linux.git/drivers/acpi/scan.c, branch v5.4.237

ACPI: scan: Create platform device for BCM4752 and LNV4752 ACPI nodes

2022-01-27T08:19:35+00:00

[ Upstream commit f85196bdd5a50da74670250564740fc852b3c239 ]

BCM4752 and LNV4752 ACPI nodes describe a Broadcom 4752 GPS module
attached to an UART of the system.

The GPS modules talk a custom protocol which only works with a closed-
source Android gpsd daemon which knows this protocol.

The ACPI nodes also describe GPIOs to turn the GPS on/off these are
handled by the net/rfkill/rfkill-gpio.c code. This handling predates the
addition of enumeration of ACPI instantiated serdevs to the kernel and
was broken by that addition, because the ACPI scan code now no longer
instantiates platform_device-s for these nodes.

Rename the i2c_multi_instantiate_ids HID list to ignore_serial_bus_ids
and add the BCM4752 and LNV4752 HIDs, so that rfkill-gpio gets
a platform_device to bind to again; and so that a tty cdev for gpsd
gets created for these.

Fixes: e361d1f85855 ("ACPI / scan: Fix enumeration for special UART devices")
Signed-off-by: Hans de Goede 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

ACPI: scan: Fix a memory leak in an error handling path

2021-05-19T08:08:30+00:00

[ Upstream commit 0c8bd174f0fc131bc9dfab35cd8784f59045da87 ]

If 'acpi_device_set_name()' fails, we must free
'acpi_device_bus_id->bus_id' or there is a (potential) memory leak.

Fixes: eb50aaf960e3 ("ACPI: scan: Use unique number for instance_no")
Signed-off-by: Christophe JAILLET 
Reviewed-by: Andy Shevchenko 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

ACPI: scan: Use unique number for instance_no

2021-03-30T12:35:28+00:00

[ Upstream commit eb50aaf960e3bedfef79063411ffd670da94b84b ]

The decrementation of acpi_device_bus_id->instance_no
in acpi_device_del() is incorrect, because it may cause
a duplicate instance number to be allocated next time
a device with the same acpi_device_bus_id is added.

Replace above mentioned approach by using IDA framework.

While at it, define the instance range to be [0, 4096).

Fixes: e49bd2dd5a50 ("ACPI: use PNPID:instance_no as bus_id of ACPI device")
Fixes: ca9dc8d42b30 ("ACPI / scan: Fix acpi_bus_id_list bookkeeping")
Signed-off-by: Andy Shevchenko 
Cc: 4.10+  # 4.10+
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

ACPI: scan: Rearrange memory allocation in acpi_device_add()

2021-03-30T12:35:28+00:00

[ Upstream commit c1013ff7a5472db637c56bb6237f8343398c03a7 ]

The upfront allocation of new_bus_id is done to avoid allocating
memory under acpi_device_lock, but it doesn't really help,
because (1) it leads to many unnecessary memory allocations for
_ADR devices, (2) kstrdup_const() is run under that lock anyway and
(3) it complicates the code.

Rearrange acpi_device_add() to allocate memory for a new struct
acpi_device_bus_id instance only when necessary, eliminate a redundant
local variable from it and reduce the number of labels in there.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Hans de Goede 
Signed-off-by: Sasha Levin

ACPI: scan: Make acpi_bus_get_device() clear return pointer on error

2021-01-27T10:47:40+00:00

commit 78a18fec5258c8df9435399a1ea022d73d3eceb9 upstream.

Set the acpi_device pointer which acpi_bus_get_device() returns-by-
reference to NULL on errors.

We've recently had 2 cases where callers of acpi_bus_get_device()
did not properly error check the return value, so set the returned-
by-reference acpi_device pointer to NULL, because at least some
callers of acpi_bus_get_device() expect that to be done on errors.

[ rjw: This issue was exposed by commit 71da201f38df ("ACPI: scan:
  Defer enumeration of devices with _DEP lists") which caused it to
  be much more likely to occur on some systems, but the real defect
  had been introduced by an earlier commit. ]

Fixes: 40e7fcb19293 ("ACPI: Add _DEP support to fix battery issue on Asus T100TA")
Fixes: bcfcd409d4db ("usb: split code locating ACPI companion into port and device")
Reported-by: Pierre-Louis Bossart 
Tested-by: Pierre-Louis Bossart 
Diagnosed-by: Rafael J. Wysocki 
Signed-off-by: Hans de Goede 
Cc: All applicable 
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

ACPI: scan: Harden acpi_device_add() against device ID overflows

2021-01-19T17:26:12+00:00

commit a58015d638cd4e4555297b04bec9b49028369075 upstream.

Linux VM on Hyper-V crashes with the latest mainline:

[    4.069624] detected buffer overflow in strcpy
[    4.077733] kernel BUG at lib/string.c:1149!
..
[    4.085819] RIP: 0010:fortify_panic+0xf/0x11
...
[    4.085819] Call Trace:
[    4.085819]  acpi_device_add.cold.15+0xf2/0xfb
[    4.085819]  acpi_add_single_object+0x2a6/0x690
[    4.085819]  acpi_bus_check_add+0xc6/0x280
[    4.085819]  acpi_ns_walk_namespace+0xda/0x1aa
[    4.085819]  acpi_walk_namespace+0x9a/0xc2
[    4.085819]  acpi_bus_scan+0x78/0x90
[    4.085819]  acpi_scan_init+0xfa/0x248
[    4.085819]  acpi_init+0x2c1/0x321
[    4.085819]  do_one_initcall+0x44/0x1d0
[    4.085819]  kernel_init_freeable+0x1ab/0x1f4

This is because of the recent buffer overflow detection in the
commit 6a39e62abbaf ("lib: string.h: detect intra-object overflow in
fortified string functions")

Here acpi_device_bus_id->bus_id can only hold 14 characters, while the
the acpi_device_hid(device) returns a 22-char string
"HYPER_V_GEN_COUNTER_V1".

