<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/init/Kconfig, branch linux-6.8.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>rust: make mutually exclusive with CFI_CLANG</title>
<updated>2024-05-02T14:35:25+00:00</updated>
<author>
<name>Conor Dooley</name>
<email>conor.dooley@microchip.com</email>
</author>
<published>2024-04-04T14:17:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f94e59d1c3699bb3470e5e601cbe96411137e975'/>
<id>f94e59d1c3699bb3470e5e601cbe96411137e975</id>
<content type='text'>
commit 8933cf4651e02853ca679be7b2d978dfcdcc5e0c upstream.

On RISC-V and arm64, and presumably x86, if CFI_CLANG is enabled,
loading a rust module will trigger a kernel panic. Support for
sanitisers, including kcfi (CFI_CLANG), is in the works, but for now
they're nightly-only options in rustc. Make RUST depend on !CFI_CLANG
to prevent configuring a kernel without symmetrical support for kfi.

[ Matthew Maurer writes [1]:

    This patch is fine by me - the last patch needed for KCFI to be
    functional in Rust just landed upstream last night, so we should
    revisit this (in the form of enabling it) once we move to
    `rustc-1.79.0` or later.

  Ramon de C Valle also gave feedback [2] on the status of KCFI for
  Rust and created a tracking issue [3] in upstream Rust.   - Miguel ]

Fixes: 2f7ab1267dc9 ("Kbuild: add Rust support")
Cc: stable@vger.kernel.org
Signed-off-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Acked-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Link: https://lore.kernel.org/rust-for-linux/CAGSQo024u1gHJgzsO38Xg3c4or+JupoPABQx_+0BLEpPg0cOEA@mail.gmail.com/ [1]
Link: https://lore.kernel.org/rust-for-linux/CAOcBZOS2kPyH0Dm7Fuh4GC3=v7nZhyzBj_-dKu3PfAnrHZvaxg@mail.gmail.com/ [2]
Link: https://github.com/rust-lang/rust/issues/123479 [3]
Link: https://lore.kernel.org/r/20240404-providing-emporium-e652e359c711@spud
[ Added feedback from the list, links, and used Cc for the tag. ]
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 8933cf4651e02853ca679be7b2d978dfcdcc5e0c upstream.

On RISC-V and arm64, and presumably x86, if CFI_CLANG is enabled,
loading a rust module will trigger a kernel panic. Support for
sanitisers, including kcfi (CFI_CLANG), is in the works, but for now
they're nightly-only options in rustc. Make RUST depend on !CFI_CLANG
to prevent configuring a kernel without symmetrical support for kfi.

[ Matthew Maurer writes [1]:

    This patch is fine by me - the last patch needed for KCFI to be
    functional in Rust just landed upstream last night, so we should
    revisit this (in the form of enabling it) once we move to
    `rustc-1.79.0` or later.

  Ramon de C Valle also gave feedback [2] on the status of KCFI for
  Rust and created a tracking issue [3] in upstream Rust.   - Miguel ]

Fixes: 2f7ab1267dc9 ("Kbuild: add Rust support")
Cc: stable@vger.kernel.org
Signed-off-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Acked-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Link: https://lore.kernel.org/rust-for-linux/CAGSQo024u1gHJgzsO38Xg3c4or+JupoPABQx_+0BLEpPg0cOEA@mail.gmail.com/ [1]
Link: https://lore.kernel.org/rust-for-linux/CAOcBZOS2kPyH0Dm7Fuh4GC3=v7nZhyzBj_-dKu3PfAnrHZvaxg@mail.gmail.com/ [2]
Link: https://github.com/rust-lang/rust/issues/123479 [3]
Link: https://lore.kernel.org/r/20240404-providing-emporium-e652e359c711@spud
[ Added feedback from the list, links, and used Cc for the tag. ]
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rust: don't select CONSTRUCTORS</title>
<updated>2024-05-02T14:35:25+00:00</updated>
<author>
<name>Alice Ryhl</name>
<email>aliceryhl@google.com</email>
</author>
<published>2024-03-08T09:36:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7e69585203a35d5b96b56f9fdf7aa47995ee802a'/>
<id>7e69585203a35d5b96b56f9fdf7aa47995ee802a</id>
<content type='text'>
commit 7d49f53af4b988b188d3932deac2c9c80fd7d9ce upstream.

