bool is the most sensible return value for a yes/no return. Also
add __init as this funtion is only called from the early boot code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20230531125535.676098-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Don't require the use of dynamic debug (or modification of the kernel to
add a #define DEBUG to the top of this file) to get the printk message
about driver probe timing. This printk is only emitted when
initcall_debug is enabled on the kernel commandline, and it isn't
immediately obvious that you have to do something else to debug boot
timing issues related to driver probe. Add a comment too so it doesn't
get converted back to pr_debug().
Fixes: eb7fbc9fb1 ("driver core: Add missing '\n' in log messages")
Cc: stable <stable@kernel.org>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Brian Norris <briannorris@chromium.org>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20230412225842.3196599-1-swboyd@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the file is written to and sync_state() hasn't been called for the
device yet, then call sync_state() for the device independent of the
state of its consumers.
This is useful for supplier devices that have one or more consumers that
don't have a driver but the consumers are in a state that don't use the
resources supplied by the supplier device.
This gives finer grained control than using the
fw_devlink.sync_state=timeout kernel commandline parameter.
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20230304005355.746421-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When all devices that could probe have finished probing (based on
deferred_probe_timeout configuration or late_initcall() when
!CONFIG_MODULES), this parameter controls what to do with devices that
haven't yet received their sync_state() calls.
fw_devlink.sync_state=strict is the default and the driver core will
continue waiting on all consumers of a device to probe successfully
before sync_state() is called for the device. This is the default
behavior since calling sync_state() on a device when all its consumers
haven't probed could make some systems unusable/unstable. When this
option is selected, we also print the list of devices that haven't had
sync_state() called on them by the time all devices the could probe have
finished probing.
fw_devlink.sync_state=timeout will cause the driver core to give up
waiting on consumers and call sync_state() on any devices that haven't
yet received their sync_state() calls. This option is provided for
systems that won't become unusable/unstable as they might be able to
save power (depends on state of hardware before kernel starts) if all
devices get their sync_state().
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20230304005355.746421-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230202141621.2296458-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The logic to touch the bus notifier was open-coded in numberous places
in the driver core. Clean that up by creating a local bus_notify()
function and have everyone call this function instead, making the
reading of the caller code simpler and easier to maintain over time.
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230111092331.3946745-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It is not used outside of its compilation unit, so there's no need to
export this variable.
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Andrew Halaney <ahalaney@redhat.com>
Acked-by: John Stultz <jstultz@google.com>
Link: https://lore.kernel.org/r/20221227232152.3094584-1-javierm@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a driver registers with a bus, it will attempt to match with every
device on the bus through the __driver_attach() function. Currently, if
the bus_type.match() function encounters an error that is not
-EPROBE_DEFER, __driver_attach() will return a negative error code, which
causes the driver registration logic to stop trying to match with the
remaining devices on the bus.
This behavior is not correct; a failure while matching a driver to a
device does not mean that the driver won't be able to match and bind
with other devices on the bus. Update the logic in __driver_attach()
to reflect this.
Fixes: 656b8035b0 ("ARM: 8524/1: driver cohandle -EPROBE_DEFER from bus_type.match()")
Cc: stable@vger.kernel.org
Cc: Saravana Kannan <saravanak@google.com>
Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com>
Link: https://lore.kernel.org/r/20220921001414.4046492-1-isaacmanjarres@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
driver_allows_async_probing is only used in drivers/base/dd.c, so mark
it static and remove the declaration in drivers/base/base.h.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221030092255.872280-1-hch@lst.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge 6.0-rc5 into driver-core-next
We need the driver core and debugfs changes in this branch.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Both __device_attach_driver() and __driver_attach() check the return
code of the bus_type.match() function to see if the device needs to be
added to the deferred probe list. After adding the device to the list,
the logic attempts to bind the device to the driver anyway, as if the
device had matched with the driver, which is not correct.
If __device_attach_driver() detects that the device in question is not
ready to match with a driver on the bus, then it doesn't make sense for
the device to attempt to bind with the current driver or continue
attempting to match with any of the other drivers on the bus. So, update
the logic in __device_attach_driver() to reflect this.
