<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/scripts, branch v6.15-rc4</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>Fix mis-uses of 'cc-option' for warning disablement</title>
<updated>2025-04-23T17:08:29+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-04-23T17:08:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a79be02bba5c31f967885c7f3bf3a756d77d11d9'/>
<id>a79be02bba5c31f967885c7f3bf3a756d77d11d9</id>
<content type='text'>
This was triggered by one of my mis-uses causing odd build warnings on
sparc in linux-next, but while figuring out why the "obviously correct"
use of cc-option caused such odd breakage, I found eight other cases of
the same thing in the tree.

The root cause is that 'cc-option' doesn't work for checking negative
warning options (ie things like '-Wno-stringop-overflow') because gcc
will silently accept options it doesn't recognize, and so 'cc-option'
ends up thinking they are perfectly fine.

And it all works, until you have a situation where _another_ warning is
emitted.  At that point the compiler will go "Hmm, maybe the user
intended to disable this warning but used that wrong option that I
didn't recognize", and generate a warning for the unrecognized negative
option.

Which explains why we have several cases of this in the tree: the
'cc-option' test really doesn't work for this situation, but most of the
time it simply doesn't matter that ity doesn't work.

The reason my recently added case caused problems on sparc was pointed
out by Thomas Weißschuh: the sparc build had a previous explicit warning
that then triggered the new one.

I think the best fix for this would be to make 'cc-option' a bit smarter
about this sitation, possibly by adding an intentional warning to the
test case that then triggers the unrecognized option warning reliably.

But the short-term fix is to replace 'cc-option' with an existing helper
designed for this exact case: 'cc-disable-warning', which picks the
negative warning but uses the positive form for testing the compiler
support.

Reported-by: Stephen Rothwell &lt;sfr@canb.auug.org.au&gt;
Link: https://lore.kernel.org/all/20250422204718.0b4e3f81@canb.auug.org.au/
Explained-by: Thomas Weißschuh &lt;linux@weissschuh.net&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>
This was triggered by one of my mis-uses causing odd build warnings on
sparc in linux-next, but while figuring out why the "obviously correct"
use of cc-option caused such odd breakage, I found eight other cases of
the same thing in the tree.

The root cause is that 'cc-option' doesn't work for checking negative
warning options (ie things like '-Wno-stringop-overflow') because gcc
will silently accept options it doesn't recognize, and so 'cc-option'
ends up thinking they are perfectly fine.

And it all works, until you have a situation where _another_ warning is
emitted.  At that point the compiler will go "Hmm, maybe the user
intended to disable this warning but used that wrong option that I
didn't recognize", and generate a warning for the unrecognized negative
option.

Which explains why we have several cases of this in the tree: the
'cc-option' test really doesn't work for this situation, but most of the
time it simply doesn't matter that ity doesn't work.

The reason my recently added case caused problems on sparc was pointed
out by Thomas Weißschuh: the sparc build had a previous explicit warning
that then triggered the new one.

I think the best fix for this would be to make 'cc-option' a bit smarter
about this sitation, possibly by adding an intentional warning to the
test case that then triggers the unrecognized option warning reliably.

But the short-term fix is to replace 'cc-option' with an existing helper
designed for this exact case: 'cc-disable-warning', which picks the
negative warning but uses the positive form for testing the compiler
support.

Reported-by: Stephen Rothwell &lt;sfr@canb.auug.org.au&gt;
Link: https://lore.kernel.org/all/20250422204718.0b4e3f81@canb.auug.org.au/
Explained-by: Thomas Weißschuh &lt;linux@weissschuh.net&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'rust-fixes-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux</title>
<updated>2025-04-19T17:02:43+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-04-19T17:02:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0bd2f269ae892ce7283fee8fcfe2c6c971d871bc'/>
<id>0bd2f269ae892ce7283fee8fcfe2c6c971d871bc</id>
<content type='text'>
Pull rust fixes from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Fix missing KASAN LLVM flags on first build (and fix spurious
     rebuilds) by skipping '--target'

   - Fix Make &lt; 4.3 build error by using '$(pound)'

   - Fix UML build error by removing 'volatile' qualifier from io
     helpers

   - Fix UML build error by adding 'dma_{alloc,free}_attrs()' helpers

   - Clean gendwarfksyms warnings by avoiding to export '__pfx' symbols

   - Clean objtool warning by adding a new 'noreturn' function for
     1.86.0

   - Disable 'needless_continue' Clippy lint due to new 1.86.0 warnings

   - Add missing 'ffi' crate to 'generate_rust_analyzer.py'

  'pin-init' crate:

   - Import a couple fixes from upstream"

