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<Box<T>>' 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.
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Merge tag 'rust-6.12' of https://github.com/Rust-for-Linux/linux
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<Box<T>>' 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
...
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 <aliceryhl@google.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Matt Gilbride <mattgilbride@google.com>
Link: https://lore.kernel.org/r/20240822-b4-rbtree-v12-5-014561758a57@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
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 <aliceryhl@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Matt Gilbride <mattgilbride@google.com>
Link: https://lore.kernel.org/r/20240822-b4-rbtree-v12-4-014561758a57@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
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 <wedsonaf@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Matt Gilbride <mattgilbride@google.com>
Link: https://lore.kernel.org/r/20240822-b4-rbtree-v12-3-014561758a57@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
- Add Iterator implementation for `RBTree`, allowing
iteration over (key, value) pairs in key order.
- Add individual `keys()` and `values()` functions to iterate over keys
or values alone.
- Update doctests to use iteration instead of explicitly getting items.
Iteration is needed by the binder driver to enumerate all values in a
tree for oneway spam detection [1].
Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-17-08ba9197f637@google.com/ [1]
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Matt Gilbride <mattgilbride@google.com>
Link: https://lore.kernel.org/r/20240822-b4-rbtree-v12-2-014561758a57@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The rust rbtree exposes a map-like interface over keys and values,
backed by the kernel red-black tree implementation. Values can be
inserted, deleted, and retrieved from a `RBTree` by key.
This base abstraction is used by binder to store key/value
pairs and perform lookups, for example the patch
"[PATCH RFC 03/20] rust_binder: add threading support"
in the binder RFC [1].
Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-3-08ba9197f637@google.com/ [1]
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Matt Gilbride <mattgilbride@google.com>
Link: https://lore.kernel.org/r/20240822-b4-rbtree-v12-1-014561758a57@google.com
[ Updated link to docs.kernel.org. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Add unified genphy_read_status function for C22 and C45
registers. Instead of having genphy_c22 and genphy_c45 methods, this
unifies genphy_read_status functions for C22 and C45.
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add the unified read/write API for C22 and C45 registers. The
abstractions support access to only C22 registers now. Instead of
adding read/write_c45 methods specifically for C45, a new reg module
supports the unified API to access C22 and C45 registers with trait,
by calling an appropriate phylib functions.
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Implement AsRef<kernel::device::Device> trait for Device. A PHY driver
needs a reference to device::Device to call the firmware API.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Support phy_driver probe callback, used to set up device-specific
structures.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add rust equivalent to include/linux/sizes.h, makes code more
readable. Only SZ_*K that QT2025 PHY driver uses are added.
Make generated constants accessible with a proper type.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Upstream Rust's libs-api team has consensus for stabilizing some of
`feature(new_uninit)`, but not for `Box<MaybeUninit<T>>::write`. Instead,
we can use `MaybeUninit<T>::write`, so Rust for Linux can drop the
feature after stabilization. That will happen after merging, as the FCP
has completed [1].
This is required before stabilization because remaining-unstable API
will be divided into new features. This code doesn't know about those
yet. It can't: they haven't landed, as the relevant PR is blocked on
rustc's CI testing Rust-for-Linux without this patch.
[ The PR has landed [2] and will be released in Rust 1.82.0 (expected on
2024-10-17), so we could conditionally enable the new unstable feature
(`box_uninit_write` [3]) instead, but just for a single `unsafe` block
it is probably not worth it. For the time being, I added it to the
"nice to have" section of our unstable features list. - Miguel ]
Link: https://github.com/rust-lang/rust/issues/63291#issuecomment-2183022955 [1]
Link: https://github.com/rust-lang/rust/pull/129416 [2]
Link: https://github.com/rust-lang/rust/issues/129397 [3]
Signed-off-by: Jubilee Young <workingjubilee@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
[ Reworded slightly. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Add a method for `ARef` that is analogous to `Arc::into_raw`. It is the
inverse operation of `ARef::from_raw`, and allows you to convert the
`ARef` back into a raw pointer while retaining ownership of the
refcount.
This new function will be used by [1] for converting the type in an
`ARef` using `ARef::from_raw(ARef::into_raw(me).cast())`. Alice has
also needed the same function for other use-cases in the past, but [1]
is the first to go upstream.
This was implemented independently by Kartik and Alice. The two versions
were merged by Alice, so all mistakes are Alice's.
Link: https://lore.kernel.org/r/20240801-vma-v3-1-db6c1c0afda9@google.com [1]
Link: https://github.com/Rust-for-Linux/linux/issues/1044
Signed-off-by: Kartik Prajapati <kartikprajapati987@gmail.com>
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
[ Reworded to correct the author reference and changed tag to Link
since it is not a bug. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Use links to docs.kernel.org instead of www.kernel.org/doc/html/latest
in the code documentation. The links are shorter and cleaner.
Link: https://github.com/Rust-for-Linux/linux/issues/1101
Signed-off-by: Michael Vetter <jubalh@iodoru.org>
[ Reworded slightly. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
One way to explain what `ListArc` does is that it controls exclusive
access to the prev/next pointer field in a refcounted object. The
feature of having a special reference to a refcounted object with
exclusive access to specific fields is useful for other things, so
provide a general utility for that.
This is used by Rust Binder to keep track of which processes have a
reference to a given node. This involves an object for each process/node
pair, that is referenced by both the process and the node. For some
fields in this object, only the process's reference needs to access
them (and it needs mutable access), so Binder uses a ListArc to give the
process's reference exclusive access.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-10-f5f5e8075da0@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Support linked lists that can hold many different structs at once. This
is generally done using trait objects. The main challenge is figuring
what the struct is given only a pointer to the ListLinks.