Per ACPI Spec v6.2, Section 6.1.5 _HID (Hardware ID), if the ID is a
string, it must be of the form AAA#### or NNNN####, i.e. 7 chars or 8
chars.

The field bus_id in struct acpi_device_bus_id was originally defined as
char bus_id[9], and later was enlarged to char bus_id[15] in 2007 in the
commit bb0958544f3c ("ACPI: use more understandable bus_id for ACPI
devices")

Fix the issue by changing the field bus_id to const char *, and use
kstrdup_const() to initialize it.

Signed-off-by: Dexuan Cui 
Tested-By: Jethro Beekman 
[ rjw: Subject change, whitespace adjustment ]
Cc: All applicable 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

ACPI: PM: Avoid using power resources if there are none for D0

2020-06-17T14:40:28+00:00

commit 956ad9d98b73f59e442cc119c98ba1e04e94fe6d upstream.

As recently reported, some platforms provide a list of power
resources for device power state D3hot, through the _PR3 object,
but they do not provide a list of power resources for device power
state D0.

Among other things, this causes acpi_device_get_power() to return
D3hot as the current state of the device in question if all of the
D3hot power resources are "on", because it sees the power_resources
flag set and calls acpi_power_get_inferred_state() which finds that
D3hot is the shallowest power state with all of the associated power
resources turned "on", so that's what it returns.  Moreover, that
value takes precedence over the acpi_dev_pm_explicit_get() return
value, because it means a deeper power state.  The device may very
well be in D0 physically at that point, however.

Moreover, the presence of _PR3 without _PR0 for a given device
means that only one D3-level power state can be supported by it.
Namely, because there are no power resources to turn "off" when
transitioning the device from D0 into D3cold (which should be
supported since _PR3 is present), the evaluation of _PS3 should
be sufficient to put it straight into D3cold, but this means that
the effect of turning "on" the _PR3 power resources is unclear,
so it is better to avoid doing that altogether.  Consequently,
there is no practical way do distinguish D3cold from D3hot for
the device in question and the power states of it can be labeled
so that D3hot is the deepest supported one (and Linux assumes
that putting a device into D3hot via ACPI may cause power to be
removed from it anyway, for legacy reasons).

To work around the problem described above modify the ACPI
enumeration of devices so that power resources are only used
for device power management if the list of D0 power resources
is not empty and make it mart D3cold as supported only if that
is the case and the D3hot list of power resources is not empty
too.

Fixes: ef85bdbec444 ("ACPI / scan: Consolidate extraction of power resources lists")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=205057
Link: https://lore.kernel.org/linux-acpi/20200603194659.185757-1-hdegoede@redhat.com/
Reported-by: Hans de Goede 
Tested-by: Hans de Goede 
Tested-by: youling257@gmail.com
Cc: 3.10+  # 3.10+
Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Hans de Goede 
Signed-off-by: Greg Kroah-Hartman

ACPI: platform: Unregister stale platform devices

2020-01-26T09:01:04+00:00

[ Upstream commit cb0701acfa7e3fe9e919cf2aa2aa939b7fd603c2 ]

When commit 68bdb6773289 ("ACPI: add support for ACPI reconfiguration
notifiers") introduced reconfiguration notifiers, it missed the point
that the ACPI table, which might be loaded and then unloaded via
ConfigFS, could contain devices that were not enumerated by their
parents.

In such cases, the stale platform device is dangling in the system
while the rest of the devices from the same table are already gone.

Introduce acpi_platform_device_remove_notify() notifier that, in
similar way to I²C or SPI buses, unregisters the platform devices
on table removal event.

Fixes: 68bdb6773289 ("ACPI: add support for ACPI reconfiguration notifiers")
Depends-on: 00500147cbd3 ("drivers: Introduce device lookup variants by ACPI_COMPANION device")
Signed-off-by: Andy Shevchenko 
[ rjw: Changelog & function rename ]
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

drivers/acpi/scan.c: document why we don't need the device_hotplug_lock

2019-08-03T14:02:01+00:00

Let's document why the lock is not needed in acpi_scan_init(), right now
this is not really obvious.

[akpm@linux-foundation.org: fix tpyo]
Link: http://lkml.kernel.org/r/20190731135306.31524-1-david@redhat.com
Signed-off-by: David Hildenbrand 
Acked-by: Michal Hocko 
Acked-by: Rafael J. Wysocki 
Cc: Oscar Salvador 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

treewide: Add SPDX license identifier for missed files

2019-05-21T08:50:45+00:00

Add SPDX license identifiers to all files which:

 - Have no license information of any form

 - Have EXPORT_.*_SYMBOL_GPL inside which was used in the
   initial scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman