Commit 246dc53f authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'rust-fixes-6.2' of https://github.com/Rust-for-Linux/linux 

Pull rust fix from Miguel Ojeda:

 - Avoid evaluating arguments in 'pr_*' macros in 'unsafe' blocks

* tag 'rust-fixes-6.2' of https://github.com/Rust-for-Linux/linux:
  rust: print: avoid evaluating arguments in `pr_*` macros in `unsafe` blocks
parents b2f31717 6618d69a

rust/kernel/print.rs

+18 −11
Original line number Diff line number Diff line
@@ -142,18 +142,25 @@ pub fn call_printk_cont(args: fmt::Arguments<'_>) { 
macro_rules! print_macro (

    // The non-continuation cases (most of them, e.g. `INFO`).

    ($format_string:path, false, $($arg:tt)+) => (

        // To remain sound, `arg`s must be expanded outside the `unsafe` block.

        // Typically one would use a `let` binding for that; however, `format_args!`

        // takes borrows on the arguments, but does not extend the scope of temporaries.

        // Therefore, a `match` expression is used to keep them around, since

        // the scrutinee is kept until the end of the `match`.

        match format_args!($($arg)+) {

            // SAFETY: This hidden macro should only be called by the documented

            // printing macros which ensure the format string is one of the fixed

            // ones. All `__LOG_PREFIX`s are null-terminated as they are generated

            // by the `module!` proc macro or fixed values defined in a kernel

            // crate.

        unsafe {

            args => unsafe {

                $crate::print::call_printk(

                    &$format_string,

                    crate::__LOG_PREFIX,

                format_args!($($arg)+),

                    args,

                );

            }

        }

    );



    // The `CONT` case.