Commit Graph
7 Commits
Author SHA1 Message Date
Shankari Anand 9907e1df31 rust: mm: update ARef and AlwaysRefCounted imports from sync::aref
Update call sites in the mm subsystem to import `ARef` and
`AlwaysRefCounted` from `sync::aref` instead of `types`.

This aligns with the ongoing effort to move `ARef` and `AlwaysRefCounted`
to sync.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Shankari Anand <[email protected]>
Suggested-by: Benno Lossin <[email protected]>
Link: https://github.com/Rust-for-Linux/linux/issues/1173
Acked-by: Alice Ryhl <[email protected]>
Cc: Alex Gaynor <[email protected]>
Cc: Andreas Hindborg <[email protected]>
Cc: Björn Roy Baron <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: Danilo Krummrich <[email protected]>
Cc: Gary Guo <[email protected]>
Cc: Liam Howlett <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Cc: Miguel Ojeda <[email protected]>
Cc: Trevor Gross <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
2025-09-13 16:55:15 -07:00
Baptiste Lepers 5cc5e030bc rust: mm: mark VmaNew as transparent
Unsafe code in VmaNew's methods assumes that the type has the same layout
as the inner `bindings::vm_area_struct`.  This is not guaranteed by the
default struct representation in Rust, but requires specifying the
`transparent` representation.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: dcb81aeab4 ("mm: rust: add VmaNew for f_ops->mmap()")
Signed-off-by: Baptiste Lepers <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Cc: Alex Gaynor <[email protected]>
Cc: Andreas Hindborg <[email protected]>
Cc: Björn Roy Baron <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: Danilo Krummrich <[email protected]>
Cc: Gary Guo <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: Liam Howlett <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Cc: Miguel Ojeda <[email protected]>
Cc: Trevor Gross <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
2025-08-27 22:45:41 -07:00
Tamir Duberstein 5e30550558 rust: enable clippy::as_underscore lint
In Rust 1.63.0, Clippy introduced the `as_underscore` lint [1]:

> The conversion might include lossy conversion or a dangerous cast that
> might go undetected due to the type being inferred.
>
> The lint is allowed by default as using `_` is less wordy than always
> specifying the type.

Always specifying the type is especially helpful in function call
contexts where the inferred type may change at a distance. Specifying
the type also allows Clippy to spot more cases of `useless_conversion`.

The primary downside is the need to specify the type in trivial getters.
There are 4 such functions: 3 have become slightly less ergonomic, 1 was
revealed to be a `useless_conversion`.

While this doesn't eliminate unchecked `as` conversions, it makes such
conversions easier to scrutinize.  It also has the slight benefit of
removing a degree of freedom on which to bikeshed. Thus apply the
changes and enable the lint -- no functional change intended.

Link: https://rust-lang.github.io/rust-clippy/master/index.html#as_underscore [1]
Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Boqun Feng <[email protected]>
Signed-off-by: Tamir Duberstein <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Acked-by: Danilo Krummrich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Changed `isize` to `c_long`. - Miguel ]
Signed-off-by: Miguel Ojeda <[email protected]>
2025-06-22 23:09:17 +02:00
Alice Ryhl 5a78977262 mm: rust: make CONFIG_MMU ifdefs more narrow
Currently the entire kernel::mm module is ifdef'd out when CONFIG_MMU=n.
However, there are some downstream users of the module in
rust/kernel/task.rs and rust/kernel/miscdevice.rs. Thus, update the cfgs
so that only MmWithUserAsync is removed with CONFIG_MMU=n.

The code is moved into a new file, since the #[cfg()] annotation
otherwise has to be duplicated several times.

Link: https://lkml.kernel.org/r/[email protected]
Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Fixes: 5bb9ed6cdf ("mm: rust: add abstraction for struct mm_struct")
Signed-off-by: Alice Ryhl <[email protected]>
Reviewed-by: Boqun Feng <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: Liam Howlett <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
2025-05-31 22:46:12 -07:00
Alice Ryhl dcb81aeab4 mm: rust: add VmaNew for f_ops->mmap()
This type will be used when setting up a new vma in an f_ops->mmap() hook.
Using a separate type from VmaRef allows us to have a separate set of
operations that you are only able to use during the mmap() hook.  For
example, the VM_MIXEDMAP flag must not be changed after the initial setup
that happens during the f_ops->mmap() hook.

To avoid setting invalid flag values, the methods for clearing VM_MAYWRITE
and similar involve a check of VM_WRITE, and return an error if VM_WRITE
is set.  Trying to use `try_clear_maywrite` without checking the return
value results in a compilation error because the `Result` type is marked
#[must_use].

For now, there's only a method for VM_MIXEDMAP and not VM_PFNMAP.  When we
add a VM_PFNMAP method, we will need some way to prevent you from setting
both VM_MIXEDMAP and VM_PFNMAP on the same vma.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Alice Ryhl <[email protected]>
Acked-by: Lorenzo Stoakes <[email protected]>
Acked-by: Liam R. Howlett <[email protected]>
Reviewed-by: Jann Horn <[email protected]>
Reviewed-by: Andreas Hindborg <[email protected]>
Cc: Alex Gaynor <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Balbir Singh <[email protected]>
Cc: Benno Lossin <[email protected]>
Cc: Björn Roy Baron <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: Gary Guo <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: John Hubbard <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Miguel Ojeda <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Trevor Gross <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
2025-05-11 17:48:25 -07:00
Alice Ryhl bf3d331bb8 mm: rust: add vm_insert_page
The vm_insert_page method is only usable on vmas with the VM_MIXEDMAP
flag, so we introduce a new type to keep track of such vmas.

The approach used in this patch assumes that we will not need to encode
many flag combinations in the type.  I don't think we need to encode more
than VM_MIXEDMAP and VM_PFNMAP as things are now.  However, if that
becomes necessary, using generic parameters in a single type would scale
better as the number of flags increases.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Alice Ryhl <[email protected]>
Acked-by: Lorenzo Stoakes <[email protected]>
Acked-by: Liam R. Howlett <[email protected]>
Reviewed-by: Andreas Hindborg <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Cc: Alex Gaynor <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Balbir Singh <[email protected]>
Cc: Benno Lossin <[email protected]>
Cc: Björn Roy Baron <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: John Hubbard <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Miguel Ojeda <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Trevor Gross <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
2025-05-11 17:48:24 -07:00
Alice Ryhl 040f404b73 mm: rust: add vm_area_struct methods that require read access
This adds a type called VmaRef which is used when referencing a vma that
you have read access to.  Here, read access means that you hold either the
mmap read lock or the vma read lock (or stronger).

Additionally, a vma_lookup method is added to the mmap read guard, which
enables you to obtain a &VmaRef in safe Rust code.

This patch only provides a way to lock the mmap read lock, but a follow-up
patch also provides a way to just lock the vma read lock.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Alice Ryhl <[email protected]>
Acked-by: Lorenzo Stoakes <[email protected]>
Acked-by: Liam R. Howlett <[email protected]>
Reviewed-by: Jann Horn <[email protected]>
Reviewed-by: Andreas Hindborg <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Cc: Alex Gaynor <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Balbir Singh <[email protected]>
Cc: Benno Lossin <[email protected]>
Cc: Björn Roy Baron <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: John Hubbard <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Miguel Ojeda <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Trevor Gross <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
2025-05-11 17:48:24 -07:00