style. This patch takes cares of the indentation as described in chapter 1. Main changes: * Re-structure the ioctl switch call for all drivers as follows: switch (cmd) { case WDIOC_GETSUPPORT: case WDIOC_GETSTATUS: case WDIOC_GETBOOTSTATUS: case WDIOC_GETTEMP: case WDIOC_SETOPTIONS: case WDIOC_KEEPALIVE: case WDIOC_SETTIMEOUT: case WDIOC_GETTIMEOUT: case WDIOC_GETTIMELEFT: default: } This to make the migration from the drivers to the uniform watchdog device driver easier in the future. Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2008-06-21[WATCHDOG 47/57] softdog: clean up, coding style and switch to unlocked_ioctlAlan Cox1-41/+46
Review and switch to unlocked_ioctl Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2007-10-18mv watchdog tree under driversWim Van Sebroeck1-0/+310
move watchdog tree from drivers/char/watchdog to drivers/watchdog. Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
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