<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/drivers/firmware/efi/apple-properties.c, branch linux-6.5.y</title>
<subtitle>Hosts the 0x221E linux distro kernel.</subtitle>
<id>https://universe.0xinfinity.dev/distro/kernel/atom?h=linux-6.5.y</id>
<link rel='self' href='https://universe.0xinfinity.dev/distro/kernel/atom?h=linux-6.5.y'/>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/'/>
<updated>2022-03-01T08:02:21Z</updated>
<entry>
<title>efi: fix return value of __setup handlers</title>
<updated>2022-03-01T08:02:21Z</updated>
<author>
<name>Randy Dunlap</name>
<email>rdunlap@infradead.org</email>
</author>
<published>2022-03-01T04:18:51Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=9feaf8b387ee0ece9c1d7add308776b502a35d0c'/>
<id>urn:sha1:9feaf8b387ee0ece9c1d7add308776b502a35d0c</id>
<content type='text'>
When "dump_apple_properties" is used on the kernel boot command line,
it causes an Unknown parameter message and the string is added to init's
argument strings:

  Unknown kernel command line parameters "dump_apple_properties
    BOOT_IMAGE=/boot/bzImage-517rc6 efivar_ssdt=newcpu_ssdt", will be
    passed to user space.

 Run /sbin/init as init process
   with arguments:
     /sbin/init
     dump_apple_properties
   with environment:
     HOME=/
     TERM=linux
     BOOT_IMAGE=/boot/bzImage-517rc6
     efivar_ssdt=newcpu_ssdt

Similarly when "efivar_ssdt=somestring" is used, it is added to the
Unknown parameter message and to init's environment strings, polluting
them (see examples above).

Change the return value of the __setup functions to 1 to indicate
that the __setup options have been handled.

Fixes: 58c5475aba67 ("x86/efi: Retrieve and assign Apple device properties")
Fixes: 475fb4e8b2f4 ("efi / ACPI: load SSTDs from EFI variables")
Signed-off-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Reported-by: Igor Zhbanov &lt;i.zhbanov@omprussia.ru&gt;
Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Cc: Ard Biesheuvel &lt;ardb@kernel.org&gt;
Cc: linux-efi@vger.kernel.org
Cc: Lukas Wunner &lt;lukas@wunner.de&gt;
Cc: Octavian Purdila &lt;octavian.purdila@intel.com&gt;
Cc: "Rafael J. Wysocki" &lt;rafael@kernel.org&gt;
Cc: Matt Fleming &lt;matt@codeblueprint.co.uk&gt;
Link: https://lore.kernel.org/r/20220301041851.12459-1-rdunlap@infradead.org
Signed-off-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
</content>
</entry>
<entry>
<title>efi/apple-properties: Handle device properties with software node API</title>
<updated>2021-05-22T12:06:59Z</updated>
<author>
<name>Heikki Krogerus</name>
<email>heikki.krogerus@linux.intel.com</email>
</author>
<published>2021-03-04T08:28:37Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=55fc610c8cdae353737dbc2d59febd3c1a697095'/>
<id>urn:sha1:55fc610c8cdae353737dbc2d59febd3c1a697095</id>
<content type='text'>
The old device property API is going to be removed.
Replacing the device_add_properties() call with the software
node API equivalent, device_create_managed_software_node().

Signed-off-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Acked-by: Lukas Wunner &lt;lukas@wunner.de&gt;
Signed-off-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
</content>
</entry>
<entry>
<title>efi/apple-properties: Reinstate support for boolean properties</title>
<updated>2020-12-31T09:28:53Z</updated>
<author>
<name>Lukas Wunner</name>
<email>lukas@wunner.de</email>
</author>
<published>2020-12-31T05:10:32Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=355845b738e76445c8522802552146d96cb4afa7'/>
<id>urn:sha1:355845b738e76445c8522802552146d96cb4afa7</id>
<content type='text'>
Since commit 4466bf82821b ("efi/apple-properties: use
PROPERTY_ENTRY_U8_ARRAY_LEN"), my MacBook Pro issues a -ENODATA error
when trying to assign EFI properties to the discrete GPU:

pci 0000:01:00.0: assigning 56 device properties
pci 0000:01:00.0: error -61 assigning properties

That's because some of the properties have no value.  They're booleans
whose presence can be checked by drivers, e.g. "use-backlight-blanking".