This was originally part of commit 4b9a68f2e59a0 ("rust: add support for
static synchronisation primitives") from the old Rust branch, which used
module constructors to initialize globals containing various
synchronisation primitives with pin-init. That commit has never been
upstreamed, but the `select CONSTRUCTORS` statement ended up being
included in the patch that initially added Rust support to the Linux
Kernel.

We are not using module constructors, so let's remove the select.

Signed-off-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Reviewed-by: Benno Lossin &lt;benno.lossin@proton.me&gt;
Cc: stable@vger.kernel.org
Fixes: 2f7ab1267dc9 ("Kbuild: add Rust support")
Link: https://lore.kernel.org/r/20240308-constructors-v1-1-4c811342391c@google.com
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 7d49f53af4b988b188d3932deac2c9c80fd7d9ce upstream.

This was originally part of commit 4b9a68f2e59a0 ("rust: add support for
static synchronisation primitives") from the old Rust branch, which used
module constructors to initialize globals containing various
synchronisation primitives with pin-init. That commit has never been
upstreamed, but the `select CONSTRUCTORS` statement ended up being
included in the patch that initially added Rust support to the Linux
Kernel.

We are not using module constructors, so let's remove the select.

Signed-off-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Reviewed-by: Benno Lossin &lt;benno.lossin@proton.me&gt;
Cc: stable@vger.kernel.org
Fixes: 2f7ab1267dc9 ("Kbuild: add Rust support")
Link: https://lore.kernel.org/r/20240308-constructors-v1-1-4c811342391c@google.com
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>init/Kconfig: lower GCC version check for -Warray-bounds</title>
<updated>2024-03-05T00:40:33+00:00</updated>
<author>
<name>Kees Cook</name>
<email>keescook@chromium.org</email>
</author>
<published>2024-02-23T17:08:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3e00f5802fabf2f504070a591b14b648523ede13'/>
<id>3e00f5802fabf2f504070a591b14b648523ede13</id>
<content type='text'>
We continue to see false positives from -Warray-bounds even in GCC 10,
which is getting reported in a few places[1] still:

security/security.c:811:2: warning: `memcpy' offset 32 is out of the bounds [0, 0] [-Warray-bounds]

Lower the GCC version check from 11 to 10.

Link: https://lkml.kernel.org/r/20240223170824.work.768-kees@kernel.org
Reported-by: Lu Yao &lt;yaolu@kylinos.cn&gt;
Closes: https://lore.kernel.org/lkml/20240117014541.8887-1-yaolu@kylinos.cn/
Link: https://lore.kernel.org/linux-next/65d84438.620a0220.7d171.81a7@mx.google.com [1]
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Reviewed-by: Paul Moore &lt;paul@paul-moore.com&gt;
Cc: Ard Biesheuvel &lt;ardb@kernel.org&gt;
Cc: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: "Gustavo A. R. Silva" &lt;gustavoars@kernel.org&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Marc Aurèle La France &lt;tsi@tuyoix.net&gt;
Cc: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Cc: Nathan Chancellor &lt;nathan@kernel.org&gt;
Cc: Nhat Pham &lt;nphamcs@gmail.com&gt;
Cc: Petr Mladek &lt;pmladek@suse.com&gt;
Cc: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We continue to see false positives from -Warray-bounds even in GCC 10,
which is getting reported in a few places[1] still:

security/security.c:811:2: warning: `memcpy' offset 32 is out of the bounds [0, 0] [-Warray-bounds]

Lower the GCC version check from 11 to 10.

