<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/init/Kconfig, branch v6.13-rc7</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge tag 'mm-nonmm-stable-2024-11-24-02-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm</title>
<updated>2024-11-26T00:09:48+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-11-26T00:09:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f5f4745a7f057b58c9728ee4e2c5d6d79f382fe7'/>
<id>f5f4745a7f057b58c9728ee4e2c5d6d79f382fe7</id>
<content type='text'>
Pull non-MM updates from Andrew Morton:

 - The series "resource: A couple of cleanups" from Andy Shevchenko
   performs some cleanups in the resource management code

 - The series "Improve the copy of task comm" from Yafang Shao addresses
   possible race-induced overflows in the management of
   task_struct.comm[]

 - The series "Remove unnecessary header includes from
   {tools/}lib/list_sort.c" from Kuan-Wei Chiu adds some cleanups and a
   small fix to the list_sort library code and to its selftest

 - The series "Enhance min heap API with non-inline functions and
   optimizations" also from Kuan-Wei Chiu optimizes and cleans up the
   min_heap library code

 - The series "nilfs2: Finish folio conversion" from Ryusuke Konishi
   finishes off nilfs2's folioification

 - The series "add detect count for hung tasks" from Lance Yang adds
   more userspace visibility into the hung-task detector's activity

 - Apart from that, singelton patches in many places - please see the
   individual changelogs for details

* tag 'mm-nonmm-stable-2024-11-24-02-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits)
  gdb: lx-symbols: do not error out on monolithic build
  kernel/reboot: replace sprintf() with sysfs_emit()
  lib: util_macros_kunit: add kunit test for util_macros.h
  util_macros.h: fix/rework find_closest() macros
  Improve consistency of '#error' directive messages
  ocfs2: fix uninitialized value in ocfs2_file_read_iter()
  hung_task: add docs for hung_task_detect_count
  hung_task: add detect count for hung tasks
  dma-buf: use atomic64_inc_return() in dma_buf_getfile()
  fs/proc/kcore.c: fix coccinelle reported ERROR instances
  resource: avoid unnecessary resource tree walking in __region_intersects()
  ocfs2: remove unused errmsg function and table
  ocfs2: cluster: fix a typo
  lib/scatterlist: use sg_phys() helper
  checkpatch: always parse orig_commit in fixes tag
  nilfs2: convert metadata aops from writepage to writepages
  nilfs2: convert nilfs_recovery_copy_block() to take a folio
  nilfs2: convert nilfs_page_count_clean_buffers() to take a folio
  nilfs2: remove nilfs_writepage
  nilfs2: convert checkpoint file to be folio-based
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull non-MM updates from Andrew Morton:

 - The series "resource: A couple of cleanups" from Andy Shevchenko
   performs some cleanups in the resource management code

 - The series "Improve the copy of task comm" from Yafang Shao addresses
   possible race-induced overflows in the management of
   task_struct.comm[]

 - The series "Remove unnecessary header includes from
   {tools/}lib/list_sort.c" from Kuan-Wei Chiu adds some cleanups and a
   small fix to the list_sort library code and to its selftest

 - The series "Enhance min heap API with non-inline functions and
   optimizations" also from Kuan-Wei Chiu optimizes and cleans up the
   min_heap library code

 - The series "nilfs2: Finish folio conversion" from Ryusuke Konishi
   finishes off nilfs2's folioification

 - The series "add detect count for hung tasks" from Lance Yang adds
   more userspace visibility into the hung-task detector's activity

 - Apart from that, singelton patches in many places - please see the
   individual changelogs for details