We do this by storing a pointer to the struct next to the ListLinks
field. The container_of operation will then just read that pointer. When
the type is a trait object, that pointer will be a fat pointer whose
metadata is a vtable that tells you what kind of struct it is.
Heterogeneous lists are heavily used by Rust Binder. There are a lot of
so-called todo lists containing various events that need to be delivered
to userspace next time userspace calls into the driver. And there are
quite a few different todo item types: incoming transaction, changes to
refcounts, death notifications, and more.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-9-f5f5e8075da0@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The cursor is very similar to the list iterator, but it has one
important feature that the iterator doesn't: it can be used to remove
items from the linked list.
This feature cannot be added to the iterator because the references you
get from the iterator are considered borrows of the original list,
rather than borrows of the iterator. This means that there's no way to
prevent code like this:
let item = iter.next();
iter.remove();
use(item);
If `iter` was a cursor instead of an iterator, then `item` will be
considered a borrow of `iter`. Since `remove` destroys `iter`, this
means that the borrow-checker will prevent uses of `item` after the call
to `remove`.
So there is a trade-off between supporting use in traditional for loops,
and supporting removal of elements as you iterate. Iterators and cursors
represents two different choices on that spectrum.
Rust Binder needs cursors for the list of death notifications that a
process is currently handling. When userspace tells Binder that it has
finished processing the death notification, Binder will iterate the list
to search for the relevant item and remove it.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-8-f5f5e8075da0@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Rust Binder has lists containing stuff such as all contexts or all
processes, and sometimes needs to iterate over them. This patch enables
Rust Binder to do that using a normal for loop.
The iterator returns the ArcBorrow type, so it is possible to grab a
refcount to values while iterating.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-7-f5f5e8075da0@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Add the actual linked list itself.
The linked list uses the following design: The List type itself just has
a single pointer to the first element of the list. And the actual list
items then form a cycle. So the last item is `first->prev`.
This is slightly different from the usual kernel linked list. Matching
that exactly would amount to giving List two pointers, and having it be
part of the cycle of items. This alternate design has the advantage that
the cycle is never completely empty, which can reduce the number of
branches in some cases. However, it also has the disadvantage that List
must be pinned, which this design is trying to avoid.
Having the list items form a cycle rather than having null pointers at
the beginning/end is convenient for several reasons. For one, it lets us
store only one pointer in List, and it simplifies the implementation of
several functions.
Unfortunately, the `remove` function that removes an arbitrary element
from the list has to be unsafe. This is needed because there is no way
to handle the case where you pass an element from the wrong list. For
example, if it is the first element of some other list, then that other
list's `first` pointer would not be updated. Similarly, it could be a
data race if you try to remove it from two different lists in parallel.
(There's no problem with passing `remove` an item that's not in any
list. Additionally, other removal methods such as `pop_front` need not
be unsafe, as they can't be used to remove items from another list.)
A future patch in this series will introduce support for cursors that
can be used to remove arbitrary items without unsafe code.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-6-f5f5e8075da0@google.com
[ Fixed a few typos. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Adds a macro for safely implementing the ListItem trait. As part of the
implementation of the macro, we also provide a HasListLinks trait
similar to the workqueue's HasWorkItem trait.
The HasListLinks trait is only necessary if you are implementing
ListItem using the impl_list_item macro.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-5-f5f5e8075da0@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Define the ListLinks struct, which wraps the prev/next pointers that
will be used to insert values into a List in a future patch. Also
define the ListItem trait, which is implemented by structs that have a
ListLinks field.
The ListItem trait provides four different methods that are all
essentially container_of or the reverse of container_of. Two of them are
used before inserting/after removing an item from the list, and the two
others are used when looking at a value without changing whether it is
in a list. This distinction is introduced because it is needed for the
patch that adds support for heterogeneous lists, which are implemented
by adding a third pointer field with a fat pointer to the full struct.
When inserting into the heterogeneous list, the pointer-to-self is
updated to have the right vtable, and the container_of operation is
implemented by just returning that pointer instead of using the real
container_of operation.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-4-f5f5e8075da0@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Add the ability to track whether a ListArc exists for a given value,
allowing for the creation of ListArcs without going through UniqueArc.
The `impl_list_arc_safe!` macro is extended with a `tracked_by` strategy
that defers the tracking of ListArcs to a field of the struct.
Additionally, the AtomicListArcTracker type is introduced, which can
track whether a ListArc exists using an atomic. By deferring the
tracking to a field of type AtomicListArcTracker, structs gain the
ability to create ListArcs without going through a UniqueArc.
Rust Binder uses this for some objects where we want to be able to
insert them into a linked list at any time. Using the
AtomicListArcTracker, we are able to check whether an item is already in
the list, and if not, we can create a `ListArc` and push it.
The macro has the ability to defer the tracking of ListArcs to a field,
using whatever strategy that field has. Since we don't add any
strategies other than AtomicListArcTracker, another similar option would
be to hard-code that the field should be an AtomicListArcTracker.
