<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/init, branch v6.6.102</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v6.6.102</id>
<link rel='self' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v6.6.102'/>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/'/>
<updated>2025-05-02T05:50:57Z</updated>
<entry>
<title>sched/isolation: Make CONFIG_CPU_ISOLATION depend on CONFIG_SMP</title>
<updated>2025-05-02T05:50:57Z</updated>
<author>
<name>Oleg Nesterov</name>
<email>oleg@redhat.com</email>
</author>
<published>2025-03-30T13:49:55Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=b205d02726b32c2f491a1a267557da5344432428'/>
<id>urn:sha1:b205d02726b32c2f491a1a267557da5344432428</id>
<content type='text'>
[ Upstream commit 975776841e689dd8ba36df9fa72ac3eca3c2957a ]

kernel/sched/isolation.c obviously makes no sense without CONFIG_SMP, but
the Kconfig entry we have right now:

	config CPU_ISOLATION
		bool "CPU isolation"
		depends on SMP || COMPILE_TEST

allows the creation of pointless .config's which cause
build failures.

Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Signed-off-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Link: https://lore.kernel.org/r/20250330134955.GA7910@redhat.com

Closes: https://lore.kernel.org/oe-kbuild-all/202503260646.lrUqD3j5-lkp@intel.com/
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>rust: Disallow BTF generation with Rust + LTO</title>
<updated>2025-03-22T19:50:48Z</updated>
<author>
<name>Matthew Maurer</name>
<email>mmaurer@google.com</email>
</author>
<published>2025-01-08T23:35:08Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=b78467d3ba1c1350b2d8f86eaa694778d8af23ae'/>
<id>urn:sha1:b78467d3ba1c1350b2d8f86eaa694778d8af23ae</id>
<content type='text'>
commit 5daa0c35a1f0e7a6c3b8ba9cb721e7d1ace6e619 upstream.

The kernel cannot currently self-parse BTF containing Rust debug
information. pahole uses the language of the CU to determine whether to
filter out debug information when generating the BTF. When LTO is
enabled, Rust code can cross CU boundaries, resulting in Rust debug
information in CUs labeled as C. This results in a system which cannot
parse its own BTF.

Signed-off-by: Matthew Maurer &lt;mmaurer@google.com&gt;
Cc: stable@vger.kernel.org
Fixes: c1177979af9c ("btf, scripts: Exclude Rust CUs with pahole")
Link: https://lore.kernel.org/r/20250108-rust-btf-lto-incompat-v1-1-60243ff6d820@google.com
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>Compiler Attributes: disable __counted_by for clang &lt; 19.1.3</title>
<updated>2024-12-09T09:32:46Z</updated>
<author>
<name>Jan Hendrik Farr</name>
<email>kernel@jfarr.cc</email>
</author>
<published>2024-10-29T14:00:36Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=5540869a3f75d75bff313b338570dcb10e0955e1'/>
<id>urn:sha1:5540869a3f75d75bff313b338570dcb10e0955e1</id>
<content type='text'>
commit f06e108a3dc53c0f5234d18de0bd224753db5019 upstream.

This patch disables __counted_by for clang versions &lt; 19.1.3 because
of the two issues listed below. It does this by introducing
CONFIG_CC_HAS_COUNTED_BY.

1. clang &lt; 19.1.2 has a bug that can lead to __bdos returning 0:
https://github.com/llvm/llvm-project/pull/110497

2. clang &lt; 19.1.3 has a bug that can lead to __bdos being off by 4:
https://github.com/llvm/llvm-project/pull/112636