* tag 'mm-nonmm-stable-2024-11-24-02-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits)
  gdb: lx-symbols: do not error out on monolithic build
  kernel/reboot: replace sprintf() with sysfs_emit()
  lib: util_macros_kunit: add kunit test for util_macros.h
  util_macros.h: fix/rework find_closest() macros
  Improve consistency of '#error' directive messages
  ocfs2: fix uninitialized value in ocfs2_file_read_iter()
  hung_task: add docs for hung_task_detect_count
  hung_task: add detect count for hung tasks
  dma-buf: use atomic64_inc_return() in dma_buf_getfile()
  fs/proc/kcore.c: fix coccinelle reported ERROR instances
  resource: avoid unnecessary resource tree walking in __region_intersects()
  ocfs2: remove unused errmsg function and table
  ocfs2: cluster: fix a typo
  lib/scatterlist: use sg_phys() helper
  checkpatch: always parse orig_commit in fixes tag
  nilfs2: convert metadata aops from writepage to writepages
  nilfs2: convert nilfs_recovery_copy_block() to take a folio
  nilfs2: convert nilfs_page_count_clean_buffers() to take a folio
  nilfs2: remove nilfs_writepage
  nilfs2: convert checkpoint file to be folio-based
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'hardening-v6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux</title>
<updated>2024-11-25T23:22:35+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-11-25T23:22:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=36843bfbf7fdeab459e164b0ed8bb939660c378b'/>
<id>36843bfbf7fdeab459e164b0ed8bb939660c378b</id>
<content type='text'>
Pull hardening updates from Kees Cook:

 - Disable __counted_by in Clang &lt; 19.1.3 (Jan Hendrik Farr)

 - string_helpers: Silence output truncation warning (Bartosz
   Golaszewski)

 - compiler.h: Avoid needing BUILD_BUG_ON_ZERO() (Philipp Reisner)

 - MAINTAINERS: Add kernel hardening keywords __counted_by{_le|_be}
   (Thorsten Blum)

* tag 'hardening-v6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  Compiler Attributes: disable __counted_by for clang &lt; 19.1.3
  compiler.h: Fix undefined BUILD_BUG_ON_ZERO()
  lib: string_helpers: silence snprintf() output truncation warning
  MAINTAINERS: Add kernel hardening keywords __counted_by{_le|_be}
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull hardening updates from Kees Cook:

 - Disable __counted_by in Clang &lt; 19.1.3 (Jan Hendrik Farr)

 - string_helpers: Silence output truncation warning (Bartosz
   Golaszewski)

 - compiler.h: Avoid needing BUILD_BUG_ON_ZERO() (Philipp Reisner)

 - MAINTAINERS: Add kernel hardening keywords __counted_by{_le|_be}
   (Thorsten Blum)

* tag 'hardening-v6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  Compiler Attributes: disable __counted_by for clang &lt; 19.1.3
  compiler.h: Fix undefined BUILD_BUG_ON_ZERO()
  lib: string_helpers: silence snprintf() output truncation warning
  MAINTAINERS: Add kernel hardening keywords __counted_by{_le|_be}
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'trace-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace</title>
<updated>2024-11-22T21:27:01+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-11-22T21:27:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=06afb0f36106ecb839c5e2509905e68c1e2677de'/>
<id>06afb0f36106ecb839c5e2509905e68c1e2677de</id>
<content type='text'>
Pull tracing updates from Steven Rostedt:

 - Addition of faultable tracepoints

   There's a tracepoint attached to both a system call entry and exit.
   This location is known to allow page faults. The tracepoints are
   called under an rcu_read_lock() which does not allow faults that can
   sleep. This limits the ability of tracepoint handlers to page fault
   in user space system call parameters. Now these tracepoints have been
   made "faultable", allowing the callbacks to fault in user space
   parameters and record them.

   Note, only the infrastructure has been implemented. The consumers
   (perf, ftrace, BPF) now need to have their code modified to allow
   faults.

 - Fix up of BPF code for the tracepoint faultable logic

 - Update tracepoints to use the new static branch API

 - Remove trace_*_rcuidle() variants and the SRCU protection they used

 - Remove unused TRACE_EVENT_FL_FILTERED logic

 - Replace strncpy() with strscpy() and memcpy()

 - Use replace per_cpu_ptr(smp_processor_id()) with this_cpu_ptr()

 - Fix perf events to not duplicate samples when tracing is enabled

 - Replace atomic64_add_return(1, counter) with
   atomic64_inc_return(counter)

 - Make stack trace buffer 4K instead of PAGE_SIZE

 - Remove TRACE_FLAG_IRQS_NOSUPPORT flag as it was never used

 - Get the true return address for function tracer when function graph
   tracer is also running.

   When function_graph trace is running along with function tracer, the
   parent function of the function tracer sometimes is
   "return_to_handler", which is the function graph trampoline to record
   the exit of the function. Use existing logic that calls into the
   fgraph infrastructure to find the real return address.