If __driver_attach() detects that a driver tried to match with a device
that is not ready to match yet, then the driver should not attempt to bind
with the device. However, the driver can still attempt to match and bind
with other devices on the bus, as drivers can be bound to multiple
devices. So, update the logic in __driver_attach() to reflect this.
Fixes: 656b8035b0 ("ARM: 8524/1: driver cohandle -EPROBE_DEFER from bus_type.match()")
Cc: stable@vger.kernel.org
Cc: Saravana Kannan <saravanak@google.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Saravana Kannan <saravanak@google.com>
Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com>
Link: https://lore.kernel.org/r/20220817184026.3468620-1-isaacmanjarres@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 9cbffc7a59.
There are a few more issues to fix that have been reported in the thread
for the original series [1]. We'll need to fix those before this will work.
So, revert it for now.
[1] - https://lore.kernel.org/lkml/20220601070707.3946847-1-saravanak@google.com/
Fixes: 9cbffc7a59 ("driver core: Delete driver_deferred_probe_check_state()")
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Peng Fan <peng.fan@nxp.com>
Tested-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20220819221616.2107893-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In __driver_attach function, There are also AA deadlock problem,
like the commit b232b02bf3 ("driver core: fix deadlock in
__device_attach").
stack like commit b232b02bf3 ("driver core: fix deadlock in
__device_attach").
list below:
In __driver_attach function, The lock holding logic is as follows:
...
__driver_attach
if (driver_allows_async_probing(drv))
device_lock(dev) // get lock dev
async_schedule_dev(__driver_attach_async_helper, dev); // func
async_schedule_node
async_schedule_node_domain(func)
entry = kzalloc(sizeof(struct async_entry), GFP_ATOMIC);
/* when fail or work limit, sync to execute func, but
__driver_attach_async_helper will get lock dev as
will, which will lead to A-A deadlock. */
if (!entry || atomic_read(&entry_count) > MAX_WORK) {
func;
else
queue_work_node(node, system_unbound_wq, &entry->work)
device_unlock(dev)
As above show, when it is allowed to do async probes, because of
out of memory or work limit, async work is not be allowed, to do
sync execute instead. it will lead to A-A deadlock because of
__driver_attach_async_helper getting lock dev.
Reproduce:
and it can be reproduce by make the condition
(if (!entry || atomic_read(&entry_count) > MAX_WORK)) untenable, like
below:
[ 370.785650] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables
this message.
[ 370.787154] task:swapper/0 state:D stack: 0 pid: 1 ppid:
0 flags:0x00004000
[ 370.788865] Call Trace:
[ 370.789374] <TASK>
[ 370.789841] __schedule+0x482/0x1050
[ 370.790613] schedule+0x92/0x1a0
[ 370.791290] schedule_preempt_disabled+0x2c/0x50
[ 370.792256] __mutex_lock.isra.0+0x757/0xec0
[ 370.793158] __mutex_lock_slowpath+0x1f/0x30
[ 370.794079] mutex_lock+0x50/0x60
[ 370.794795] __device_driver_lock+0x2f/0x70
[ 370.795677] ? driver_probe_device+0xd0/0xd0
[ 370.796576] __driver_attach_async_helper+0x1d/0xd0
[ 370.797318] ? driver_probe_device+0xd0/0xd0
[ 370.797957] async_schedule_node_domain+0xa5/0xc0
[ 370.798652] async_schedule_node+0x19/0x30
[ 370.799243] __driver_attach+0x246/0x290
[ 370.799828] ? driver_allows_async_probing+0xa0/0xa0
[ 370.800548] bus_for_each_dev+0x9d/0x130
[ 370.801132] driver_attach+0x22/0x30
[ 370.801666] bus_add_driver+0x290/0x340
[ 370.802246] driver_register+0x88/0x140
[ 370.802817] ? virtio_scsi_init+0x116/0x116
[ 370.803425] scsi_register_driver+0x1a/0x30
[ 370.804057] init_sd+0x184/0x226
[ 370.804533] do_one_initcall+0x71/0x3a0
[ 370.805107] kernel_init_freeable+0x39a/0x43a
[ 370.805759] ? rest_init+0x150/0x150
[ 370.806283] kernel_init+0x26/0x230
[ 370.806799] ret_from_fork+0x1f/0x30
To fix the deadlock, move the async_schedule_dev outside device_lock,
as we can see, in async_schedule_node_domain, the parameter of
queue_work_node is system_unbound_wq, so it can accept concurrent
operations. which will also not change the code logic, and will
not lead to deadlock.
