'struct watchdog_ops' and 'struct watchdog_info' are not modified in this
driver.
Constifying these structure moves some data to a read-only section, so
increases overall security, especially when the structure holds some
function pointers.
On a x86_64, with allmodconfig:
Before:
======
text data bss dec hex filename
7319 1768 0 9087 237f drivers/watchdog/apple_wdt.o
After:
=====
text data bss dec hex filename
7543 1544 0 9087 237f drivers/watchdog/apple_wdt.o
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/99019b7e560c2d9c087be340e68f9cce4db1988e.1786283336.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Commit 645ad41da8b2 ("watchdog: pretimeout: Add "dump" pretimeout
governor") added the "dump" watchdog pretimeout governor, but restricted
it to built-in code because trigger_all_cpu_backtrace() was not exported
to loadable modules.
Now that CPU backtrace APIs are supported for loadable kernel modules
via cpumask_backtrace(), convert WATCHDOG_PRETIMEOUT_GOV_DUMP to
tristate. This allows kernels to deliver the pretimeout governor as a
loadable kernel module.
Signed-off-by: Mayank Rungta <mrungta@google.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/r/20260730-export-cpu-backtrace-apis-v1-2-bace8e1cb817@google.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Currently, CPU backtrace functions cannot be called from loadable
modules because the underlying helper arch_trigger_cpumask_backtrace()
is not exported.
Instead of exporting arch_trigger_cpumask_backtrace() individually
across every supported architecture, introduce and export a common
helper, cpumask_backtrace(), in lib/nmi_backtrace.c. Update the four
inline CPU backtrace macros in include/linux/nmi.h to route through this
centralized helper.
Signed-off-by: Mayank Rungta <mrungta@google.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/r/20260730-export-cpu-backtrace-apis-v1-1-bace8e1cb817@google.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
scripts/kernel-doc -none reports:
Warning: drivers/watchdog/booke_wdt.c:158 function parameter 'data'
not described in '__booke_wdt_disable'
__booke_wdt_disable() is invoked through on_each_cpu(), so it takes a
void * argument that it does not use. Its kernel-doc comment does not
describe the parameter at all.
Document it as unused.
Assisted-by: Claude:claude-opus-5
Signed-off-by: Babanpreet Singh <bbnpreetsingh@gmail.com>
Link: https://lore.kernel.org/r/20260730060617.7-3-bbnpreetsingh@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Some firmwares describe WDAT registers inside memory ranges marked as
ACPI NVS in the E820 map, failing with -EBUSY during probe, leaving the
hardware watchdog unserviced and triggering periodic system resets.
This issue was observed on a OnLogic Karbon 524 device (when watchdog is
enabled in BIOS):
wdat_wdt wdat_wdt: error -EBUSY: can't request region for resource [mem 0x63df7a98]
wdat_wdt wdat_wdt: probe with driver wdat_wdt failed with error -16
Check whether the region falls inside ACPI NVS before requesting it and,
if so, map it without reservation.
Signed-off-by: Renê de Souza Pinto <rene@renesp.com.br>
Link: https://lore.kernel.org/r/20260804103958.3684195-1-rene@renesp.com.br
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Add driver support for the Watchdog Timer (WDT) integrated in
Nuvoton MA35D1 SoC. This driver provides standard watchdog functionality,
including timeout configuration, ping, and system reset support via
the watchdog framework.
Signed-off-by: Zi-Yu Chen <zychennvt@gmail.com>
Link: https://lore.kernel.org/r/20260804070351.1846165-3-zychennvt@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Add device tree binding documentation for the watchdog timer (WDT)
controller found on Nuvoton MA35D1 SoC.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Zi-Yu Chen <zychennvt@gmail.com>
Link: https://lore.kernel.org/r/20260804070351.1846165-2-zychennvt@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Report bootstatus on IPQ5332 and IPQ9574. These SoCs use different
restart-reason values from IPQ5424 for watchdog reset and powerunder
reset events, so add separate match data for them and use it when
decoding the restart reason.
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Kathiravan Thirumoorthy <kathiravan.thirumoorthy@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260728-qcom_wdt_powerunder-v1-2-de8d9e964e7d@oss.qualcomm.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
On IPQ platforms, identify the restart reason as POWERUNDER, similar to
CARDRESET, and expose it via the bootstatus sysfs interface.