 - Remove (un)regfunc pointers out of tracepoint structure

 - Added last minute bug fix for setting pending modules in stack
   function filter.

     echo "write*:mod:ext3" &gt; /sys/kernel/tracing/stack_trace_filter

   Would cause a kernel NULL dereference.

 - Minor clean ups

* tag 'trace-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (31 commits)
  ftrace: Fix regression with module command in stack_trace_filter
  tracing: Fix function name for trampoline
  ftrace: Get the true parent ip for function tracer
  tracing: Remove redundant check on field-&gt;field in histograms
  bpf: ensure RCU Tasks Trace GP for sleepable raw tracepoint BPF links
  bpf: decouple BPF link/attach hook and BPF program sleepable semantics
  bpf: put bpf_link's program when link is safe to be deallocated
  tracing: Replace strncpy() with strscpy() when copying comm
  tracing: Add might_fault() check in __DECLARE_TRACE_SYSCALL
  tracing: Fix syscall tracepoint use-after-free
  tracing: Introduce tracepoint_is_faultable()
  tracing: Introduce tracepoint extended structure
  tracing: Remove TRACE_FLAG_IRQS_NOSUPPORT
  tracing: Replace multiple deprecated strncpy with memcpy
  tracing: Make percpu stack trace buffer invariant to PAGE_SIZE
  tracing: Use atomic64_inc_return() in trace_clock_counter()
  trace/trace_event_perf: remove duplicate samples on the first tracepoint event
  tracing/bpf: Add might_fault check to syscall probes
  tracing/perf: Add might_fault check to syscall probes
  tracing/ftrace: Add might_fault check to syscall probes
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull tracing updates from Steven Rostedt:

 - Addition of faultable tracepoints

   There's a tracepoint attached to both a system call entry and exit.
   This location is known to allow page faults. The tracepoints are
   called under an rcu_read_lock() which does not allow faults that can
   sleep. This limits the ability of tracepoint handlers to page fault
   in user space system call parameters. Now these tracepoints have been
   made "faultable", allowing the callbacks to fault in user space
   parameters and record them.

   Note, only the infrastructure has been implemented. The consumers
   (perf, ftrace, BPF) now need to have their code modified to allow
   faults.

 - Fix up of BPF code for the tracepoint faultable logic

 - Update tracepoints to use the new static branch API

 - Remove trace_*_rcuidle() variants and the SRCU protection they used

 - Remove unused TRACE_EVENT_FL_FILTERED logic

 - Replace strncpy() with strscpy() and memcpy()

 - Use replace per_cpu_ptr(smp_processor_id()) with this_cpu_ptr()

 - Fix perf events to not duplicate samples when tracing is enabled

 - Replace atomic64_add_return(1, counter) with
   atomic64_inc_return(counter)

 - Make stack trace buffer 4K instead of PAGE_SIZE

 - Remove TRACE_FLAG_IRQS_NOSUPPORT flag as it was never used

 - Get the true return address for function tracer when function graph
   tracer is also running.

   When function_graph trace is running along with function tracer, the
   parent function of the function tracer sometimes is
   "return_to_handler", which is the function graph trampoline to record
   the exit of the function. Use existing logic that calls into the
   fgraph infrastructure to find the real return address.

 - Remove (un)regfunc pointers out of tracepoint structure

 - Added last minute bug fix for setting pending modules in stack
   function filter.

     echo "write*:mod:ext3" &gt; /sys/kernel/tracing/stack_trace_filter

   Would cause a kernel NULL dereference.