However, Rust Binder has a case where the AtomicListArcTracker is not
stored directly in the struct, but in a sub-struct. Furthermore, the
outer struct is generic:
struct Wrapper<T: ?Sized> {
links: ListLinks,
inner: T,
}
Here, the Wrapper struct implements ListArcSafe with `tracked_by inner`,
and then the various types used with `inner` also uses the macro to
implement ListArcSafe. Some of them use the untracked strategy, and some
of them use tracked_by with an AtomicListArcTracker. This way, Wrapper
just inherits whichever choice `inner` has made.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-3-f5f5e8075da0@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The `ListArc` type can be thought of as a special reference to a
refcounted object that owns the permission to manipulate the
`next`/`prev` pointers stored in the refcounted object. By ensuring that
each object has only one `ListArc` reference, the owner of that
reference is assured exclusive access to the `next`/`prev` pointers.
When a `ListArc` is inserted into a `List`, the `List` takes ownership
of the `ListArc` reference.
There are various strategies for ensuring that a value has only one
`ListArc` reference. The simplest is to convert a `UniqueArc` into a
`ListArc`. However, the refcounted object could also keep track of
whether a `ListArc` exists using a boolean, which could allow for the
creation of new `ListArc` references from an `Arc` reference. Whatever
strategy is used, the relevant tracking is referred to as "the tracking
inside `T`", and the `ListArcSafe` trait (and its subtraits) are used to
update the tracking when a `ListArc` is created or destroyed.
Note that we allow the case where the tracking inside `T` thinks that a
`ListArc` exists, but actually, there isn't a `ListArc`. However, we do
not allow the opposite situation where a `ListArc` exists, but the
tracking thinks it doesn't. This is because the former can at most
result in us failing to create a `ListArc` when the operation could
succeed, whereas the latter can result in the creation of two `ListArc`
references. Only the latter situation can lead to memory safety issues.
This patch introduces the `impl_list_arc_safe!` macro that allows you to
implement `ListArcSafe` for types using the strategy where a `ListArc`
can only be created from a `UniqueArc`. Other strategies are introduced
in later patches.
This is part of the linked list that Rust Binder will use for many
different things. The strategy where a `ListArc` can only be created
from a `UniqueArc` is actually sufficient for most of the objects that
Rust Binder needs to insert into linked lists. Usually, these are todo
items that are created and then immediately inserted into a queue.
The const generic ID allows objects to have several prev/next pointer
pairs so that the same object can be inserted into several different
lists. You are able to have several `ListArc` references as long as they
correspond to different pointer pairs. The ID itself is purely a
compile-time concept and will not be present in the final binary. Both
the `List` and the `ListArc` will need to agree on the ID for them to
work together. Rust Binder uses this in a few places (e.g. death
recipients) where the same object can be inserted into both generic todo
lists and some other lists for tracking the status of the object.
The ID is a const generic rather than a type parameter because the
`pair_from_unique` method needs to be able to assert that the two ids
are different. There's no easy way to assert that when using types
instead of integers.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-2-f5f5e8075da0@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Add a macro to statically check if a field of a struct is marked with
`#[pin]` ie that it is structurally pinned. This can be used when
`unsafe` code needs to rely on fields being structurally pinned.
The macro has a special "inline" mode for the case where the type
depends on generic parameters from the surrounding scope.
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-1-f5f5e8075da0@google.com
[ Replaced `compile_fail` with `ignore` and a TODO note. Removed
`pub` from example to clean `unreachable_pub` lint. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Sometimes it is necessary to split allocation and initialization into
two steps. One such situation is when reusing existing allocations
obtained via `Box::drop_contents`. See [1] for an example.
In order to support this use case add `write_[pin_]init` functions to the
pin-init API. These functions operate on already allocated smart
pointers that wrap `MaybeUninit<T>`.
Link: https://lore.kernel.org/rust-for-linux/f026532f-8594-4f18-9aa5-57ad3f5bc592@proton.me/ [1]
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240819112415.99810-2-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Sometimes (see [1]) it is necessary to drop the value inside of a
`Box<T>`, but retain the allocation. For example to reuse the allocation
in the future.
Introduce a new function `drop_contents` that turns a `Box<T>` into
`Box<MaybeUninit<T>>` by dropping the value.
Link: https://lore.kernel.org/rust-for-linux/20240418-b4-rbtree-v3-5-323e134390ce@google.com/ [1]
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240819112415.99810-1-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
When allocating `struct gendisk`, `GenDiskBuilder` is using a dynamic
lock class key without registering the key. This is an incorrect use of
the API, which causes a `WARN` trace.
Fix the issue by using a static lock class key, which is more appropriate
for the situation anyway.
Fixes: 3253aba340 ("rust: block: introduce `kernel::block::mq` module")
Reported-by: Behme Dirk (XC-CP/ESB5) <Dirk.Behme@de.bosch.com>
Closes: https://rust-for-linux.zulipchat.com/#narrow/stream/x/topic/x/near/457090036
Signed-off-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Dirk Behme <dirk.behme@de.bosch.com>
Link: https://lore.kernel.org/r/20240815074519.2684107-3-nmi@metaspace.dk
[ Applied `rustfmt`, reworded slightly and made Zulip link
a permalink. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
For the new Rust support for 32-bit arm [1], Clippy warns:
error: useless conversion to the same type: `i32`
--> rust/kernel/error.rs:139:36
|
139 | unsafe { bindings::ERR_PTR(self.0.into()) as *mut _ }
| ^^^^^^^^^^^^^ help: consider removing `.into()`: `self.0`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_conversion
= note: `-D clippy::useless-conversion` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(clippy::useless_conversion)]`
The `self.0.into()` converts an `c_int` into `ERR_PTR`'s parameter
which is a `c_long`. Thus, both types are `i32` in 32-bit. Therefore,
allow it for those architectures.