Fixes: c8248faf3ca2 ("Compiler Attributes: counted_by: Adjust name and identifier expansion")
Cc: stable@vger.kernel.org # 6.6.x: 16c31dd7fdf6: Compiler Attributes: counted_by: bump min gcc version
Cc: stable@vger.kernel.org # 6.6.x: 2993eb7a8d34: Compiler Attributes: counted_by: fixup clang URL
Cc: stable@vger.kernel.org # 6.6.x: 231dc3f0c936: lkdtm/bugs: Improve warning message for compilers without counted_by support
Cc: stable@vger.kernel.org # 6.6.x
Reported-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Closes: https://lore.kernel.org/all/20240913164630.GA4091534@thelio-3990X/
Reported-by: kernel test robot &lt;oliver.sang@intel.com&gt;
Closes: https://lore.kernel.org/oe-lkp/202409260949.a1254989-oliver.sang@intel.com
Link: https://lore.kernel.org/all/Zw8iawAF5W2uzGuh@archlinux/T/#m204c09f63c076586a02d194b87dffc7e81b8de7b
Suggested-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Signed-off-by: Jan Hendrik Farr &lt;kernel@jfarr.cc&gt;
Reviewed-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Tested-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Reviewed-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
Reviewed-by: Thorsten Blum &lt;thorsten.blum@linux.dev&gt;
Link: https://lore.kernel.org/r/20241029140036.577804-2-kernel@jfarr.cc
Signed-off-by: Kees Cook &lt;kees@kernel.org&gt;
Signed-off-by: Jan Hendrik Farr &lt;kernel@jfarr.cc&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>initramfs: avoid filename buffer overrun</title>
<updated>2024-12-09T09:31:44Z</updated>
<author>
<name>David Disseldorp</name>
<email>ddiss@suse.de</email>
</author>
<published>2024-10-30T03:55:10Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=1a423bbbeaf9e3e20c4686501efd9b661fe834db'/>
<id>urn:sha1:1a423bbbeaf9e3e20c4686501efd9b661fe834db</id>
<content type='text'>
[ Upstream commit e017671f534dd3f568db9e47b0583e853d2da9b5 ]

The initramfs filename field is defined in
Documentation/driver-api/early-userspace/buffer-format.rst as:

 37 cpio_file := ALGN(4) + cpio_header + filename + "\0" + ALGN(4) + data
...
 55 ============= ================== =========================
 56 Field name    Field size         Meaning
 57 ============= ================== =========================
...
 70 c_namesize    8 bytes            Length of filename, including final \0

When extracting an initramfs cpio archive, the kernel's do_name() path
handler assumes a zero-terminated path at @collected, passing it
directly to filp_open() / init_mkdir() / init_mknod().

If a specially crafted cpio entry carries a non-zero-terminated filename
and is followed by uninitialized memory, then a file may be created with
trailing characters that represent the uninitialized memory. The ability
to create an initramfs entry would imply already having full control of
the system, so the buffer overrun shouldn't be considered a security
vulnerability.

Append the output of the following bash script to an existing initramfs
and observe any created /initramfs_test_fname_overrunAA* path. E.g.
  ./reproducer.sh | gzip &gt;&gt; /myinitramfs

It's easiest to observe non-zero uninitialized memory when the output is
gzipped, as it'll overflow the heap allocated @out_buf in __gunzip(),
rather than the initrd_start+initrd_size block.

---- reproducer.sh ----
nilchar="A"	# change to "\0" to properly zero terminate / pad
magic="070701"
ino=1
mode=$(( 0100777 ))
uid=0
gid=0
nlink=1
mtime=1
filesize=0
devmajor=0
devminor=1
rdevmajor=0
rdevminor=0
csum=0
fname="initramfs_test_fname_overrun"
namelen=$(( ${#fname} + 1 ))	# plus one to account for terminator

printf "%s%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%s" \
	$magic $ino $mode $uid $gid $nlink $mtime $filesize \
	$devmajor $devminor $rdevmajor $rdevminor $namelen $csum $fname

termpadlen=$(( 1 + ((4 - ((110 + $namelen) &amp; 3)) % 4) ))
printf "%.s${nilchar}" $(seq 1 $termpadlen)
---- reproducer.sh ----

Symlink filename fields handled in do_symlink() won't overrun past the
data segment, due to the explicit zero-termination of the symlink
target.

Fix filename buffer overrun by aborting the initramfs FSM if any cpio
entry doesn't carry a zero-terminator at the expected (name_len - 1)
offset.

Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2")
Signed-off-by: David Disseldorp &lt;ddiss@suse.de&gt;
Link: https://lore.kernel.org/r/20241030035509.20194-2-ddiss@suse.de
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>rcu-tasks: Initialize data to eliminate RCU-tasks/do_exit() deadlocks</title>
<updated>2024-11-08T15:28:22Z</updated>
<author>
<name>Paul E. McKenney</name>
<email>paulmck@kernel.org</email>
</author>
<published>2024-02-05T21:10:19Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=7679283e61a8b8378850e302deb5e64497b6dfbe'/>
<id>urn:sha1:7679283e61a8b8378850e302deb5e64497b6dfbe</id>
<content type='text'>
[ Upstream commit 46faf9d8e1d52e4a91c382c6c72da6bd8e68297b ]

Holding a mutex across synchronize_rcu_tasks() and acquiring
that same mutex in code called from do_exit() after its call to
exit_tasks_rcu_start() but before its call to exit_tasks_rcu_stop()
results in deadlock.  This is by design, because tasks that are far
enough into do_exit() are no longer present on the tasks list, making
it a bit difficult for RCU Tasks to find them, let alone wait on them
to do a voluntary context switch.  However, such deadlocks are becoming
more frequent.  In addition, lockdep currently does not detect such
deadlocks and they can be difficult to reproduce.

