Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Clone this repository
For self-hosted knots, clone URLs may differ based on your setup.
Download tar.gz
Pull x86 platform driver fixes from Andy Shevchenko:
- fix a couple of Mellanox driver enumeration issues
- fix ASUS laptop regression with backlight
- fix Dell computers that got a wrong mode (tablet versus laptop) after
resume
* tag 'platform-drivers-x86-v5.2-3' of git://git.infradead.org/linux-platform-drivers-x86:
platform/mellanox: mlxreg-hotplug: Add devm_free_irq call to remove flow
platform/x86: mlx-platform: Fix parent device in i2c-mux-reg device registration
platform/x86: intel-vbtn: Report switch events when event wakes device
platform/x86: asus-wmi: Only Tell EC the OS will handle display hotkeys from asus_nb_wmi
Pull USB fixes from Greg KH:
"Here are some small USB driver fixes for 5.2-rc5
Nothing major, just some small gadget fixes, usb-serial new device
ids, a few new quirks, and some small fixes for some regressions that
have been found after the big 5.2-rc1 merge.
All of these have been in linux-next for a while with no reported
issues"
* tag 'usb-5.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
usb: typec: Make sure an alt mode exist before getting its partner
usb: gadget: udc: lpc32xx: fix return value check in lpc32xx_udc_probe()
usb: gadget: dwc2: fix zlp handling
usb: dwc2: Set actual frame number for completed ISOC transfer for none DDMA
usb: gadget: udc: lpc32xx: allocate descriptor with GFP_ATOMIC
usb: gadget: fusb300_udc: Fix memory leak of fusb300->ep[i]
usb: phy: mxs: Disable external charger detect in mxs_phy_hw_init()
usb: dwc2: Fix DMA cache alignment issues
usb: dwc2: host: Fix wMaxPacketSize handling (fix webcam regression)
USB: Fix chipmunk-like voice when using Logitech C270 for recording audio.
USB: usb-storage: Add new ID to ums-realtek
usb: typec: ucsi: ccg: fix memory leak in do_flash
USB: serial: option: add Telit 0x1260 and 0x1261 compositions
USB: serial: pl2303: add Allied Telesis VT-Kit3
USB: serial: option: add support for Simcom SIM7500/SIM7600 RNDIS mode
Add devm_free_irq() call to mlxreg-hotplug remove() for clean release
of devices irq resource. Fix debugobjects warning triggered by rmmod
It prevents of use-after-free memory, related to
mlxreg_hotplug_work_handler.
Issue has been reported as debugobjects warning triggered by
'rmmod mlxtreg-hotplug' flow, while running kernel with
CONFIG_DEBUG_OBJECTS* options.
[ 2489.623551] ODEBUG: free active (active state 0) object type: work_struct hint: mlxreg_hotplug_work_handler+0x0/0x7f0 [mlxreg_hotplug]
[ 2489.637097] WARNING: CPU: 5 PID: 3924 at lib/debugobjects.c:328 debug_print_object+0xfe/0x180
[ 2489.637165] RIP: 0010:debug_print_object+0xfe/0x180
?