Link: https://lore.kernel.org/rust-for-linux/2dbd1491-149d-443c-9802-75786a6a3b73@gmail.com/ [1]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Christian Schrefl <chrisi.schrefl@gmail.com>
Link: https://lore.kernel.org/r/20240730155702.1110144-1-ojeda@kernel.org
[ Fixed typo in tag. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
There are no guarantees for the pointer returned by `into_foreign`.
This is simply because there is no safety documentation stating any
guarantees. Therefore dereferencing and all other operations for that
pointer are not allowed in a general context (i.e. when the concrete
type implementing the trait is not known).
This might be confusing, therefore add normal documentation to state
that there are no guarantees given for the pointer.
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240730182251.1466684-1-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
We already implement ForeignOwnable for Box<T>, but it may be useful to
store pinned data in a ForeignOwnable container. This patch makes that
possible.
This will be used together with upcoming miscdev abstractions, which
Binder will use when binderfs is disabled.
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20240730-foreign-ownable-pin-box-v1-1-b1d70cdae541@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
For pinned and unpinned initialization of structs, a trait named
`InPlaceInit` exists for uniform access. `Arc` did not implement
`InPlaceInit` yet, although the functions already existed. The main
reason for that, was that the trait itself returned a `Pin<Self>`. The
`Arc` implementation of the kernel is already implicitly pinned.
To enable `Arc` to implement `InPlaceInit` and to have uniform access,
for in-place and pinned in-place initialization, an associated type is
introduced for `InPlaceInit`. The new implementation of `InPlaceInit`
for `Arc` sets `Arc` as the associated type. Older implementations use
an explicit `Pin<T>` as the associated type. The implemented methods for
`Arc` are mostly moved from a direct implementation on `Arc`. There
should be no user impact. The implementation for `ListArc` is omitted,
because it is not merged yet.
Link: https://github.com/Rust-for-Linux/linux/issues/1079
Signed-off-by: Alex Mantel <alexmantel93@mailbox.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20240727042442.682109-1-alexmantel93@mailbox.org
[ Removed "Rusts" (Benno). - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
remove an extra quote from the doc comment so that rustdoc
no longer genertes a link to a nonexistent file.
Signed-off-by: Andrew Ballance <andrewjballance@gmail.com>
Reviewed-by: Danilo Krummrich <dakr@redhat.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Fixes: de6582833d ("rust: add firmware abstractions")
Link: https://lore.kernel.org/r/20240709004426.44854-1-andrewjballance@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The highlight is the establishment of a minimum version for the Rust
toolchain, including 'rustc' (and bundled tools) and 'bindgen'.
The initial minimum will be the pinned version we currently have, i.e.
we are just widening the allowed versions. That covers 3 stable Rust
releases: 1.78.0, 1.79.0, 1.80.0 (getting released tomorrow), plus beta,
plus nightly.
This should already be enough for kernel developers in distributions
that provide recent Rust compiler versions routinely, such as Arch
Linux, Debian Unstable (outside the freeze period), Fedora Linux,
Gentoo Linux (especially the testing channel), Nix (unstable) and
openSUSE Slowroll and Tumbleweed.
In addition, the kernel is now being built-tested by Rust's pre-merge
CI. That is, every change that is attempting to land into the Rust
compiler is tested against the kernel, and it is merged only if it
passes. Similarly, the bindgen tool has agreed to build the kernel in
their CI too.
Thus, with the pre-merge CI in place, both projects hope to avoid
unintentional changes to Rust that break the kernel. This means that,
in general, apart from intentional changes on their side (that we
will need to workaround conditionally on our side), the upcoming Rust
compiler versions should generally work.
In addition, the Rust project has proposed getting the kernel into
stable Rust (at least solving the main blockers) as one of its three
flagship goals for 2024H2 [1].
I would like to thank Niko, Sid, Emilio et al. for their help promoting
the collaboration between Rust and the kernel.
[1] https://rust-lang.github.io/rust-project-goals/2024h2/index.html#flagship-goals
Toolchain and infrastructure:
- Support several Rust toolchain versions.
- Support several bindgen versions.
- Remove 'cargo' requirement and simplify 'rusttest', thanks to 'alloc'
having been dropped last cycle.
- Provide proper error reporting for the 'rust-analyzer' target.
'kernel' crate:
- Add 'uaccess' module with a safe userspace pointers abstraction.
- Add 'page' module with a 'struct page' abstraction.
- Support more complex generics in workqueue's 'impl_has_work!' macro.
'macros' crate:
- Add 'firmware' field support to the 'module!' macro.
- Improve 'module!' macro documentation.
Documentation:
- Provide instructions on what packages should be installed to build
the kernel in some popular Linux distributions.
- Introduce the new kernel.org LLVM+Rust toolchains.
- Explain '#[no_std]'.
And a few other small bits.
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Merge tag 'rust-6.11' of https://github.com/Rust-for-Linux/linux
Pull Rust updates from Miguel Ojeda:
"The highlight is the establishment of a minimum version for the Rust
toolchain, including 'rustc' (and bundled tools) and 'bindgen'.
The initial minimum will be the pinned version we currently have, i.e.
we are just widening the allowed versions. That covers three stable
Rust releases: 1.78.0, 1.79.0, 1.80.0 (getting released tomorrow),
plus beta, plus nightly.
This should already be enough for kernel developers in distributions
that provide recent Rust compiler versions routinely, such as Arch
Linux, Debian Unstable (outside the freeze period), Fedora Linux,
Gentoo Linux (especially the testing channel), Nix (unstable) and
openSUSE Slowroll and Tumbleweed.
