In the match() callback, the struct device_driver * should not be
changed, so change the function callback to be a const *. This is one
step of many towards making the driver core safe to have struct
device_driver in read-only memory.
Because the match() callback is in all busses, all busses are modified
to handle this properly. This does entail switching some container_of()
calls to container_of_const() to properly handle the constant *.
For some busses, like PCI and USB and HV, the const * is cast away in
the match callback as those busses do want to modify those structures at
this point in time (they have a local lock in the driver structure.)
That will have to be changed in the future if they wish to have their
struct device * in read-only-memory.
Cc: Rafael J. Wysocki <rafael@kernel.org>
Reviewed-by: Alex Elder <elder@kernel.org>
Acked-by: Sumit Garg <sumit.garg@linaro.org>
Link: https://lore.kernel.org/r/2024070136-wrongdoer-busily-01e8@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
struct platform_driver::remove returning an integer made driver authors
expect that returning an error code was proper error handling. However
the driver core ignores the error and continues to remove the device
because there is nothing the core could do anyhow and reentering the
remove callback again is only calling for trouble.
To prevent such wrong assumptions, change the return type of the remove
callback to void. This was prepared by introducing an alternative remove
callback returning void and converting all drivers to that. So .remove()
can be changed without further changes in drivers.
This corresponds to step b) of the plan outlined in commit
5c5a7680e6 ("platform: Provide a remove callback that returns no value").
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
There's no reason the generic platform bus code needs to call
of_platform_register_reconfig_notifier(). The notifier can be setup
before the platform bus is. Let's move it into of_core_init() which is
called just before platform_bus_init() instead to keep more of the DT
bits in the DT code.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20230717143718.1715773-1-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
__platform_driver_probe() pokes around in some bus and driver private
lists and locks in a way that is not needed at all. The code only wants
to know if a device was bound to the driver that was registered, so walk
all devices on the bus to see if there was a match. If there is not a
match, return an error. This is the same logic as was originally
present, but just done in a simpler and more obvious way that is not a
layering violation.
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230131082459.301603-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
struct platform_driver::remove returning an integer made driver authors
expect that returning an error code was proper error handling. However
the driver core ignores the error and continues to remove the device
because there is nothing the core could do anyhow and reentering the
remove callback again is only calling for trouble.
So this is an source for errors typically yielding resource leaks in the
error path.
As there are too many platform drivers to neatly convert them all to
return void in a single go, do it in several steps after this patch:
a) Convert all drivers to implement .remove_new() returning void instead
of .remove() returning int;
b) Change struct platform_driver::remove() to return void and so make
it identical to .remove_new();
c) Change all drivers back to .remove() now with the better prototype;
d) drop struct platform_driver::remove_new().
While this touches all drivers eventually twice, steps a) and c) can be
done one driver after another and so reduces coordination efforts
immensely and simplifies review.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20221209150914.3557650-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Not only platform devices described by OF have named interrupts, but
devices described by ACPI also have named interrupts. The fwnode is an
abstraction to different standards, and using fwnode_irq_get_byname can
support more devices.
Signed-off-by: Soha Jin <soha@lohu.info>
Tested-by: Wende Tan <twd2.me@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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
...
The devices on platform/amba/fsl-mc/PCI buses could be bound to drivers
with the device DMA managed by kernel drivers or user-space applications.
Unfortunately, multiple devices may be placed in the same IOMMU group
because they cannot be isolated from each other. The DMA on these devices
must either be entirely under kernel control or userspace control, never
a mixture. Otherwise the driver integrity is not guaranteed because they
could access each other through the peer-to-peer accesses which by-pass
the IOMMU protection.
This checks and sets the default DMA mode during driver binding, and
cleanups during driver unbinding. In the default mode, the device DMA is
managed by the device driver which handles DMA operations through the
kernel DMA APIs (see Documentation/core-api/dma-api.rst).