Link: https://lkml.kernel.org/r/20240223170824.work.768-kees@kernel.org
Reported-by: Lu Yao &lt;yaolu@kylinos.cn&gt;
Closes: https://lore.kernel.org/lkml/20240117014541.8887-1-yaolu@kylinos.cn/
Link: https://lore.kernel.org/linux-next/65d84438.620a0220.7d171.81a7@mx.google.com [1]
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Reviewed-by: Paul Moore &lt;paul@paul-moore.com&gt;
Cc: Ard Biesheuvel &lt;ardb@kernel.org&gt;
Cc: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: "Gustavo A. R. Silva" &lt;gustavoars@kernel.org&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Marc Aurèle La France &lt;tsi@tuyoix.net&gt;
Cc: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Cc: Nathan Chancellor &lt;nathan@kernel.org&gt;
Cc: Nhat Pham &lt;nphamcs@gmail.com&gt;
Cc: Petr Mladek &lt;pmladek@suse.com&gt;
Cc: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>update workarounds for gcc "asm goto" issue</title>
<updated>2024-02-15T19:14:33+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-02-15T19:14:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=68fb3ca0e408e00db1c3f8fccdfa19e274c033be'/>
<id>68fb3ca0e408e00db1c3f8fccdfa19e274c033be</id>
<content type='text'>
In commit 4356e9f841f7 ("work around gcc bugs with 'asm goto' with
outputs") I did the gcc workaround unconditionally, because the cause of
the bad code generation wasn't entirely clear.

In the meantime, Jakub Jelinek debugged the issue, and has come up with
a fix in gcc [2], which also got backported to the still maintained
branches of gcc-11, gcc-12 and gcc-13.

Note that while the fix technically wasn't in the original gcc-14
branch, Jakub says:

 "while it is true that no GCC 14 snapshots until today (or whenever the
  fix will be committed) have the fix, for GCC trunk it is up to the
  distros to use the latest snapshot if they use it at all and would
  allow better testing of the kernel code without the workaround, so
  that if there are other issues they won't be discovered years later.
  Most userland code doesn't actually use asm goto with outputs..."

so we will consider gcc-14 to be fixed - if somebody is using gcc
snapshots of the gcc-14 before the fix, they should upgrade.

Note that while the bug goes back to gcc-11, in practice other gcc
changes seem to have effectively hidden it since gcc-12.1 as per a
bisect by Jakub.  So even a gcc-14 snapshot without the fix likely
doesn't show actual problems.

Also, make the default 'asm_goto_output()' macro mark the asm as
volatile by hand, because of an unrelated gcc issue [1] where it doesn't
match the documented behavior ("asm goto is always volatile").

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103979 [1]
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113921 [2]
Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/
Requested-by: Jakub Jelinek &lt;jakub@redhat.com&gt;
Cc: Uros Bizjak &lt;ubizjak@gmail.com&gt;
Cc: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Cc: Sean Christopherson &lt;seanjc@google.com&gt;
Cc: Andrew Pinski &lt;quic_apinski@quicinc.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In commit 4356e9f841f7 ("work around gcc bugs with 'asm goto' with
outputs") I did the gcc workaround unconditionally, because the cause of
the bad code generation wasn't entirely clear.

In the meantime, Jakub Jelinek debugged the issue, and has come up with
a fix in gcc [2], which also got backported to the still maintained
branches of gcc-11, gcc-12 and gcc-13.

Note that while the fix technically wasn't in the original gcc-14
branch, Jakub says:

 "while it is true that no GCC 14 snapshots until today (or whenever the
  fix will be committed) have the fix, for GCC trunk it is up to the
  distros to use the latest snapshot if they use it at all and would
  allow better testing of the kernel code without the workaround, so
  that if there are other issues they won't be discovered years later.
  Most userland code doesn't actually use asm goto with outputs..."

so we will consider gcc-14 to be fixed - if somebody is using gcc
snapshots of the gcc-14 before the fix, they should upgrade.

Note that while the bug goes back to gcc-11, in practice other gcc
changes seem to have effectively hidden it since gcc-12.1 as per a
bisect by Jakub.  So even a gcc-14 snapshot without the fix likely
doesn't show actual problems.

Also, make the default 'asm_goto_output()' macro mark the asm as
volatile by hand, because of an unrelated gcc issue [1] where it doesn't
match the documented behavior ("asm goto is always volatile").