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Kathiravan Thirumoorthy <kathiravan.thirumoorthy@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260728-qcom_wdt_powerunder-v1-1-de8d9e964e7d@oss.qualcomm.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
If some, but not all, watchdog devices have device tree aliases, those
without aliases might (depending on probe order) be assigned an id
which would otherwise be assigned to one of those with an alias.
This is problematic when for example watchdog0 is an alias for an
always-running gpio watchdog that userspace must handle, but the SOC's
watchdog device(s) get probed first and thus one of those become
/dev/watchdog0, and then at some point later, the gpio watchdog device
gets probed and becomes /dev/watchdog5.
Ensure that ids for devices without a device tree alias are allocated
from among those where no watchdogX alias exists.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Link: https://lore.kernel.org/r/20260714105356.2931450-1-linux@rasmusvillemoes.dk
[groeck: Use scnprintf() instead of snprintf() to make gcc happy]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
The driver has a match table for the pci bus wired into its driver
structure, but the table is not exported with MODULE_DEVICE_TABLE().
Add the missing MODULE_DEVICE_TABLE() entry so module alias information
is generated for automatic module loading.
This is a source-level fix. It does not claim dynamic hardware
reproduction; the evidence is the driver-owned match table, its use by
the driver registration structure, and the missing module alias
publication.
Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
Link: https://lore.kernel.org/r/20260705001613.68871-1-pengpeng@iscas.ac.cn
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Add the compatible for the watchdog of the Rockchip RV1106, which is
compatible with the Synopsys DesignWare watchdog.
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20260714131856.v2.1.b5339e64b3fe4338b3924ebd9dc0096904699744@changeid
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
To make the realtek watchdog driver functional when SWAP_IO_SPACE
config is enabled, change all of the register access to be done
by regmap API which helps us to tweak endianness with big-endian
or little-endian property from within the device tree node.
Add the REGMAP_MMIO as a select to REALTEK_OTTO_WDT now that the
regmap is used.
Signed-off-by: Rustam Adilov <adilov@disroot.org>
Link: https://lore.kernel.org/r/20260710074316.46643-2-adilov@disroot.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
The NPCM750 uses RESSR and the NPCM845 uses INTCR2 to latch reset
indications. Read those bits during probe and map them into watchdog
bootstatus flags.
For NPCM845, cache the sampled INTCR2 state in SCRPAD10 after the reset
status bits are cleared so later probes can report the same boot-time
state. Also report WDIOF_CARDRESET for the watchdog instance whose reset
bit is latched, while leaving WPCM450 behavior unchanged.
Signed-off-by: Tomer Maimon <tmaimon77@gmail.com>
Link: https://lore.kernel.org/r/20260706144828.3517631-4-tmaimon77@gmail.com
[groeck: Declare npcm750_data and npcm845_data with __maybe_unused]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Add documentation describing how the NPCM watchdog driver reports reset
causes through bootstatus on NPCM750 and NPCM845 systems.
Document the reset flag mapping, the watchdog instance mapping for
WDIOF_CARDRESET, and the NPCM750/NPCM845 latch handling. Also mention
sysfs bootstatus reporting when watchdog sysfs support is enabled.
Signed-off-by: Tomer Maimon <tmaimon77@gmail.com>
Link: https://lore.kernel.org/r/20260706144828.3517631-3-tmaimon77@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
NPCM750 and NPCM845 latch watchdog reset indications in the SoC
GCR block rather than in the watchdog block itself.
Add the optional nuvoton,sysgcr phandle so watchdog nodes can
reference the shared GCR reset-status registers that hold those
latched watchdog reset indications.
This is needed by the following reset-status support, which reads
those latches and reports watchdog-caused resets through bootstatus.
Signed-off-by: Tomer Maimon <tmaimon77@gmail.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20260706144828.3517631-2-tmaimon77@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
The watchdog on Apple silicon M3 Pro, Max and Ultra SoCs is compatible
with the t8103 (M1) one. Add "apple,t6030-wdt" for M3 Pro and
"apple,t6031-wdt" for M3 Max and Ultra as per-SoC compatibles.