In addition, the kernel is now being built-tested by Rust's pre-merge
CI. That is, every change that is attempting to land into the Rust
compiler is tested against the kernel, and it is merged only if it
passes. Similarly, the bindgen tool has agreed to build the kernel in
their CI too.
Thus, with the pre-merge CI in place, both projects hope to avoid
unintentional changes to Rust that break the kernel. This means that,
in general, apart from intentional changes on their side (that we will
need to workaround conditionally on our side), the upcoming Rust
compiler versions should generally work.
In addition, the Rust project has proposed getting the kernel into
stable Rust (at least solving the main blockers) as one of its three
flagship goals for 2024H2 [1].
I would like to thank Niko, Sid, Emilio et al. for their help
promoting the collaboration between Rust and the kernel.
Toolchain and infrastructure:
- Support several Rust toolchain versions.
- Support several bindgen versions.
- Remove 'cargo' requirement and simplify 'rusttest', thanks to
'alloc' having been dropped last cycle.
- Provide proper error reporting for the 'rust-analyzer' target.
'kernel' crate:
- Add 'uaccess' module with a safe userspace pointers abstraction.
- Add 'page' module with a 'struct page' abstraction.
- Support more complex generics in workqueue's 'impl_has_work!'
macro.
'macros' crate:
- Add 'firmware' field support to the 'module!' macro.
- Improve 'module!' macro documentation.
Documentation:
- Provide instructions on what packages should be installed to build
the kernel in some popular Linux distributions.
- Introduce the new kernel.org LLVM+Rust toolchains.
- Explain '#[no_std]'.
And a few other small bits"
Link: https://rust-lang.github.io/rust-project-goals/2024h2/index.html#flagship-goals [1]
* tag 'rust-6.11' of https://github.com/Rust-for-Linux/linux: (26 commits)
docs: rust: quick-start: add section on Linux distributions
rust: warn about `bindgen` versions 0.66.0 and 0.66.1
rust: start supporting several `bindgen` versions
rust: work around `bindgen` 0.69.0 issue
rust: avoid assuming a particular `bindgen` build
rust: start supporting several compiler versions
rust: simplify Clippy warning flags set
rust: relax most deny-level lints to warnings
rust: allow `dead_code` for never constructed bindings
rust: init: simplify from `map_err` to `inspect_err`
rust: macros: indent list item in `paste!`'s docs
rust: add abstraction for `struct page`
rust: uaccess: add typed accessors for userspace pointers
uaccess: always export _copy_[from|to]_user with CONFIG_RUST
rust: uaccess: add userspace pointers
kbuild: rust-analyzer: improve comment documentation
kbuild: rust-analyzer: better error handling
docs: rust: no_std is used
rust: alloc: add __GFP_HIGHMEM flag
rust: alloc: fix typo in docs for GFP_NOWAIT
...
Here is the big set of driver core changes for 6.11-rc1.
Lots of stuff in here, with not a huge diffstat, but apis are evolving
which required lots of files to be touched. Highlights of the changes
in here are:
- platform remove callback api final fixups (Uwe took many releases to
get here, finally!)
- Rust bindings for basic firmware apis and initial driver-core
interactions. It's not all that useful for a "write a whole driver
in rust" type of thing, but the firmware bindings do help out the
phy rust drivers, and the driver core bindings give a solid base on
which others can start their work. There is still a long way to go
here before we have a multitude of rust drivers being added, but
it's a great first step.
- driver core const api changes. This reached across all bus types,
and there are some fix-ups for some not-common bus types that
linux-next and 0-day testing shook out. This work is being done to
help make the rust bindings more safe, as well as the C code, moving
toward the end-goal of allowing us to put driver structures into
read-only memory. We aren't there yet, but are getting closer.
- minor devres cleanups and fixes found by code inspection
- arch_topology minor changes
- other minor driver core cleanups
All of these have been in linux-next for a very long time with no
reported problems.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Here is the big set of driver core changes for 6.11-rc1.
Lots of stuff in here, with not a huge diffstat, but apis are evolving
which required lots of files to be touched. Highlights of the changes
in here are:
- platform remove callback api final fixups (Uwe took many releases
to get here, finally!)
- Rust bindings for basic firmware apis and initial driver-core
interactions.
It's not all that useful for a "write a whole driver in rust" type
of thing, but the firmware bindings do help out the phy rust
drivers, and the driver core bindings give a solid base on which
others can start their work.
There is still a long way to go here before we have a multitude of
rust drivers being added, but it's a great first step.
- driver core const api changes.
This reached across all bus types, and there are some fix-ups for
some not-common bus types that linux-next and 0-day testing shook
out.
This work is being done to help make the rust bindings more safe,
as well as the C code, moving toward the end-goal of allowing us to
put driver structures into read-only memory. We aren't there yet,
but are getting closer.
