linux-stable.git/drivers/acpi/device_sysfs.c, branch linux-5.4.y Linux kernel stable tree ACPI: sysfs: validate return type of _STR method 2024-11-08T15:20:34+00:00 Thomas Weißschuh linux@weissschuh.net 2024-07-09T20:37:24+00:00 2364b6af90c6b6d8a4783e0d3481ca80af699554 commit 4bb1e7d027413835b086aed35bc3f0713bc0f72b upstream. Only buffer objects are valid return values of _STR. If something else is returned description_show() will access invalid memory. Fixes: d1efe3c324ea ("ACPI: Add new sysfs interface to export device description") Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Link: https://patch.msgid.link/20240709-acpi-sysfs-groups-v2-1-058ab0667fa8@weissschuh.net Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 4bb1e7d027413835b086aed35bc3f0713bc0f72b upstream.

Only buffer objects are valid return values of _STR.

If something else is returned description_show() will access invalid
memory.

Fixes: d1efe3c324ea ("ACPI: Add new sysfs interface to export device description")
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20240709-acpi-sysfs-groups-v2-1-058ab0667fa8@weissschuh.net
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ACPI: sysfs: Fix create_pnp_modalias() and create_of_modalias() 2023-11-20T09:30:10+00:00 Christophe JAILLET christophe.jaillet@wanadoo.fr 2023-10-23T18:32:54+00:00 19d527337870c93c9761e770a9b576815f79ec7e [ Upstream commit 48cf49d31994ff97b33c4044e618560ec84d35fb ] snprintf() does not return negative values on error. To know if the buffer was too small, the returned value needs to be compared with the length of the passed buffer. If it is greater or equal, the output has been truncated, so add checks for the truncation to create_pnp_modalias() and create_of_modalias(). Also make them return -ENOMEM in that case, as they already do that elsewhere. Moreover, the remaining size of the buffer used by snprintf() needs to be updated after the first write to avoid out-of-bounds access as already done correctly in create_pnp_modalias(), but not in create_of_modalias(), so change the latter accordingly. Fixes: 8765c5ba1949 ("ACPI / scan: Rework modalias creation when "compatible" is present") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> [ rjw: Merge two patches into one, combine changelogs, add subject ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 48cf49d31994ff97b33c4044e618560ec84d35fb ]

snprintf() does not return negative values on error.

To know if the buffer was too small, the returned value needs to be
compared with the length of the passed buffer. If it is greater or
equal, the output has been truncated, so add checks for the truncation
to create_pnp_modalias() and create_of_modalias(). Also make them
return -ENOMEM in that case, as they already do that elsewhere.

Moreover, the remaining size of the buffer used by snprintf() needs to
be updated after the first write to avoid out-of-bounds access as
already done correctly in create_pnp_modalias(), but not in
create_of_modalias(), so change the latter accordingly.

Fixes: 8765c5ba1949 ("ACPI / scan: Rework modalias creation when "compatible" is present")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
[ rjw: Merge two patches into one, combine changelogs, add subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ACPI: Use DEVICE_ATTR_<RW|RO|WO> macros 2021-07-14T14:53:25+00:00 Dwaipayan Ray dwaipayanray1@gmail.com 2020-12-17T12:45:36+00:00 6d79e36c9ecea6cb60a45d7f3ab2b37f0c53b227 [ Upstream commit 0f39ee8324e75c9d370e84a61323ceb194641a18 ] Instead of open coding DEVICE_ATTR(), use the DEVICE_ATTR_RW(), DEVICE_ATTR_RO() and DEVICE_ATTR_WO() macros wherever possible. This required a few functions to be renamed but the functionality itself is unchanged. Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 0f39ee8324e75c9d370e84a61323ceb194641a18 ]

Instead of open coding DEVICE_ATTR(), use the
DEVICE_ATTR_RW(), DEVICE_ATTR_RO() and DEVICE_ATTR_WO()
macros wherever possible.

This required a few functions to be renamed but the
functionality itself is unchanged.

Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ACPI: sysfs: Fix a buffer overrun problem with description_show() 2021-07-14T14:53:24+00:00 Krzysztof Wilczyński kw@linux.com 2021-06-03T17:12:01+00:00 258f5c1a5d3d0fb430504950ae25fe52780c50e3 [ Upstream commit 888be6067b97132c3992866bbcf647572253ab3f ] Currently, a device description can be obtained using ACPI, if the _STR method exists for a particular device, and then exposed to the userspace via a sysfs object as a string value. If the _STR method is available for a given device then the data (usually a Unicode string) is read and stored in a buffer (of the ACPI_TYPE_BUFFER type) with a pointer to said buffer cached in the struct acpi_device_pnp for later access. The description_show() function is responsible for exposing the device description to the userspace via a corresponding sysfs object and internally calls the utf16s_to_utf8s() function with a pointer to the buffer that contains the Unicode string so that it can be converted from UTF16 encoding to UTF8 and thus allowing for the value to be safely stored and later displayed. When invoking the utf16s_to_utf8s() function, the description_show() function also sets a limit of the data that can be saved into a provided buffer as a result of the character conversion to be a total of PAGE_SIZE, and upon completion, the utf16s_to_utf8s() function returns an integer value denoting the number of bytes that have been written into the provided buffer. Following the execution of the utf16s_to_utf8s() a newline character will be added at the end of the resulting buffer so that when the value is read in the userspace through the sysfs object then it would include newline making it more accessible when working with the sysfs file system in the shell, etc. Normally, this wouldn't be a problem, but if the function utf16s_to_utf8s() happens to return the number of bytes written to be precisely PAGE_SIZE, then we would overrun the buffer and write the newline character outside the allotted space which can have undefined consequences or result in a failure. To fix this buffer overrun, ensure that there always is enough space left for the newline character to be safely appended. Fixes: d1efe3c324ea ("ACPI: Add new sysfs interface to export device description") Signed-off-by: Krzysztof Wilczyński <kw@linux.com> Reviewed-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 888be6067b97132c3992866bbcf647572253ab3f ]

Currently, a device description can be obtained using ACPI, if the _STR
method exists for a particular device, and then exposed to the userspace
via a sysfs object as a string value.

If the _STR method is available for a given device then the data
(usually a Unicode string) is read and stored in a buffer (of the
ACPI_TYPE_BUFFER type) with a pointer to said buffer cached in the
struct acpi_device_pnp for later access.

The description_show() function is responsible for exposing the device
description to the userspace via a corresponding sysfs object and
internally calls the utf16s_to_utf8s() function with a pointer to the
buffer that contains the Unicode string so that it can be converted from
UTF16 encoding to UTF8 and thus allowing for the value to be safely
stored and later displayed.

When invoking the utf16s_to_utf8s() function, the description_show()
function also sets a limit of the data that can be saved into a provided
buffer as a result of the character conversion to be a total of
PAGE_SIZE, and upon completion, the utf16s_to_utf8s() function returns
an integer value denoting the number of bytes that have been written
into the provided buffer.

Following the execution of the utf16s_to_utf8s() a newline character
will be added at the end of the resulting buffer so that when the value
is read in the userspace through the sysfs object then it would include
newline making it more accessible when working with the sysfs file
system in the shell, etc.  Normally, this wouldn't be a problem, but if
the function utf16s_to_utf8s() happens to return the number of bytes
written to be precisely PAGE_SIZE, then we would overrun the buffer and
write the newline character outside the allotted space which can have
undefined consequences or result in a failure.

To fix this buffer overrun, ensure that there always is enough space
left for the newline character to be safely appended.