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Janne Grunau <j@jannau.net>
Link: https://lore.kernel.org/r/20260715-apple-t603x-initial-devices-v2-6-df65b2485710@jannau.net
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
If the watchdog is already running when the driver is initialized, the
driver currently refreshes it once using the default timeout of 60
seconds.
Since commit ee142889e3 ("watchdog: Introduce WDOG_HW_RUNNING flag"),
the watchdog core can kick an already running watchdog alive until
userspace open the device.
Add the WDOG_HW_RUNNING flag to the watchdog status if the watchdog is
already running.
Signed-off-by: Paul Louvel <paul.louvel@bootlin.com>
Link: https://lore.kernel.org/r/20260707-w83627hf_wdt-nct6126d-v4-3-829e5f63d548@bootlin.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
The watchdog identity string reported via WDIOC_GETSUPPORT has always
been hardcoded to "W83627HF Watchdog", even though this driver supports
a wide range of Nuvoton/Winbond Super I/O chips.
This is misleading, since the driver itself correctly log the chip name
in wdt_init(), but could report later a different chip name with
WDIOC_GETSUPPORT.
Instead format the identity at probe time using the actual chip name
that was detected.
Signed-off-by: Paul Louvel <paul.louvel@bootlin.com>
Link: https://lore.kernel.org/r/20260707-w83627hf_wdt-nct6126d-v4-2-829e5f63d548@bootlin.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Currently, the NCT6126 is probed as a NCT6116 because the NCT6126 shares
the same high-byte chip ID as the NCT6116.
Read the low byte of the chip ID as well to distinguish between the two
devices and identify the NCT6126 correctly.
Signed-off-by: Paul Louvel <paul.louvel@bootlin.com>
Link: https://lore.kernel.org/r/20260707-w83627hf_wdt-nct6126d-v4-1-829e5f63d548@bootlin.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Add a new "dump" pretimeout governor that triggers a backtrace of all
CPUs (via trigger_all_cpu_backtrace()) to the kernel log buffer. This
provides diagnostic information right before the hardware watchdog
fires.
In addition, update the WATCHDOG_PRETIMEOUT_GOV_SEL Kconfig logic to
fall back to the "panic" governor only when both "noop" and "dump"
governors are disabled.
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://lore.kernel.org/r/20260707102105.3600275-1-tzungbi@kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
The watchdog on the Apple silicon t8132 (M4) SoC is compatible with the
existing driver. Add "apple,t8132-wdt" as SoC specific compatible under
"apple,t8103-wdt" used by the driver.
The M4 wdt block additionally has a secondary watchdog, which is
disabled by m1n1 and can safely be ignored by Linux.
Signed-off-by: Yureka Lilian <yureka@cyberchaos.dev>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260705-apple-m4-initial-devicetrees-v1-3-e5655ee56523@cyberchaos.dev
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Named initializers are better readable and more robust to changes of the
struct definition. This robustness is relevant for a planned change to
struct platform_device_id replacing .driver_data by an anonymous union.
For one driver drop the unused assignment to .driver_data instead.
While touching these arrays unify spacing and usage of commas.
There is no effect on the compiled arrays.
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/22bc09d0c9c8dfe75a205b0a9ccc98ccfba1de10.1781622532.git.u.kleine-koenig@baylibre.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
- Fix use-after-free in eventfs_remove_rec()
The freeing of the eventfs_inode children used list_for_each_entry() where
the child is freed via srcu, but there's still a chance that it gets freed.
It should be using list_for_each_entry_safe().
- Fix eventfs_inode SRCU use of list in freeing
The iterator uses an SRCU protected list walk on the eventfs inodes. The
eventfs inode uses its "list" field in a union with the RCU list head.
When the inode gets added to the SRCU list it immediately corrupts the
list pointer and can cause an issue with the iterator. Move the RCU list
head to be shared with the children list head which allows the iterator to
check the parent inode if is freed before referencing the child. Have the
iterator check the parent "is_freed" field and break out if it is set.
Also add memory barriers to make sure the ordering is correct.
- Fix various RCU synchronization issues with direct_functions
Updates to direct_functions have some missing RCU protection and
synchronization. Restructure the code a bit to make sure updates to the
direct_functions are protected.
- Remove an unneeded comma from a scope_guard()
There's a spurious comma in a scope_guard(). Remove it.
- Fix race in per CPU buffer swap in the ring buffer
When a per CPU buffer swap happens, it must make sure that it doesn't
occur while a writer is active. Instead it returns an -EBUSY. But there's
a small race window when a writer moves from one sub-buffer to the next
that it resets the "committing" counter. If a swap happens at that moment,
the buffer used for the commit of an event will not match the buffer the
event is actually on. Instead of using the "committing" counter, use the
recursive detection counter that does not get reset when the writer
crosses sub-buffers.
- Fix off-by-one in ftrace_free_mem()
The function ftrace_free_mem() gets an "end_ptr" as a parameter that is
exclusive to the rang to be freed. But its value is used to search for the
records that expects an inclusive value. Subtract one from the parameter
to convert it to an inclusive range.
- Disable resizing of the ring buffer for persistent buffers
Resizing the persistent buffer has undefined behavior. Prevent it from
being resized.
- Disable changing ring buffer subbuf order when resizing is disabled
The ring buffer subbuffer order can not be changed during resizing. Use
that instead of just checking if the buffer is mapped as mapped buffers
also have resizing disabled.
- Initialize subbuf_order of reader pages when they are created
In rb_allocate_cpu_buffer() the bpage->order is not updated to the current
subbuf_order leaving it as zero. This value is used when the page is freed.
- Fix test_ringbuffer() to test for ERR_PTR before calling kthread_stop()
The rb_threads[] array is assigned the output of kthread_run_on_cpu()
which could return an ERR_PTR. At the end of the test, all threads in the
array are cleaned up by kthread_stop() passing in the value in the array
if it isn't zero. But if the array contains an ERR_PTR, kthread_stop()
will not be able to handle it properly.
-----BEGIN PGP SIGNATURE-----
iIoEABYKADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCanicmBQccm9zdGVkdEBn
b29kbWlzLm9yZwAKCRAp5XQQmuv6quonAP9HgM214Bt43edhuJb3oFy9fdS+sqYZ
RIJ9q90iMDUH0AEAk3650lu7u80YniD4INKNrz5QMM2EbIMaNqtqwkS8uwQ=
=tZwi
-----END PGP SIGNATURE-----
Merge tag 'trace-v7.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
- Fix use-after-free in eventfs_remove_rec()
The freeing of the eventfs_inode children used list_for_each_entry()
where the child is freed via srcu, but there's still a chance that it
gets freed. It should be using list_for_each_entry_safe().
- Fix eventfs_inode SRCU use of list in freeing
The iterator uses an SRCU protected list walk on the eventfs inodes.
The eventfs inode uses its "list" field in a union with the RCU list
head. When the inode gets added to the SRCU list it immediately
corrupts the list pointer and can cause an issue with the iterator.
Move the RCU list head to be shared with the children list head which
allows the iterator to check the parent inode if is freed before
referencing the child. Have the iterator check the parent "is_freed"
field and break out if it is set. Also add memory barriers to make
sure the ordering is correct.
- Fix various RCU synchronization issues with direct_functions
Updates to direct_functions have some missing RCU protection and
synchronization. Restructure the code a bit to make sure updates to
the direct_functions are protected.
- Remove an unneeded comma from a scope_guard()
There's a spurious comma in a scope_guard(). Remove it.
- Fix race in per CPU buffer swap in the ring buffer
When a per CPU buffer swap happens, it must make sure that it doesn't
occur while a writer is active. Instead it returns an -EBUSY. But
there's a small race window when a writer moves from one sub-buffer
to the next that it resets the "committing" counter. If a swap
happens at that moment, the buffer used for the commit of an event
will not match the buffer the event is actually on. Instead of using
the "committing" counter, use the recursive detection counter that
does not get reset when the writer crosses sub-buffers.
- Fix off-by-one in ftrace_free_mem()
The function ftrace_free_mem() gets an "end_ptr" as a parameter that
is exclusive to the rang to be freed. But its value is used to search
for the records that expects an inclusive value. Subtract one from
the parameter to convert it to an inclusive range.
- Disable resizing of the ring buffer for persistent buffers
Resizing the persistent buffer has undefined behavior. Prevent it
from being resized.
- Disable changing ring buffer subbuf order when resizing is disabled
The ring buffer subbuffer order can not be changed during resizing.