In addition, if a task voluntarily context switches during that time
(for example, if it blocks acquiring a mutex), then this task is in an
RCU Tasks quiescent state.  And with some adjustments, RCU Tasks could
just as well take advantage of that fact.

This commit therefore initializes the data structures that will be needed
to rely on these quiescent states and to eliminate these deadlocks.

Link: https://lore.kernel.org/all/20240118021842.290665-1-chenzhongjin@huawei.com/

Reported-by: Chen Zhongjin &lt;chenzhongjin@huawei.com&gt;
Reported-by: Yang Jihong &lt;yangjihong1@huawei.com&gt;
Signed-off-by: Paul E. McKenney &lt;paulmck@kernel.org&gt;
Tested-by: Yang Jihong &lt;yangjihong1@huawei.com&gt;
Tested-by: Chen Zhongjin &lt;chenzhongjin@huawei.com&gt;
Reviewed-by: Frederic Weisbecker &lt;frederic@kernel.org&gt;
Signed-off-by: Boqun Feng &lt;boqun.feng@gmail.com&gt;
Stable-dep-of: fd70e9f1d85f ("rcu-tasks: Fix access non-existent percpu rtpcp variable in rcu_tasks_need_gpcb()")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>rust: fix the default format for CONFIG_{RUSTC,BINDGEN}_VERSION_TEXT</title>
<updated>2024-08-29T15:33:29Z</updated>
<author>
<name>Masahiro Yamada</name>
<email>masahiroy@kernel.org</email>
</author>
<published>2024-07-27T14:03:00Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=881eb2fae123cea9bd393c90b5c07b3cbadc0e32'/>
<id>urn:sha1:881eb2fae123cea9bd393c90b5c07b3cbadc0e32</id>
<content type='text'>
[ Upstream commit aacf93e87f0d808ef46e621aa56caea336b4433c ]

Another oddity in these config entries is their default value can fall
back to 'n', which is a value for bool or tristate symbols.

The '|| echo n' is an incorrect workaround to avoid the syntax error.
This is not a big deal, as the entry is hidden by 'depends on RUST' in
situations where '$(RUSTC) --version' or '$(BINDGEN) --version' fails.
Anyway, it looks odd.

The default of a string type symbol should be a double-quoted string
literal. Turn it into an empty string when the version command fails.

Fixes: 2f7ab1267dc9 ("Kbuild: add Rust support")
Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Link: https://lore.kernel.org/r/20240727140302.1806011-2-masahiroy@kernel.org
[ Rebased on top of v6.11-rc1. - Miguel ]
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>rust: suppress error messages from CONFIG_{RUSTC,BINDGEN}_VERSION_TEXT</title>
<updated>2024-08-29T15:33:29Z</updated>
<author>
<name>Masahiro Yamada</name>
<email>masahiroy@kernel.org</email>
</author>
<published>2024-07-27T14:02:59Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=b4dad0cab6875d7054548ef0bd48ffb58583e68a'/>
<id>urn:sha1:b4dad0cab6875d7054548ef0bd48ffb58583e68a</id>
<content type='text'>
[ Upstream commit 5ce86c6c861352c9346ebb5c96ed70cb67414aa3 ]

While this is a somewhat unusual case, I encountered odd error messages
when I ran Kconfig in a foreign architecture chroot.

  $ make allmodconfig
  sh: 1: rustc: not found
  sh: 1: bindgen: not found
  #
  # configuration written to .config
  #

The successful execution of 'command -v rustc' does not necessarily mean
that 'rustc --version' will succeed.

  $ sh -c 'command -v rustc'
  /home/masahiro/.cargo/bin/rustc
  $ sh -c 'rustc --version'
  sh: 1: rustc: not found

Here, 'rustc' is built for x86, and I ran it in an arm64 system.