Fixes: d1efe3c324ea ("ACPI: Add new sysfs interface to export device description")
Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ACPI: sysfs: Prefer "compatible" modalias 2021-02-03T22:25:56+00:00 Kai-Heng Feng kai.heng.feng@canonical.com 2021-01-22T12:53:02+00:00 93603a27fc31f3161bfe30c867c07b407e187e35 commit 36af2d5c4433fb40ee2af912c4ac0a30991aecfc upstream. Commit 8765c5ba1949 ("ACPI / scan: Rework modalias creation when "compatible" is present") may create two "MODALIAS=" in one uevent file if specific conditions are met. This breaks systemd-udevd, which assumes each "key" in one uevent file to be unique. The internal implementation of systemd-udevd overwrites the first MODALIAS with the second one, so its kmod rule doesn't load the driver for the first MODALIAS. So if both the ACPI modalias and the OF modalias are present, use the latter to ensure that there will be only one MODALIAS. Link: https://github.com/systemd/systemd/pull/18163 Suggested-by: Mika Westerberg <mika.westerberg@linux.intel.com> Fixes: 8765c5ba1949 ("ACPI / scan: Rework modalias creation when "compatible" is present") Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: 4.1+ <stable@vger.kernel.org> # 4.1+ [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 36af2d5c4433fb40ee2af912c4ac0a30991aecfc upstream.

Commit 8765c5ba1949 ("ACPI / scan: Rework modalias creation when
"compatible" is present") may create two "MODALIAS=" in one uevent
file if specific conditions are met.

This breaks systemd-udevd, which assumes each "key" in one uevent file
to be unique. The internal implementation of systemd-udevd overwrites
the first MODALIAS with the second one, so its kmod rule doesn't load
the driver for the first MODALIAS.

So if both the ACPI modalias and the OF modalias are present, use the
latter to ensure that there will be only one MODALIAS.

Link: https://github.com/systemd/systemd/pull/18163
Suggested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Fixes: 8765c5ba1949 ("ACPI / scan: Rework modalias creation when "compatible" is present")
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: 4.1+ <stable@vger.kernel.org> # 4.1+
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30T18:26:41+00:00 Thomas Gleixner tglx@linutronix.de 2019-05-27T06:55:21+00:00 1802d0beecafe581ad584634ba92f8a471d8a63a Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 655 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 655 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ACPI: bus: change _ADR representation to 64 bits 2019-05-10T10:30:45+00:00 Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com 2019-05-01T12:53:22+00:00 ca6f998cf9a259fe6019d44768064e0cfe8a925b Standards such as the MIPI DisCo for SoundWire 1.0 specification assume the _ADR field is 64 bits. _ADR is defined as an "Integer" represented as 64 bits since ACPI 2.0 released in 2002. The low levels already use _ADR as 64 bits, e.g. in struct acpi_device_info. This patch bumps the representation used for sysfs to 64 bits. To avoid any compatibility/ABI issues, the printf format is only extended to 16 characters when the actual _ADR value exceeds the 32 bit maximum. Example with a SoundWire device, the results show the complete vendorID and linkID which were omitted before: Before: $ more /sys/bus/acpi/devices/device\:38/adr 0x5d070000 After: $ more /sys/bus/acpi/devices/device\:38/adr 0x000010025d070000 Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> [ rjw: Replace 0xFFFFFFFF with U32_MAX, clean up subject ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Standards such as the MIPI DisCo for SoundWire 1.0 specification
assume the _ADR field is 64 bits.

_ADR is defined as an "Integer" represented as 64 bits since ACPI 2.0
released in 2002. The low levels already use _ADR as 64 bits, e.g. in
struct acpi_device_info.

This patch bumps the representation used for sysfs to 64 bits. To
avoid any compatibility/ABI issues, the printf format is only extended
to 16 characters when the actual _ADR value exceeds the 32 bit
maximum.

Example with a SoundWire device, the results show the complete
vendorID and linkID which were omitted before:

Before:
$ more /sys/bus/acpi/devices/device\:38/adr
0x5d070000
After:
$ more /sys/bus/acpi/devices/device\:38/adr
0x000010025d070000

