Hi George, On 05.03.25 11:10, George Cherian wrote: > This series adds a new kernel command line option to watchdog core to > stop the watchdog on panic. This is useul in certain systems which prevents > successful loading of kdump kernel due to watchdog reset. > > Some of the watchdog drivers stop function could sleep. For such > drivers the stop_on_panic is not valid as the notifier callback happens > in atomic context. Introduce WDIOF_STOP_MAYSLEEP flag to watchdog_info > options to indicate whether the stop function would sleep. Did you consider having a reset_on_panic instead, which sets a user-specified timeout on panic? This would make the mechanism useful also for watchdogs that can't be disabled and would protect against system lock up: Consider a memory-corruption bug (perhaps externally via DMA), which partially overwrites both main and kdump kernel. With a disabled watchdog, the system may not be able to recover on its own. If you did consider it, what made you decide against it? Thanks, Ahmad > > > Changelog: > v1 -> v2 > - Remove the per driver flag setting option > - Take the parameter via kernel command-line parameter to watchdog_core. > > v2 -> v3 > - Remove the helper function watchdog_stop_on_panic() from watchdog.h. > - There are no users for this. > > v3 -> v4 > - Since the panic notifier is in atomic context, watchdog functions > which sleep can't be called. > - Add an options flag WDIOF_STOP_MAYSLEEP to indicate whether stop > function sleeps. > - Simplify the stop_on_panic kernel command line parsing. > - Enable the panic notiffier only if the watchdog stop function doesn't > sleep > > George Cherian (2): > watchdog: Add a new flag WDIOF_STOP_MAYSLEEP > drivers: watchdog: Add support for panic notifier callback > > drivers/watchdog/advantech_ec_wdt.c | 3 ++- > drivers/watchdog/arm_smc_wdt.c | 3 ++- > drivers/watchdog/armada_37xx_wdt.c | 2 +- > drivers/watchdog/asm9260_wdt.c | 2 +- > drivers/watchdog/bcm47xx_wdt.c | 3 ++- > drivers/watchdog/bd9576_wdt.c | 2 +- > drivers/watchdog/bd96801_wdt.c | 2 +- > drivers/watchdog/cgbc_wdt.c | 2 +- > drivers/watchdog/cros_ec_wdt.c | 5 ++++- > drivers/watchdog/da9052_wdt.c | 3 ++- > drivers/watchdog/da9055_wdt.c | 4 +++- > drivers/watchdog/da9062_wdt.c | 4 +++- > drivers/watchdog/da9063_wdt.c | 4 +++- > drivers/watchdog/db8500_wdt.c | 5 ++++- > drivers/watchdog/dw_wdt.c | 5 +++-- > drivers/watchdog/f71808e_wdt.c | 3 ++- > drivers/watchdog/gpio_wdt.c | 2 +- > drivers/watchdog/i6300esb.c | 5 ++++- > drivers/watchdog/imx_sc_wdt.c | 2 +- > drivers/watchdog/intel-mid_wdt.c | 5 ++++- > drivers/watchdog/it87_wdt.c | 5 ++++- > drivers/watchdog/jz4740_wdt.c | 5 ++++- > drivers/watchdog/kempld_wdt.c | 3 ++- > drivers/watchdog/lenovo_se10_wdt.c | 5 ++++- > drivers/watchdog/max77620_wdt.c | 5 ++++- > drivers/watchdog/mei_wdt.c | 3 ++- > drivers/watchdog/menf21bmc_wdt.c | 4 +++- > drivers/watchdog/mlx_wdt.c | 2 +- > drivers/watchdog/msc313e_wdt.c | 5 ++++- > drivers/watchdog/npcm_wdt.c | 3 ++- > drivers/watchdog/omap_wdt.c | 5 ++++- > drivers/watchdog/pm8916_wdt.c | 5 +++-- > drivers/watchdog/pseries-wdt.c | 2 +- > drivers/watchdog/rave-sp-wdt.c | 5 ++++- > drivers/watchdog/renesas_wdt.c | 7 ++++-- > drivers/watchdog/retu_wdt.c | 5 ++++- > drivers/watchdog/rn5t618_wdt.c | 6 +++-- > drivers/watchdog/rzg2l_wdt.c | 5 ++++- > drivers/watchdog/rzv2h_wdt.c | 5 ++++- > drivers/watchdog/shwdt.c | 6 +++-- > drivers/watchdog/sl28cpld_wdt.c | 5 ++++- > drivers/watchdog/softdog.c | 5 ++++- > drivers/watchdog/sp805_wdt.c | 5 ++++- > drivers/watchdog/starfive-wdt.c | 3 ++- > drivers/watchdog/stpmic1_wdt.c | 5 ++++- > drivers/watchdog/ts4800_wdt.c | 5 ++++- > drivers/watchdog/twl4030_wdt.c | 5 ++++- > drivers/watchdog/uniphier_wdt.c | 3 ++- > drivers/watchdog/w83627hf_wdt.c | 5 ++++- > drivers/watchdog/watchdog_core.c | 35 +++++++++++++++++++++++++++++ > drivers/watchdog/wm831x_wdt.c | 5 ++++- > drivers/watchdog/wm8350_wdt.c | 5 ++++- > drivers/watchdog/xen_wdt.c | 5 ++++- > drivers/watchdog/ziirave_wdt.c | 5 ++++- > include/linux/watchdog.h | 2 ++ > include/uapi/linux/watchdog.h | 1 + > 56 files changed, 198 insertions(+), 58 deletions(-) > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
