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A mirror of the official Linux kernel repository just in case
a5a3c952e8
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<T>` 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 <aliceryhl@google.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Closes: https://rust-for-linux.zulipchat.com/#narrow/stream/x/topic/x/near/465412664
Fixes:
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.