linux-toradex.git/rust, branch v6.12-rc1

Merge tag 'rust-6.12' of https://github.com/Rust-for-Linux/linux

2024-09-25T17:25:40+00:00

Pull Rust updates from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Support 'MITIGATION_{RETHUNK,RETPOLINE,SLS}' (which cleans up
     objtool warnings), teach objtool about 'noreturn' Rust symbols and
     mimic '___ADDRESSABLE()' for 'module_{init,exit}'. With that, we
     should be objtool-warning-free, so enable it to run for all Rust
     object files.

   - KASAN (no 'SW_TAGS'), KCFI and shadow call sanitizer support.

   - Support 'RUSTC_VERSION', including re-config and re-build on
     change.

   - Split helpers file into several files in a folder, to avoid
     conflicts in it. Eventually those files will be moved to the right
     places with the new build system. In addition, remove the need to
     manually export the symbols defined there, reusing existing
     machinery for that.

   - Relax restriction on configurations with Rust + GCC plugins to just
     the RANDSTRUCT plugin.

  'kernel' crate:

   - New 'list' module: doubly-linked linked list for use with reference
     counted values, which is heavily used by the upcoming Rust Binder.

     This includes 'ListArc' (a wrapper around 'Arc' that is guaranteed
     unique for the given ID), 'AtomicTracker' (tracks whether a
     'ListArc' exists using an atomic), 'ListLinks' (the prev/next
     pointers for an item in a linked list), 'List' (the linked list
     itself), 'Iter' (an iterator over a 'List'), 'Cursor' (a cursor
     into a 'List' that allows to remove elements), 'ListArcField' (a
     field exclusively owned by a 'ListArc'), as well as support for
     heterogeneous lists.

   - New 'rbtree' module: red-black tree abstractions used by the
     upcoming Rust Binder.

     This includes 'RBTree' (the red-black tree itself), 'RBTreeNode' (a
     node), 'RBTreeNodeReservation' (a memory reservation for a node),
     'Iter' and 'IterMut' (immutable and mutable iterators), 'Cursor'
     (bidirectional cursor that allows to remove elements), as well as
     an entry API similar to the Rust standard library one.

   - 'init' module: add 'write_[pin_]init' methods and the
     'InPlaceWrite' trait. Add the 'assert_pinned!' macro.

   - 'sync' module: implement the 'InPlaceInit' trait for 'Arc' by
     introducing an associated type in the trait.

   - 'alloc' module: add 'drop_contents' method to 'BoxExt'.

   - 'types' module: implement the 'ForeignOwnable' trait for
     'Pin>' and improve the trait's documentation. In addition,
     add the 'into_raw' method to the 'ARef' type.

   - 'error' module: in preparation for the upcoming Rust support for
     32-bit architectures, like arm, locally allow Clippy lint for
     those.

  Documentation:

   - https://rust.docs.kernel.org has been announced, so link to it.

   - Enable rustdoc's "jump to definition" feature, making its output a
     bit closer to the experience in a cross-referencer.

   - Debian Testing now also provides recent Rust releases (outside of
     the freeze period), so add it to the list.

  MAINTAINERS:

   - Trevor is joining as reviewer of the "RUST" entry.

  And a few other small bits"

* tag 'rust-6.12' of https://github.com/Rust-for-Linux/linux: (54 commits)
  kasan: rust: Add KASAN smoke test via UAF
  kbuild: rust: Enable KASAN support
  rust: kasan: Rust does not support KHWASAN
  kbuild: rust: Define probing macros for rustc
  kasan: simplify and clarify Makefile
  rust: cfi: add support for CFI_CLANG with Rust
  cfi: add CONFIG_CFI_ICALL_NORMALIZE_INTEGERS
  rust: support for shadow call stack sanitizer
  docs: rust: include other expressions in conditional compilation section
  kbuild: rust: replace proc macros dependency on `core.o` with the version text
  kbuild: rust: rebuild if the version text changes
  kbuild: rust: re-run Kconfig if the version text changes
  kbuild: rust: add `CONFIG_RUSTC_VERSION`
  rust: avoid `box_uninit_write` feature
  MAINTAINERS: add Trevor Gross as Rust reviewer
  rust: rbtree: add `RBTree::entry`
  rust: rbtree: add cursor
  rust: rbtree: add mutable iterator
  rust: rbtree: add iterator
  rust: rbtree: add red-black tree implementation backed by the C version
  ...

rust: cfi: add support for CFI_CLANG with Rust

2024-09-16T15:29:58+00:00

Make it possible to use the Control Flow Integrity (CFI) sanitizer when
Rust is enabled. Enabling CFI with Rust requires that CFI is configured
to normalize integer types so that all integer types of the same size
and signedness are compatible under CFI.

Rust and C use the same LLVM backend for code generation, so Rust KCFI
is compatible with the KCFI used in the kernel for C. In the case of
FineIBT, CFI also depends on -Zpatchable-function-entry for rewriting
the function prologue, so we set that flag for Rust as well. The flag
for FineIBT requires rustc 1.80.0 or later, so include a Kconfig
requirement for that.

Enabling Rust will select CFI_ICALL_NORMALIZE_INTEGERS because the flag
is required to use Rust with CFI. Using select rather than `depends on`
avoids the case where Rust is not visible in menuconfig due to
CFI_ICALL_NORMALIZE_INTEGERS not being enabled. One disadvantage of
select is that RUST must `depends on` all of the things that
CFI_ICALL_NORMALIZE_INTEGERS depends on to avoid invalid configurations.

Alice has been using KCFI on her phone for several months, so it is
reasonably well tested on arm64.

Signed-off-by: Matthew Maurer 
Co-developed-by: Alice Ryhl 
Signed-off-by: Alice Ryhl 
Reviewed-by: Sami Tolvanen 
Tested-by: Gatlin Newhouse 
Acked-by: Kees Cook 
Acked-by: Peter Zijlstra (Intel) 
Link: https://lore.kernel.org/r/20240801-kcfi-v2-2-c93caed3d121@google.com
[ Replaced `!FINEIBT` requirement with `!CALL_PADDING` to prevent
  a build error on older Rust compilers. Fixed typo. - Miguel ]
Signed-off-by: Miguel Ojeda

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2024-09-06T03:37:20+00:00

Cross-merge networking fixes after downstream PR.

Conflicts:

drivers/net/phy/phy_device.c
  2560db6ede1a ("net: phy: Fix missing of_node_put() for leds")
  1dce520abd46 ("net: phy: Use for_each_available_child_of_node_scoped()")
https://lore.kernel.org/20240904115823.74333648@canb.auug.org.au

Adjacent changes:

drivers/net/ethernet/xilinx/xilinx_axienet.h
drivers/net/ethernet/xilinx/xilinx_axienet_main.c
  858430db28a5 ("net: xilinx: axienet: Fix race in axienet_stop")
  76abb5d675c4 ("net: xilinx: axienet: Add statistics support")

Signed-off-by: Jakub Kicinski

kbuild: rust: replace proc macros dependency on `core.o` with the version text

2024-09-05T20:44:51+00:00

With the `RUSTC_VERSION_TEXT` rebuild support in place, now proc macros
can depend on that instead of `core.o`.

This means that both the `core` and `macros` crates can be built in
parallel, and that touching `core.o` does not trigger a rebuild of the
proc macros.

This could be accomplished using the same approach as for `core`
(i.e. depending directly on `include/config/RUSTC_VERSION_TEXT`). However,
that is considered an implementation detail [1], and thus it is best
to avoid it. Instead, let fixdep find a string that we explicitly
write down in the source code for this purpose (like it is done for
`include/linux/compiler-version.h`), which we can easily do (unlike for
`core`) since this is our own source code.

Suggested-by: Masahiro Yamada 
Link: https://lore.kernel.org/rust-for-linux/CAK7LNAQBG0nDupXSgAAk-6nOqeqGVkr3H1RjYaqRJ1OxmLm6xA@mail.gmail.com/ [1]
Reviewed-by: Nicolas Schier 
Tested-by: Alice Ryhl 
Acked-by: Masahiro Yamada 
Link: https://lore.kernel.org/r/20240902165535.1101978-5-ojeda@kernel.org
Signed-off-by: Miguel Ojeda

kbuild: rust: rebuild if the version text changes

2024-09-05T20:44:41+00:00

Now that `RUSTC_VERSION_TEXT` exists, use it to rebuild `core` when the
version text changes (which in turn will trigger a rebuild of all the
kernel Rust code).

This also applies to proc macros (which only work with the `rustc` that
compiled them), via the already existing dependency on `core.o`. That
is cleaned up in the next commit.

However, this does not cover host programs written in Rust, which is
the same case in the C side.

This is accomplished by referencing directly the generated file, instead
of using the `fixdep` header trick, since we cannot change the Rust
standard library sources. This is not too much of a burden, since it
only needs to be done for `core`.

Tested-by: Alice Ryhl 
Reviewed-by: Nicolas Schier 
Acked-by: Masahiro Yamada 
Link: https://lore.kernel.org/r/20240902165535.1101978-4-ojeda@kernel.org
Signed-off-by: Miguel Ojeda

rust: avoid `box_uninit_write` feature

2024-09-04T21:11:31+00:00

Like commit 0903b9e2a46c ("rust: alloc: eschew
`Box>::write`"), but for the new `rbtree` and `alloc` code.

That is, `feature(new_uninit)` [1] got partially stabilized [2]
for Rust 1.82.0 (expected to be released on 2024-10-17), but it
did not include `Box>::write`, which got split into
`feature(box_uninit_write)` [3].

To avoid relying on a new unstable feature, rewrite the `write` +
`assume_init` pair manually.