* tag 'rust-fixes-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux:
  rust: helpers: Add dma_alloc_attrs() and dma_free_attrs()
  rust: helpers: Remove volatile qualifier from io helpers
  rust: kbuild: use `pound` to support GNU Make &lt; 4.3
  objtool/rust: add one more `noreturn` Rust function for Rust 1.86.0
  rust: kasan/kbuild: fix missing flags on first build
  rust: disable `clippy::needless_continue`
  rust: kbuild: Don't export __pfx symbols
  rust: pin-init: use Markdown autolinks in Rust comments
  rust: pin-init: alloc: restrict `impl ZeroableOption` for `Box` to `T: Sized`
  scripts: generate_rust_analyzer: Add ffi crate
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull rust fixes from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Fix missing KASAN LLVM flags on first build (and fix spurious
     rebuilds) by skipping '--target'

   - Fix Make &lt; 4.3 build error by using '$(pound)'

   - Fix UML build error by removing 'volatile' qualifier from io
     helpers

   - Fix UML build error by adding 'dma_{alloc,free}_attrs()' helpers

   - Clean gendwarfksyms warnings by avoiding to export '__pfx' symbols

   - Clean objtool warning by adding a new 'noreturn' function for
     1.86.0

   - Disable 'needless_continue' Clippy lint due to new 1.86.0 warnings

   - Add missing 'ffi' crate to 'generate_rust_analyzer.py'

  'pin-init' crate:

   - Import a couple fixes from upstream"

* tag 'rust-fixes-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux:
  rust: helpers: Add dma_alloc_attrs() and dma_free_attrs()
  rust: helpers: Remove volatile qualifier from io helpers
  rust: kbuild: use `pound` to support GNU Make &lt; 4.3
  objtool/rust: add one more `noreturn` Rust function for Rust 1.86.0
  rust: kasan/kbuild: fix missing flags on first build
  rust: disable `clippy::needless_continue`
  rust: kbuild: Don't export __pfx symbols
  rust: pin-init: use Markdown autolinks in Rust comments
  rust: pin-init: alloc: restrict `impl ZeroableOption` for `Box` to `T: Sized`
  scripts: generate_rust_analyzer: Add ffi crate
</pre>
</div>
</content>
</entry>
<entry>
<title>rust: kbuild: use `pound` to support GNU Make &lt; 4.3</title>
<updated>2025-04-15T18:45:46+00:00</updated>
<author>
<name>Miguel Ojeda</name>
<email>ojeda@kernel.org</email>
</author>
<published>2025-04-14T17:12:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1c4494c14b4124f3a13a7f4912b84b633ff4f9ba'/>
<id>1c4494c14b4124f3a13a7f4912b84b633ff4f9ba</id>
<content type='text'>
GNU Make 4.3 changed the behavior of `#` inside commands in commit
c6966b323811 ("[SV 20513] Un-escaped # are not comments in function
invocations"):

    * WARNING: Backward-incompatibility!
      Number signs (#) appearing inside a macro reference or function invocation
      no longer introduce comments and should not be escaped with backslashes:
      thus a call such as:
        foo := $(shell echo '#')
      is legal.  Previously the number sign needed to be escaped, for example:
        foo := $(shell echo '\#')
      Now this latter will resolve to "\#".  If you want to write makefiles
      portable to both versions, assign the number sign to a variable:
        H := \#
        foo := $(shell echo '$H')
      This was claimed to be fixed in 3.81, but wasn't, for some reason.
      To detect this change search for 'nocomment' in the .FEATURES variable.

Unlike other commits in the kernel about this issue, such as commit
633174a7046e ("lib/raid6/test/Makefile: Use $(pound) instead of \#
for Make 4.3"), that fixed the issue for newer GNU Makes, in our case
it was the opposite, i.e. we need to fix it for the older ones: someone
building with e.g. 4.2.1 gets the following error:

    scripts/Makefile.compiler:81: *** unterminated call to function 'call': missing ')'.  Stop.

Thus use the existing variable to fix it.

Reported-by: moyi geek &lt;1441339168@qq.com&gt;
Closes: https://rust-for-linux.zulipchat.com/#narrow/channel/291565/topic/x/near/512001985
Cc: stable@vger.kernel.org
Fixes: e72a076c620f ("kbuild: fix issues with rustc-option")
Reviewed-by: Nicolas Schier &lt;nicolas@fjasle.eu&gt;
Reviewed-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Link: https://lore.kernel.org/r/20250414171241.2126137-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
GNU Make 4.3 changed the behavior of `#` inside commands in commit
c6966b323811 ("[SV 20513] Un-escaped # are not comments in function
invocations"):

    * WARNING: Backward-incompatibility!
      Number signs (#) appearing inside a macro reference or function invocation
      no longer introduce comments and should not be escaped with backslashes:
      thus a call such as:
        foo := $(shell echo '#')
      is legal.  Previously the number sign needed to be escaped, for example:
        foo := $(shell echo '\#')
      Now this latter will resolve to "\#".  If you want to write makefiles
      portable to both versions, assign the number sign to a variable:
        H := \#
        foo := $(shell echo '$H')
      This was claimed to be fixed in 3.81, but wasn't, for some reason.
      To detect this change search for 'nocomment' in the .FEATURES variable.