Commit 6e98503dba64 ("efi/apple-properties: Remove redundant attribute
initialization from unmarshal_key_value_pairs()") employed a trick to
store such booleans as u8 arrays (which is the data type used for all
other EFI properties on Macs):  It cleared the property_entry's
"is_array" flag, thereby denoting that the value is stored inline in the
property_entry.

Commit 4466bf82821b erroneously removed that trick.  It was probably a
little fragile to begin with.

Reinstate support for boolean properties by explicitly invoking the
PROPERTY_ENTRY_BOOL() initializer for properties with zero-length value.

Fixes: 4466bf82821b ("efi/apple-properties: use PROPERTY_ENTRY_U8_ARRAY_LEN")
Cc: &lt;stable@vger.kernel.org&gt;
Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Signed-off-by: Lukas Wunner &lt;lukas@wunner.de&gt;
Link: https://lore.kernel.org/r/be958bda75331a011d53c696d1deec8dccd06fd2.1609388549.git.lukas@wunner.de
Signed-off-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
</content>
</entry>
<entry>
<title>efi/dev-path-parser: Add struct definition for vendor type device path nodes</title>
<updated>2020-02-23T20:59:42Z</updated>
<author>
<name>Ard Biesheuvel</name>
<email>ardb@kernel.org</email>
</author>
<published>2020-02-10T08:46:57Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=db8952e7094fde3a397321240d5d57ec111258d8'/>
<id>urn:sha1:db8952e7094fde3a397321240d5d57ec111258d8</id>
<content type='text'>
In preparation of adding support for loading the initrd via a special
device path, add the struct definition of a vendor GUIDed device path
node to efi.h.

Since we will be producing these data structures rather than just
consumsing the ones instantiated by the firmware, refactor the various
device path node definitions so we can take the size of each node using
sizeof() rather than having to resort to opaque arithmetic in the static
initializers.

While at it, drop the #if IS_ENABLED() check for the declaration of
efi_get_device_by_path(), which is unnecessary, and constify its first
argument as well.

Signed-off-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
</content>
</entry>
<entry>
<title>efi/apple-properties: Replace zero-length array with flexible-array member</title>
<updated>2020-02-22T22:37:37Z</updated>
<author>
<name>Gustavo A. R. Silva</name>
<email>gustavo@embeddedor.com</email>
</author>
<published>2020-02-11T23:14:21Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=3b9274ea1c0279b369212ccd440c9d61efdfa562'/>
<id>urn:sha1:3b9274ea1c0279b369212ccd440c9d61efdfa562</id>
<content type='text'>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertenly introduced[3] to the codebase from now on.

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva &lt;gustavo@embeddedor.com&gt;
Link: https://lore.kernel.org/r/20200211231421.GA15697@embeddedor
Signed-off-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
</content>
</entry>
<entry>
<title>efi/apple-properties: use PROPERTY_ENTRY_U8_ARRAY_LEN</title>
<updated>2019-11-05T22:18:10Z</updated>
<author>
<name>Dmitry Torokhov</name>
<email>dmitry.torokhov@gmail.com</email>
</author>
<published>2019-10-23T20:02:21Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=4466bf82821be512da5ae973097a9afd38cf36f6'/>
<id>urn:sha1:4466bf82821be512da5ae973097a9afd38cf36f6</id>
<content type='text'>
Let's switch to using PROPERTY_ENTRY_U8_ARRAY_LEN() to initialize
property entries. Also, when dumping data, rely on local variables
instead of poking into the property entry structure directly.

Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Signed-off-by: Dmitry Torokhov &lt;dmitry.torokhov@gmail.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
</entry>
<entry>
<title>efi: Replace GPL license boilerplate with SPDX headers</title>
<updated>2019-02-04T07:27:25Z</updated>
<author>
<name>Ard Biesheuvel</name>
<email>ard.biesheuvel@linaro.org</email>
</author>
<published>2019-02-02T09:41:15Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=4febfb8dd08b6f8bafc19f3f9e382a477425b578'/>
<id>urn:sha1:4febfb8dd08b6f8bafc19f3f9e382a477425b578</id>
<content type='text'>
Replace all GPL license blurbs with an equivalent SPDX header (most
files are GPLv2, some are GPLv2+). While at it, drop some outdated
header changelogs as well.

Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Cc: AKASHI Takahiro &lt;takahiro.akashi@linaro.org&gt;
Cc: Alexander Graf &lt;agraf@suse.de&gt;
Cc: Bjorn Andersson &lt;bjorn.andersson@linaro.org&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Heinrich Schuchardt &lt;xypron.glpk@gmx.de&gt;
Cc: Jeffrey Hugo &lt;jhugo@codeaurora.org&gt;
Cc: Lee Jones &lt;lee.jones@linaro.org&gt;
Cc: Leif Lindholm &lt;leif.lindholm@linaro.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Matt Fleming &lt;matt@codeblueprint.co.uk&gt;
Cc: Peter Jones &lt;pjones@redhat.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Sai Praneeth Prakhya &lt;sai.praneeth.prakhya@intel.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20190202094119.13230-7-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
</entry>
<entry>
<title>mm: remove include/linux/bootmem.h</title>
<updated>2018-10-31T15:54:16Z</updated>
<author>
<name>Mike Rapoport</name>
<email>rppt@linux.vnet.ibm.com</email>
</author>
<published>2018-10-30T22:09:49Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=57c8a661d95dff48dd9c2f2496139082bbaf241a'/>
<id>urn:sha1:57c8a661d95dff48dd9c2f2496139082bbaf241a</id>
<content type='text'>
Move remaining definitions and declarations from include/linux/bootmem.h
into include/linux/memblock.h and remove the redundant header.

The includes were replaced with the semantic patch below and then
semi-automated removal of duplicated '#include &lt;linux/memblock.h&gt;

@@
@@
- #include &lt;linux/bootmem.h&gt;
+ #include &lt;linux/memblock.h&gt;

[sfr@canb.auug.org.au: dma-direct: fix up for the removal of linux/bootmem.h]
  Link: http://lkml.kernel.org/r/20181002185342.133d1680@canb.auug.org.au
[sfr@canb.auug.org.au: powerpc: fix up for removal of linux/bootmem.h]
  Link: http://lkml.kernel.org/r/20181005161406.73ef8727@canb.auug.org.au
[sfr@canb.auug.org.au: x86/kaslr, ACPI/NUMA: fix for linux/bootmem.h removal]
  Link: http://lkml.kernel.org/r/20181008190341.5e396491@canb.auug.org.au
Link: http://lkml.kernel.org/r/1536927045-23536-30-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport &lt;rppt@linux.vnet.ibm.com&gt;
Signed-off-by: Stephen Rothwell &lt;sfr@canb.auug.org.au&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Chris Zankel &lt;chris@zankel.net&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Cc: Greentime Hu &lt;green.hu@gmail.com&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Guan Xuetao &lt;gxt@pku.edu.cn&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: "James E.J. Bottomley" &lt;jejb@parisc-linux.org&gt;
Cc: Jonas Bonn &lt;jonas@southpole.se&gt;
Cc: Jonathan Corbet &lt;corbet@lwn.net&gt;
Cc: Ley Foon Tan &lt;lftan@altera.com&gt;
Cc: Mark Salter &lt;msalter@redhat.com&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Matt Turner &lt;mattst88@gmail.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Michal Simek &lt;monstr@monstr.eu&gt;
Cc: Palmer Dabbelt &lt;palmer@sifive.com&gt;
Cc: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: Richard Kuo &lt;rkuo@codeaurora.org&gt;
Cc: Richard Weinberger &lt;richard@nod.at&gt;
Cc: Rich Felker &lt;dalias@libc.org&gt;
Cc: Russell King &lt;linux@armlinux.org.uk&gt;
Cc: Serge Semin &lt;fancer.lancer@gmail.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>memblock: replace free_bootmem_late with memblock_free_late</title>
<updated>2018-10-31T15:54:16Z</updated>
<author>
<name>Mike Rapoport</name>
<email>rppt@linux.vnet.ibm.com</email>
</author>
<published>2018-10-30T22:09:25Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=53ab85ebfd27cdf16c8ddc72781c072a63bef3cb'/>
<id>urn:sha1:53ab85ebfd27cdf16c8ddc72781c072a63bef3cb</id>
<content type='text'>
The free_bootmem_late and memblock_free_late do exactly the same thing:
they iterate over a range and give pages to the page allocator.