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103979 [1]
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113921 [2]
Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/
Requested-by: Jakub Jelinek &lt;jakub@redhat.com&gt;
Cc: Uros Bizjak &lt;ubizjak@gmail.com&gt;
Cc: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Cc: Sean Christopherson &lt;seanjc@google.com&gt;
Cc: Andrew Pinski &lt;quic_apinski@quicinc.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Kconfig: Disable -Wstringop-overflow for GCC globally</title>
<updated>2024-02-01T22:57:17+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-02-01T22:57:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=021533194476035883300d60fbb3136426ac8ea5'/>
<id>021533194476035883300d60fbb3136426ac8ea5</id>
<content type='text'>
It turns out it was never just gcc-11 that was broken.  Apparently it
just happens to work on x86-64 with other gcc versions.

On arm64, I see warnings with gcc version 13.2.1, and the kernel test
robot reports the same problem on s390 with gcc 13.2.0.

Admittedly it seems to be just the new Xe drm driver, but this is
keeping me from doing my normal arm64 build testing.  So it gets
reverted until somebody figures out what causes the problem (and why it
doesn't show on x86-64, which is what makes me suspect it was never just
about gcc-11, and more about just random happenstance).

This also changes the Kconfig naming a bit - just make the "disable this
for GCC" conditional be one simple Kconfig entry, and we can put the gcc
version dependencies in that entry once we figure out what the correct
rules are.

The version dependency _may_ still end up being "gcc version larger than
11" if the issue is purely in the Xe driver, but even if that ends up
the case, let's make that all part of the "GCC_NO_STRINGOP_OVERFLOW"
logic.

For now, we just disable it for all gcc versions while the exact cause
is unknown.

Link: https://lore.kernel.org/all/202401161031.hjGJHMiJ-lkp@intel.com/T/
Cc: Gustavo A. R. Silva &lt;gustavoars@kernel.org&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
It turns out it was never just gcc-11 that was broken.  Apparently it
just happens to work on x86-64 with other gcc versions.

On arm64, I see warnings with gcc version 13.2.1, and the kernel test
robot reports the same problem on s390 with gcc 13.2.0.

Admittedly it seems to be just the new Xe drm driver, but this is
keeping me from doing my normal arm64 build testing.  So it gets
reverted until somebody figures out what causes the problem (and why it
doesn't show on x86-64, which is what makes me suspect it was never just
about gcc-11, and more about just random happenstance).

This also changes the Kconfig naming a bit - just make the "disable this
for GCC" conditional be one simple Kconfig entry, and we can put the gcc
version dependencies in that entry once we figure out what the correct
rules are.

The version dependency _may_ still end up being "gcc version larger than
11" if the issue is purely in the Xe driver, but even if that ends up
the case, let's make that all part of the "GCC_NO_STRINGOP_OVERFLOW"
logic.

For now, we just disable it for all gcc versions while the exact cause
is unknown.

Link: https://lore.kernel.org/all/202401161031.hjGJHMiJ-lkp@intel.com/T/
Cc: Gustavo A. R. Silva &lt;gustavoars@kernel.org&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>init: Kconfig: Disable -Wstringop-overflow for GCC-11</title>
<updated>2024-01-21T23:45:31+00:00</updated>
<author>
<name>Gustavo A. R. Silva</name>
<email>gustavoars@kernel.org</email>
</author>
<published>2023-11-30T20:29:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a5e0ace04fbf56c1794b1a2fa7a93672753b3fc7'/>
<id>a5e0ace04fbf56c1794b1a2fa7a93672753b3fc7</id>
<content type='text'>
-Wstringop-overflow is buggy in GCC-11. Therefore, we should disable
this option specifically for that compiler version. To achieve this,
we introduce a new configuration option: GCC11_NO_STRINGOP_OVERFLOW.

The compiler option related to string operation overflow is now managed
under configuration CC_STRINGOP_OVERFLOW. This option is enabled by
default for all other versions of GCC that support it.

Link: https://lore.kernel.org/lkml/b3c99290-40bc-426f-b3d2-1aa903f95c4e@embeddedor.com/
Link: https://lore.kernel.org/lkml/20231128091351.2bfb38dd@canb.auug.org.au/
Reviewed-by: Kees Cook &lt;keescook@chromium.org&gt;
Link: https://lore.kernel.org/linux-hardening/ZWj1+jkweEDWbmAR@work/
Signed-off-by: Gustavo A. R. Silva &lt;gustavoars@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
-Wstringop-overflow is buggy in GCC-11. Therefore, we should disable
this option specifically for that compiler version. To achieve this,
we introduce a new configuration option: GCC11_NO_STRINGOP_OVERFLOW.