[ 2489.637214] Call Trace:
[ 2489.637225] __debug_check_no_obj_freed+0x25e/0x320
[ 2489.637231] kfree+0x82/0x110
[ 2489.637238] release_nodes+0x33c/0x4e0
[ 2489.637242] ? devres_remove_group+0x1b0/0x1b0
[ 2489.637247] device_release_driver_internal+0x146/0x270
[ 2489.637251] driver_detach+0x73/0xe0
[ 2489.637254] bus_remove_driver+0xa1/0x170
[ 2489.637261] __x64_sys_delete_module+0x29e/0x320
[ 2489.637265] ? __ia32_sys_delete_module+0x320/0x320
[ 2489.637268] ? blkcg_exit_queue+0x20/0x20
[ 2489.637273] ? task_work_run+0x7d/0x100
[ 2489.637278] ? exit_to_usermode_loop+0x5b/0xf0
[ 2489.637281] do_syscall_64+0x73/0x160
[ 2489.637287] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 2489.637290] RIP: 0033:0x7f95c3596fd7
The difference in release flow with and with no devm_free_irq is listed
below:
bus: 'platform': remove driver mlxreg-hotplug
mlxreg_hotplug_remove(start)
-> devm_free_irq (with new code)
mlxreg_hotplug_remove (end)
release_nodes (start)
mlxreg-hotplug: DEVRES REL devm_hwmon_release (8 bytes)
device: 'hwmon3': device_unregister
PM: Removing info for No Bus:hwmon3
mlxreg-hotplug: DEVRES REL devm_kzalloc_release (88 bytes)
mlxreg-hotplug: DEVRES REL devm_kzalloc_release (6 bytes)
mlxreg-hotplug: DEVRES REL devm_kzalloc_release (5 bytes)
mlxreg-hotplug: DEVRES REL devm_kzalloc_release (5 bytes)
mlxreg-hotplug: DEVRES REL devm_kzalloc_release (5 bytes)
mlxreg-hotplug: DEVRES REL devm_kzalloc_release (5 bytes)
mlxreg-hotplug: DEVRES REL devm_kzalloc_release (5 bytes)
mlxreg-hotplug: DEVRES REL devm_kzalloc_release (5 bytes)
mlxreg-hotplug: DEVRES REL devm_kzalloc_release (5 bytes)
mlxreg-hotplug: DEVRES REL devm_kzalloc_release (5 bytes)
mlxreg-hotplug: DEVRES REL devm_kzalloc_release (5 bytes)
mlxreg-hotplug: DEVRES REL devm_kzalloc_release (5 bytes)
mlxreg-hotplug: DEVRES REL devm_irq_release (16 bytes) (no new code)
mlxreg-hotplug: DEVRES REL devm_kzalloc_release (1376 bytes)
------------[ cut here ]------------ (no new code):
ODEBUG: free active (active state 0) object type: work_struct hint: mlxreg_hotplug_work_handler
release_nodes(end)
driver: 'mlxreg-hotplug': driver_release
Fixes: 1f976f6978bf ("platform/x86: Move Mellanox platform hotplug driver to platform/mellanox")
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Pull powerpc fixes from Michael Ellerman:
"One fix for a regression introduced by our 32-bit KASAN support, which
broke booting on machines with "bootx" early debugging enabled.
A fix for a bug which broke kexec on 32-bit, introduced by changes to
the 32-bit STRICT_KERNEL_RWX support in v5.1.
Finally two fixes going to stable for our THP split/collapse handling,
discovered by Nick. The first fixes random crashes and/or corruption
in guests under sufficient load.
Thanks to: Nicholas Piggin, Christophe Leroy, Aaro Koskinen, Mathieu
Malaterre"
* tag 'powerpc-5.2-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/32s: fix booting with CONFIG_PPC_EARLY_DEBUG_BOOTX
powerpc/64s: __find_linux_pte() synchronization vs pmdp_invalidate()
powerpc/64s: Fix THP PMD collapse serialisation
powerpc: Fix kexec failure on book3s/32
Adding check to typec_altmode_get_partner() to prevent
potential NULL pointer dereference.
Reported-by: Vladimir Yerilov <openmindead@gmail.com>
Fixes: ad74b8649bea ("usb: typec: ucsi: Preliminary support for alternate modes")
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix the issue found while running kernel with the option
CONFIG_DEBUG_TEST_DRIVER_REMOVE.
Driver 'mlx-platform' registers 'i2c_mlxcpld' device and then registers
few underlying 'i2c-mux-reg' devices:
priv->pdev_i2c = platform_device_register_simple("i2c_mlxcpld", nr,
NULL, 0);
...
for (i = 0; i < ARRAY_SIZE(mlxplat_mux_data); i++) {
priv->pdev_mux[i] = platform_device_register_resndata(
&mlxplat_dev->dev,
"i2c-mux-reg", i, NULL,
0, &mlxplat_mux_data[i],
sizeof(mlxplat_mux_data[i]));
But actual parent of "i2c-mux-reg" device is priv->pdev_i2c->dev and
not mlxplat_dev->dev.
Patch fixes parent device parameter in a call to
platform_device_register_resndata() for "i2c-mux-reg".
It solves the race during initialization flow while 'i2c_mlxcpld.1' is
removing after probe, while 'i2c-mux-reg.0' is still in probing flow:
'i2c_mlxcpld.1' flow: probe -> remove -> probe.
'i2c-mux-reg.0' flow: probe -> ...