- minor devres cleanups and fixes found by code inspection
- arch_topology minor changes
- other minor driver core cleanups
All of these have been in linux-next for a very long time with no
reported problems"
* tag 'driver-core-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (55 commits)
ARM: sa1100: make match function take a const pointer
sysfs/cpu: Make crash_hotplug attribute world-readable
dio: Have dio_bus_match() callback take a const *
zorro: make match function take a const pointer
driver core: module: make module_[add|remove]_driver take a const *
driver core: make driver_find_device() take a const *
driver core: make driver_[create|remove]_file take a const *
firmware_loader: fix soundness issue in `request_internal`
firmware_loader: annotate doctests as `no_run`
devres: Correct code style for functions that return a pointer type
devres: Initialize an uninitialized struct member
devres: Fix memory leakage caused by driver API devm_free_percpu()
devres: Fix devm_krealloc() wasting memory
driver core: platform: Switch to use kmemdup_array()
driver core: have match() callback in struct bus_type take a const *
MAINTAINERS: add Rust device abstractions to DRIVER CORE
device: rust: improve safety comments
MAINTAINERS: add Danilo as FIRMWARE LOADER maintainer
MAINTAINERS: add Rust FW abstractions to FIRMWARE LOADER
firmware: rust: improve safety comments
...
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Merge tag 'slab-for-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab
Pull slab updates from Vlastimil Babka:
"The most prominent change this time is the kmem_buckets based
hardening of kmalloc() allocations from Kees Cook.
We have also extended the kmalloc() alignment guarantees for
non-power-of-two sizes in a way that benefits rust.
The rest are various cleanups and non-critical fixups.
- Dedicated bucket allocator (Kees Cook)
This series [1] enhances the probabilistic defense against heap
spraying/grooming of CONFIG_RANDOM_KMALLOC_CACHES from last year.
kmalloc() users that are known to be useful for exploits can get
completely separate set of kmalloc caches that can't be shared with
other users. The first converted users are alloc_msg() and
memdup_user().
The hardening is enabled by CONFIG_SLAB_BUCKETS.
- Extended kmalloc() alignment guarantees (Vlastimil Babka)
For years now we have guaranteed natural alignment for power-of-two
allocations, but nothing was defined for other sizes (in practice,
we have two such buckets, kmalloc-96 and kmalloc-192).
To avoid unnecessary padding in the rust layer due to its alignment
rules, extend the guarantee so that the alignment is at least the
largest power-of-two divisor of the requested size.
This fits what rust needs, is a superset of the existing
power-of-two guarantee, and does not in practice change the layout
(and thus does not add overhead due to padding) of the kmalloc-96
and kmalloc-192 caches, unless slab debugging is enabled for them.
- Cleanups and non-critical fixups (Chengming Zhou, Suren
Baghdasaryan, Matthew Willcox, Alex Shi, and Vlastimil Babka)
Various tweaks related to the new alloc profiling code, folio
conversion, debugging and more leftovers after SLAB"
Link: https://lore.kernel.org/all/20240701190152.it.631-kees@kernel.org/ [1]
* tag 'slab-for-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
mm/memcg: alignment memcg_data define condition
mm, slab: move prepare_slab_obj_exts_hook under CONFIG_MEM_ALLOC_PROFILING
mm, slab: move allocation tagging code in the alloc path into a hook
mm/util: Use dedicated slab buckets for memdup_user()
ipc, msg: Use dedicated slab buckets for alloc_msg()
mm/slab: Introduce kmem_buckets_create() and family
mm/slab: Introduce kvmalloc_buckets_node() that can take kmem_buckets argument
mm/slab: Plumb kmem_buckets into __do_kmalloc_node()
mm/slab: Introduce kmem_buckets typedef
slab, rust: extend kmalloc() alignment guarantees to remove Rust padding
slab: delete useless RED_INACTIVE and RED_ACTIVE
slab: don't put freepointer outside of object if only orig_size
slab: make check_object() more consistent
mm: Reduce the number of slab->folio casts
mm, slab: don't wrap internal functions with alloc_hooks()
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Merge tag 'for-6.11/block-20240710' of git://git.kernel.dk/linux
Pull block updates from Jens Axboe:
- NVMe updates via Keith:
- Device initialization memory leak fixes (Keith)
- More constants defined (Weiwen)
- Target debugfs support (Hannes)
- PCIe subsystem reset enhancements (Keith)
- Queue-depth multipath policy (Redhat and PureStorage)
- Implement get_unique_id (Christoph)
- Authentication error fixes (Gaosheng)
- MD updates via Song
- sync_action fix and refactoring (Yu Kuai)
- Various small fixes (Christoph Hellwig, Li Nan, and Ofir Gal, Yu
Kuai, Benjamin Marzinski, Christophe JAILLET, Yang Li)
- Fix loop detach/open race (Gulam)
- Fix lower control limit for blk-throttle (Yu)
- Add module descriptions to various drivers (Jeff)
- Add support for atomic writes for block devices, and statx reporting
for same. Includes SCSI and NVMe (John, Prasad, Alan)
- Add IO priority information to block trace points (Dongliang)
- Various zone improvements and tweaks (Damien)
- mq-deadline tag reservation improvements (Bart)
- Ignore direct reclaim swap writes in writeback throttling (Baokun)
- Block integrity improvements and fixes (Anuj)
- Add basic support for rust based block drivers. Has a dummy null_blk
variant for now (Andreas)
- Series converting driver settings to queue limits, and cleanups and
fixes related to that (Christoph)
- Cleanup for poking too deeply into the bvec internals, in preparation
for DMA mapping API changes (Christoph)
- Various minor tweaks and fixes (Jiapeng, John, Kanchan, Mikulas,
Ming, Zhu, Damien, Christophe, Chaitanya)
* tag 'for-6.11/block-20240710' of git://git.kernel.dk/linux: (206 commits)
floppy: add missing MODULE_DESCRIPTION() macro
loop: add missing MODULE_DESCRIPTION() macro
ublk_drv: add missing MODULE_DESCRIPTION() macro
xen/blkback: add missing MODULE_DESCRIPTION() macro
block/rnbd: Constify struct kobj_type
block: take offset into account in blk_bvec_map_sg again
block: fix get_max_segment_size() warning
loop: Don't bother validating blocksize
virtio_blk: Don't bother validating blocksize
null_blk: Don't bother validating blocksize
block: Validate logical block size in blk_validate_limits()
virtio_blk: Fix default logical block size fallback
nvmet-auth: fix nvmet_auth hash error handling
nvme: implement ->get_unique_id
block: pass a phys_addr_t to get_max_segment_size
block: add a bvec_phys helper
blk-lib: check for kill signal in ioctl BLKZEROOUT
block: limit the Write Zeroes to manually writing zeroes fallback
block: refacto blkdev_issue_zeroout
block: move read-only and supported checks into (__)blkdev_issue_zeroout
...