For cases where the devices are assigned for userspace control through the
userspace driver framework(i.e. VFIO), the drivers(for example, vfio_pci/
vfio_platfrom etc.) may set a new flag (driver_managed_dma) to skip this
default setting in the assumption that the drivers know what they are
doing with the device DMA.
Calling iommu_device_use_default_domain() before {of,acpi}_dma_configure
is currently a problem. As things stand, the IOMMU driver ignored the
initial iommu_probe_device() call when the device was added, since at
that point it had no fwspec yet. In this situation,
{of,acpi}_iommu_configure() are retriggering iommu_probe_device() after
the IOMMU driver has seen the firmware data via .of_xlate to learn that
it actually responsible for the given device. As the result, before
that gets fixed, iommu_use_default_domain() goes at the end, and calls
arch_teardown_dma_ops() if it fails.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Stuart Yoder <stuyoder@gmail.com>
Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com>
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>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20220418005000.897664-5-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
The commit a85a6c86c2 ("driver core: platform: Clarify that IRQ 0 is
invalid") only calls WARN() when IRQ0 is about to be returned, however
using IRQ0 is considered invalid (according to Linus) outside the arch/
code where it's used by the i8253 drivers. Many driver subsystems treat
0 specially (e.g. as an indication of the polling mode by libata), so
the users of platform_get_irq[_byname]() in them would have to filter
out IRQ0 explicitly and this (quite obviously) doesn't scale...
Let's finally get this straight and return -EINVAL instead of IRQ0!
Fixes: a85a6c86c2 ("driver core: platform: Clarify that IRQ 0 is invalid")
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Link: https://lore.kernel.org/r/025679e1-1f0a-ae4b-4369-01164f691511@omp.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Several core drivers and buses expect that driver_override is a
dynamically allocated memory thus later they can kfree() it.
However such assumption is not documented, there were in the past and
there are already users setting it to a string literal. This leads to
kfree() of static memory during device release (e.g. in error paths or
during unbind):
kernel BUG at ../mm/slub.c:3960!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM
...
(kfree) from [<c058da50>] (platform_device_release+0x88/0xb4)
(platform_device_release) from [<c0585be0>] (device_release+0x2c/0x90)
(device_release) from [<c0a69050>] (kobject_put+0xec/0x20c)
(kobject_put) from [<c0f2f120>] (exynos5_clk_probe+0x154/0x18c)
(exynos5_clk_probe) from [<c058de70>] (platform_drv_probe+0x6c/0xa4)
(platform_drv_probe) from [<c058b7ac>] (really_probe+0x280/0x414)
(really_probe) from [<c058baf4>] (driver_probe_device+0x78/0x1c4)
(driver_probe_device) from [<c0589854>] (bus_for_each_drv+0x74/0xb8)
(bus_for_each_drv) from [<c058b48c>] (__device_attach+0xd4/0x16c)
(__device_attach) from [<c058a638>] (bus_probe_device+0x88/0x90)
(bus_probe_device) from [<c05871fc>] (device_add+0x3dc/0x62c)
(device_add) from [<c075ff10>] (of_platform_device_create_pdata+0x94/0xbc)
(of_platform_device_create_pdata) from [<c07600ec>] (of_platform_bus_create+0x1a8/0x4fc)
(of_platform_bus_create) from [<c0760150>] (of_platform_bus_create+0x20c/0x4fc)
(of_platform_bus_create) from [<c07605f0>] (of_platform_populate+0x84/0x118)
(of_platform_populate) from [<c0f3c964>] (of_platform_default_populate_init+0xa0/0xb8)
(of_platform_default_populate_init) from [<c01031f8>] (do_one_initcall+0x8c/0x404)
Provide a helper which clearly documents the usage of driver_override.
This will allow later to reuse the helper and reduce the amount of
duplicated code.
Convert the platform driver to use a new helper and make the
driver_override field const char (it is not modified by the core).
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220419113435.246203-2-krzysztof.kozlowski@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