[ 12:621096] Registering platform device 'i2c_mlxcpld.1'. Parent at platform
[ 12:621117] device: 'i2c_mlxcpld.1': device_add
[ 12:621155] bus: 'platform': add device i2c_mlxcpld.1
[ 12:621384] Registering platform device 'i2c-mux-reg.0'. Parent at mlxplat
[ 12:621395] device: 'i2c-mux-reg.0': device_add
[ 12:621425] bus: 'platform': add device i2c-mux-reg.0
[ 12:621806] Registering platform device 'i2c-mux-reg.1'. Parent at mlxplat
[ 12:621828] device: 'i2c-mux-reg.1': device_add
[ 12:621892] bus: 'platform': add device i2c-mux-reg.1
[ 12:621906] bus: 'platform': add driver i2c_mlxcpld
[ 12:621996] bus: 'platform': driver_probe_device: matched device i2c_mlxcpld.1 with driver i2c_mlxcpld
[ 12:622003] bus: 'platform': really_probe: probing driver i2c_mlxcpld with device i2c_mlxcpld.1
[ 12:622100] i2c_mlxcpld i2c_mlxcpld.1: no default pinctrl state
[ 12:622293] device: 'i2c-1': device_add
[ 12:627280] bus: 'i2c': add device i2c-1
[ 12:627692] device: 'i2c-1': device_add
[ 12.629639] bus: 'platform': add driver i2c-mux-reg
[ 12.629718] bus: 'platform': driver_probe_device: matched device i2c-mux-reg.0 with driver i2c-mux-reg
[ 12.629723] bus: 'platform': really_probe: probing driver i2c-mux-reg with device i2c-mux-reg.0
[ 12.629818] i2c-mux-reg i2c-mux-reg.0: no default pinctrl state
[ 12.629981] platform i2c-mux-reg.0: Driver i2c-mux-reg requests probe deferral
[ 12.629986] platform i2c-mux-reg.0: Added to deferred list
[ 12.629992] bus: 'platform': driver_probe_device: matched device i2c-mux-reg.1 with driver i2c-mux-reg
[ 12.629997] bus: 'platform': really_probe: probing driver i2c-mux-reg with device i2c-mux-reg.1
[ 12.630091] i2c-mux-reg i2c-mux-reg.1: no default pinctrl state
[ 12.630247] platform i2c-mux-reg.1: Driver i2c-mux-reg requests probe deferral
[ 12.630252] platform i2c-mux-reg.1: Added to deferred list
[ 12.640892] devices_kset: Moving i2c-mux-reg.0 to end of list
[ 12.640900] platform i2c-mux-reg.0: Retrying from deferred list
[ 12.640911] bus: 'platform': driver_probe_device: matched device i2c-mux-reg.0 with driver i2c-mux-reg
[ 12.640919] bus: 'platform': really_probe: probing driver i2c-mux-reg with device i2c-mux-reg.0
[ 12.640999] i2c-mux-reg i2c-mux-reg.0: no default pinctrl state
[ 12.641177] platform i2c-mux-reg.0: Driver i2c-mux-reg requests probe deferral
[ 12.641187] platform i2c-mux-reg.0: Added to deferred list
[ 12.641198] devices_kset: Moving i2c-mux-reg.1 to end of list
[ 12.641219] platform i2c-mux-reg.1: Retrying from deferred list
[ 12.641237] bus: 'platform': driver_probe_device: matched device i2c-mux-reg.1 with driver i2c-mux-reg
[ 12.641247] bus: 'platform': really_probe: probing driver i2c-mux-reg with device i2c-mux-reg.1
[ 12.641331] i2c-mux-reg i2c-mux-reg.1: no default pinctrl state
[ 12.641465] platform i2c-mux-reg.1: Driver i2c-mux-reg requests probe deferral
[ 12.641469] platform i2c-mux-reg.1: Added to deferred list
[ 12.646427] device: 'i2c-1': device_add
[ 12.646647] bus: 'i2c': add device i2c-1
[ 12.647104] device: 'i2c-1': device_add
[ 12.669231] devices_kset: Moving i2c-mux-reg.0 to end of list
[ 12.669240] platform i2c-mux-reg.0: Retrying from deferred list
[ 12.669258] bus: 'platform': driver_probe_device: matched device i2c-mux-reg.0 with driver i2c-mux-reg
[ 12.669263] bus: 'platform': really_probe: probing driver i2c-mux-reg with device i2c-mux-reg.0
[ 12.669343] i2c-mux-reg i2c-mux-reg.0: no default pinctrl state
[ 12.669585] device: 'i2c-2': device_add
[ 12.669795] bus: 'i2c': add device i2c-2
[ 12.670201] device: 'i2c-2': device_add
[ 12.671427] i2c i2c-1: Added multiplexed i2c bus 2
[ 12.671514] device: 'i2c-3': device_add
[ 12.671724] bus: 'i2c': add device i2c-3
[ 12.672136] device: 'i2c-3': device_add
[ 12.673378] i2c i2c-1: Added multiplexed i2c bus 3
[ 12.673472] device: 'i2c-4': device_add
[ 12.673676] bus: 'i2c': add device i2c-4
[ 12.674060] device: 'i2c-4': device_add
[ 12.675861] i2c i2c-1: Added multiplexed i2c bus 4
[ 12.675941] device: 'i2c-5': device_add
[ 12.676150] bus: 'i2c': add device i2c-5
[ 12.676550] device: 'i2c-5': device_add
[ 12.678103] i2c i2c-1: Added multiplexed i2c bus 5
[ 12.678193] device: 'i2c-6': device_add
[ 12.678395] bus: 'i2c': add device i2c-6
[ 12.678774] device: 'i2c-6': device_add
[ 12.679969] i2c i2c-1: Added multiplexed i2c bus 6
[ 12.680065] device: 'i2c-7': device_add
[ 12.680275] bus: 'i2c': add device i2c-7
[ 12.680913] device: 'i2c-7': device_add
[ 12.682506] i2c i2c-1: Added multiplexed i2c bus 7
[ 12.682600] device: 'i2c-8': device_add
[ 12.682808] bus: 'i2c': add device i2c-8
[ 12.683189] device: 'i2c-8': device_add
[ 12.683907] device: 'i2c-1': device_unregister
[ 12.683945] device: 'i2c-1': device_unregister
[ 12.684387] device: 'i2c-1': device_create_release
[ 12.684536] bus: 'i2c': remove device i2c-1
[ 12.686019] i2c i2c-8: Failed to create compatibility class link
[ 12.686086] ------------[ cut here ]------------
[ 12.686087] can't create symlink to mux device
[ 12.686224] Workqueue: events deferred_probe_work_func
[ 12.686135] WARNING: CPU: 7 PID: 436 at drivers/i2c/i2c-mux.c:416 i2c_mux_add_adapter+0x729/0x7d0 [i2c_mux]
[ 12.686232] RIP: 0010:i2c_mux_add_adapter+0x729/0x7d0 [i2c_mux]
[ 0x190/0x190 [i2c_mux]
[ 12.686300] ? i2c_mux_alloc+0xac/0x110 [i2c_mux]
[ 12.686306] ? i2c_mux_reg_set+0x200/0x200 [i2c_mux_reg]
[ 12.686313] i2c_mux_reg_probe+0x22c/0x731 [i2c_mux_reg]
[ 12.686322] ? i2c_mux_reg_deselect+0x60/0x60 [i2c_mux_reg]
[ 12.686346] platform_drv_probe+0xa8/0x110
[ 12.686351] really_probe+0x185/0x720
[ 12.686358] driver_probe_device+0xdf/0x1f0
...
[ 12.686522] i2c i2c-1: Added multiplexed i2c bus 8
[ 12.686621] device: 'i2c-9': device_add
[ 12.686626] kobject_add_internal failed for i2c-9 (error: -2 parent: i2c-1)
[ 12.694729] i2c-core: adapter 'i2c-1-mux (chan_id 8)': can't register device (-2)
[ 12.705726] i2c i2c-1: failed to add mux-adapter 8 as bus 9 (error=-2)
[ 12.714494] device: 'i2c-8': device_unregister
[ 12.714537] device: 'i2c-8': device_unregister
Fixes: 6613d18e9038 ("platform/x86: mlx-platform: Move module from arch/x86")
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Pull tracing fixes from Steven Rostedt:
- Out of range read of stack trace output
- Fix for NULL pointer dereference in trace_uprobe_create()
- Fix to a livepatching / ftrace permission race in the module code
- Fix for NULL pointer dereference in free_ftrace_func_mapper()
- A couple of build warning clean ups
* tag 'trace-v5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ftrace: Fix NULL pointer dereference in free_ftrace_func_mapper()
module: Fix livepatch/ftrace module text permissions race
tracing/uprobe: Fix obsolete comment on trace_uprobe_create()
tracing/uprobe: Fix NULL pointer dereference in trace_uprobe_create()
tracing: Make two symbols static
tracing: avoid build warning with HAVE_NOP_MCOUNT
tracing: Fix out-of-range read in trace_stack_print()
When booting through OF, setup_disp_bat() does nothing because
disp_BAT are not set. By change, it used to work because BOOTX
buffer is mapped 1:1 at address 0x81000000 by the bootloader, and
btext_setup_display() sets virt addr same as phys addr.