Fixes: ef0ff68351 ("driver core: Probe devices asynchronously instead of the driver")
Signed-off-by: Zhang Wensheng <zhangwensheng5@huawei.com>
Link: https://lore.kernel.org/r/20220622074327.497102-1-zhangwensheng5@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The function is no longer used. So delete it.
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20220601070707.3946847-10-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some devices might need to be probed and bound successfully before the
kernel boot sequence can finish and move on to init/userspace. For
example, a network interface might need to be bound to be able to mount
a NFS rootfs.
With fw_devlink=on by default, some of these devices might be blocked
from probing because they are waiting on a optional supplier that
doesn't have a driver. While fw_devlink will eventually identify such
devices and unblock the probing automatically, it might be too late by
the time it unblocks the probing of devices. For example, the IP4
autoconfig might timeout before fw_devlink unblocks probing of the
network interface.
This function is available to temporarily try and probe all devices that
have a driver even if some of their suppliers haven't been added or
don't have drivers.
The drivers can then decide which of the suppliers are optional vs
mandatory and probe the device if possible. By the time this function
returns, all such "best effort" probes are guaranteed to be completed.
If a device successfully probes in this mode, we delete all fw_devlink
discovered dependencies of that device where the supplier hasn't yet
probed successfully because they have to be optional dependencies.
This also means that some devices that aren't needed for init and could
have waited for their optional supplier to probe (when the supplier's
module is loaded later on) would end up probing prematurely with limited
functionality. So call this function only when boot would fail without
it.
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20220601070707.3946847-5-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since we had to effectively reverted
commit 35a672363a ("driver core: Ensure wait_for_device_probe() waits
until the deferred_probe_timeout fires") in an earlier patch, a non-zero
deferred_probe_timeout will break NFS rootfs mounting [1] again. So, set
the default back to zero until we can fix that.
[1] - https://lore.kernel.org/lkml/TYAPR01MB45443DF63B9EF29054F7C41FD8C60@TYAPR01MB4544.jpnprd01.prod.outlook.com/
Fixes: 2b28a1a84a ("driver core: Extend deferred probe timeout on driver registration")
Cc: Mark Brown <broonie@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20220526034609.480766-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mounting NFS rootfs was timing out when deferred_probe_timeout was
non-zero [1]. This was because ip_auto_config() initcall times out
waiting for the network interfaces to show up when
deferred_probe_timeout was non-zero. While ip_auto_config() calls
wait_for_device_probe() to make sure any currently running deferred
probe work or asynchronous probe finishes, that wasn't sufficient to
account for devices being deferred until deferred_probe_timeout.
Commit 35a672363a ("driver core: Ensure wait_for_device_probe() waits
until the deferred_probe_timeout fires") tried to fix that by making
sure wait_for_device_probe() waits for deferred_probe_timeout to expire
before returning.
However, if wait_for_device_probe() is called from the kernel_init()
context:
- Before deferred_probe_initcall() [2], it causes the boot process to
hang due to a deadlock.
- After deferred_probe_initcall() [3], it blocks kernel_init() from
continuing till deferred_probe_timeout expires and beats the point of
deferred_probe_timeout that's trying to wait for userspace to load
modules.
Neither of this is good. So revert the changes to
wait_for_device_probe().