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
[ rjw: Replace 0xFFFFFFFF with U32_MAX, clean up subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI / device_sysfs: Avoid OF modalias creation for removed device 2019-03-12T08:56:18+00:00 Andy Shevchenko andriy.shevchenko@linux.intel.com 2019-03-11T16:41:03+00:00 f16eb8a4b096514ac06fb25bf599dcc792899b3d If SSDT overlay is loaded via ConfigFS and then unloaded the device, we would like to have OF modalias for, already gone. Thus, acpi_get_name() returns no allocated buffer for such case and kernel crashes afterwards: ACPI: Host-directed Dynamic ACPI Table Unload ads7950 spi-PRP0001:00: Dropping the link to regulator.0 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 #PF error: [normal kernel read fault] PGD 80000000070d6067 P4D 80000000070d6067 PUD 70d0067 PMD 0 Oops: 0000 [#1] SMP PTI CPU: 0 PID: 40 Comm: kworker/u4:2 Not tainted 5.0.0+ #96 Hardware name: Intel Corporation Merrifield/BODEGA BAY, BIOS 542 2015.01.21:18.19.48 Workqueue: kacpi_hotplug acpi_device_del_work_fn RIP: 0010:create_of_modalias.isra.1+0x4c/0x150 Code: 00 00 48 89 44 24 18 31 c0 48 8d 54 24 08 48 c7 44 24 10 00 00 00 00 48 c7 44 24 08 ff ff ff ff e8 7a b0 03 00 48 8b 4c 24 10 <0f> b6 01 84 c0 74 27 48 c7 c7 00 09 f4 a5 0f b6 f0 8d 50 20 f6 04 RSP: 0000:ffffa51040297c10 EFLAGS: 00010246 RAX: 0000000000001001 RBX: 0000000000000785 RCX: 0000000000000000 RDX: 0000000000001001 RSI: 0000000000000286 RDI: ffffa2163dc042e0 RBP: ffffa216062b1196 R08: 0000000000001001 R09: ffffa21639873000 R10: ffffffffa606761d R11: 0000000000000001 R12: ffffa21639873218 R13: ffffa2163deb5060 R14: ffffa216063d1010 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffffa2163e000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000007114000 CR4: 00000000001006f0 Call Trace: __acpi_device_uevent_modalias+0xb0/0x100 spi_uevent+0xd/0x40 ... In order to fix above let create_of_modalias() check the status returned by acpi_get_name() and bail out in case of failure. Fixes: 8765c5ba1949 ("ACPI / scan: Rework modalias creation when "compatible" is present") Link: https://bugzilla.kernel.org/show_bug.cgi?id=201381 Reported-by: Ferry Toth <fntoth@gmail.com> Tested-by: Ferry Toth<fntoth@gmail.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Cc: 4.1+ <stable@vger.kernel.org> # 4.1+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
If SSDT overlay is loaded via ConfigFS and then unloaded the device,
we would like to have OF modalias for, already gone. Thus, acpi_get_name()
returns no allocated buffer for such case and kernel crashes afterwards:

 ACPI: Host-directed Dynamic ACPI Table Unload
 ads7950 spi-PRP0001:00: Dropping the link to regulator.0
 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
 #PF error: [normal kernel read fault]
 PGD 80000000070d6067 P4D 80000000070d6067 PUD 70d0067 PMD 0
 Oops: 0000 [#1] SMP PTI
 CPU: 0 PID: 40 Comm: kworker/u4:2 Not tainted 5.0.0+ #96
 Hardware name: Intel Corporation Merrifield/BODEGA BAY, BIOS 542 2015.01.21:18.19.48
 Workqueue: kacpi_hotplug acpi_device_del_work_fn
 RIP: 0010:create_of_modalias.isra.1+0x4c/0x150
 Code: 00 00 48 89 44 24 18 31 c0 48 8d 54 24 08 48 c7 44 24 10 00 00 00 00 48 c7 44 24 08 ff ff ff ff e8 7a b0 03 00 48 8b 4c 24 10 <0f> b6 01 84 c0 74 27 48 c7 c7 00 09 f4 a5 0f b6 f0 8d 50 20 f6 04
 RSP: 0000:ffffa51040297c10 EFLAGS: 00010246
 RAX: 0000000000001001 RBX: 0000000000000785 RCX: 0000000000000000
 RDX: 0000000000001001 RSI: 0000000000000286 RDI: ffffa2163dc042e0
 RBP: ffffa216062b1196 R08: 0000000000001001 R09: ffffa21639873000
 R10: ffffffffa606761d R11: 0000000000000001 R12: ffffa21639873218
 R13: ffffa2163deb5060 R14: ffffa216063d1010 R15: 0000000000000000
 FS:  0000000000000000(0000) GS:ffffa2163e000000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 0000000007114000 CR4: 00000000001006f0
 Call Trace:
  __acpi_device_uevent_modalias+0xb0/0x100
  spi_uevent+0xd/0x40

 ...