But since commit 215b823707ce ("powerpc/32s: set up an early static
hash table for KASAN."), a temporary page table overrides the
bootloader mapping.
This 0x81000000 is also problematic with the newly implemented
Kernel Userspace Access Protection (KUAP) because it is within user
address space.
This patch fixes those issues by properly setting disp_BAT through
a call to btext_prepare_BAT(), allowing setup_disp_bat() to
properly setup BAT3 for early bootx screen buffer access.
Reported-by: Mathieu Malaterre <malat@debian.org>
Fixes: 215b823707ce ("powerpc/32s: set up an early static hash table for KASAN.")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Tested-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Johan writes:
USB-serial fixes for 5.2-rc5
Here are some new device ids for option and pl2303.
All have been in linux-next with no reported issues.
Signed-off-by: Johan Hovold <johan@kernel.org>
* tag 'usb-serial-5.2-rc5' of https://git.kernel.org/pub/scm/linux/kernel/git/johan/usb-serial:
USB: serial: option: add Telit 0x1260 and 0x1261 compositions
USB: serial: pl2303: add Allied Telesis VT-Kit3
USB: serial: option: add support for Simcom SIM7500/SIM7600 RNDIS mode
When a switch event, such as tablet mode/laptop mode or docked/undocked,
wakes a device make sure that the value of the swich is reported.
Without when a device is put in tablet mode from laptop mode when it is
suspended or vice versa the device will wake up but mode will be
incorrect.
Tested by suspending a device in laptop mode and putting it in tablet
mode, the device resumes and is in tablet mode. When suspending the
device in tablet mode and putting it in laptop mode the device resumes
and is in laptop mode.
Signed-off-by: Mathew King <mathewk@chromium.org>
Reviewed-by: Jett Rink <jettrink@chromium.org>
Reviewed-by: Mario Limonciello <mario.limonciello@dell.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Pull cgroup fixes from Tejun Heo:
"This has an unusually high density of tricky fixes:
- task_get_css() could deadlock when it races against a dying cgroup.
- cgroup.procs didn't list thread group leaders with live threads.
This could mislead readers to think that a cgroup is empty when
it's not. Fixed by making PROCS iterator include dead tasks. I made
a couple mistakes making this change and this pull request contains
a couple follow-up patches.
- When cpusets run out of online cpus, it updates cpusmasks of member
tasks in bizarre ways. Joel improved the behavior significantly"
* 'for-5.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cpuset: restore sanity to cpuset_cpus_allowed_fallback()
cgroup: Fix css_task_iter_advance_css_set() cset skip condition
cgroup: css_task_iter_skip()'d iterators must be advanced before accessed
cgroup: Include dying leaders with live threads in PROCS iterations
cgroup: Implement css_task_iter_skip()
cgroup: Call cgroup_release() before __exit_signal()
docs cgroups: add another example size for hugetlb
cgroup: Use css_tryget() instead of css_tryget_online() in task_get_css()
The mapper may be NULL when called from register_ftrace_function_probe()
with probe->data == NULL.