[1] - https://lore.kernel.org/lkml/TYAPR01MB45443DF63B9EF29054F7C41FD8C60@TYAPR01MB4544.jpnprd01.prod.outlook.com/
[2] - https://lore.kernel.org/lkml/YowHNo4sBjr9ijZr@dev-arch.thelio-3990X/
[3] - https://lore.kernel.org/lkml/Yo3WvGnNk3LvLb7R@linutronix.de/
Fixes: 35a672363a ("driver core: Ensure wait_for_device_probe() waits until the deferred_probe_timeout fires")
Cc: John Stultz <jstultz@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Cc: Basil Eljuse <Basil.Eljuse@arm.com>
Cc: Ferry Toth <fntoth@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Anders Roxell <anders.roxell@linaro.org>
Cc: linux-pm@vger.kernel.org
Reported-by: Nathan Chancellor <nathan@kernel.org>
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: John Stultz <jstultz@google.com>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20220526034609.480766-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Here is the set of driver core changes for 5.19-rc1.
Note, I'm not really happy with this pull request as-is, see below for
details, but overall this is all good for everything but a small set of
systems, which we have a fix for already.
Lots of tiny driver core changes and cleanups happened this cycle,
but the two major things were:
- firmware_loader reorganization and additions including the
ability to have XZ compressed firmware images and the ability
for userspace to initiate the firmware load when it needs to,
instead of being always initiated by the kernel. FPGA devices
specifically want this ability to have their firmware changed
over the lifetime of the system boot, and this allows them to
work without having to come up with yet-another-custom-uapi
interface for loading firmware for them.
- physical location support added to sysfs so that devices that
know this information, can tell userspace where they are
located in a common way. Some ACPI devices already support
this today, and more bus types should support this in the
future.
Smaller changes included:
- driver_override api cleanups and fixes
- error path cleanups and fixes
- get_abi script fixes
- deferred probe timeout changes.
It's that last change that I'm the most worried about. It has been
reported to cause boot problems for a number of systems, and I have a
tested patch series that resolves this issue. But I didn't get it
merged into my tree before 5.18-final came out, so it has not gotten any
linux-next testing.
I'll send the fixup patches (there are 2) as a follow-on series to this
pull request if you want to take them directly, _OR_ I can just revert
the probe timeout changes and they can wait for the next -rc1 merge
cycle. Given that the fixes are tested, and pretty simple, I'm leaning
toward that choice. Sorry this all came at the end of the merge window,
I should have resolved this all 2 weeks ago, that's my fault as it was
in the middle of some travel for me.
All have been tested in linux-next for weeks, with no reported issues
other than the above-mentioned boot time outs.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Here is the set of driver core changes for 5.19-rc1.
Lots of tiny driver core changes and cleanups happened this cycle, but
the two major things are:
- firmware_loader reorganization and additions including the ability
to have XZ compressed firmware images and the ability for userspace
to initiate the firmware load when it needs to, instead of being
always initiated by the kernel. FPGA devices specifically want this
ability to have their firmware changed over the lifetime of the
system boot, and this allows them to work without having to come up
with yet-another-custom-uapi interface for loading firmware for
them.
- physical location support added to sysfs so that devices that know
this information, can tell userspace where they are located in a
common way. Some ACPI devices already support this today, and more
bus types should support this in the future.
Smaller changes include:
- driver_override api cleanups and fixes
- error path cleanups and fixes
- get_abi script fixes
- deferred probe timeout changes.
It's that last change that I'm the most worried about. It has been
reported to cause boot problems for a number of systems, and I have a
tested patch series that resolves this issue. But I didn't get it
merged into my tree before 5.18-final came out, so it has not gotten
any linux-next testing.
I'll send the fixup patches (there are 2) as a follow-on series to this
pull request.
All have been tested in linux-next for weeks, with no reported issues
other than the above-mentioned boot time-outs"
* tag 'driver-core-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (55 commits)
driver core: fix deadlock in __device_attach
kernfs: Separate kernfs_pr_cont_buf and rename_lock.
topology: Remove unused cpu_cluster_mask()
driver core: Extend deferred probe timeout on driver registration
MAINTAINERS: add Russ Weight as a firmware loader maintainer
driver: base: fix UAF when driver_attach failed
test_firmware: fix end of loop test in upload_read_show()
driver core: location: Add "back" as a possible output for panel
driver core: location: Free struct acpi_pld_info *pld
driver core: Add "*" wildcard support to driver_async_probe cmdline param
driver core: location: Check for allocations failure
arch_topology: Trace the update thermal pressure
kernfs: Rename kernfs_put_open_node to kernfs_unlink_open_file.
export: fix string handling of namespace in EXPORT_SYMBOL_NS
rpmsg: use local 'dev' variable
rpmsg: Fix calling device_lock() on non-initialized device
firmware_loader: describe 'module' parameter of firmware_upload_register()
firmware_loader: Move definitions from sysfs_upload.h to sysfs.h
firmware_loader: Fix configs for sysfs split
selftests: firmware: Add firmware upload selftests
...