The compiler option related to string operation overflow is now managed
under configuration CC_STRINGOP_OVERFLOW. This option is enabled by
default for all other versions of GCC that support it.

Link: https://lore.kernel.org/lkml/b3c99290-40bc-426f-b3d2-1aa903f95c4e@embeddedor.com/
Link: https://lore.kernel.org/lkml/20231128091351.2bfb38dd@canb.auug.org.au/
Reviewed-by: Kees Cook &lt;keescook@chromium.org&gt;
Link: https://lore.kernel.org/linux-hardening/ZWj1+jkweEDWbmAR@work/
Signed-off-by: Gustavo A. R. Silva &lt;gustavoars@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>init/Kconfig: move more items into the EXPERT menu</title>
<updated>2023-12-20T23:02:58+00:00</updated>
<author>
<name>Randy Dunlap</name>
<email>rdunlap@infradead.org</email>
</author>
<published>2023-12-08T04:58:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a751ea34f8c80f2c3cb8e26451a53f900a8b6214'/>
<id>a751ea34f8c80f2c3cb8e26451a53f900a8b6214</id>
<content type='text'>
KCMP, RSEQ, CACHESTAT_SYSCALL, and PC104 depend on EXPERT but not shown in
the EXPERT menu.  Move some lines around so that they are displayed in the
EXPERT menu.

Drop one useless comment.

Change "enabled" to "enable" for DEBUG_RSEQ.

Link: https://lkml.kernel.org/r/20231208045819.2922-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Reviewed-by: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: "Paul E. McKenney" &lt;paulmck@kernel.org&gt;
Cc: Boqun Feng &lt;boqun.feng@gmail.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
KCMP, RSEQ, CACHESTAT_SYSCALL, and PC104 depend on EXPERT but not shown in
the EXPERT menu.  Move some lines around so that they are displayed in the
EXPERT menu.

Drop one useless comment.

Change "enabled" to "enable" for DEBUG_RSEQ.

Link: https://lkml.kernel.org/r/20231208045819.2922-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Reviewed-by: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: "Paul E. McKenney" &lt;paulmck@kernel.org&gt;
Cc: Boqun Feng &lt;boqun.feng@gmail.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arch: Remove Itanium (IA-64) architecture</title>
<updated>2023-09-11T08:13:17+00:00</updated>
<author>
<name>Ard Biesheuvel</name>
<email>ardb@kernel.org</email>
</author>
<published>2022-10-20T13:54:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=cf8e8658100d4eae80ce9b21f7a81cb024dd5057'/>
<id>cf8e8658100d4eae80ce9b21f7a81cb024dd5057</id>
<content type='text'>
The Itanium architecture is obsolete, and an informal survey [0] reveals
that any residual use of Itanium hardware in production is mostly HP-UX
or OpenVMS based. The use of Linux on Itanium appears to be limited to
enthusiasts that occasionally boot a fresh Linux kernel to see whether
things are still working as intended, and perhaps to churn out some
distro packages that are rarely used in practice.

None of the original companies behind Itanium still produce or support
any hardware or software for the architecture, and it is listed as
'Orphaned' in the MAINTAINERS file, as apparently, none of the engineers
that contributed on behalf of those companies (nor anyone else, for that
matter) have been willing to support or maintain the architecture
upstream or even be responsible for applying the odd fix. The Intel
firmware team removed all IA-64 support from the Tianocore/EDK2
reference implementation of EFI in 2018. (Itanium is the original
architecture for which EFI was developed, and the way Linux supports it
deviates significantly from other architectures.) Some distros, such as
Debian and Gentoo, still maintain [unofficial] ia64 ports, but many have
dropped support years ago.

While the argument is being made [1] that there is a 'for the common
good' angle to being able to build and run existing projects such as the
Grid Community Toolkit [2] on Itanium for interoperability testing, the
fact remains that none of those projects are known to be deployed on
Linux/ia64, and very few people actually have access to such a system in
the first place. Even if there were ways imaginable in which Linux/ia64
could be put to good use today, what matters is whether anyone is
actually doing that, and this does not appear to be the case.