This issue can be reproduced as follow (it may be covered by compiler
optimization sometime):
/ # cat /sys/kernel/debug/tracing/set_ftrace_filter
#### all functions enabled ####
/ # echo foo_bar:dump > /sys/kernel/debug/tracing/set_ftrace_filter
[ 206.949100] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[ 206.952402] Mem abort info:
[ 206.952819] ESR = 0x96000006
[ 206.955326] Exception class = DABT (current EL), IL = 32 bits
[ 206.955844] SET = 0, FnV = 0
[ 206.956272] EA = 0, S1PTW = 0
[ 206.956652] Data abort info:
[ 206.957320] ISV = 0, ISS = 0x00000006
[ 206.959271] CM = 0, WnR = 0
[ 206.959938] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000419f3a000
[ 206.960483] [0000000000000000] pgd=0000000411a87003, pud=0000000411a83003, pmd=0000000000000000
[ 206.964953] Internal error: Oops: 96000006 [#1] SMP
[ 206.971122] Dumping ftrace buffer:
[ 206.973677] (ftrace buffer empty)
[ 206.975258] Modules linked in:
[ 206.976631] Process sh (pid: 281, stack limit = 0x(____ptrval____))
[ 206.978449] CPU: 10 PID: 281 Comm: sh Not tainted 5.2.0-rc1+ #17
[ 206.978955] Hardware name: linux,dummy-virt (DT)
[ 206.979883] pstate: 60000005 (nZCv daif -PAN -UAO)
[ 206.980499] pc : free_ftrace_func_mapper+0x2c/0x118
[ 206.980874] lr : ftrace_count_free+0x68/0x80
[ 206.982539] sp : ffff0000182f3ab0
[ 206.983102] x29: ffff0000182f3ab0 x28: ffff8003d0ec1700
[ 206.983632] x27: ffff000013054b40 x26: 0000000000000001
[ 206.984000] x25: ffff00001385f000 x24: 0000000000000000
[ 206.984394] x23: ffff000013453000 x22: ffff000013054000
[ 206.984775] x21: 0000000000000000 x20: ffff00001385fe28
[ 206.986575] x19: ffff000013872c30 x18: 0000000000000000
[ 206.987111] x17: 0000000000000000 x16: 0000000000000000
[ 206.987491] x15: ffffffffffffffb0 x14: 0000000000000000
[ 206.987850] x13: 000000000017430e x12: 0000000000000580
[ 206.988251] x11: 0000000000000000 x10: cccccccccccccccc
[ 206.988740] x9 : 0000000000000000 x8 : ffff000013917550
[ 206.990198] x7 : ffff000012fac2e8 x6 : ffff000012fac000
[ 206.991008] x5 : ffff0000103da588 x4 : 0000000000000001
[ 206.991395] x3 : 0000000000000001 x2 : ffff000013872a28
[ 206.991771] x1 : 0000000000000000 x0 : 0000000000000000
[ 206.992557] Call trace:
[ 206.993101] free_ftrace_func_mapper+0x2c/0x118
[ 206.994827] ftrace_count_free+0x68/0x80
[ 206.995238] release_probe+0xfc/0x1d0
[ 206.995555] register_ftrace_function_probe+0x4a8/0x868
[ 206.995923] ftrace_trace_probe_callback.isra.4+0xb8/0x180
[ 206.996330] ftrace_dump_callback+0x50/0x70
[ 206.996663] ftrace_regex_write.isra.29+0x290/0x3a8
[ 206.997157] ftrace_filter_write+0x44/0x60
[ 206.998971] __vfs_write+0x64/0xf0
[ 206.999285] vfs_write+0x14c/0x2f0
[ 206.999591] ksys_write+0xbc/0x1b0
[ 206.999888] __arm64_sys_write+0x3c/0x58
[ 207.000246] el0_svc_common.constprop.0+0x408/0x5f0
[ 207.000607] el0_svc_handler+0x144/0x1c8
[ 207.000916] el0_svc+0x8/0xc
[ 207.003699] Code: aa0003f8 a9025bf5 aa0103f5 f946ea80 (f9400303)
[ 207.008388] ---[ end trace 7b6d11b5f542bdf1 ]---
[ 207.010126] Kernel panic - not syncing: Fatal exception
[ 207.011322] SMP: stopping secondary CPUs
[ 207.013956] Dumping ftrace buffer:
[ 207.014595] (ftrace buffer empty)
[ 207.015632] Kernel Offset: disabled
[ 207.017187] CPU features: 0x002,20006008
[ 207.017985] Memory Limit: none
[ 207.019825] ---[ end Kernel panic - not syncing: Fatal exception ]---
Link: http://lkml.kernel.org/r/20190606031754.10798-1-liwei391@huawei.com
Signed-off-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The change to pmdp_invalidate() to mark the pmd with _PAGE_INVALID
broke the synchronisation against lock free lookups,
__find_linux_pte()'s pmd_none() check no longer returns true for such
cases.
Fix this by adding a check for this condition as well.
Fixes: da7ad366b497 ("powerpc/mm/book3s: Update pmd_present to look at _PAGE_PRESENT bit")
Cc: stable@vger.kernel.org # v4.20+
Suggested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>