linux-stable.git/drivers/base/driver.c, branch v4.14.331

driver: platform: Add helper for safer setting of driver_override

2023-11-08T10:21:07+00:00

commit 6c2f421174273de8f83cde4286d1c076d43a2d35 upstream.

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 [] (platform_device_release+0x88/0xb4)
    (platform_device_release) from [] (device_release+0x2c/0x90)
    (device_release) from [] (kobject_put+0xec/0x20c)
    (kobject_put) from [] (exynos5_clk_probe+0x154/0x18c)
    (exynos5_clk_probe) from [] (platform_drv_probe+0x6c/0xa4)
    (platform_drv_probe) from [] (really_probe+0x280/0x414)
    (really_probe) from [] (driver_probe_device+0x78/0x1c4)
    (driver_probe_device) from [] (bus_for_each_drv+0x74/0xb8)
    (bus_for_each_drv) from [] (__device_attach+0xd4/0x16c)
    (__device_attach) from [] (bus_probe_device+0x88/0x90)
    (bus_probe_device) from [] (device_add+0x3dc/0x62c)
    (device_add) from [] (of_platform_device_create_pdata+0x94/0xbc)
    (of_platform_device_create_pdata) from [] (of_platform_bus_create+0x1a8/0x4fc)
    (of_platform_bus_create) from [] (of_platform_bus_create+0x20c/0x4fc)
    (of_platform_bus_create) from [] (of_platform_populate+0x84/0x118)
    (of_platform_populate) from [] (of_platform_default_populate_init+0xa0/0xb8)
    (of_platform_default_populate_init) from [] (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 
Acked-by: Rafael J. Wysocki 
Signed-off-by: Krzysztof Kozlowski 
Link: https://lore.kernel.org/r/20220419113435.246203-2-krzysztof.kozlowski@linaro.org
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Lee Jones 
Signed-off-by: Greg Kroah-Hartman

driver core: add missing blank line after declaration

2015-03-25T13:36:30+00:00

Found using checkpatch.pl
Signed-off-by: Lavinia Tache 
Signed-off-by: Greg Kroah-Hartman

driver core: add #include to core files.

2013-08-27T17:24:15+00:00

This is needed to fix the build on sh systems.

Reported-by: kbuild test robot 
Signed-off-by: Greg Kroah-Hartman

sysfs: add sysfs_create/remove_groups()

2013-08-21T23:02:19+00:00

These functions are being open-coded in 3 different places in the driver
core, and other driver subsystems will want to start doing this as well,
so move it to the sysfs core to keep it all in one place, where we know
it is written properly.

Signed-off-by: Greg Kroah-Hartman

driver core: bus_type: add drv_groups

2013-08-12T22:33:31+00:00

attribute groups are much more flexible than just a list of attributes,
due to their support for visibility of the attributes, and binary
attributes. Add drv_groups to struct bus_type which should be used
instead of drv_attrs.

drv_attrs will be removed from the structure soon.

Signed-off-by: Greg Kroah-Hartman

driver core: don't trigger uevent after failure

2012-07-17T17:40:23+00:00

Do not send the uevent if driver_add_groups failed.

Reported-by: Ming Lei 
Signed-off-by: Sebastian Ott 
Signed-off-by: Greg Kroah-Hartman

driver core: move uevent call to driver_register

2012-07-17T01:04:25+00:00

Device driver attribute groups are created after userspace is notified
via an add event. Fix this by moving the kobject_uevent call to
driver_register after the attribute groups are added.

Signed-off-by: Sebastian Ott 
Signed-off-by: Greg Kroah-Hartman

Driver Core: don't oops with unregistered driver in driver_find_device()

2012-05-14T15:46:01+00:00

driver_find_device() can be called with an unregistered driver. Need
to check driver_private to see if it's populated or not, especially
under deferrable probe.

In the case that there are 2 drivers, one depends on the other. With
-EPROBE_DEFER, two drivers can use deferred probe to ensure that their
relative probe order doesn't matter. If dependee driver is probed
first, then the dependant's driver_find_device('dependee')
succeeds. If the dependant is probed first, then the dependant's
driver_find_device('dependee') should return NULL, and the dependant
should get -EPROBE_DEFER. driver_find_device() needs to return NULL if
it's not populated.

In [PATCHv5 2/3] ARM: tegra: Add SMMU enabler in AHB:
  http://article.gmane.org/gmane.linux.ports.tegra/4658

"tegra_ahb_driver" may not be populated when it's called.

For more SMMU/AHB specific discussion, refer to the following thread:
  https://lkml.org/lkml/2012/5/10/21

Signed-off-by: Hiroshi DOYU 
Cc: Stephen Warren 
Signed-off-by: Greg Kroah-Hartman

Revert "driver core: check start node in klist_iter_init_node"

2012-04-20T02:17:30+00:00

This reverts commit a15d49fd3094cff90e5410ca454a870e0a722fe1 as that
patch broke the build.

Cc: Hannes Reinecke 
Reported-by: Stephen Rothwell 
Signed-off-by: Greg Kroah-Hartman

driver core: check start node in klist_iter_init_node

2012-04-18T22:39:52+00:00

klist_iter_init_node() takes a node as a start argument.
However, this node might not be valid anymore.
This patch updates the klist_iter_init_node() and
dependent functions to return an error if so.
All calling functions have been audited to check
for a return code here.

Signed-off-by: Hannes Reinecke 
Cc: Greg Kroah-Hartmann 
Cc: Kay Sievers 
Cc: Stable Kernel 
Cc: Linux Kernel 
Signed-off-by: Greg Kroah-Hartman