The current code:

  command -v $(RUSTC) &gt;/dev/null 2&gt;&amp;1 &amp;&amp; $(RUSTC) --version || echo n

can be turned into:

  command -v $(RUSTC) &gt;/dev/null 2&gt;&amp;1 &amp;&amp; $(RUSTC) --version 2&gt;/dev/null || echo n

However, I did not understand the necessity of 'command -v $(RUSTC)'.

I simplified it to:

  $(RUSTC) --version 2&gt;/dev/null || echo n

Fixes: 2f7ab1267dc9 ("Kbuild: add Rust support")
Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Link: https://lore.kernel.org/r/20240727140302.1806011-1-masahiroy@kernel.org
[ Rebased on top of v6.11-rc1. - Miguel ]
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>rust: work around `bindgen` 0.69.0 issue</title>
<updated>2024-08-29T15:33:29Z</updated>
<author>
<name>Miguel Ojeda</name>
<email>ojeda@kernel.org</email>
</author>
<published>2024-07-09T16:06:03Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=34e1335905f2311a3d788108ae0a5102719f068d'/>
<id>urn:sha1:34e1335905f2311a3d788108ae0a5102719f068d</id>
<content type='text'>
[ Upstream commit 9e98db17837093cb0f4dcfcc3524739d93249c45 ]

`bindgen` 0.69.0 contains a bug: `--version` does not work without
providing a header [1]:

    error: the following required arguments were not provided:
      &lt;HEADER&gt;

    Usage: bindgen &lt;FLAGS&gt; &lt;OPTIONS&gt; &lt;HEADER&gt; -- &lt;CLANG_ARGS&gt;...

Thus, in preparation for supporting several `bindgen` versions, work
around the issue by passing a dummy argument.

Include a comment so that we can remove the workaround in the future.

Link: https://github.com/rust-lang/rust-bindgen/pull/2678 [1]
Reviewed-by: Finn Behrens &lt;me@kloenk.dev&gt;
Tested-by: Benno Lossin &lt;benno.lossin@proton.me&gt;
Tested-by: Andreas Hindborg &lt;a.hindborg@samsung.com&gt;
Link: https://lore.kernel.org/r/20240709160615.998336-9-ojeda@kernel.org
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
Stable-dep-of: 5ce86c6c8613 ("rust: suppress error messages from CONFIG_{RUSTC,BINDGEN}_VERSION_TEXT")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>rust: SHADOW_CALL_STACK is incompatible with Rust</title>
<updated>2024-08-11T10:47:24Z</updated>
<author>
<name>Alice Ryhl</name>
<email>aliceryhl@google.com</email>
</author>
<published>2024-07-29T14:22:49Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=5e5a29bd54a287c20c135ee07bdaa9cb05c5098a'/>
<id>urn:sha1:5e5a29bd54a287c20c135ee07bdaa9cb05c5098a</id>
<content type='text'>
commit f126745da81783fb1d082e67bf14c6795e489a88 upstream.

When using the shadow call stack sanitizer, all code must be compiled
with the -ffixed-x18 flag, but this flag is not currently being passed
to Rust. This results in crashes that are extremely difficult to debug.

To ensure that nobody else has to go through the same debugging session
that I had to, prevent configurations that enable both SHADOW_CALL_STACK
and RUST.

It is rather common for people to backport 724a75ac9542 ("arm64: rust:
Enable Rust support for AArch64"), so I recommend applying this fix all
the way back to 6.1.

Cc: stable@vger.kernel.org # 6.1 and later
Fixes: 724a75ac9542 ("arm64: rust: Enable Rust support for AArch64")
Signed-off-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Acked-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
Link: https://lore.kernel.org/r/20240729-shadow-call-stack-v4-1-2a664b082ea4@google.com
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>smp: Provide 'setup_max_cpus' definition on UP too</title>
<updated>2024-06-16T11:47:49Z</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2024-02-26T11:07:31Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=8353b7f70dd22461e3adb9a0edf8f2f09ccd9aa6'/>
<id>urn:sha1:8353b7f70dd22461e3adb9a0edf8f2f09ccd9aa6</id>
<content type='text'>
commit 3c2f8859ae1ce53f2a89c8e4ca4092101afbff67 upstream.

This was already defined locally by init/main.c, but let's make
it generic, as arch/x86/kernel/cpu/topology.c is going to make
use of it to have more uniform code.

Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
</feed>