There are no emulators widely available, and so boot testing Itanium is
generally infeasible for ordinary contributors. GCC still supports IA-64
but its compile farm [3] no longer has any IA-64 machines. GLIBC would
like to get rid of IA-64 [4] too because it would permit some overdue
code cleanups. In summary, the benefits to the ecosystem of having IA-64
be part of it are mostly theoretical, whereas the maintenance overhead
of keeping it supported is real.

So let's rip off the band aid, and remove the IA-64 arch code entirely.
This follows the timeline proposed by the Debian/ia64 maintainer [5],
which removes support in a controlled manner, leaving IA-64 in a known
good state in the most recent LTS release. Other projects will follow
once the kernel support is removed.

[0] https://lore.kernel.org/all/CAMj1kXFCMh_578jniKpUtx_j8ByHnt=s7S+yQ+vGbKt9ud7+kQ@mail.gmail.com/
[1] https://lore.kernel.org/all/0075883c-7c51-00f5-2c2d-5119c1820410@web.de/
[2] https://gridcf.org/gct-docs/latest/index.html
[3] https://cfarm.tetaneutral.net/machines/list/
[4] https://lore.kernel.org/all/87bkiilpc4.fsf@mid.deneb.enyo.de/
[5] https://lore.kernel.org/all/ff58a3e76e5102c94bb5946d99187b358def688a.camel@physik.fu-berlin.de/

Acked-by: Tony Luck &lt;tony.luck@intel.com&gt;
Signed-off-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The Itanium architecture is obsolete, and an informal survey [0] reveals
that any residual use of Itanium hardware in production is mostly HP-UX
or OpenVMS based. The use of Linux on Itanium appears to be limited to
enthusiasts that occasionally boot a fresh Linux kernel to see whether
things are still working as intended, and perhaps to churn out some
distro packages that are rarely used in practice.

None of the original companies behind Itanium still produce or support
any hardware or software for the architecture, and it is listed as
'Orphaned' in the MAINTAINERS file, as apparently, none of the engineers
that contributed on behalf of those companies (nor anyone else, for that
matter) have been willing to support or maintain the architecture
upstream or even be responsible for applying the odd fix. The Intel
firmware team removed all IA-64 support from the Tianocore/EDK2
reference implementation of EFI in 2018. (Itanium is the original
architecture for which EFI was developed, and the way Linux supports it
deviates significantly from other architectures.) Some distros, such as
Debian and Gentoo, still maintain [unofficial] ia64 ports, but many have
dropped support years ago.

While the argument is being made [1] that there is a 'for the common
good' angle to being able to build and run existing projects such as the
Grid Community Toolkit [2] on Itanium for interoperability testing, the
fact remains that none of those projects are known to be deployed on
Linux/ia64, and very few people actually have access to such a system in
the first place. Even if there were ways imaginable in which Linux/ia64
could be put to good use today, what matters is whether anyone is
actually doing that, and this does not appear to be the case.

There are no emulators widely available, and so boot testing Itanium is
generally infeasible for ordinary contributors. GCC still supports IA-64
but its compile farm [3] no longer has any IA-64 machines. GLIBC would
like to get rid of IA-64 [4] too because it would permit some overdue
code cleanups. In summary, the benefits to the ecosystem of having IA-64
be part of it are mostly theoretical, whereas the maintenance overhead
of keeping it supported is real.

So let's rip off the band aid, and remove the IA-64 arch code entirely.
This follows the timeline proposed by the Debian/ia64 maintainer [5],
which removes support in a controlled manner, leaving IA-64 in a known
good state in the most recent LTS release. Other projects will follow
once the kernel support is removed.