Replace calls to free_bootmem_late with calls to memblock_free_late and
remove the bootmem variant.

Link: http://lkml.kernel.org/r/1536927045-23536-25-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport &lt;rppt@linux.vnet.ibm.com&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Chris Zankel &lt;chris@zankel.net&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Cc: Greentime Hu &lt;green.hu@gmail.com&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Guan Xuetao &lt;gxt@pku.edu.cn&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: "James E.J. Bottomley" &lt;jejb@parisc-linux.org&gt;
Cc: Jonas Bonn &lt;jonas@southpole.se&gt;
Cc: Jonathan Corbet &lt;corbet@lwn.net&gt;
Cc: Ley Foon Tan &lt;lftan@altera.com&gt;
Cc: Mark Salter &lt;msalter@redhat.com&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Matt Turner &lt;mattst88@gmail.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Michal Simek &lt;monstr@monstr.eu&gt;
Cc: Palmer Dabbelt &lt;palmer@sifive.com&gt;
Cc: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: Richard Kuo &lt;rkuo@codeaurora.org&gt;
Cc: Richard Weinberger &lt;richard@nod.at&gt;
Cc: Rich Felker &lt;dalias@libc.org&gt;
Cc: Russell King &lt;linux@armlinux.org.uk&gt;
Cc: Serge Semin &lt;fancer.lancer@gmail.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>device property: Get rid of union aliasing</title>
<updated>2018-05-17T10:47:21Z</updated>
<author>
<name>Andy Shevchenko</name>
<email>andriy.shevchenko@linux.intel.com</email>
</author>
<published>2018-05-15T17:32:02Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=63dcc7090137a893322432e156d66be3ce104615'/>
<id>urn:sha1:63dcc7090137a893322432e156d66be3ce104615</id>
<content type='text'>
Commit 318a19718261 (device property: refactor built-in properties
support) went way too far and brought a union aliasing. Partially
revert it here to get rid of union aliasing.

Note, all Apple properties are considered as u8 arrays. To get a value
of any of them the caller must use device_property_read_u8_array().

What's union aliasing?
~~~~~~~~~~~~~~~~~~~~~~

The C99 standard in section 6.2.5 paragraph 20 defines union type as
"an overlapping nonempty set of member objects". It also states in
section 6.7.2.1 paragraph 14 that "the value of at most one of the
members can be stored in a union object at any time'.

Union aliasing is a type punning mechanism using union members to store
as one type and read back as another.

Why it's not good?
~~~~~~~~~~~~~~~~~~

Section 6.2.6.1 paragraph 6 says that a union object may not be a trap
representation, although its member objects may be.

Meanwhile annex J.1 says that "the value of a union member other than
the last one stored into" is unspecified [removed in C11].

In TC3, a footnote is added which specifies that accessing a member of a
union other than the last one stored causes "the object representation"
to be re-interpreted in the new type and specifically refers to this as
"type punning". This conflicts to some degree with Annex J.1.

While it's working in Linux with GCC, the use of union members to do
type punning is not clear area in the C standard and might lead to
unspecified behaviour.

More information is available in this [1] blog post.

[1]: https://davmac.wordpress.com/2010/02/26/c99-revisited/

Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Acked-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Reviewed-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
</entry>
</feed>