 - Minor clean ups

* tag 'trace-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (31 commits)
  ftrace: Fix regression with module command in stack_trace_filter
  tracing: Fix function name for trampoline
  ftrace: Get the true parent ip for function tracer
  tracing: Remove redundant check on field-&gt;field in histograms
  bpf: ensure RCU Tasks Trace GP for sleepable raw tracepoint BPF links
  bpf: decouple BPF link/attach hook and BPF program sleepable semantics
  bpf: put bpf_link's program when link is safe to be deallocated
  tracing: Replace strncpy() with strscpy() when copying comm
  tracing: Add might_fault() check in __DECLARE_TRACE_SYSCALL
  tracing: Fix syscall tracepoint use-after-free
  tracing: Introduce tracepoint_is_faultable()
  tracing: Introduce tracepoint extended structure
  tracing: Remove TRACE_FLAG_IRQS_NOSUPPORT
  tracing: Replace multiple deprecated strncpy with memcpy
  tracing: Make percpu stack trace buffer invariant to PAGE_SIZE
  tracing: Use atomic64_inc_return() in trace_clock_counter()
  trace/trace_event_perf: remove duplicate samples on the first tracepoint event
  tracing/bpf: Add might_fault check to syscall probes
  tracing/perf: Add might_fault check to syscall probes
  tracing/ftrace: Add might_fault check to syscall probes
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Compiler Attributes: disable __counted_by for clang &lt; 19.1.3</title>
<updated>2024-11-19T16:48:27+00:00</updated>
<author>
<name>Jan Hendrik Farr</name>
<email>kernel@jfarr.cc</email>
</author>
<published>2024-10-29T14:00:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f06e108a3dc53c0f5234d18de0bd224753db5019'/>
<id>f06e108a3dc53c0f5234d18de0bd224753db5019</id>
<content type='text'>
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;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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;
</pre>
</div>
</content>
</entry>
<entry>
<title>lib/Makefile: make union-find compilation conditional on CONFIG_CPUSETS</title>
<updated>2024-11-06T01:12:32+00:00</updated>
<author>
<name>Kuan-Wei Chiu</name>
<email>visitorckw@gmail.com</email>
</author>
<published>2024-10-11T14:12:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=bf9850f6ea3577a099b0ed43f6e19ca43ef08704'/>
<id>bf9850f6ea3577a099b0ed43f6e19ca43ef08704</id>
<content type='text'>
Currently, cpuset is the only user of the union-find implementation. 
Compiling union-find in all configurations unnecessarily increases the
code size when building the kernel without cgroup support.  Modify the
build system to compile union-find only when CONFIG_CPUSETS is enabled.

Link: https://lore.kernel.org/lkml/1ccd6411-5002-4574-bb8e-3e64bba6a757@redhat.com/
Link: https://lkml.kernel.org/r/20241011141214.87096-1-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu &lt;visitorckw@gmail.com&gt;
Suggested-by: Waiman Long &lt;llong@redhat.com&gt;
Acked-by: Waiman Long &lt;longman@redhat.com&gt;
Acked-by: Tejun Heo &lt;tj@kernel.org&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Cc: Ching-Chun (Jim) Huang &lt;jserv@ccns.ncku.edu.tw&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Michal Koutný &lt;mkoutny@suse.com&gt;
Cc: Xavier &lt;xavier_qy@163.com&gt;
Cc: Zefan Li &lt;lizefan.x@bytedance.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>
Currently, cpuset is the only user of the union-find implementation. 
Compiling union-find in all configurations unnecessarily increases the
code size when building the kernel without cgroup support.  Modify the
build system to compile union-find only when CONFIG_CPUSETS is enabled.

Link: https://lore.kernel.org/lkml/1ccd6411-5002-4574-bb8e-3e64bba6a757@redhat.com/
Link: https://lkml.kernel.org/r/20241011141214.87096-1-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu &lt;visitorckw@gmail.com&gt;
Suggested-by: Waiman Long &lt;llong@redhat.com&gt;
Acked-by: Waiman Long &lt;longman@redhat.com&gt;
Acked-by: Tejun Heo &lt;tj@kernel.org&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Cc: Ching-Chun (Jim) Huang &lt;jserv@ccns.ncku.edu.tw&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Michal Koutný &lt;mkoutny@suse.com&gt;
Cc: Xavier &lt;xavier_qy@163.com&gt;
Cc: Zefan Li &lt;lizefan.x@bytedance.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cfi: fix conditions for HAVE_CFI_ICALL_NORMALIZE_INTEGERS</title>
<updated>2024-10-13T20:23:13+00:00</updated>
<author>
<name>Alice Ryhl</name>
<email>aliceryhl@google.com</email>
</author>
<published>2024-10-10T09:38:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8b8ca9c25fe69c2162e3235c7d6c341127abeed6'/>
<id>8b8ca9c25fe69c2162e3235c7d6c341127abeed6</id>
<content type='text'>
The HAVE_CFI_ICALL_NORMALIZE_INTEGERS option has some tricky conditions
when KASAN or GCOV are turned on, as in that case we need some clang and
rustc fixes [1][2] to avoid boot failures. The intent with the current
setup is that you should be able to override the check and turn on the
option if your clang/rustc has the fix. However, this override does not
work in practice. Thus, use the new RUSTC_LLVM_VERSION to correctly
implement the check for whether the fix is available.

