linux.git/drivers/watchdog, branch v5.4.64

watchdog: initialize device before misc_register

2020-08-21T11:05:36+00:00

[ Upstream commit cb36e29bb0e4b0c33c3d5866a0a4aebace4c99b7 ]

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
[] (unwind_backtrace) from [] (show_stack+0x18/0x1c)
[] (show_stack) from [] (dump_stack+0xb4/0xe8)
[] (dump_stack) from [] (__warn+0xfc/0x114)
[] (__warn) from [] (warn_slowpath_fmt+0x50/0x74)
[] (warn_slowpath_fmt) from [] (kobject_get+0x50/0x54)
[] (kobject_get) from [] (get_device+0x1c/0x24)
[] (get_device) from [] (watchdog_open+0x90/0xf0)
[] (watchdog_open) from [] (misc_open+0x130/0x17c)
[] (misc_open) from [] (chrdev_open+0xec/0x1a8)
[] (chrdev_open) from [] (do_dentry_open+0x204/0x3cc)
[] (do_dentry_open) from [] (path_openat+0x330/0x1148)
[] (path_openat) from [] (do_filp_open+0x78/0xec)
[] (do_filp_open) from [] (do_sys_open+0x130/0x1f4)
[] (do_sys_open) from [] (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
[] (unwind_backtrace) from [] (show_stack+0x18/0x1c)
[] (show_stack) from [] (dump_stack+0xb4/0xe8)
[] (dump_stack) from [] (__warn+0xfc/0x114)
[] (__warn) from [] (warn_slowpath_fmt+0x50/0x74)
[] (warn_slowpath_fmt) from [] (kobject_get+0x24/0x54)
[] (kobject_get) from [] (get_device+0x1c/0x24)
[] (get_device) from [] (watchdog_open+0x90/0xf0)
[] (watchdog_open) from [] (misc_open+0x130/0x17c)
[] (misc_open) from [] (chrdev_open+0xec/0x1a8)
[] (chrdev_open) from [] (do_dentry_open+0x204/0x3cc)
[] (do_dentry_open) from [] (path_openat+0x330/0x1148)
[] (path_openat) from [] (do_filp_open+0x78/0xec)
[] (do_filp_open) from [] (do_sys_open+0x130/0x1f4)
[] (do_sys_open) from [] (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 
Reviewed-by: Alexander Sverdlin 
Signed-off-by: Krzysztof Sobota 
Link: https://lore.kernel.org/r/20200717103109.14660-1-krzysztof.sobota@nokia.com
Signed-off-by: Guenter Roeck 
Signed-off-by: Wim Van Sebroeck 
Signed-off-by: Sasha Levin

watchdog: f71808e_wdt: clear watchdog timeout occurred flag

2020-08-21T11:05:28+00:00

commit 4f39d575844148fbf3081571a1f3b4ae04150958 upstream.

The flag indicating a watchdog timeout having occurred normally persists
till Power-On Reset of the Fintek Super I/O chip. The user can clear it
by writing a `1' to the bit.

The driver doesn't offer a restart method, so regular system reboot
might not reset the Super I/O and if the watchdog isn't enabled, we
won't touch the register containing the bit on the next boot.
In this case all subsequent regular reboots will be wrongly flagged
by the driver as being caused by the watchdog.

Fix this by having the flag cleared after read. This is also done by
other drivers like those for the i6300esb and mpc8xxx_wdt.

Fixes: b97cb21a4634 ("watchdog: f71808e_wdt: Fix WDTMOUT_STS register read")
Cc: stable@vger.kernel.org
Signed-off-by: Ahmad Fatoum 
Reviewed-by: Guenter Roeck 
Link: https://lore.kernel.org/r/20200611191750.28096-5-a.fatoum@pengutronix.de
Signed-off-by: Guenter Roeck 
Signed-off-by: Wim Van Sebroeck 
Signed-off-by: Greg Kroah-Hartman

watchdog: f71808e_wdt: remove use of wrong watchdog_info option

2020-08-21T11:05:28+00:00

commit 802141462d844f2e6a4d63a12260d79b7afc4c34 upstream.

The flags that should be or-ed into the watchdog_info.options by drivers
all start with WDIOF_, e.g. WDIOF_SETTIMEOUT, which indicates that the
driver's watchdog_ops has a usable set_timeout.

WDIOC_SETTIMEOUT was used instead, which expands to 0xc0045706, which
equals:

   WDIOF_FANFAULT | WDIOF_EXTERN1 | WDIOF_PRETIMEOUT | WDIOF_ALARMONLY |
   WDIOF_MAGICCLOSE | 0xc0045000

These were so far indicated to userspace on WDIOC_GETSUPPORT.
As the driver has not yet been migrated to the new watchdog kernel API,
the constant can just be dropped without substitute.

Fixes: 96cb4eb019ce ("watchdog: f71808e_wdt: new watchdog driver for Fintek F71808E and F71882FG")
Cc: stable@vger.kernel.org
Signed-off-by: Ahmad Fatoum 
Reviewed-by: Guenter Roeck 
Link: https://lore.kernel.org/r/20200611191750.28096-4-a.fatoum@pengutronix.de
Signed-off-by: Guenter Roeck 
Signed-off-by: Wim Van Sebroeck 
Signed-off-by: Greg Kroah-Hartman

watchdog: f71808e_wdt: indicate WDIOF_CARDRESET support in watchdog_info.options

2020-08-21T11:05:28+00:00

commit e871e93fb08a619dfc015974a05768ed6880fd82 upstream.

