[v11,0/8] Rust support for mm_struct, vm_area_struct, and mmap

Message

Alice Ryhl Dec. 11, 2024, 10:37 a.m. UTC

This updates the vm_area_struct support to use the approach we discussed
at LPC where there are several different Rust wrappers for
vm_area_struct depending on the kind of access you have to the vma. Each
case allows a different set of operations on the vma.

Patch 8 in particular could use review.

To: Miguel Ojeda <[e-mail]>
To: Matthew Wilcox <[e-mail]>
To: Lorenzo Stoakes <[e-mail]>
To: Vlastimil Babka <[e-mail]>
To: John Hubbard <[e-mail]>
To: Liam R. Howlett <[e-mail]>
To: Andrew Morton <[e-mail]>
To: Greg Kroah-Hartman <[e-mail]>
To: Arnd Bergmann <[e-mail]>
To: Christian Brauner <[e-mail]>
To: Jann Horn <[e-mail]>
To: Suren Baghdasaryan <[e-mail]>
Cc: Alex Gaynor <[e-mail]>
Cc: Boqun Feng <[e-mail]>
Cc: Gary Guo <[e-mail]>
Cc: Björn Roy Baron <[e-mail]>
Cc: Benno Lossin <[e-mail]>
Cc: Andreas Hindborg <[e-mail]>
Cc: Trevor Gross <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Cc: Alice Ryhl <[e-mail]>

Changes in v11:
- Add accessor for the vm_mm field of vm_area_struct.
- Pass the file to MiscDevice::mmap for consistency with
  https://lore.kernel.org/r/[e-mail]
- Link to v10: https://lore.kernel.org/r/[e-mail]

Changes in v10:
- Update docs for `set_io`.
- Check address in `zap_page_range_single`.
- Completely redo the last patch.
- Link to v9: https://lore.kernel.org/r/[e-mail]

Changes in v9:
- Be more explicit about VmAreaNew being used with f_ops->mmap().
- Point out that clearing VM_MAYWRITE is irreversible.
- Use __vm_flags to set the flags.
- Use as_ and into_ prefixes for conversions.
- Update lock_vma_under_rcu docs and commit msg
- Mention that VmAreaRef::end is exclusive.
- Reword docs for zap_page_range_single.
- Minor fixes to flag docs.
- Add way to access current->mm without a refcount increment.
- Link to v8: https://lore.kernel.org/r/[e-mail]

Changes in v8:
- Split series into more commits to ease review.
- Improve read locks based on Lorenzo's doc: either the mmap or vma lock
  can be used.
- Get rid of mmap write lock because it's possible to avoid the need for
  it.
- Do not allow invalid flag combinations on VmAreaNew.
- Link to v7: https://lore.kernel.org/r/[e-mail]

Changes in v7:
- Make the mmap read/write lock guards respect strict owner semantics.
- Link to v6: https://lore.kernel.org/r/[e-mail]

Changes in v6:
- Introduce VmArea{Ref,Mut,New} distinction.
- Add a second patchset for miscdevice.
- Rebase on char-misc-next (currently on v6.12-rc2).
- Link to v5: https://lore.kernel.org/r/[e-mail]

Changes in v5:
- Rename VmArea::from_raw_vma to from_raw.
- Use Pin for mutable VmArea references.
- Go through `ARef::from` in `mmgrab_current`.
- Link to v4: https://lore.kernel.org/r/[e-mail]

Changes in v4:
- Pull out ARef::into_raw into a separate patch.
- Update invariants and struct documentation.
- Rename from_raw_mm to from_raw.
- Link to v3: https://lore.kernel.org/r/[e-mail]

Changes in v3:
- Reorder entries in mm.rs.
- Use ARef for mmput_async helper.
- Clarify that VmArea requires you to hold the mmap read or write lock.
- Link to v2: https://lore.kernel.org/r/[e-mail]

Changes in v2:
- mm.rs is redesigned from scratch making use of AsRef
- Add notes about whether destructors may sleep
- Rename Area to VmArea
- Link to v1: https://lore.kernel.org/r/[e-mail]

---
Alice Ryhl (8):
      mm: rust: add abstraction for struct mm_struct
      mm: rust: add vm_area_struct methods that require read access
      mm: rust: add vm_insert_page
      mm: rust: add lock_vma_under_rcu
      mm: rust: add mmput_async support
      mm: rust: add VmAreaNew for f_ops->mmap()
      rust: miscdevice: add mmap support
      task: rust: rework how current is accessed

 rust/helpers/helpers.c    |   1 +
 rust/helpers/mm.c         |  50 ++++++
 rust/kernel/lib.rs        |   1 +
 rust/kernel/miscdevice.rs |  37 ++++
 rust/kernel/mm.rs         | 323 ++++++++++++++++++++++++++++++++++
 rust/kernel/mm/virt.rs    | 439 ++++++++++++++++++++++++++++++++++++++++++++++
 rust/kernel/task.rs       | 284 ++++++++++++++++++------------
 7 files changed, 1018 insertions(+), 117 deletions(-)
---
base-commit: fac04efc5c793dccbd07e2d59af9f90b7fc0dca4
change-id: 20240723-vma-f80119f9fb35

Best regards,

Comments

Alice Ryhl Dec. 11, 2024, 10:47 a.m. UTC | #1

On Wed, Dec 11, 2024 at 11:37 AM Alice Ryhl <[e-mail]> wrote:
>
> This updates the vm_area_struct support to use the approach we discussed
> at LPC where there are several different Rust wrappers for
> vm_area_struct depending on the kind of access you have to the vma. Each
> case allows a different set of operations on the vma.
>
> Patch 8 in particular could use review.
>
> To: Miguel Ojeda <[e-mail]>
> To: Matthew Wilcox <[e-mail]>
> To: Lorenzo Stoakes <[e-mail]>
> To: Vlastimil Babka <[e-mail]>
> To: John Hubbard <[e-mail]>
> To: Liam R. Howlett <[e-mail]>
> To: Andrew Morton <[e-mail]>
> To: Greg Kroah-Hartman <[e-mail]>
> To: Arnd Bergmann <[e-mail]>
> To: Christian Brauner <[e-mail]>
> To: Jann Horn <[e-mail]>
> To: Suren Baghdasaryan <[e-mail]>
> Cc: Alex Gaynor <[e-mail]>
> Cc: Boqun Feng <[e-mail]>
> Cc: Gary Guo <[e-mail]>
> Cc: Björn Roy Baron <[e-mail]>
> Cc: Benno Lossin <[e-mail]>
> Cc: Andreas Hindborg <[e-mail]>
> Cc: Trevor Gross <[e-mail]>
> Cc: [e-mail]
> Cc: [e-mail]
> Cc: [e-mail]
> Cc: Alice Ryhl <[e-mail]>

When I sent this series, b4 put the changelog stub for v12 above the
cover letter for some reason. Also, I'm not sure why the list of
recipients were included in the cover letter. Any ideas what I'm doing
wrong?

This is what I sent:
https://github.com/Darksonn/linux/tree/b4/vma-v11

Alice