Unlike other commits in the kernel about this issue, such as commit
633174a7046e ("lib/raid6/test/Makefile: Use $(pound) instead of \#
for Make 4.3"), that fixed the issue for newer GNU Makes, in our case
it was the opposite, i.e. we need to fix it for the older ones: someone
building with e.g. 4.2.1 gets the following error:

    scripts/Makefile.compiler:81: *** unterminated call to function 'call': missing ')'.  Stop.

Thus use the existing variable to fix it.

Reported-by: moyi geek &lt;1441339168@qq.com&gt;
Closes: https://rust-for-linux.zulipchat.com/#narrow/channel/291565/topic/x/near/512001985
Cc: stable@vger.kernel.org
Fixes: e72a076c620f ("kbuild: fix issues with rustc-option")
Reviewed-by: Nicolas Schier &lt;nicolas@fjasle.eu&gt;
Reviewed-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Link: https://lore.kernel.org/r/20250414171241.2126137-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rust: kasan/kbuild: fix missing flags on first build</title>
<updated>2025-04-14T14:10:59+00:00</updated>
<author>
<name>Miguel Ojeda</name>
<email>ojeda@kernel.org</email>
</author>
<published>2025-04-08T22:03:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=46e24a545cdb4556f8128c90ecc34eeae52477a0'/>
<id>46e24a545cdb4556f8128c90ecc34eeae52477a0</id>
<content type='text'>
If KASAN is enabled, and one runs in a clean repository e.g.:

    make LLVM=1 prepare
    make LLVM=1 prepare

Then the Rust code gets rebuilt, which should not happen.

The reason is some of the LLVM KASAN `rustc` flags are added in the
second run:

    -Cllvm-args=-asan-instrumentation-with-call-threshold=10000
    -Cllvm-args=-asan-stack=0
    -Cllvm-args=-asan-globals=1
    -Cllvm-args=-asan-kernel-mem-intrinsic-prefix=1

Further runs do not rebuild Rust because the flags do not change anymore.

Rebuilding like that in the second run is bad, even if this just happens
with KASAN enabled, but missing flags in the first one is even worse.

The root issue is that we pass, for some architectures and for the moment,
a generated `target.json` file. That file is not ready by the time `rustc`
gets called for the flag test, and thus the flag test fails just because
the file is not available, e.g.:

    $ ... --target=./scripts/target.json ... -Cllvm-args=...
    error: target file "./scripts/target.json" does not exist

There are a few approaches we could take here to solve this. For instance,
we could ensure that every time that the config is rebuilt, we regenerate
the file and recompute the flags. Or we could use the LLVM version to
check for these flags, instead of testing the flag (which may have other
advantages, such as allowing us to detect renames on the LLVM side).

However, it may be easier than that: `rustc` is aware of the `-Cllvm-args`
regardless of the `--target` (e.g. I checked that the list printed
is the same, plus that I can check for these flags even if I pass
a completely unrelated target), and thus we can just eliminate the
dependency completely.

Thus filter out the target.

This does mean that `rustc-option` cannot be used to test a flag that
requires the right target, but we don't have other users yet, it is a
minimal change and we want to get rid of custom targets in the future.

We could only filter in the case `target.json` is used, to make it work
in more cases, but then it would be harder to notice that it may not
work in a couple architectures.

Cc: Matthew Maurer &lt;mmaurer@google.com&gt;
Cc: Sami Tolvanen &lt;samitolvanen@google.com&gt;
Cc: stable@vger.kernel.org
Fixes: e3117404b411 ("kbuild: rust: Enable KASAN support")
Tested-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Link: https://lore.kernel.org/r/20250408220311.1033475-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If KASAN is enabled, and one runs in a clean repository e.g.:

    make LLVM=1 prepare
    make LLVM=1 prepare

Then the Rust code gets rebuilt, which should not happen.

The reason is some of the LLVM KASAN `rustc` flags are added in the
second run:

    -Cllvm-args=-asan-instrumentation-with-call-threshold=10000
    -Cllvm-args=-asan-stack=0
    -Cllvm-args=-asan-globals=1
    -Cllvm-args=-asan-kernel-mem-intrinsic-prefix=1

Further runs do not rebuild Rust because the flags do not change anymore.

Rebuilding like that in the second run is bad, even if this just happens
with KASAN enabled, but missing flags in the first one is even worse.

The root issue is that we pass, for some architectures and for the moment,
a generated `target.json` file. That file is not ready by the time `rustc`
gets called for the flag test, and thus the flag test fails just because
the file is not available, e.g.:

    $ ... --target=./scripts/target.json ... -Cllvm-args=...
    error: target file "./scripts/target.json" does not exist

There are a few approaches we could take here to solve this. For instance,
we could ensure that every time that the config is rebuilt, we regenerate
the file and recompute the flags. Or we could use the LLVM version to
check for these flags, instead of testing the flag (which may have other
advantages, such as allowing us to detect renames on the LLVM side).

However, it may be easier than that: `rustc` is aware of the `-Cllvm-args`
regardless of the `--target` (e.g. I checked that the list printed
is the same, plus that I can check for these flags even if I pass
a completely unrelated target), and thus we can just eliminate the
dependency completely.

Thus filter out the target.

This does mean that `rustc-option` cannot be used to test a flag that
requires the right target, but we don't have other users yet, it is a
minimal change and we want to get rid of custom targets in the future.

We could only filter in the case `target.json` is used, to make it work
in more cases, but then it would be harder to notice that it may not
work in a couple architectures.

Cc: Matthew Maurer &lt;mmaurer@google.com&gt;
Cc: Sami Tolvanen &lt;samitolvanen@google.com&gt;
Cc: stable@vger.kernel.org
Fixes: e3117404b411 ("kbuild: rust: Enable KASAN support")
Tested-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Link: https://lore.kernel.org/r/20250408220311.1033475-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>genksyms: Handle typeof_unqual keyword and __seg_{fs,gs} qualifiers</title>
<updated>2025-04-14T07:19:04+00:00</updated>
<author>
<name>Uros Bizjak</name>
<email>ubizjak@gmail.com</email>
</author>
<published>2025-04-13T22:07:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1013f5636fd808569c1f4c40a58a4efc70713a28'/>
<id>1013f5636fd808569c1f4c40a58a4efc70713a28</id>
<content type='text'>
Handle typeof_unqual, __typeof_unqual and __typeof_unqual__ keywords
using TYPEOF_KEYW token in the same way as typeof keyword.

Also ignore x86 __seg_fs and __seg_gs named address space qualifiers
using X86_SEG_KEYW token in the same way as const, volatile or
restrict qualifiers.

Fixes: ac053946f5c4 ("compiler.h: introduce TYPEOF_UNQUAL() macro")
Closes: https://lore.kernel.org/lkml/81a25a60-de78-43fb-b56a-131151e1c035@molgen.mpg.de/
Reported-by: Paul Menzel &lt;pmenzel@molgen.mpg.de&gt;
Signed-off-by: Uros Bizjak &lt;ubizjak@gmail.com&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Link: https://lore.kernel.org/r/20250413220749.270704-1-ubizjak@gmail.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Handle typeof_unqual, __typeof_unqual and __typeof_unqual__ keywords
using TYPEOF_KEYW token in the same way as typeof keyword.

Also ignore x86 __seg_fs and __seg_gs named address space qualifiers
using X86_SEG_KEYW token in the same way as const, volatile or
restrict qualifiers.

Fixes: ac053946f5c4 ("compiler.h: introduce TYPEOF_UNQUAL() macro")
Closes: https://lore.kernel.org/lkml/81a25a60-de78-43fb-b56a-131151e1c035@molgen.mpg.de/
Reported-by: Paul Menzel &lt;pmenzel@molgen.mpg.de&gt;
Signed-off-by: Uros Bizjak &lt;ubizjak@gmail.com&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Link: https://lore.kernel.org/r/20250413220749.270704-1-ubizjak@gmail.com
</pre>
</div>
</content>
</entry>
<entry>
<title>scripts: generate_rust_analyzer: Add ffi crate</title>
<updated>2025-04-08T17:47:06+00:00</updated>
<author>
<name>Lukas Fischer</name>
<email>kernel@o1oo11oo.de</email>
</author>
<published>2025-04-04T12:51:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=05a2b0011c4b6cbbc9b577f6abebe4e9333b0cf6'/>
<id>05a2b0011c4b6cbbc9b577f6abebe4e9333b0cf6</id>
<content type='text'>
Commit d072acda4862 ("rust: use custom FFI integer types") did not
update rust-analyzer to include the new crate.

To enable rust-analyzer support for these custom ffi types, add the
`ffi` crate as a dependency to the `bindings`, `uapi` and `kernel`
crates, which all directly depend on it.

Fixes: d072acda4862 ("rust: use custom FFI integer types")
Signed-off-by: Lukas Fischer &lt;kernel@o1oo11oo.de&gt;
Reviewed-by: Tamir Duberstein &lt;tamird@gmail.com&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250404125150.85783-2-kernel@o1oo11oo.de
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit d072acda4862 ("rust: use custom FFI integer types") did not
update rust-analyzer to include the new crate.

To enable rust-analyzer support for these custom ffi types, add the
`ffi` crate as a dependency to the `bindings`, `uapi` and `kernel`
crates, which all directly depend on it.

Fixes: d072acda4862 ("rust: use custom FFI integer types")
Signed-off-by: Lukas Fischer &lt;kernel@o1oo11oo.de&gt;
Reviewed-by: Tamir Duberstein &lt;tamird@gmail.com&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250404125150.85783-2-kernel@o1oo11oo.de
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Disable SLUB_TINY for build testing</title>
<updated>2025-04-06T17:00:04+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-04-06T17:00:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6f110a5e4f9977c31ce76fefbfef6fd4eab6bfb7'/>
<id>6f110a5e4f9977c31ce76fefbfef6fd4eab6bfb7</id>
<content type='text'>
... and don't error out so hard on missing module descriptions.

Before commit 6c6c1fc09de3 ("modpost: require a MODULE_DESCRIPTION()")
we used to warn about missing module descriptions, but only when
building with extra warnigns (ie 'W=1').

After that commit the warning became an unconditional hard error.

And it turns out not all modules have been converted despite the claims
to the contrary.  As reported by Damian Tometzki, the slub KUnit test
didn't have a module description, and apparently nobody ever really
noticed.

The reason nobody noticed seems to be that the slub KUnit tests get
disabled by SLUB_TINY, which also ends up disabling a lot of other code,
both in tests and in slub itself.  And so anybody doing full build tests
didn't actually see this failre.

So let's disable SLUB_TINY for build-only tests, since it clearly ends
up limiting build coverage.  Also turn the missing module descriptions
error back into a warning, but let's keep it around for non-'W=1'
builds.

Reported-by: Damian Tometzki &lt;damian@riscv-rocks.de&gt;
Link: https://lore.kernel.org/all/01070196099fd059-e8463438-7b1b-4ec8-816d-173874be9966-000000@eu-central-1.amazonses.com/
Cc: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Cc: Jeff Johnson &lt;jeff.johnson@oss.qualcomm.com&gt;
Fixes: 6c6c1fc09de3 ("modpost: require a MODULE_DESCRIPTION()")
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
... and don't error out so hard on missing module descriptions.

Before commit 6c6c1fc09de3 ("modpost: require a MODULE_DESCRIPTION()")
we used to warn about missing module descriptions, but only when
building with extra warnigns (ie 'W=1').

After that commit the warning became an unconditional hard error.

And it turns out not all modules have been converted despite the claims
to the contrary.  As reported by Damian Tometzki, the slub KUnit test
didn't have a module description, and apparently nobody ever really
noticed.

The reason nobody noticed seems to be that the slub KUnit tests get
disabled by SLUB_TINY, which also ends up disabling a lot of other code,
both in tests and in slub itself.  And so anybody doing full build tests
didn't actually see this failre.

So let's disable SLUB_TINY for build-only tests, since it clearly ends
up limiting build coverage.  Also turn the missing module descriptions
error back into a warning, but let's keep it around for non-'W=1'
builds.

Reported-by: Damian Tometzki &lt;damian@riscv-rocks.de&gt;
Link: https://lore.kernel.org/all/01070196099fd059-e8463438-7b1b-4ec8-816d-173874be9966-000000@eu-central-1.amazonses.com/
Cc: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Cc: Jeff Johnson &lt;jeff.johnson@oss.qualcomm.com&gt;
Fixes: 6c6c1fc09de3 ("modpost: require a MODULE_DESCRIPTION()")
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'kbuild-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild</title>
<updated>2025-04-05T22:46:50+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-04-05T22:46:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f4d2ef48250ad057e4f00087967b5ff366da9f39'/>
<id>f4d2ef48250ad057e4f00087967b5ff366da9f39</id>
<content type='text'>
Pull Kbuild updates from Masahiro Yamada:

 - Improve performance in gendwarfksyms

 - Remove deprecated EXTRA_*FLAGS and KBUILD_ENABLE_EXTRA_GCC_CHECKS

 - Support CONFIG_HEADERS_INSTALL for ARCH=um

 - Use more relative paths to sources files for better reproducibility

 - Support the loong64 Debian architecture

 - Add Kbuild bash completion

 - Introduce intermediate vmlinux.unstripped for architectures that need
   static relocations to be stripped from the final vmlinux

 - Fix versioning in Debian packages for -rc releases

 - Treat missing MODULE_DESCRIPTION() as an error

 - Convert Nios2 Makefiles to use the generic rule for built-in DTB

 - Add debuginfo support to the RPM package

* tag 'kbuild-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (40 commits)
  kbuild: rpm-pkg: build a debuginfo RPM
  kconfig: merge_config: use an empty file as initfile
  nios2: migrate to the generic rule for built-in DTB
  rust: kbuild: skip `--remap-path-prefix` for `rustdoc`
  kbuild: pacman-pkg: hardcode module installation path
  kbuild: deb-pkg: don't set KBUILD_BUILD_VERSION unconditionally
  modpost: require a MODULE_DESCRIPTION()
  kbuild: make all file references relative to source root
  x86: drop unnecessary prefix map configuration
  kbuild: deb-pkg: add comment about future removal of KDEB_COMPRESS
  kbuild: Add a help message for "headers"
  kbuild: deb-pkg: remove "version" variable in mkdebian
  kbuild: deb-pkg: fix versioning for -rc releases
  Documentation/kbuild: Fix indentation in modules.rst example
  x86: Get rid of Makefile.postlink
  kbuild: Create intermediate vmlinux build with relocations preserved
  kbuild: Introduce Kconfig symbol for linking vmlinux with relocations
  kbuild: link-vmlinux.sh: Make output file name configurable
  kbuild: do not generate .tmp_vmlinux*.map when CONFIG_VMLINUX_MAP=y
  Revert "kheaders: Ignore silly-rename files"
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull Kbuild updates from Masahiro Yamada:

 - Improve performance in gendwarfksyms

 - Remove deprecated EXTRA_*FLAGS and KBUILD_ENABLE_EXTRA_GCC_CHECKS

 - Support CONFIG_HEADERS_INSTALL for ARCH=um

 - Use more relative paths to sources files for better reproducibility

 - Support the loong64 Debian architecture

 - Add Kbuild bash completion

 - Introduce intermediate vmlinux.unstripped for architectures that need
   static relocations to be stripped from the final vmlinux

 - Fix versioning in Debian packages for -rc releases

 - Treat missing MODULE_DESCRIPTION() as an error

 - Convert Nios2 Makefiles to use the generic rule for built-in DTB

 - Add debuginfo support to the RPM package

* tag 'kbuild-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (40 commits)
  kbuild: rpm-pkg: build a debuginfo RPM
  kconfig: merge_config: use an empty file as initfile
  nios2: migrate to the generic rule for built-in DTB
  rust: kbuild: skip `--remap-path-prefix` for `rustdoc`
  kbuild: pacman-pkg: hardcode module installation path
  kbuild: deb-pkg: don't set KBUILD_BUILD_VERSION unconditionally
  modpost: require a MODULE_DESCRIPTION()
  kbuild: make all file references relative to source root
  x86: drop unnecessary prefix map configuration
  kbuild: deb-pkg: add comment about future removal of KDEB_COMPRESS
  kbuild: Add a help message for "headers"
  kbuild: deb-pkg: remove "version" variable in mkdebian
  kbuild: deb-pkg: fix versioning for -rc releases
  Documentation/kbuild: Fix indentation in modules.rst example
  x86: Get rid of Makefile.postlink
  kbuild: Create intermediate vmlinux build with relocations preserved
  kbuild: Introduce Kconfig symbol for linking vmlinux with relocations
  kbuild: link-vmlinux.sh: Make output file name configurable
  kbuild: do not generate .tmp_vmlinux*.map when CONFIG_VMLINUX_MAP=y
  Revert "kheaders: Ignore silly-rename files"
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>kbuild: rpm-pkg: build a debuginfo RPM</title>
<updated>2025-04-05T21:22:01+00:00</updated>
<author>
<name>Uday Shankar</name>
<email>ushankar@purestorage.com</email>
</author>
<published>2025-03-31T22:46:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a7c699d090a1f3795c3271c2b399230e182db06e'/>
<id>a7c699d090a1f3795c3271c2b399230e182db06e</id>
<content type='text'>
The rpm-pkg make target currently suffers from a few issues related to
debuginfo:
1. debuginfo for things built into the kernel (vmlinux) is not available
   in any RPM produced by make rpm-pkg. This makes using tools like
   systemtap against a make rpm-pkg kernel impossible.
2. debug source for the kernel is not available. This means that
   commands like 'disas /s' in gdb, which display source intermixed with
   assembly, can only print file names/line numbers which then must be
   painstakingly resolved to actual source in a separate editor.
3. debuginfo for modules is available, but it remains bundled with the
   .ko files that contain module code, in the main kernel RPM. This is a
   waste of space for users who do not need to debug the kernel (i.e.
   most users).

Address all of these issues by additionally building a debuginfo RPM
when the kernel configuration allows for it, in line with standard
patterns followed by RPM distributors. With these changes:
1. systemtap now works (when these changes are backported to 6.11, since
   systemtap lags a bit behind in compatibility), as verified by the
   following simple test script:

   # stap -e 'probe kernel.function("do_sys_open").call { printf("%s\n", $$parms); }'
   dfd=0xffffffffffffff9c filename=0x7fe18800b160 flags=0x88800 mode=0x0
   ...