Use that instead of just checking if the buffer is mapped as mapped
buffers also have resizing disabled.
- Initialize subbuf_order of reader pages when they are created
In rb_allocate_cpu_buffer() the bpage->order is not updated to the
current subbuf_order leaving it as zero. This value is used when the
page is freed.
- Fix test_ringbuffer() to test for ERR_PTR before calling
kthread_stop()
The rb_threads[] array is assigned the output of kthread_run_on_cpu()
which could return an ERR_PTR. At the end of the test, all threads in
the array are cleaned up by kthread_stop() passing in the value in
the array if it isn't zero. But if the array contains an ERR_PTR,
kthread_stop() will not be able to handle it properly.
* tag 'trace-v7.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ring-buffer: Fix crash passing ERR_PTR to kthread_stop()
ring-buffer: Initialise reader page order in rb_allocate_cpu_buffer()
ring-buffer: Prevent subbuf order change when resizing is disabled
ring-buffer: Prevent resizing of persistent ring buffer
ftrace: Fix off-by-one fentry site disable in ftrace_free_mem()
ring-buffer: Use current_context for safe per-CPU buffer swap
ftrace: Drop extra comma in trace_buffered_event_enable
ftrace: Protect direct_functions in update_ftrace_direct_mod
ftrace: Protect direct_functions in update_ftrace_direct_del
ftrace: Protect direct_functions in ftrace_find_rec_direct
eventfs: Use children field for rcu head and add memory barriers
eventfs: Fix use-after-free in eventfs_remove_rec()
- Fix potential uninitialized memory reads and buffer overflows from
malformed zcrypt CCA and EP11 requests by properly validating lengths
and payloads
- Fix possible out of bounds accesses in zcrypt EP11 domain handling by
replacing fixed payload layout assumptions with parsing ASN.1 fields
with bounds checks
- Fix zcrypt CCA and EP11 request and reply buffer allocations missing
required 4-byte padding, and scrub the full allocation on release
- Fix zcrypt CCA and EP11 messages leaking up to 3 uninitialized bytes
of memory by zeroing trailing alignment padding
-----BEGIN PGP SIGNATURE-----
iQEzBAABCgAdFiEE3QHqV+H2a8xAv27vjYWKoQLXFBgFAmp4YYUACgkQjYWKoQLX
FBh1tgf/ZZMzYxWDawMfYg2SoE16aLEG6M+I8qa1EmpxCXwu2Evl17LdMtkZFL1C
ClDux15JGBhbpYyHyXhlsnUMRSHKLatLF2LU4KR6g3q5JgFcNRUVzSH8uuE40en5
UspMeEG09NENUJGveyZ8tEbGmkbI1hxAzicD4nRMTuin8VpXWKvHaNeQYXhkuDtr
5nuCiRmJUgMrwAVgtTXkdWzMaR0QwLWwkkLXLhnQk6NWyz1EhYmXWT+YG2axu7/y
KUWU5jEs1AutO7YUxgTzrvxjS4M5IbokSXNyTUlLUqmPzdbXVWrpuF0nFEorBCA3
TzA7NCaJAChYWFfg54zQYdd4ijnf2Q==
=iulo
-----END PGP SIGNATURE-----
Merge tag 's390-7.2-7' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 fixes from Vasily Gorbik:
- Fix potential uninitialized memory reads and buffer overflows from
malformed zcrypt CCA and EP11 requests by properly validating lengths
and payloads
- Fix possible out of bounds accesses in zcrypt EP11 domain handling by
replacing fixed payload layout assumptions with parsing ASN.1 fields
with bounds checks
- Fix zcrypt CCA and EP11 request and reply buffer allocations missing
required 4-byte padding, and scrub the full allocation on release
- Fix zcrypt CCA and EP11 messages leaking up to 3 uninitialized bytes
of memory by zeroing trailing alignment padding
* tag 's390-7.2-7' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/zcrypt: Pad trailing CCA or EP11 message with zeros
s390/zcrypt: Improve EP11 CPRB domain handling with ASN.1 parsing
s390/zcrypt: Improve EP11 CPRB length and overflow checks
s390/zcrypt: Improve CCA CPRB length and overflow checks
s390/zcrypt: Fix CPRB memory allocation in zcrypt misc code
In test_ringbuffer()'s out_free cleanup loop, the check
`!rb_threads[cpu]` only catches NULL entries and misses entries that
hold an ERR_PTR.
rb_threads[] is static, so unassigned slots are NULL. But when
kthread_run_on_cpu() fails for a cpu, it stores ERR_PTR(-ENOMEM) (or
-EINTR) in rb_threads[cpu] before the creation loop jumps to out_free.