Additionally, remove KASAN_HW_TAGS from the list of incompatible
options. The CFI_ICALL_NORMALIZE_INTEGERS option is incompatible with
KASAN because LLVM will emit some constructors when using KASAN that are
assigned incorrect CFI tags. These constructors are emitted due to use
of -fsanitize=kernel-address or -fsanitize=kernel-hwaddress that are
respectively passed when KASAN_GENERIC or KASAN_SW_TAGS are enabled.
However, the KASAN_HW_TAGS option relies on hardware support for MTE
instead and does not pass either flag. (Note also that KASAN_HW_TAGS
does not `select CONSTRUCTORS`.)

Link: https://github.com/llvm/llvm-project/pull/104826 [1]
Link: https://github.com/rust-lang/rust/pull/129373 [2]
Fixes: 4c66f8307ac0 ("cfi: encode cfi normalized integers + kasan/gcov bug in Kconfig")
Signed-off-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Reviewed-by: Sami Tolvanen &lt;samitolvanen@google.com&gt;
Link: https://lore.kernel.org/r/20241010-icall-detect-vers-v1-2-8f114956aa88@google.com
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The HAVE_CFI_ICALL_NORMALIZE_INTEGERS option has some tricky conditions
when KASAN or GCOV are turned on, as in that case we need some clang and
rustc fixes [1][2] to avoid boot failures. The intent with the current
setup is that you should be able to override the check and turn on the
option if your clang/rustc has the fix. However, this override does not
work in practice. Thus, use the new RUSTC_LLVM_VERSION to correctly
implement the check for whether the fix is available.

Additionally, remove KASAN_HW_TAGS from the list of incompatible
options. The CFI_ICALL_NORMALIZE_INTEGERS option is incompatible with
KASAN because LLVM will emit some constructors when using KASAN that are
assigned incorrect CFI tags. These constructors are emitted due to use
of -fsanitize=kernel-address or -fsanitize=kernel-hwaddress that are
respectively passed when KASAN_GENERIC or KASAN_SW_TAGS are enabled.
However, the KASAN_HW_TAGS option relies on hardware support for MTE
instead and does not pass either flag. (Note also that KASAN_HW_TAGS
does not `select CONSTRUCTORS`.)

Link: https://github.com/llvm/llvm-project/pull/104826 [1]
Link: https://github.com/rust-lang/rust/pull/129373 [2]
Fixes: 4c66f8307ac0 ("cfi: encode cfi normalized integers + kasan/gcov bug in Kconfig")
Signed-off-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Reviewed-by: Sami Tolvanen &lt;samitolvanen@google.com&gt;
Link: https://lore.kernel.org/r/20241010-icall-detect-vers-v1-2-8f114956aa88@google.com
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>kbuild: rust: add `CONFIG_RUSTC_LLVM_VERSION`</title>
<updated>2024-10-13T20:22:28+00:00</updated>
<author>
<name>Gary Guo</name>
<email>gary@garyguo.net</email>
</author>
<published>2024-10-11T11:40:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=af0121c2d303111d363c62e40413ffb39d5dc0f1'/>
<id>af0121c2d303111d363c62e40413ffb39d5dc0f1</id>
<content type='text'>
Each version of Rust supports a range of LLVM versions. There are cases where
we want to gate a config on the LLVM version instead of the Rust version.
Normalized cfi integer tags are one example [1].

The invocation of rustc-version is being moved from init/Kconfig to
scripts/Kconfig.include for consistency with cc-version.