A new complexity lint, `manual_inspect` [1], has been introduced in
the upcoming Rust 1.81 (currently in nightly), which checks for uses of
`map*` which return the original item:
error:
--> rust/kernel/init.rs:846:23
|
846 | (self.1)(val).map_err(|e| {
| ^^^^^^^
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#manual_inspect
= note: `-D clippy::manual-inspect` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(clippy::manual_inspect)]`
help: try
|
846 ~ (self.1)(val).inspect_err(|e| {
847 | // SAFETY: `slot` was initialized above.
848 ~ unsafe { core::ptr::drop_in_place(slot) };
|
Thus clean them up.
Link: https://rust-lang.github.io/rust-clippy/master/index.html#/manual_inspect [1]
Tested-by: Benno Lossin <benno.lossin@proton.me>
Tested-by: Andreas Hindborg <a.hindborg@samsung.com>
Link: https://lore.kernel.org/r/20240709160615.998336-3-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
`request_internal` must be called with one of the following function
pointers: request_firmware(), firmware_request_nowarn(),
firmware_request_platform() or request_firmware_direct().
The previous `FwFunc` alias did not guarantee this, which is unsound.
In order to fix this up, implement `FwFunc` as new type with a
corresponding type invariant.
Reported-by: Gary Guo <gary@garyguo.net>
Closes: https://lore.kernel.org/lkml/20240620143611.7995e0bb@eugeo/
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Reviewed-by: Christian Schrefl <chrisi.schrefl@gmail.com>
Link: https://lore.kernel.org/r/20240708200724.3203-2-dakr@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The doctests of `Firmware` are compile-time only tests, since they
require a proper `Device` and a valid path to a (firmware) blob in order
to do something sane on runtime - we can't satisfy both of those
requirements.
Hence, configure the example as `no_run`.
Unfortunately, the kernel's Rust build system can't consider the
`no_run` attribute yet. Hence, for the meantime, wrap the example code
into a new function and never actually call it.
Fixes: de6582833d ("rust: add firmware abstractions")
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://lore.kernel.org/r/20240708200724.3203-1-dakr@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Adds a new struct called `Page` that wraps a pointer to `struct page`.
This struct is assumed to hold ownership over the page, so that Rust
code can allocate and manage pages directly.
The page type has various methods for reading and writing into the page.
These methods will temporarily map the page to allow the operation. All
of these methods use a helper that takes an offset and length, performs
bounds checks, and returns a pointer to the given offset in the page.
This patch only adds support for pages of order zero, as that is all
Rust Binder needs. However, it is written to make it easy to add support
for higher-order pages in the future. To do that, you would add a const
generic parameter to `Page` that specifies the order. Most of the
methods do not need to be adjusted, as the logic for dealing with
mapping multiple pages at once can be isolated to just the
`with_pointer_into_page` method.
Rust Binder needs to manage pages directly as that is how transactions
are delivered: Each process has an mmap'd region for incoming
transactions. When an incoming transaction arrives, the Binder driver
will choose a region in the mmap, allocate and map the relevant pages
manually, and copy the incoming transaction directly into the page. This
architecture allows the driver to copy transactions directly from the
address space of one process to another, without an intermediate copy
to a kernel buffer.
This code is based on Wedson's page abstractions from the old rust
branch, but it has been modified by Alice by removing the incomplete
support for higher-order pages, by introducing the `with_*` helpers
to consolidate the bounds checking logic into a single place, and
various other changes.
Co-developed-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240528-alice-mm-v7-4-78222c31b8f4@google.com
[ Fixed typos and added a few intra-doc links. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Add safe methods for reading and writing Rust values to and from
userspace pointers.
The C methods for copying to/from userspace use a function called
`check_object_size` to verify that the kernel pointer is not dangling.
However, this check is skipped when the length is a compile-time
constant, with the assumption that such cases trivially have a correct
kernel pointer.
In this patch, we apply the same optimization to the typed accessors.
For both methods, the size of the operation is known at compile time to
be size_of of the type being read or written. Since the C side doesn't
provide a variant that skips only this check, we create custom helpers
for this purpose.
The majority of reads and writes to userspace pointers in the Rust
Binder driver uses these accessor methods. Benchmarking has found that
skipping the `check_object_size` check makes a big difference for the
cases being skipped here. (And that the check doesn't make a difference
for the cases that use the raw read/write methods.)
This code is based on something that was originally written by Wedson on
the old rust branch. It was modified by Alice to skip the
`check_object_size` check, and to update various comments, including the
notes about kernel pointers in `WritableToBytes`.