[0] https://lore.kernel.org/all/CAMj1kXFCMh_578jniKpUtx_j8ByHnt=s7S+yQ+vGbKt9ud7+kQ@mail.gmail.com/
[1] https://lore.kernel.org/all/0075883c-7c51-00f5-2c2d-5119c1820410@web.de/
[2] https://gridcf.org/gct-docs/latest/index.html
[3] https://cfarm.tetaneutral.net/machines/list/
[4] https://lore.kernel.org/all/87bkiilpc4.fsf@mid.deneb.enyo.de/
[5] https://lore.kernel.org/all/ff58a3e76e5102c94bb5946d99187b358def688a.camel@physik.fu-berlin.de/

Acked-by: Tony Luck &lt;tony.luck@intel.com&gt;
Signed-off-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'mm-nonmm-stable-2023-08-28-22-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm</title>
<updated>2023-08-29T21:53:51+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-08-29T21:53:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d68b4b6f307d155475cce541f2aee938032ed22e'/>
<id>d68b4b6f307d155475cce541f2aee938032ed22e</id>
<content type='text'>
Pull non-MM updates from Andrew Morton:

 - An extensive rework of kexec and crash Kconfig from Eric DeVolder
   ("refactor Kconfig to consolidate KEXEC and CRASH options")

 - kernel.h slimming work from Andy Shevchenko ("kernel.h: Split out a
   couple of macros to args.h")

 - gdb feature work from Kuan-Ying Lee ("Add GDB memory helper
   commands")

 - vsprintf inclusion rationalization from Andy Shevchenko
   ("lib/vsprintf: Rework header inclusions")

 - Switch the handling of kdump from a udev scheme to in-kernel
   handling, by Eric DeVolder ("crash: Kernel handling of CPU and memory
   hot un/plug")

 - Many singleton patches to various parts of the tree

* tag 'mm-nonmm-stable-2023-08-28-22-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (81 commits)
  document while_each_thread(), change first_tid() to use for_each_thread()
  drivers/char/mem.c: shrink character device's devlist[] array
  x86/crash: optimize CPU changes
  crash: change crash_prepare_elf64_headers() to for_each_possible_cpu()
  crash: hotplug support for kexec_load()
  x86/crash: add x86 crash hotplug support
  crash: memory and CPU hotplug sysfs attributes
  kexec: exclude elfcorehdr from the segment digest
  crash: add generic infrastructure for crash hotplug support
  crash: move a few code bits to setup support of crash hotplug
  kstrtox: consistently use _tolower()
  kill do_each_thread()
  nilfs2: fix WARNING in mark_buffer_dirty due to discarded buffer reuse
  scripts/bloat-o-meter: count weak symbol sizes
  treewide: drop CONFIG_EMBEDDED
  lockdep: fix static memory detection even more
  lib/vsprintf: declare no_hash_pointers in sprintf.h
  lib/vsprintf: split out sprintf() and friends
  kernel/fork: stop playing lockless games for exe_file replacement
  adfs: delete unused "union adfs_dirtail" definition
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull non-MM updates from Andrew Morton:

 - An extensive rework of kexec and crash Kconfig from Eric DeVolder
   ("refactor Kconfig to consolidate KEXEC and CRASH options")

 - kernel.h slimming work from Andy Shevchenko ("kernel.h: Split out a
   couple of macros to args.h")

 - gdb feature work from Kuan-Ying Lee ("Add GDB memory helper
   commands")

 - vsprintf inclusion rationalization from Andy Shevchenko
   ("lib/vsprintf: Rework header inclusions")

 - Switch the handling of kdump from a udev scheme to in-kernel
   handling, by Eric DeVolder ("crash: Kernel handling of CPU and memory
   hot un/plug")