2. disas /s works correctly in gdb, with source and disassembly
   interspersed:

   # gdb vmlinux --batch -ex 'disas /s blk_op_str'
   Dump of assembler code for function blk_op_str:
   block/blk-core.c:
   125     {
      0xffffffff814c8740 &lt;+0&gt;:     endbr64

   127
   128             if (op &lt; ARRAY_SIZE(blk_op_name) &amp;&amp; blk_op_name[op])
      0xffffffff814c8744 &lt;+4&gt;:     mov    $0xffffffff824a7378,%rax
      0xffffffff814c874b &lt;+11&gt;:    cmp    $0x23,%edi
      0xffffffff814c874e &lt;+14&gt;:    ja     0xffffffff814c8768 &lt;blk_op_str+40&gt;
      0xffffffff814c8750 &lt;+16&gt;:    mov    %edi,%edi

   126             const char *op_str = "UNKNOWN";
      0xffffffff814c8752 &lt;+18&gt;:    mov    $0xffffffff824a7378,%rdx

   127
   128             if (op &lt; ARRAY_SIZE(blk_op_name) &amp;&amp; blk_op_name[op])
      0xffffffff814c8759 &lt;+25&gt;:    mov    -0x7dfa0160(,%rdi,8),%rax

   126             const char *op_str = "UNKNOWN";
      0xffffffff814c8761 &lt;+33&gt;:    test   %rax,%rax
      0xffffffff814c8764 &lt;+36&gt;:    cmove  %rdx,%rax

   129                     op_str = blk_op_name[op];
   130
   131             return op_str;
   132     }
      0xffffffff814c8768 &lt;+40&gt;:    jmp    0xffffffff81d01360 &lt;__x86_return_thunk&gt;
   End of assembler dump.

3. The size of the main kernel package goes down substantially,
   especially if many modules are built (quite typical). Here is a
   comparison of installed size of the kernel package (configured with
   allmodconfig, dwarf4 debuginfo, and module compression turned off)
   before and after this patch:

   # rpm -qi kernel-6.13* | grep -E '^(Version|Size)'
   Version     : 6.13.0postpatch+
   Size        : 1382874089
   Version     : 6.13.0prepatch+
   Size        : 17870795887

   This is a ~92% size reduction.

Note that a debuginfo package can only be produced if the following
configs are set:
- CONFIG_DEBUG_INFO=y
- CONFIG_MODULE_COMPRESS=n
- CONFIG_DEBUG_INFO_SPLIT=n

The first of these is obvious - we can't produce debuginfo if the build
does not generate it. The second two requirements can in principle be
removed, but doing so is difficult with the current approach, which uses
a generic rpmbuild script find-debuginfo.sh that processes all packaged
executables. If we want to remove those requirements the best path
forward is likely to add some debuginfo extraction/installation logic to
the modules_install target (controllable by flags). That way, it's
easier to operate on modules before they're compressed, and the logic
can be reused by all packaging targets.

Signed-off-by: Uday Shankar &lt;ushankar@purestorage.com&gt;
Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The rpm-pkg make target currently suffers from a few issues related to
debuginfo:
1. debuginfo for things built into the kernel (vmlinux) is not available
   in any RPM produced by make rpm-pkg. This makes using tools like
   systemtap against a make rpm-pkg kernel impossible.
2. debug source for the kernel is not available. This means that
   commands like 'disas /s' in gdb, which display source intermixed with
   assembly, can only print file names/line numbers which then must be
   painstakingly resolved to actual source in a separate editor.
3. debuginfo for modules is available, but it remains bundled with the
   .ko files that contain module code, in the main kernel RPM. This is a
   waste of space for users who do not need to debug the kernel (i.e.
   most users).

Address all of these issues by additionally building a debuginfo RPM
when the kernel configuration allows for it, in line with standard
patterns followed by RPM distributors. With these changes:
1. systemtap now works (when these changes are backported to 6.11, since
   systemtap lags a bit behind in compatibility), as verified by the
   following simple test script:

   # stap -e 'probe kernel.function("do_sys_open").call { printf("%s\n", $$parms); }'
   dfd=0xffffffffffffff9c filename=0x7fe18800b160 flags=0x88800 mode=0x0
   ...