Co-developed-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240528-alice-mm-v7-3-78222c31b8f4@google.com
[ Wrapped docs to 100 and added a few intra-doc links. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
A pointer to an area in userspace memory, which can be either read-only
or read-write.
All methods on this struct are safe: attempting to read or write on bad
addresses (either out of the bound of the slice or unmapped addresses)
will return `EFAULT`. Concurrent access, *including data races to/from
userspace memory*, is permitted, because fundamentally another userspace
thread/process could always be modifying memory at the same time (in the
same way that userspace Rust's `std::io` permits data races with the
contents of files on disk). In the presence of a race, the exact byte
values read/written are unspecified but the operation is well-defined.
Kernelspace code should validate its copy of data after completing a
read, and not expect that multiple reads of the same address will return
the same value.
These APIs are designed to make it difficult to accidentally write
TOCTOU bugs. Every time you read from a memory location, the pointer is
advanced by the length so that you cannot use that reader to read the
same memory location twice. Preventing double-fetches avoids TOCTOU
bugs. This is accomplished by taking `self` by value to prevent
obtaining multiple readers on a given `UserSlice`, and the readers only
permitting forward reads. If double-fetching a memory location is
necessary for some reason, then that is done by creating multiple
readers to the same memory location.
Constructing a `UserSlice` performs no checks on the provided address
and length, it can safely be constructed inside a kernel thread with no
current userspace process. Reads and writes wrap the kernel APIs
`copy_from_user` and `copy_to_user`, which check the memory map of the
current process and enforce that the address range is within the user
range (no additional calls to `access_ok` are needed).
This code is based on something that was originally written by Wedson on
the old rust branch. It was modified by Alice by removing the
`IoBufferReader` and `IoBufferWriter` traits, and various other changes.
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240528-alice-mm-v7-1-78222c31b8f4@google.com
[ Wrapped docs to 100 and added a few intra-doc links. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Make it possible to allocate memory that doesn't need to mapped into the
kernel's address space. This flag is useful together with
Page::alloc_page [1].
Rust Binder needs this for the memory that holds incoming transactions
for each process. Each process will have a few megabytes of memory
allocated with this flag, which is mapped into the process using
vm_insert_page. When the kernel copies data for an incoming transaction
into a process's memory region, it will use kmap_local_page to
temporarily map pages that are being modified. There is no need for them
to take up address space in the kernel when the kernel is not writing an
incoming transaction into the page.
Link: https://lore.kernel.org/all/20240528-alice-mm-v7-4-78222c31b8f4@google.com/ [1]
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240607-highmem-v1-1-d18c5ca4072f@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Fix a typo in alloc.rs by replacing Ror with For.
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Link: https://lore.kernel.org/r/20240529083452.779865-1-aliceryhl@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Slab allocators have been guaranteeing natural alignment for
power-of-two sizes since commit 59bb47985c ("mm, sl[aou]b: guarantee
natural alignment for kmalloc(power-of-two)"), while any other sizes are
guaranteed to be aligned only to ARCH_KMALLOC_MINALIGN bytes (although
in practice are aligned more than that in non-debug scenarios).
Rust's allocator API specifies size and alignment per allocation, which
have to satisfy the following rules, per Alice Ryhl [1]:
1. The alignment is a power of two.
2. The size is non-zero.
3. When you round up the size to the next multiple of the alignment,
then it must not overflow the signed type isize / ssize_t.
In order to map this to kmalloc()'s guarantees, some requested
allocation sizes have to be padded to the next power-of-two size [2].
For example, an allocation of size 96 and alignment of 32 will be padded
to an allocation of size 128, because the existing kmalloc-96 bucket
doesn't guarantee alignent above ARCH_KMALLOC_MINALIGN. Without slab
debugging active, the layout of the kmalloc-96 slabs however naturally
align the objects to 32 bytes, so extending the size to 128 bytes is
wasteful.
To improve the situation we can extend the kmalloc() alignment
guarantees in a way that
1) doesn't change the current slab layout (and thus does not increase
internal fragmentation) when slab debugging is not active
2) reduces waste in the Rust allocator use case
3) is a superset of the current guarantee for power-of-two sizes.
The extended guarantee is that alignment is at least the largest
power-of-two divisor of the requested size. For power-of-two sizes the
largest divisor is the size itself, but let's keep this case documented
separately for clarity.
For current kmalloc size buckets, it means kmalloc-96 will guarantee
alignment of 32 bytes and kmalloc-196 will guarantee 64 bytes.
This covers the rules 1 and 2 above of Rust's API as long as the size is
a multiple of the alignment. The Rust layer should now only need to
round up the size to the next multiple if it isn't, while enforcing the
rule 3.
Implementation-wise, this changes the alignment calculation in
create_boot_cache(). While at it also do the calulation only for caches
with the SLAB_KMALLOC flag, because the function is also used to create
the initial kmem_cache and kmem_cache_node caches, where no alignment
guarantee is necessary.
In the Rust allocator's krealloc_aligned(), remove the code that padded
sizes to the next power of two (suggested by Alice Ryhl) as it's no
longer necessary with the new guarantees.
Reported-by: Alice Ryhl <aliceryhl@google.com>
Reported-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/all/CAH5fLggjrbdUuT-H-5vbQfMazjRDpp2%2Bk3%3DYhPyS17ezEqxwcw@mail.gmail.com/ [1]
Link: https://lore.kernel.org/all/CAH5fLghsZRemYUwVvhk77o6y1foqnCeDzW4WZv6ScEWna2+_jw@mail.gmail.com/ [2]
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