In __device_attach function, The lock holding logic is as follows:
...
__device_attach
device_lock(dev) // get lock dev
async_schedule_dev(__device_attach_async_helper, dev); // func
async_schedule_node
async_schedule_node_domain(func)
entry = kzalloc(sizeof(struct async_entry), GFP_ATOMIC);
/* when fail or work limit, sync to execute func, but
__device_attach_async_helper will get lock dev as
well, which will lead to A-A deadlock. */
if (!entry || atomic_read(&entry_count) > MAX_WORK) {
func;
else
queue_work_node(node, system_unbound_wq, &entry->work)
device_unlock(dev)
As shown above, when it is allowed to do async probes, because of
out of memory or work limit, async work is not allowed, to do
sync execute instead. it will lead to A-A deadlock because of
__device_attach_async_helper getting lock dev.
To fix the deadlock, move the async_schedule_dev outside device_lock,
as we can see, in async_schedule_node_domain, the parameter of
queue_work_node is system_unbound_wq, so it can accept concurrent
operations. which will also not change the code logic, and will
not lead to deadlock.
Fixes: 765230b5f0 ("driver-core: add asynchronous probing support for drivers")
Signed-off-by: Zhang Wensheng <zhangwensheng5@huawei.com>
Link: https://lore.kernel.org/r/20220518074516.1225580-1-zhangwensheng5@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The deferred probe timer that's used for this currently starts at
late_initcall and runs for driver_deferred_probe_timeout seconds. The
assumption being that all available drivers would be loaded and
registered before the timer expires. This means, the
driver_deferred_probe_timeout has to be pretty large for it to cover the
worst case. But if we set the default value for it to cover the worst
case, it would significantly slow down the average case. For this
reason, the default value is set to 0.
Also, with CONFIG_MODULES=y and the current default values of
driver_deferred_probe_timeout=0 and fw_devlink=on, devices with missing
drivers will cause their consumer devices to always defer their probes.
This is because device links created by fw_devlink defer the probe even
before the consumer driver's probe() is called.
Instead of a fixed timeout, if we extend an unexpired deferred probe
timer on every successful driver registration, with the expectation more
modules would be loaded in the near future, then the default value of
driver_deferred_probe_timeout only needs to be as long as the worst case
time difference between two consecutive module loads.
So let's implement that and set the default value to 10 seconds when
CONFIG_MODULES=y.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Rob Herring <robh@kernel.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Will Deacon <will@kernel.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Kevin Hilman <khilman@kernel.org>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Cc: linux-gpio@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: iommu@lists.linux-foundation.org
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20220429220933.1350374-1-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There's currently no way to use driver_async_probe kernel cmdline param
to enable default async probe for all drivers. So, add support for "*"
to match with all driver names. When "*" is used, all other drivers
listed in driver_async_probe are drivers that will NOT match the "*".
For example:
* driver_async_probe=drvA,drvB,drvC
drvA, drvB and drvC do asynchronous probing.
* driver_async_probe=*
All drivers do asynchronous probing except those that have set
PROBE_FORCE_SYNCHRONOUS flag.
* driver_async_probe=*,drvA,drvB,drvC
All drivers do asynchronous probing except drvA, drvB, drvC and those
that have set PROBE_FORCE_SYNCHRONOUS flag.
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Feng Tang <feng.tang@intel.com>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20220504005344.117803-1-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The bus_type structure defines dma_configure() callback for bus drivers
to configure DMA on the devices. This adds the paired dma_cleanup()
callback and calls it during driver unbinding so that bus drivers can do
some cleanup work.