In order to fix above let create_of_modalias() check the status returned
by acpi_get_name() and bail out in case of failure.

Fixes: 8765c5ba1949 ("ACPI / scan: Rework modalias creation when "compatible" is present")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=201381
Reported-by: Ferry Toth <fntoth@gmail.com>
Tested-by: Ferry Toth<fntoth@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: 4.1+ <stable@vger.kernel.org> # 4.1+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
treewide: Use DEVICE_ATTR_RO 2018-01-09T15:34:34+00:00 Joe Perches joe@perches.com 2017-12-19T18:15:08+00:00 c828a8920307185b7194b575731e8387c99a5a67 Convert DEVICE_ATTR uses to DEVICE_ATTR_RO where possible. Done with perl script: $ git grep -w --name-only DEVICE_ATTR | \ xargs perl -i -e 'local $/; while (<>) { s/\bDEVICE_ATTR\s*\(\s*(\w+)\s*,\s*\(?(?:\s*S_IRUGO\s*|\s*0444\s*)\)?\s*,\s*\1_show\s*,\s*NULL\s*\)/DEVICE_ATTR_RO(\1)/g; print;}' Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Robert Jarzmik <robert.jarzmik@free.fr> Acked-by: Sagi Grimberg <sagi@grimberg.me> Acked-by: Zhang Rui <rui.zhang@intel.com> Acked-by: Harald Freudenberger <freude@linux.vnet.ibm.com> Acked-by: Jani Nikula <jani.nikula@intel.com> Acked-by: Corey Minyard <cminyard@mvista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Convert DEVICE_ATTR uses to DEVICE_ATTR_RO where possible.

Done with perl script:

$ git grep -w --name-only DEVICE_ATTR | \
  xargs perl -i -e 'local $/; while (<>) { s/\bDEVICE_ATTR\s*\(\s*(\w+)\s*,\s*\(?(?:\s*S_IRUGO\s*|\s*0444\s*)\)?\s*,\s*\1_show\s*,\s*NULL\s*\)/DEVICE_ATTR_RO(\1)/g; print;}'

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Sagi Grimberg <sagi@grimberg.me>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Acked-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ACPI / bus: Leave modalias empty for devices which are not present 2017-11-20T22:48:51+00:00 Hans de Goede hdegoede@redhat.com 2017-10-15T19:24:49+00:00 10809bb976648ac58194a629e3d7af99e7400297 Most Bay and Cherry Trail devices use a generic DSDT with all possible peripheral devices present in the DSDT, with their _STA returning 0x00 or 0x0f based on AML variables which describe what is actually present on the board. Since ACPI device objects with a 0x00 status (not present) still get an entry under /sys/bus/acpi/devices, and those entry had an acpi:PNPID modalias, userspace would end up loading modules for non present hardware. This commit fixes this by leaving the modalias empty for non present devices. This results in 10 modules less being loaded with a generic distro kernel config on my Cherry Trail test-device (a GPD pocket). Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Most Bay and Cherry Trail devices use a generic DSDT with all possible
peripheral devices present in the DSDT, with their _STA returning 0x00 or
0x0f based on AML variables which describe what is actually present on
the board.

Since ACPI device objects with a 0x00 status (not present) still get an
entry under /sys/bus/acpi/devices, and those entry had an acpi:PNPID
modalias, userspace would end up loading modules for non present hardware.

This commit fixes this by leaving the modalias empty for non present
devices. This results in 10 modules less being loaded with a generic
distro kernel config on my Cherry Trail test-device (a GPD pocket).

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>