Link: https://lore.kernel.org/all/20240925-cfi-norm-kasan-fix-v1-1-0328985cdf33@google.com/ [1]
Signed-off-by: Gary Guo &lt;gary@garyguo.net&gt;
Link: https://lore.kernel.org/r/20241011114040.3900487-1-gary@garyguo.net
[ Added missing `-llvm` to the Usage documentation. - Miguel ]
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Each version of Rust supports a range of LLVM versions. There are cases where
we want to gate a config on the LLVM version instead of the Rust version.
Normalized cfi integer tags are one example [1].

The invocation of rustc-version is being moved from init/Kconfig to
scripts/Kconfig.include for consistency with cc-version.

Link: https://lore.kernel.org/all/20240925-cfi-norm-kasan-fix-v1-1-0328985cdf33@google.com/ [1]
Signed-off-by: Gary Guo &lt;gary@garyguo.net&gt;
Link: https://lore.kernel.org/r/20241011114040.3900487-1-gary@garyguo.net
[ Added missing `-llvm` to the Usage documentation. - Miguel ]
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing: Allow system call tracepoints to handle page faults</title>
<updated>2024-10-09T21:08:03+00:00</updated>
<author>
<name>Mathieu Desnoyers</name>
<email>mathieu.desnoyers@efficios.com</email>
</author>
<published>2024-10-09T01:07:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a363d27cdbc2bc2d1899b5a1520b64e3590fcd9a'/>
<id>a363d27cdbc2bc2d1899b5a1520b64e3590fcd9a</id>
<content type='text'>
Use Tasks Trace RCU to protect iteration of system call enter/exit
tracepoint probes to allow those probes to handle page faults.

In preparation for this change, all tracers registering to system call
enter/exit tracepoints should expect those to be called with preemption
enabled.

This allows tracers to fault-in userspace system call arguments such as
path strings within their probe callbacks.

Cc: Michael Jeanson &lt;mjeanson@efficios.com&gt;
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Yonghong Song &lt;yhs@fb.com&gt;
Cc: Paul E. McKenney &lt;paulmck@kernel.org&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Andrii Nakryiko &lt;andrii.nakryiko@gmail.com&gt;
Cc: bpf@vger.kernel.org
Cc: Joel Fernandes &lt;joel@joelfernandes.org&gt;
Link: https://lore.kernel.org/20241009010718.2050182-6-mathieu.desnoyers@efficios.com
Signed-off-by: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Use Tasks Trace RCU to protect iteration of system call enter/exit
tracepoint probes to allow those probes to handle page faults.

In preparation for this change, all tracers registering to system call
enter/exit tracepoints should expect those to be called with preemption
enabled.

This allows tracers to fault-in userspace system call arguments such as
path strings within their probe callbacks.

Cc: Michael Jeanson &lt;mjeanson@efficios.com&gt;
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Yonghong Song &lt;yhs@fb.com&gt;
Cc: Paul E. McKenney &lt;paulmck@kernel.org&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Andrii Nakryiko &lt;andrii.nakryiko@gmail.com&gt;
Cc: bpf@vger.kernel.org
Cc: Joel Fernandes &lt;joel@joelfernandes.org&gt;
Link: https://lore.kernel.org/20241009010718.2050182-6-mathieu.desnoyers@efficios.com
Signed-off-by: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cfi: encode cfi normalized integers + kasan/gcov bug in Kconfig</title>
<updated>2024-09-26T19:27:27+00:00</updated>
<author>
<name>Alice Ryhl</name>
<email>aliceryhl@google.com</email>
</author>
<published>2024-09-25T08:10:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4c66f8307ac099f89038878b7789d72163a74751'/>
<id>4c66f8307ac099f89038878b7789d72163a74751</id>
<content type='text'>
There is a bug in the LLVM implementation of KASAN and GCOV that makes
these options incompatible with the CFI_ICALL_NORMALIZE_INTEGERS option.

The bug has already been fixed in llvm/clang [1] and rustc [2]. However,
Kconfig currently has no way to gate features on the LLVM version inside
rustc, so we cannot write down a precise `depends on` clause in this
case. Instead, a `def_bool` option is defined for whether
CFI_ICALL_NORMALIZE_INTEGERS is available, and its default value is set
to false when GCOV or KASAN are turned on. End users using a patched
clang/rustc can turn on the HAVE_CFI_ICALL_NORMALIZE_INTEGERS option
directly to override this.