One use case for this paired DMA callbacks is for the bus driver to check
for DMA ownership conflicts during driver binding, where multiple devices
belonging to a same IOMMU group (the minimum granularity of isolation and
protection) may be assigned to kernel drivers or user space respectively.
Without this change, for example, the vfio driver has to listen to a bus
BOUND_DRIVER event and then BUG_ON() in case of dma ownership conflict.
This leads to bad user experience since careless driver binding operation
may crash the system if the admin overlooks the group restriction. Aside
from bad design, this leads to a security problem as a root user, even with
lockdown=integrity, can force the kernel to BUG.
With this change, the bus driver could check and set the DMA ownership in
driver binding process and fail on ownership conflicts. The DMA ownership
should be released during driver unbinding.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20220418005000.897664-3-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
When there are 2 matched drivers for a device using
async probe mechanism, the dev->p->async_driver might
be overridden by the last attached driver.
So just skip the later one if the previous matched driver
was not handled by async thread yet.
Below is my use case which having this problem.
Make both driver mmcblk and mmc_test allow async probe,
the dev->p->async_driver will be overridden by the later driver
mmc_test and bind to the device then claim it for testing.
When it happen, mmcblk will never do probe again.
Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Link: https://lore.kernel.org/r/20220316074328.1801-1-mark-pk.tsai@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a driver for an interrupt controller is missing, of_irq_get()
returns -EPROBE_DEFER ad infinitum, causing
fwnode_mdiobus_phy_device_register(), and ultimately, the entire
of_mdiobus_register() call, to fail. In turn, any phy_connect() call
towards a PHY on this MDIO bus will also fail.
This is not what is expected to happen, because the PHY library falls
back to poll mode when of_irq_get() returns a hard error code, and the
MDIO bus, PHY and attached Ethernet controller work fine, albeit
suboptimally, when the PHY library polls for link status. However,
-EPROBE_DEFER has special handling given the assumption that at some
point probe deferral will stop, and the driver for the supplier will
kick in and create the IRQ domain.
Reasons for which the interrupt controller may be missing:
- It is not yet written. This may happen if a more recent DT blob (with
an interrupt-parent for the PHY) is used to boot an old kernel where
the driver didn't exist, and that kernel worked with the
vintage-correct DT blob using poll mode.
- It is compiled out. Behavior is the same as above.
- It is compiled as a module. The kernel will wait for a number of
seconds specified in the "deferred_probe_timeout" boot parameter for
user space to load the required module. The current default is 0,
which times out at the end of initcalls. It is possible that this
might cause regressions unless users adjust this boot parameter.
The proposed solution is to use the driver_deferred_probe_check_state()
helper function provided by the driver core, which gives up after some
-EPROBE_DEFER attempts, taking "deferred_probe_timeout" into consideration.
The return code is changed from -EPROBE_DEFER into -ENODEV or
-ETIMEDOUT, depending on whether the kernel is compiled with support for
modules or not.
Fixes: 66bdede495 ("of_mdio: Fix broken PHY IRQ in case of probe deferral")
Suggested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20220407165538.4084809-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The global variable driver_deferred_probe_enable has a default value of
false and does not need to be initialized to false.
Signed-off-by: lizhe <sensor1010@163.com>
Link: https://lore.kernel.org/r/20220309135418.31101-1-sensor1010@163.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When "driver_async_probe=nulltty" is used on the kernel boot command line,
it causes an Unknown parameter message and the string is added to init's
environment strings, polluting them.
Unknown kernel command line parameters "BOOT_IMAGE=/boot/bzImage-517rc6
driver_async_probe=nulltty", will be passed to user space.
Run /sbin/init as init process
with arguments:
/sbin/init
with environment:
HOME=/
TERM=linux
BOOT_IMAGE=/boot/bzImage-517rc6
driver_async_probe=nulltty
Change the return value of the __setup function to 1 to indicate
that the __setup option has been handled.
Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Fixes: 1ea61b68d0 ("async: Add cmdline option to specify drivers to be async probed")
Cc: Feng Tang <feng.tang@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Reviewed-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20220301041829.15137-1-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are 3 copies of the same device sysfs cleanup and drv/bus remove()
hooks used for probe failure, testing re-probing, and device unbinding.
Let's refactor the code to its own function.