Link: https://github.com/rust-lang/rust/issues/63291 [1]
Link: https://github.com/rust-lang/rust/pull/129401 [2]
Link: https://github.com/rust-lang/rust/issues/129397 [3]
Reviewed-by: Alice Ryhl 
Reviewed-by: Matt Gilbride 
Link: https://lore.kernel.org/r/20240904144229.18592-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda

rust: macros: provide correct provenance when constructing THIS_MODULE

2024-09-02T07:14:28+00:00

Currently while defining `THIS_MODULE` symbol in `module!()`, the
pointer used to construct `ThisModule` is derived from an immutable
reference of `__this_module`, which means the pointer doesn't have
the provenance for writing, and that means any write to that pointer
is UB regardless of data races or not. However, the usage of
`THIS_MODULE` includes passing this pointer to functions that may write
to it (probably in unsafe code), and this will create soundness issues.

One way to fix this is using `addr_of_mut!()` but that requires the
unstable feature "const_mut_refs". So instead of `addr_of_mut()!`,
an extern static `Opaque` is used here: since `Opaque` is transparent
to `T`, an extern static `Opaque` will just wrap the C symbol (defined
in a C compile unit) in an `Opaque`, which provides a pointer with
writable provenance via `Opaque::get()`. This fix the potential UBs
because of pointer provenance unmatched.

Reported-by: Alice Ryhl 
Signed-off-by: Boqun Feng 
Reviewed-by: Alice Ryhl 
Reviewed-by: Trevor Gross 
Reviewed-by: Benno Lossin 
Reviewed-by: Gary Guo 
Closes: https://rust-for-linux.zulipchat.com/#narrow/stream/x/topic/x/near/465412664
Fixes: 1fbde52bde73 ("rust: add `macros` crate")
Cc: stable@vger.kernel.org # 6.6.x: be2ca1e03965: ("rust: types: Make Opaque::get const")
Link: https://lore.kernel.org/r/20240828180129.4046355-1-boqun.feng@gmail.com
[ Fixed two typos, reworded title. - Miguel ]
Signed-off-by: Miguel Ojeda

rust: rbtree: add `RBTree::entry`

2024-08-31T15:36:20+00:00

This mirrors the entry API [1] from the Rust standard library on
`RBTree`. This API can be used to access the entry at a specific key and
make modifications depending on whether the key is vacant or occupied.
This API is useful because it can often be used to avoid traversing the
tree multiple times.

This is used by binder to look up and conditionally access or insert a
value, depending on whether it is there or not [2].

Link: https://doc.rust-lang.org/stable/std/collections/btree_map/enum.Entry.html [1]
Link: https://android-review.googlesource.com/c/kernel/common/+/2849906 [2]
Signed-off-by: Alice Ryhl 
Tested-by: Alice Ryhl 
Reviewed-by: Boqun Feng 
Reviewed-by: Benno Lossin 
Signed-off-by: Matt Gilbride 
Link: https://lore.kernel.org/r/20240822-b4-rbtree-v12-5-014561758a57@google.com
Signed-off-by: Miguel Ojeda

rust: rbtree: add cursor

2024-08-31T15:36:20+00:00

Add a cursor interface to `RBTree`, supporting the following use cases:
- Inspect the current node pointed to by the cursor, inspect/move to
  it's neighbors in sort order (bidirectionally).
- Mutate the tree itself by removing the current node pointed to by the
  cursor, or one of its neighbors.

Add functions to obtain a cursor to the tree by key:
- The node with the smallest key
- The node with the largest key
- The node matching the given key, or the one with the next larger key

The cursor abstraction is needed by the binder driver to efficiently
search for nodes and (conditionally) modify them, as well as their
neighbors [1].

Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-6-08ba9197f637@google.com/ [1]
Co-developed-by: Alice Ryhl 
Signed-off-by: Alice Ryhl 
Tested-by: Alice Ryhl 
Reviewed-by: Boqun Feng 
Reviewed-by: Benno Lossin 
Signed-off-by: Matt Gilbride 
Link: https://lore.kernel.org/r/20240822-b4-rbtree-v12-4-014561758a57@google.com
Signed-off-by: Miguel Ojeda

rust: rbtree: add mutable iterator

2024-08-31T15:36:19+00:00

Add mutable Iterator implementation for `RBTree`,
allowing iteration over (key, value) pairs in key order. Only values are
mutable, as mutating keys implies modifying a node's position in the tree.

Mutable iteration is used by the binder driver during shutdown to
clean up the tree maintained by the "range allocator" [1].

Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-6-08ba9197f637@google.com/ [1]
Signed-off-by: Wedson Almeida Filho 
Reviewed-by: Alice Ryhl 
Tested-by: Alice Ryhl 
Reviewed-by: Boqun Feng 
Reviewed-by: Benno Lossin 
Signed-off-by: Matt Gilbride 
Link: https://lore.kernel.org/r/20240822-b4-rbtree-v12-3-014561758a57@google.com
Signed-off-by: Miguel Ojeda