 - Many singleton patches to various parts of the tree

* tag 'mm-nonmm-stable-2023-08-28-22-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (81 commits)
  document while_each_thread(), change first_tid() to use for_each_thread()
  drivers/char/mem.c: shrink character device's devlist[] array
  x86/crash: optimize CPU changes
  crash: change crash_prepare_elf64_headers() to for_each_possible_cpu()
  crash: hotplug support for kexec_load()
  x86/crash: add x86 crash hotplug support
  crash: memory and CPU hotplug sysfs attributes
  kexec: exclude elfcorehdr from the segment digest
  crash: add generic infrastructure for crash hotplug support
  crash: move a few code bits to setup support of crash hotplug
  kstrtox: consistently use _tolower()
  kill do_each_thread()
  nilfs2: fix WARNING in mark_buffer_dirty due to discarded buffer reuse
  scripts/bloat-o-meter: count weak symbol sizes
  treewide: drop CONFIG_EMBEDDED
  lockdep: fix static memory detection even more
  lib/vsprintf: declare no_hash_pointers in sprintf.h
  lib/vsprintf: split out sprintf() and friends
  kernel/fork: stop playing lockless games for exe_file replacement
  adfs: delete unused "union adfs_dirtail" definition
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>treewide: drop CONFIG_EMBEDDED</title>
<updated>2023-08-21T20:46:25+00:00</updated>
<author>
<name>Randy Dunlap</name>
<email>rdunlap@infradead.org</email>
</author>
<published>2023-08-16T05:50:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ef815d2cba782e96b9aad9483523d474ed41c62a'/>
<id>ef815d2cba782e96b9aad9483523d474ed41c62a</id>
<content type='text'>
There is only one Kconfig user of CONFIG_EMBEDDED and it can be switched
to EXPERT or "if !ARCH_MULTIPLATFORM" (suggested by Arnd).

Link: https://lkml.kernel.org/r/20230816055010.31534-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Acked-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Acked-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Acked-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;	[RISC-V]
Acked-by: Greg Ungerer &lt;gerg@linux-m68k.org&gt;
Acked-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Acked-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;	[powerpc]
Cc: Russell King &lt;linux@armlinux.org.uk&gt;
Cc: Vineet Gupta &lt;vgupta@kernel.org&gt;
Cc: Brian Cain &lt;bcain@quicinc.com&gt;
Cc: Michal Simek &lt;monstr@monstr.eu&gt;
Cc: Thomas Bogendoerfer &lt;tsbogend@alpha.franken.de&gt;
Cc: Dinh Nguyen &lt;dinguyen@kernel.org&gt;
Cc: Jonas Bonn &lt;jonas@southpole.se&gt;
Cc: Stefan Kristiansson &lt;stefan.kristiansson@saunalahti.fi&gt;
Cc: Stafford Horne &lt;shorne@gmail.com&gt;
Cc: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Cc: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Cc: Paul Walmsley &lt;paul.walmsley@sifive.com&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Cc: Rich Felker &lt;dalias@libc.org&gt;
Cc: John Paul Adrian Glaubitz &lt;glaubitz@physik.fu-berlin.de&gt;
Cc: Max Filippov &lt;jcmvbkbc@gmail.com&gt;
Cc: Josh Triplett &lt;josh@joshtriplett.org&gt;
Cc: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There is only one Kconfig user of CONFIG_EMBEDDED and it can be switched
to EXPERT or "if !ARCH_MULTIPLATFORM" (suggested by Arnd).

Link: https://lkml.kernel.org/r/20230816055010.31534-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Acked-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Acked-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Acked-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;	[RISC-V]
Acked-by: Greg Ungerer &lt;gerg@linux-m68k.org&gt;
Acked-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Acked-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;	[powerpc]
Cc: Russell King &lt;linux@armlinux.org.uk&gt;
Cc: Vineet Gupta &lt;vgupta@kernel.org&gt;
Cc: Brian Cain &lt;bcain@quicinc.com&gt;
Cc: Michal Simek &lt;monstr@monstr.eu&gt;
Cc: Thomas Bogendoerfer &lt;tsbogend@alpha.franken.de&gt;
Cc: Dinh Nguyen &lt;dinguyen@kernel.org&gt;
Cc: Jonas Bonn &lt;jonas@southpole.se&gt;
Cc: Stefan Kristiansson &lt;stefan.kristiansson@saunalahti.fi&gt;
Cc: Stafford Horne &lt;shorne@gmail.com&gt;
Cc: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Cc: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Cc: Paul Walmsley &lt;paul.walmsley@sifive.com&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Cc: Rich Felker &lt;dalias@libc.org&gt;
Cc: John Paul Adrian Glaubitz &lt;glaubitz@physik.fu-berlin.de&gt;
Cc: Max Filippov &lt;jcmvbkbc@gmail.com&gt;
Cc: Josh Triplett &lt;josh@joshtriplett.org&gt;
Cc: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