That entry is non-NULL, so the old `!ptr` check does not break, and the
cleanup proceeds to call kthread_stop() on the ERR_PTR. kthread_stop()
then dereferences the bogus pointer, crashing the kernel during the
late_initcall self-test.
crash logs:
BUG: kernel NULL pointer dereference, address: 000000000000001c
Oops: 0002 [#1] SMP NOPTI
CPU: 1 PID: 1 Comm: swapper/0 Not tainted 7.2.0-rc6-dirty #7 PREEMPT(lazy)
RIP: 0010:kthread_stop+0x2e/0x220
RBX: fffffffffffffff4
CR2: 000000000000001c
Call Trace:
<TASK>
test_ringbuffer+0x1ec/0x650
do_one_initcall+0x6c/0x2c0
kernel_init_freeable+0x21d/0x420
kernel_init+0x15/0x1c0
ret_from_fork+0x21b/0x320
</TASK>
Kernel panic - not syncing: Fatal exception
Cc: stable@vger.kernel.org
Fixes: 64ed3a049e ("ring-buffer: make use of the helper function kthread_run_on_cpu()")
Link: https://patch.msgid.link/20260807154145.2846521-2-sh_def@163.com
Signed-off-by: Hui Su <sh_def@163.com>
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
In rb_allocate_cpu_buffer(), bpage->order was omitted, leaving it as 0.
This is an issue for a ring-buffer with subbufs bigger than PAGE_SIZE if
when freed: free_buffer_page() relies on this value. Align the value
with the actual allocation size (buffer::subbuf_order).
Cc: stable@vger.kernel.org
Fixes: f9b94daa54 ("ring-buffer: Set new size of the ring buffer sub page")
Link: https://patch.msgid.link/20260806211306.3704194-4-vdonnefort@google.com
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When a module's init text is freed, do_init_module() calls
ftrace_free_mem() with a half-open [start, end) range. However the
ftrace_cmp_recs() comparator treats the upper bound as inclusive, as all
its other users do, passing 'ip + size - 1'. So ftrace_free_mem() can
delete a record sitting exactly at 'end', which is outside the freed
range.
For a kernel without CFI or IBT, the first record of a function is at
the function start, which for the first function in a module is also the
base of its text allocation. As the module allocator packs its regions,
that address is often the 'end' passed by a neighboring module's
do_init_module(), causing the first function's ftrace location to get
disabled, preventing an attempt to livepatch it:
livepatch: failed to find location for function 'pcspkr_probe'
Convert the exclusive end to the inclusive 'end - 1' the comparator
expects, and return early for an empty range to avoid the subtraction
from underflowing when the init text size is zero.
Cc: stable@vger.kernel.org
Fixes: 42c269c88d ("ftrace: Allow for function tracing to record init functions on boot up")
Link: https://patch.msgid.link/1b5ccfa8095bdb1277f84af1c2c2e2205aca03ae.1785992188.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The ring_buffer_swap_cpu() function currently checks the per-CPU
committing counter to determine if a buffer is actively being written to
before performing the swap. However, there exists a race window where
this check can be bypassed:
ring_buffer_lock_reserve
cpu_buffer = buffer->buffers[cpu]; // cpu_buffer_a
rb_reserve_next_event
rb_start_commit // inc committing
if (unlikely(READ_ONCE(cpu_buffer->buffer) != buffer)) {...}
__rb_reserve_next
rb_move_tail
rb_end_commit(cpu_buffer); // dec committing => 0
/* interrupt hits here, successfully swaps! */
local_inc(&cpu_buffer->committing);
ring_buffer_unlock_commit
cpu_buffer = buffer->buffers[cpu]; // cpu_buffer_b
rb_commit
rb_end_commit
RB_WARN_ON(cpu_buffer, !local_read(&cpu_buffer->committing))
// triggers warning
The committing counter can temporarily drop to 0 during a single write
operation (within rb_move_tail), creating a window where swap can
succeed even though the write is still in progress. This leads to
inconsistent buffer state and triggers the RB_WARN_ON in rb_commit().