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220223225257.1681968-3-robh@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are 3 copies of the same device cleanup code used for probe failure,
testing re-probing, and device unbinding. Changes to this code often miss
at least one of the copies of the code. See commits d0243bbd5d ("drivers
core: Free dma_range_map when driver probe failed") and d8f7a5484f
("driver core: Free DMA range map when device is released") for example.
Let's refactor the code to its own function.
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220223225257.1681968-2-robh@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If a driver cannot be bound to a device, the correct bus notifier order
should be:
- BUS_NOTIFY_BIND_DRIVER: driver is about to be bound
- BUS_NOTIFY_DRIVER_NOT_BOUND: driver failed to be bound
or no notifier if the failure happens before the actual binding.
The really_probe() notifies a BUS_NOTIFY_DRIVER_NOT_BOUND event without
a BUS_NOTIFY_BIND_DRIVER if .dma_configure() returns failure. This
change makes the notifiers in order.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20211231033901.2168664-3-baolu.lu@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver_sysfs_remove() should be called after driver_sysfs_add() in
really_probe(). The out-of-order driver_sysfs_remove() tries to remove
some nonexistent nodes under the device and driver sysfs nodes. This is
allowed, hence this change doesn't fix any problem, just a cleanup.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20211231033901.2168664-2-baolu.lu@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dma_range_map is freed to early, which might cause an oops when
a driver probe fails.
Call trace:
is_free_buddy_page+0xe4/0x1d4
__free_pages+0x2c/0x88
dma_free_contiguous+0x64/0x80
dma_direct_free+0x38/0xb4
dma_free_attrs+0x88/0xa0
dmam_release+0x28/0x34
release_nodes+0x78/0x8c
devres_release_all+0xa8/0x110
really_probe+0x118/0x2d0
__driver_probe_device+0xc8/0xe0
driver_probe_device+0x54/0xec
__driver_attach+0xe0/0xf0
bus_for_each_dev+0x7c/0xc8
driver_attach+0x30/0x3c
bus_add_driver+0x17c/0x1c4
driver_register+0xc0/0xf8
__platform_driver_register+0x34/0x40
...
This issue is introduced by commit d0243bbd5d ("drivers core:
Free dma_range_map when driver probe failed"). It frees
dma_range_map before the call to devres_release_all, which is too
early. The solution is to free dma_range_map only after
devres_release_all.
Fixes: d0243bbd5d ("drivers core: Free dma_range_map when driver probe failed")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Filip Schauer <filip@mg6.at>
Link: https://lore.kernel.org/r/20210727112311.GA7645@DESKTOP-E8BN1B0.localdomain
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the case of error handling, the error code returned by the subfunction
should be propagated instead of 0.
Fixes: 1901fb2604 ("Driver core: fix "driver" symlink timing")
Fixes: 23b6904442 ("driver core: add dev_groups to all drivers")
Fixes: 8fd456ec0c ("driver core: Add state_synced sysfs file for devices that support it")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Link: https://lore.kernel.org/r/20210707074301.2722-1-thunder.leizhen@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is intended as a replacement API for device_bind_driver(). It has at
least the following benefits:
- Internal locking. Few of the users of device_bind_driver() follow the
locking rules
- Calls device driver probe() internally. Notably this means that devm
support for probe works correctly as probe() error will call
devres_release_all()
- struct device_driver -> dev_groups is supported
- Simplified calling convention, no need to manually call probe().
The general usage is for situations that already know what driver to bind
and need to ensure the bind is synchronized with other logic. Call
device_driver_attach() after device_add().
If probe() returns a failure then this will be preserved up through to the
error return of device_driver_attach().
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20210617142218.1877096-6-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
EPROBE_DEFER is an internal kernel error code and it should not be leaked
to userspace via the bind_store() sysfs. Userspace doesn't have this
constant and cannot understand it.
Further, it doesn't really make sense to have userspace trigger a deferred
probe via bind_store(), which could eventually succeed, while
simultaneously returning an error back.
