platform/x86: make fw_attr_class constant

Since commit 43a7206b0963 ("driver core: class: make class_register() take
a const *"), the driver core allows for struct class to be in read-only
memory, so move the fw_attr_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at boot time.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: "Ricardo B. Marliere" <ricardo@marliere.net>
Link: https://lore.kernel.org/r/20240305-class_cleanup-platform-v1-1-9085c97b9355@marliere.net
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: hp-bioscfg: Remove unused obj in hp_add_other_attributes()

acpi_object *obj is unused in this function, so delete it, also
delete a unnecessary kfree(obj);

Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20231113200742.3593548-4-harshit.m.mogalapalli@oracle.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: hp-bioscfg: Fix error handling in hp_add_other_attributes()

'attr_name_kobj' is allocated using kzalloc, but on all the error paths
it is not freed, hence we have a memory leak.

Fix the error path before kobject_init_and_add() by adding kfree().

kobject_put() must be always called after passing the object to
kobject_init_and_add(). Only the error path which is immediately next
to kobject_init_and_add() calls kobject_put() and not any other error
path after it.

Fix the error handling after kobject_init_and_add() by moving the
kobject_put() into the goto label err_other_attr_init that is already
used by all the error paths after kobject_init_and_add().

Fixes: a34fc329b189 ("platform/x86: hp-bioscfg: bioscfg")
Cc: stable@vger.kernel.org # 6.6.x: c5dbf0416000: platform/x86: hp-bioscfg: Simplify return check in hp_add_other_attributes()
Cc: stable@vger.kernel.org # 6.6.x: 5736aa9537c9: platform/x86: hp-bioscfg: move mutex_lock() down in hp_add_other_attributes()
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Closes: https://lore.kernel.org/r/202309201412.on0VXJGo-lkp@intel.com/
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
[ij: Added the stable dep tags]
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20231113200742.3593548-3-harshit.m.mogalapalli@oracle.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: hp-bioscfg: move mutex_lock() down in hp_add_other_attributes()

attr_name_kobj's memory allocation is done with mutex_lock() held, this
is not needed.

Move allocation outside of mutex_lock() so unlock is not needed when
allocation fails.

Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20231113200742.3593548-2-harshit.m.mogalapalli@oracle.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: hp-bioscfg: Simplify return check in hp_add_other_attributes()

All cases in switch-case have a same goto on error, move the return
check out of the switch. This is a cleanup.

Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20231113200742.3593548-1-harshit.m.mogalapalli@oracle.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: hp-bioscfg: Fix reference leak

If a duplicate attribute is found using kset_find_obj(), a reference
to that attribute is returned which needs to be disposed accordingly
using kobject_put(). Use kobject_put() to dispose the duplicate
attribute in such a case.
As a side note, a very similar bug was fixed in
commit 7295a996fdab ("platform/x86: dell-sysman: Fix reference leak"),
so it seems that the bug was copied from that driver.

Compile-tested only.

Fixes: a34fc329b189 ("platform/x86: hp-bioscfg: bioscfg")
Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Reviewed-by: Jorge Lopez <jorge.lopez2@hp.com>
Link: https://lore.kernel.org/r/20230925142819.74525-3-W_Armin@gmx.de
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: hp-bioscfg: fix error reporting in hp_add_other_attributes()

Return a negative error code instead of returning success.

Fixes: a34fc329b189 ("platform/x86: hp-bioscfg: bioscfg")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/138641cc-52c0-41a5-8176-ad01c7e28c67@moroto.mountain
Reviewed-by: Jorge Lopez <jorge.lopez2@hp.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: hp-bioscfg: prevent a small buffer overflow

This function escapes certain special characters like \n. So if the
last character in the string is a '\n' then it gets changed into two
characters '\' and '\n'. But maybe we only have space for the '\' so
we need to check for that.

The "conv_dst_size" variable is always less than or to equal the "size"
variable. It's easier to just check "conv_dst_size" instead of checking
both.

Fixes: a34fc329b189 ("platform/x86: hp-bioscfg: bioscfg")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/b4950310-e65f-412f-8d2b-90bb074a6572@moroto.mountain
Reviewed-by: Jorge Lopez <jorge.lopez2@hp.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: hp-bioscfg: bioscfg

Add common functions support to hp-bioscfg.

HP BIOS Configuration driver purpose is to provide a driver supporting
the latest sysfs class firmware attributes framework allowing the user
to change BIOS settings and security solutions on HP Inc.’s commercial
notebooks.

Signed-off-by: Jorge Lopez <jorge.lopez2@hp.com>
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/r/20230608163319.18934-4-jorge.lopez2@hp.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>