Replace the committing counter check with current_context checks, which
are set at the entry of ring_buffer_lock_reserve() and remain valid
throughout the entire write operation, providing a reliable indicator of
buffer busy state during swap.
Cc: stable@vger.kernel.org
Fixes: 4239c38fe0 ("ring-buffer: Process commits whenever moving to a new page.")
Link: https://patch.msgid.link/20260803005640.2445666-2-wutengda@huaweicloud.com
Signed-off-by: Tengda Wu <wutengda@huaweicloud.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
that can cause stuck tasks (Yao Kai)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-----BEGIN PGP SIGNATURE-----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=3w7m
-----END PGP SIGNATURE-----
Merge tag 'locking-urgent-2026-08-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull futex fix from Ingo Molnar:
- Fix race in futex_pivot_pending() during private hash resize
that can cause stuck tasks (Yao Kai)
* tag 'locking-urgent-2026-08-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
futex: Fix race in futex_pivot_pending() during private hash resize
Here are some small USB and Thunderbolt driver fixes for 7.2-rc7 that
resolve some reported issues. Included in here are:
- new quirk for some broken USB devices
- thunderbolt device fixes for reported issues
- usb gadget driver fix
- usb atm driver fix
- xhci driver fixes.
- other minor USB driver fixes
All of these have been in linux-next this week with no reported issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iGwEABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCandKCg8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+ymavgCgzIiJ6KRqYmikyHsPpfL6GNYtOLAAmOwaDTWL
Zzvkgp8bIdQvqsPg6B0=
=lR2e
-----END PGP SIGNATURE-----
Merge tag 'usb-7.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB / Thunderbolt fixes from Greg KH:
"Here are some small USB and Thunderbolt driver fixes for 7.2-rc7 that
resolve some reported issues. Included in here are:
- new quirk for some broken USB devices
- thunderbolt device fixes for reported issues
- usb gadget driver fix
- usb atm driver fix
- xhci driver fixes.
- other minor USB driver fixes
All of these have been in linux-next this week with no reported
issues"
* tag 'usb-7.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
usb: xhci: use BIT_ULL for CRCR bits to fix incorrect 64bit mask
usb: quirks: Add ShanWan gamepad to quirk list
usb: hub: Split announce_device() to log device identity before enumeration
usb: core: Add quirk for 255-bytes initial config read
usb: atm: cxacru: properly kill rcv_urb on error in cxacru_cm()
usb: misc: usbio: check ibuf_len against rxbuf_len in bulk msg
usb: gadget: f_ncm: Use unsigned int for ndp_index
usb: cdnsp: fix incorrect endian conversions for APB timeout register
thunderbolt: Initialize ->domain_released completion before it is being used
thunderbolt: icm: Preserve USB4 proxy data-valid bit
thunderbolt: Bound the DROM dual link port number before indexing sw->ports
thunderbolt: Fix bandwidth group reservation indexing
thunderbolt: stream: Unmap buffers with mapped size
Here are some small serial and vt tty driver fixes for 7.2-rc7 that
resolve some reported problems. Included in here are:
- 2 vt core fixes
- amba-pl011 serial driver fixes
- 8250_of and 8250_dma driver fixes
- qcom-geni serial driver fix
- sc16is7xx serial driver fix
All of these have been in linux-next this week with no reported issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCandKkg8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+ylnjQCeND+mnhXzo7wmT4E2vHER2FG8UEEAmwXRTNe6
QzKAPXT2BgHPFW7Gy8dk
=UY5p
-----END PGP SIGNATURE-----
Merge tag 'tty-7.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty / serial / vt driver fixes from Greg KH:
"Here are some small serial and vt tty driver fixes for 7.2-rc7 that
resolve some reported problems. Included in here are:
- two vt core fixes
- amba-pl011 serial driver fixes
- 8250_of and 8250_dma driver fixes
- qcom-geni serial driver fix
- sc16is7xx serial driver fix
All of these have been in linux-next this week with no reported
issues"
* tag 'tty-7.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
serial: amba-pl011: synchronize DMA teardown
serial: amba-pl011: cancel RS485 hrtimers after freeing IRQ
serial: amba-pl011: fix indefinite RS485 post-send delay
vt: add permission check for KDSKBMETA ioctl
vt: stabilize tty reference in kbd_keycode with tty_port_tty_get
serial: 8250_of: clear stuck empty-FIFO RX-timeout on LPC32xx
serial: qcom-geni: fix TX DMA buffer flush
serial: 8250_dma: Clear stale RX state on shutdown
serial: sc16is7xx: enable THRI before filling TX FIFO
Here are some more small staging driver fixes, just for the rtl8723bs
driver, for some reported problems found with it now that people are
starting to actually test the thing with "bad" networks.