An alternative solution is to inspect a binary created by clang or rustc
to see whether the faulty CFI tags are in the binary. This would be a
precise check, but it would involve hard-coding the *hashed* version of
the CFI tag. This is because there's no way to get clang or rustc to
output the unhased version of the CFI tag. Relying on the precise
hashing algorithm using by CFI seems too fragile, so I have not pursued
this option. Besides, this kind of hack is exactly what lead to the LLVM
bug in the first place.

If the CFI_ICALL_NORMALIZE_INTEGERS option is used without CONFIG_RUST,
then we actually can perform a precise check today: just compare the
clang version number. This works since clang and llvm are always updated
in lockstep. However, encoding this in Kconfig would give the
HAVE_CFI_ICALL_NORMALIZE_INTEGERS option a dependency on CONFIG_RUST,
which is not possible as the reverse dependency already exists.

HAVE_CFI_ICALL_NORMALIZE_INTEGERS is defined to be a `def_bool` instead
of `bool` to avoid asking end users whether they want to turn on the
option. Turning it on explicitly is something only experts should do, so
making it hard to do so is not an issue.

I added a `depends on CFI_CLANG` clause to the new Kconfig option. I'm
not sure whether that makes sense or not, but it doesn't seem to make a
big difference.

In a future kernel release, I would like to add a Kconfig option similar
to CLANG_VERSION/RUSTC_VERSION for inspecting the version of the LLVM
inside rustc. Once that feature lands, this logic will be replaced with
a precise version check. This check is not being introduced here to
avoid introducing a new _VERSION constant in a fix.

Link: https://github.com/llvm/llvm-project/pull/104826 [1]
Link: https://github.com/rust-lang/rust/pull/129373 [2]
Fixes: ce4a2620985c ("cfi: add CONFIG_CFI_ICALL_NORMALIZE_INTEGERS")
Reported-by: kernel test robot &lt;oliver.sang@intel.com&gt;
Closes: https://lore.kernel.org/oe-lkp/202409231044.4f064459-oliver.sang@intel.com
Signed-off-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Reviewed-by: Sami Tolvanen &lt;samitolvanen@google.com&gt;
Link: https://lore.kernel.org/r/20240925-cfi-norm-kasan-fix-v1-1-0328985cdf33@google.com
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There is a bug in the LLVM implementation of KASAN and GCOV that makes
these options incompatible with the CFI_ICALL_NORMALIZE_INTEGERS option.

The bug has already been fixed in llvm/clang [1] and rustc [2]. However,
Kconfig currently has no way to gate features on the LLVM version inside
rustc, so we cannot write down a precise `depends on` clause in this
case. Instead, a `def_bool` option is defined for whether
CFI_ICALL_NORMALIZE_INTEGERS is available, and its default value is set
to false when GCOV or KASAN are turned on. End users using a patched
clang/rustc can turn on the HAVE_CFI_ICALL_NORMALIZE_INTEGERS option
directly to override this.

An alternative solution is to inspect a binary created by clang or rustc
to see whether the faulty CFI tags are in the binary. This would be a
precise check, but it would involve hard-coding the *hashed* version of
the CFI tag. This is because there's no way to get clang or rustc to
output the unhased version of the CFI tag. Relying on the precise
hashing algorithm using by CFI seems too fragile, so I have not pursued
this option. Besides, this kind of hack is exactly what lead to the LLVM
bug in the first place.

If the CFI_ICALL_NORMALIZE_INTEGERS option is used without CONFIG_RUST,
then we actually can perform a precise check today: just compare the
clang version number. This works since clang and llvm are always updated
in lockstep. However, encoding this in Kconfig would give the
HAVE_CFI_ICALL_NORMALIZE_INTEGERS option a dependency on CONFIG_RUST,
which is not possible as the reverse dependency already exists.

HAVE_CFI_ICALL_NORMALIZE_INTEGERS is defined to be a `def_bool` instead
of `bool` to avoid asking end users whether they want to turn on the
option. Turning it on explicitly is something only experts should do, so
making it hard to do so is not an issue.

I added a `depends on CFI_CLANG` clause to the new Kconfig option. I'm
not sure whether that makes sense or not, but it doesn't seem to make a
big difference.