2. disas /s works correctly in gdb, with source and disassembly
   interspersed:

   # gdb vmlinux --batch -ex 'disas /s blk_op_str'
   Dump of assembler code for function blk_op_str:
   block/blk-core.c:
   125     {
      0xffffffff814c8740 &lt;+0&gt;:     endbr64

   127
   128             if (op &lt; ARRAY_SIZE(blk_op_name) &amp;&amp; blk_op_name[op])
      0xffffffff814c8744 &lt;+4&gt;:     mov    $0xffffffff824a7378,%rax
      0xffffffff814c874b &lt;+11&gt;:    cmp    $0x23,%edi
      0xffffffff814c874e &lt;+14&gt;:    ja     0xffffffff814c8768 &lt;blk_op_str+40&gt;
      0xffffffff814c8750 &lt;+16&gt;:    mov    %edi,%edi

   126             const char *op_str = "UNKNOWN";
      0xffffffff814c8752 &lt;+18&gt;:    mov    $0xffffffff824a7378,%rdx

   127
   128             if (op &lt; ARRAY_SIZE(blk_op_name) &amp;&amp; blk_op_name[op])
      0xffffffff814c8759 &lt;+25&gt;:    mov    -0x7dfa0160(,%rdi,8),%rax

   126             const char *op_str = "UNKNOWN";
      0xffffffff814c8761 &lt;+33&gt;:    test   %rax,%rax
      0xffffffff814c8764 &lt;+36&gt;:    cmove  %rdx,%rax

   129                     op_str = blk_op_name[op];
   130
   131             return op_str;
   132     }
      0xffffffff814c8768 &lt;+40&gt;:    jmp    0xffffffff81d01360 &lt;__x86_return_thunk&gt;
   End of assembler dump.

3. The size of the main kernel package goes down substantially,
   especially if many modules are built (quite typical). Here is a
   comparison of installed size of the kernel package (configured with
   allmodconfig, dwarf4 debuginfo, and module compression turned off)
   before and after this patch:

   # rpm -qi kernel-6.13* | grep -E '^(Version|Size)'
   Version     : 6.13.0postpatch+
   Size        : 1382874089
   Version     : 6.13.0prepatch+
   Size        : 17870795887

   This is a ~92% size reduction.

Note that a debuginfo package can only be produced if the following
configs are set:
- CONFIG_DEBUG_INFO=y
- CONFIG_MODULE_COMPRESS=n
- CONFIG_DEBUG_INFO_SPLIT=n

The first of these is obvious - we can't produce debuginfo if the build
does not generate it. The second two requirements can in principle be
removed, but doing so is difficult with the current approach, which uses
a generic rpmbuild script find-debuginfo.sh that processes all packaged
executables. If we want to remove those requirements the best path
forward is likely to add some debuginfo extraction/installation logic to
the modules_install target (controllable by flags). That way, it's
easier to operate on modules before they're compressed, and the logic
can be reused by all packaging targets.

Signed-off-by: Uday Shankar &lt;ushankar@purestorage.com&gt;
Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>kconfig: merge_config: use an empty file as initfile</title>
<updated>2025-04-05T21:22:01+00:00</updated>
<author>
<name>Daniel Gomez</name>
<email>da.gomez@samsung.com</email>
</author>
<published>2025-03-28T14:28:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a26fe287eed112b4e21e854f173c8918a6a8596d'/>
<id>a26fe287eed112b4e21e854f173c8918a6a8596d</id>
<content type='text'>
The scripts/kconfig/merge_config.sh script requires an existing
$INITFILE (or the $1 argument) as a base file for merging Kconfig
fragments. However, an empty $INITFILE can serve as an initial starting
point, later referenced by the KCONFIG_ALLCONFIG Makefile variable
if -m is not used. This variable can point to any configuration file
containing preset config symbols (the merged output) as stated in
Documentation/kbuild/kconfig.rst. When -m is used $INITFILE will
contain just the merge output requiring the user to run make (i.e.
KCONFIG_ALLCONFIG=&lt;$INITFILE&gt; make &lt;allnoconfig/alldefconfig&gt; or make
olddefconfig).

Instead of failing when `$INITFILE` is missing, create an empty file and
use it as the starting point for merges.

Signed-off-by: Daniel Gomez &lt;da.gomez@samsung.com&gt;
Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The scripts/kconfig/merge_config.sh script requires an existing
$INITFILE (or the $1 argument) as a base file for merging Kconfig
fragments. However, an empty $INITFILE can serve as an initial starting
point, later referenced by the KCONFIG_ALLCONFIG Makefile variable
if -m is not used. This variable can point to any configuration file
containing preset config symbols (the merged output) as stated in
Documentation/kbuild/kconfig.rst. When -m is used $INITFILE will
contain just the merge output requiring the user to run make (i.e.
KCONFIG_ALLCONFIG=&lt;$INITFILE&gt; make &lt;allnoconfig/alldefconfig&gt; or make
olddefconfig).

Instead of failing when `$INITFILE` is missing, create an empty file and
use it as the starting point for merges.

Signed-off-by: Daniel Gomez &lt;da.gomez@samsung.com&gt;
Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