Nothing major, but good to have in the -final release. All of these
have been in linux-next for over a week with no reported problems.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCandJYA8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+ykIxACfTuHhJxAk0r/QsXGjmp/u8s733lYAnjVl7Kdm
v7Q+WL8+jJnxPW8jpWcy
=l2iZ
-----END PGP SIGNATURE-----
Merge tag 'staging-7.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging driver fixes from Greg KH:
"Here are some more small staging driver fixes, just for the rtl8723bs
driver, for some reported problems found with it now that people are
starting to actually test the thing with "bad" networks.
Nothing major, but good to have in the -final release. All of these
have been in linux-next for over a week with no reported problems"
* tag 'staging-7.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
staging: rtl8723bs: validate monitor transmit frame lengths
staging: rtl8723bs: fix missing shared-key auth challenge length check
staging: rtl8723bs: fix OOB read in WMM_param_handler()
staging: rtl8723bs: fix OOB read in rtw_get_wpa_ie()
Here are some small char/misc and nvmem and documentation fixes for
7.2-rc7 to resolve some reported issues. Included in here are:
- updates to the documentation for the kernel threat model and
security bugs to get the LLMs to actually follow what we have been
asking them to do (i.e. not claim security issues for things we do
not consider security issues.)
- nvmem driver fixes which required a tiny "layout" driver to be
added.
- fastrpc driver fixes
- mei driver fix
- counter driver fix
- binder driver fix
All of these have been in linux-next this week with no reported
problems.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCandLdw8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+yldzACZAVaM2/I0hIeTnoBqRFIZBcroUQYAoNk5zQSW
qYG0DWUf4LJwj9WPQWIS
=e+LJ
-----END PGP SIGNATURE-----
Merge tag 'char-misc-7.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char / misc and documentation fixes from Greg KH:
"Here are some small char/misc and nvmem and documentation fixes for
7.2-rc7 to resolve some reported issues. Included in here are:
- updates to the documentation for the kernel threat model and
security bugs to get the LLMs to actually follow what we have been
asking them to do (i.e. not claim security issues for things we do
not consider security issues.)
- nvmem driver fixes which required a tiny "layout" driver to be
added.
- fastrpc driver fixes
- mei driver fix
- counter driver fix
- binder driver fix
All of these have been in linux-next this week with no reported
problems"
* tag 'char-misc-7.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
docs: security-bugs: clarify some mandatory steps for AI reports
docs: coding-assistant: explain important steps when looking for bugs
docs: security-bugs: clarify what counts as a valid version
docs: threat-model: move fake devices out of "non production use"
docs: threat-model: clarify "security bug" vs "vulnerability"
counter: microchip-tcb-capture: Fix DT channel validation
mei: pull kvfree out of spinlock
rust_binder: do not query current thread for all ioctls
nvmem: layouts: Add fixed-layout driver
nvmem: apple-spmi-nvmem: wrap regmap calls to satisfy CFI
misc: fastrpc: fix memory leak in fastrpc_channel_ctx_free
misc: fastrpc: fix channel ctx ref leak when session alloc fails
misc: fastrpc: take fl->lock when moving mmaps on interrupted invoke
misc: fastrpc: Remove buffer from list prior to unmap operation
misc: fastrpc: Fix initial memory allocation for Audio PD memory pool
Drop the extra comma in "scoped_guard()" to cleanup the code.
Link: https://patch.msgid.link/20260730150411.88667-5-leon.hwang@linux.dev
Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