In a future kernel release, I would like to add a Kconfig option similar
to CLANG_VERSION/RUSTC_VERSION for inspecting the version of the LLVM
inside rustc. Once that feature lands, this logic will be replaced with
a precise version check. This check is not being introduced here to
avoid introducing a new _VERSION constant in a fix.

Link: https://github.com/llvm/llvm-project/pull/104826 [1]
Link: https://github.com/rust-lang/rust/pull/129373 [2]
Fixes: ce4a2620985c ("cfi: add CONFIG_CFI_ICALL_NORMALIZE_INTEGERS")
Reported-by: kernel test robot &lt;oliver.sang@intel.com&gt;
Closes: https://lore.kernel.org/oe-lkp/202409231044.4f064459-oliver.sang@intel.com
Signed-off-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Reviewed-by: Sami Tolvanen &lt;samitolvanen@google.com&gt;
Link: https://lore.kernel.org/r/20240925-cfi-norm-kasan-fix-v1-1-0328985cdf33@google.com
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rust: KASAN+RETHUNK requires rustc 1.83.0</title>
<updated>2024-09-26T19:27:27+00:00</updated>
<author>
<name>Alice Ryhl</name>
<email>aliceryhl@google.com</email>
</author>
<published>2024-09-26T09:38:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=93e34a0b5c0e79ce765f01fd10f7817863fba23d'/>
<id>93e34a0b5c0e79ce765f01fd10f7817863fba23d</id>
<content type='text'>
When enabling both KASAN and RETHUNK, objtool emits the following
warnings:

    rust/core.o: warning: objtool: asan.module_ctor+0x13: 'naked' return found in MITIGATION_RETHUNK build
    rust/core.o: warning: objtool: asan.module_dtor+0x13: 'naked' return found in MITIGATION_RETHUNK build

This is caused by the -Zfunction-return=thunk-extern flag in rustc not
informing LLVM about the mitigation at the module level (it does so at
the function level only currently, which covers most cases, but both
are required), which means that the KASAN functions asan.module_ctor
and asan.module_dtor are generated without the rethunk mitigation.

The other mitigations that we enabled for Rust (SLS, RETPOLINE) do not
have the same bug, as they're being applied through the target-feature
functionality instead.

This is being fixed for rustc 1.83.0, so update Kconfig to reject this
configuration on older compilers.

Link: https://github.com/rust-lang/rust/pull/130824
Fixes: d7868550d573 ("x86/rust: support MITIGATION_RETHUNK")
Reported-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
Closes: https://lore.kernel.org/all/CANiq72myZL4_poCMuNFevtpYYc0V0embjSuKb7y=C+m3vVA_8g@mail.gmail.com/
Signed-off-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Link: https://lore.kernel.org/r/20240926093849.1192264-1-aliceryhl@google.com
[ Reworded to add the details mentioned in the list. - Miguel ]
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When enabling both KASAN and RETHUNK, objtool emits the following
warnings:

    rust/core.o: warning: objtool: asan.module_ctor+0x13: 'naked' return found in MITIGATION_RETHUNK build
    rust/core.o: warning: objtool: asan.module_dtor+0x13: 'naked' return found in MITIGATION_RETHUNK build

This is caused by the -Zfunction-return=thunk-extern flag in rustc not
informing LLVM about the mitigation at the module level (it does so at
the function level only currently, which covers most cases, but both
are required), which means that the KASAN functions asan.module_ctor
and asan.module_dtor are generated without the rethunk mitigation.

The other mitigations that we enabled for Rust (SLS, RETPOLINE) do not
have the same bug, as they're being applied through the target-feature
functionality instead.

This is being fixed for rustc 1.83.0, so update Kconfig to reject this
configuration on older compilers.

Link: https://github.com/rust-lang/rust/pull/130824
Fixes: d7868550d573 ("x86/rust: support MITIGATION_RETHUNK")
Reported-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
Closes: https://lore.kernel.org/all/CANiq72myZL4_poCMuNFevtpYYc0V0embjSuKb7y=C+m3vVA_8g@mail.gmail.com/
Signed-off-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Link: https://lore.kernel.org/r/20240926093849.1192264-1-aliceryhl@google.com
[ Reworded to add the details mentioned in the list. - Miguel ]
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