The driver supports populating bootstatus with WDIOF_CARDRESET, but so
far userspace couldn't portably determine whether absence of this flag
meant no watchdog reset or no driver support. Or-in the bit to fix this.

Fixes: b97cb21a4634 ("watchdog: f71808e_wdt: Fix WDTMOUT_STS register read")
Cc: stable@vger.kernel.org
Signed-off-by: Ahmad Fatoum 
Reviewed-by: Guenter Roeck 
Link: https://lore.kernel.org/r/20200611191750.28096-3-a.fatoum@pengutronix.de
Signed-off-by: Guenter Roeck 
Signed-off-by: Wim Van Sebroeck 
Signed-off-by: Greg Kroah-Hartman

watchdog: da9062: No need to ping manually before setting timeout

2020-06-24T15:50:32+00:00

[ Upstream commit a0948ddba65f4f6d3cfb5e2b84685485d0452966 ]

There is actually no need to ping the watchdog before disabling it
during timeout change. Disabling the watchdog already takes care of
resetting the counter.

This fixes an issue during boot when the userspace watchdog handler takes
over and the watchdog is already running. Opening the watchdog in this case
leads to the first ping and directly after that without the required
heartbeat delay a second ping issued by the set_timeout call. Due to the
missing delay this resulted in a reset.

Signed-off-by: Stefan Riedmueller 
Reviewed-by: Guenter Roeck 
Reviewed-by: Adam Thomson 
Link: https://lore.kernel.org/r/20200403130728.39260-3-s.riedmueller@phytec.de
Signed-off-by: Guenter Roeck 
Signed-off-by: Wim Van Sebroeck 
Signed-off-by: Sasha Levin

watchdog: imx_sc_wdt: Fix reboot on crash

2020-06-17T14:40:27+00:00

commit e56d48e92b1017b6a8dbe64923a889283733fd96 upstream.

Currently when running the samples/watchdog/watchdog-simple.c
application and forcing a kernel crash by doing:

# ./watchdog-simple &
# echo c > /proc/sysrq-trigger

The system does not reboot as expected.

Fix it by calling imx_sc_wdt_set_timeout() to configure the i.MX8QXP
watchdog with a proper timeout.

Cc: 
Fixes: 986857acbc9a ("watchdog: imx_sc: Add i.MX system controller watchdog support")
Reported-by: Breno Lima 
Signed-off-by: Fabio Estevam 
Reviewed-by: Guenter Roeck 
Tested-by: Breno Lima 
Link: https://lore.kernel.org/r/20200412230122.5601-1-festevam@gmail.com
Signed-off-by: Guenter Roeck 
Signed-off-by: Wim Van Sebroeck 
Signed-off-by: Greg Kroah-Hartman

watchdog: reset last_hw_keepalive time at start

2020-04-29T14:32:57+00:00

[ Upstream commit 982bb70517aef2225bad1d802887b733db492cc0 ]

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 
Reviewed-by: Guenter Roeck 
Link: https://lore.kernel.org/r/20200302200426.6492-3-t-kristo@ti.com
Signed-off-by: Guenter Roeck 
Signed-off-by: Wim Van Sebroeck 
Signed-off-by: Sasha Levin

watchdog: sp805: fix restart handler

2020-04-23T08:36:15+00:00

commit ea104a9e4d3e9ebc26fb78dac35585b142ee288b upstream.

The restart handler is missing two things, first, the registers
has to be unlocked and second there is no synchronization for the
write_relaxed() calls.

This was tested on a custom board with the NXP LS1028A SoC.

Fixes: 6c5c0d48b686c ("watchdog: sp805: add restart handler")
Signed-off-by: Michael Walle 
Reviewed-by: Guenter Roeck 
Link: https://lore.kernel.org/r/20200327162450.28506-1-michael@walle.cc
Signed-off-by: Guenter Roeck 
Signed-off-by: Wim Van Sebroeck 
Signed-off-by: Greg Kroah-Hartman

watchdog: iTCO_wdt: Make ICH_RES_IO_SMI optional

2020-04-08T07:08:46+00:00

commit e42b0c24389d5a1602e77db4f6def0d5a19e3e43 upstream.

The iTCO_wdt driver only needs ICH_RES_IO_SMI I/O resource when either
turn_SMI_watchdog_clear_off module parameter is set to match ->iTCO_version
(or higher), and when legacy iTCO_vendorsupport is set. Modify the driver
so that ICH_RES_IO_SMI is optional if the two conditions are not met.

Signed-off-by: Mika Westerberg 
Reviewed-by: Guenter Roeck 
Signed-off-by: Wolfram Sang 
Signed-off-by: Greg Kroah-Hartman

watchdog: iTCO_wdt: Export vendorsupport

2020-04-08T07:08:46+00:00

commit 7ca6ee38909109751bfab79e9f6c570d2ed258c6 upstream.

In preparation for making ->smi_res optional the iTCO_wdt driver needs
to know whether vendorsupport is being set to non-zero. For this reason
export the variable.

Signed-off-by: Mika Westerberg 
Reviewed-by: Guenter Roeck 
Signed-off-by: Wolfram Sang 
Signed-off-by: Greg Kroah-Hartman