Resolve this by splitting driver_probe_device so that the version used
by the sysfs binding that turns EPROBE_DEFER into -EAGAIN, while the one
used for internally binding keeps the error code, and calls
driver_deferred_probe_add where needed. This also allows to nicely split
out the defer_all_probes / probe_count checks so that they actually allow
for full device_{block,unblock}_probing protection while not bothering
the sysfs bind case.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20210617142218.1877096-5-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Currently really_probe() returns 1 on success and 0 if the probe() call
fails. This return code arrangement is designed to be useful for
__device_attach_driver() which is walking the device list and trying every
driver. 0 means to keep trying.
However, it is not useful for the other places that call through to
really_probe() that do actually want to see the probe() return code.
For instance bind_store() would be better to return the actual error code
from the driver's probe method, not discarding it and returning -ENODEV.
Reorganize things so that really_probe() returns the error code from
->probe as a (inverted) positive number, and 0 for successful attach.
With this, __device_attach_driver can ignore the (positive) probe errors,
return 1 to exit the loop for a successful binding and pass on the
other negative errors, while device_driver_attach simplify inverts the
positive errors and returns all errors to the sysfs code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Link: https://lore.kernel.org/r/20210617142218.1877096-4-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
really_probe tries to special case errors from ->probe, but due to all
other initialization added to the function over time now a lot of
internal errors hit that code path as well. Untangle that by adding
a new probe_err local variable and apply the special casing only to
that.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Link: https://lore.kernel.org/r/20210617142218.1877096-3-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Checking if the dev is dead or if the dev is already bound is a required
precondition to invoking driver_probe_device(). All the call chains
leading here duplicate these checks.
Add it directly to driver_probe_device() so the precondition is clear and
remove the checks from device_driver_attach() and
__driver_attach_async_helper().
The other call chain going through __device_attach_driver() does have
these same checks but they are inlined into logic higher up the call stack
and can't be removed.
The sysfs uAPI call chain starting at bind_store() is a bit confused
because it reads dev->driver unlocked and returns -ENODEV if it is !NULL,
otherwise it reads it again under lock and returns 0 if it is !NULL. Fix
this to always return -EBUSY and always read dev->driver under its lock.
Done in preparation for the next patches which will add additional
callers to driver_probe_device() and will need these checks as well.
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
[hch: drop the extra checks in device_driver_attach and bind_store]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Link: https://lore.kernel.org/r/20210617142218.1877096-2-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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Merge tag 'v5.12-rc7' into driver-core-next
We need the driver core fix in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We now have three places within the same file doing the same operation
of freeing this pointer and setting it anew. A helper makes this
arguably easier to read, so add one.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.kernel.org/r/20210323153714.25120-2-a.fatoum@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
deferred_probe_timeout kernel commandline parameter allows probing of
consumer devices if the supplier devices don't have any drivers.
fw_devlink=on will indefintely block probe() calls on a device if all
its suppliers haven't probed successfully. This completely skips calls
to driver_deferred_probe_check_state() since that's only called when a
.probe() function calls framework APIs. So fw_devlink=on breaks
deferred_probe_timeout.
deferred_probe_timeout in its current state also ignores a lot of
information that's now available to the kernel. It assumes all suppliers
that haven't probed when the timer expires (or when initcalls are done
on a static kernel) will never probe and fails any calls to acquire
resources from these unprobed suppliers.
However, this assumption by deferred_probe_timeout isn't true under many
conditions. For example:
- If the consumer happens to be before the supplier in the deferred
probe list.
- If the supplier itself is waiting on its supplier to probe.
This patch fixes both these issues by relaxing device links between
devices only if the supplier doesn't have any driver that could match
with (NOT bound to) the supplier device. This way, we only fail attempts
to acquire resources from suppliers that truly don't have any driver vs
suppliers that just happen to not have probed yet.
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210402040342.2944858-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
list_for_each_entry_safe() is only useful if we are deleting nodes in a
linked list within the loop. It doesn't protect against other threads
adding/deleting nodes to the list in parallel. We need to grab
deferred_probe_mutex when traversing the deferred_probe_pending_list.
Cc: stable@vger.kernel.org
Fixes: 25b4e70dcc ("driver core: allow stopping deferred probe after init")
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210402040342.2944858-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
