diff options
Diffstat (limited to 'src/doc/unstable-book')
4 files changed, 22 insertions, 32 deletions
diff --git a/src/doc/unstable-book/src/compiler-flags/sanitizer.md b/src/doc/unstable-book/src/compiler-flags/sanitizer.md index aa776daf0..49389b28c 100644 --- a/src/doc/unstable-book/src/compiler-flags/sanitizer.md +++ b/src/doc/unstable-book/src/compiler-flags/sanitizer.md @@ -21,7 +21,8 @@ This feature allows for use of one of following sanitizers: * [MemorySanitizer](#memorysanitizer) a detector of uninitialized reads. * [MemTagSanitizer](#memtagsanitizer) fast memory error detector based on Armv8.5-A Memory Tagging Extension. -* [ShadowCallStack](#shadowcallstack) provides backward-edge control flow protection. +* [SafeStack](#safestack) provides backward-edge control flow protection by separating the stack into safe and unsafe regions. +* [ShadowCallStack](#shadowcallstack) provides backward-edge control flow protection (aarch64 only). * [ThreadSanitizer](#threadsanitizer) a fast data race detector. To enable a sanitizer compile with `-Zsanitizer=address`,`-Zsanitizer=cfi`, @@ -712,6 +713,16 @@ To enable this target feature compile with `-C target-feature="+mte"`. See the [LLVM MemTagSanitizer documentation][llvm-memtag] for more details. +# SafeStack + +SafeStack provides backward edge control flow protection by separating the stack into data which is only accessed safely (the safe stack) and all other data (the unsafe stack). + +SafeStack can be enabled with the `-Zsanitizer=safestack` option and is supported on the following targets: + +* `x86_64-unknown-linux-gnu` + +See the [Clang SafeStack documentation][clang-safestack] for more details. + # ShadowCallStack ShadowCallStack provides backward edge control flow protection by storing a function's return address in a separately allocated 'shadow call stack' and loading the return address from that shadow call stack. @@ -828,6 +839,7 @@ Sanitizers produce symbolized stacktraces when llvm-symbolizer binary is in `PAT [clang-kcfi]: https://clang.llvm.org/docs/ControlFlowIntegrity.html#fsanitize-kcfi [clang-lsan]: https://clang.llvm.org/docs/LeakSanitizer.html [clang-msan]: https://clang.llvm.org/docs/MemorySanitizer.html +[clang-safestack]: https://clang.llvm.org/docs/SafeStack.html [clang-scs]: https://clang.llvm.org/docs/ShadowCallStack.html [clang-tsan]: https://clang.llvm.org/docs/ThreadSanitizer.html [linux-kasan]: https://www.kernel.org/doc/html/latest/dev-tools/kasan.html diff --git a/src/doc/unstable-book/src/language-features/asm-experimental-arch.md b/src/doc/unstable-book/src/language-features/asm-experimental-arch.md index 532cb9eea..c634dc50d 100644 --- a/src/doc/unstable-book/src/language-features/asm-experimental-arch.md +++ b/src/doc/unstable-book/src/language-features/asm-experimental-arch.md @@ -17,7 +17,6 @@ This feature tracks `asm!` and `global_asm!` support for the following architect - AVR - MSP430 - M68k -- LoongArch - s390x ## Register classes @@ -47,8 +46,6 @@ This feature tracks `asm!` and `global_asm!` support for the following architect | M68k | `reg` | `d[0-7]`, `a[0-7]` | `r` | | M68k | `reg_data` | `d[0-7]` | `d` | | M68k | `reg_addr` | `a[0-3]` | `a` | -| LoongArch | `reg` | `$r1`, `$r[4-20]`, `$r[23,30]` | `r` | -| LoongArch | `freg` | `$f[0-31]` | `f` | | s390x | `reg` | `r[0-10]`, `r[12-14]` | `r` | | s390x | `freg` | `f[0-15]` | `f` | @@ -82,8 +79,6 @@ This feature tracks `asm!` and `global_asm!` support for the following architect | MSP430 | `reg` | None | `i8`, `i16` | | M68k | `reg`, `reg_addr` | None | `i16`, `i32` | | M68k | `reg_data` | None | `i8`, `i16`, `i32` | -| LoongArch64 | `reg` | None | `i8`, `i16`, `i32`, `i64`, `f32`, `f64` | -| LoongArch64 | `freg` | None | `f32`, `f64` | | s390x | `reg` | None | `i8`, `i16`, `i32`, `i64` | | s390x | `freg` | None | `f32`, `f64` | @@ -107,10 +102,6 @@ This feature tracks `asm!` and `global_asm!` support for the following architect | M68k | `a5` | `bp` | | M68k | `a6` | `fp` | | M68k | `a7` | `sp`, `usp`, `ssp`, `isp` | -| LoongArch | `$r0` | `zero` | -| LoongArch | `$r2` | `tp` | -| LoongArch | `$r3` | `sp` | -| LoongArch | `$r22` | `fp` | > **Notes**: > - TI does not mandate a frame pointer for MSP430, but toolchains are allowed @@ -121,7 +112,7 @@ This feature tracks `asm!` and `global_asm!` support for the following architect | Architecture | Unsupported register | Reason | | ------------ | --------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | All | `sp`, `r15` (s390x) | The stack pointer must be restored to its original value at the end of an asm code block. | -| All | `fr` (Hexagon), `$fp` (MIPS), `Y` (AVR), `r4` (MSP430), `a6` (M68k), `$fp` (LoongArch), `r11` (s390x) | The frame pointer cannot be used as an input or output. | +| All | `fr` (Hexagon), `$fp` (MIPS), `Y` (AVR), `r4` (MSP430), `a6` (M68k), `r11` (s390x) | The frame pointer cannot be used as an input or output. | | All | `r19` (Hexagon) | This is used internally by LLVM as a "base pointer" for functions with complex stack frames. | | MIPS | `$0` or `$zero` | This is a constant zero register which can't be modified. | | MIPS | `$1` or `$at` | Reserved for assembler. | @@ -132,10 +123,6 @@ This feature tracks `asm!` and `global_asm!` support for the following architect | AVR | `r0`, `r1`, `r1r0` | Due to an issue in LLVM, the `r0` and `r1` registers cannot be used as inputs or outputs. If modified, they must be restored to their original values before the end of the block. | |MSP430 | `r0`, `r2`, `r3` | These are the program counter, status register, and constant generator respectively. Neither the status register nor constant generator can be written to. | | M68k | `a4`, `a5` | Used internally by LLVM for the base pointer and global base pointer. | -| LoongArch | `$r0` or `$zero` | This is a constant zero register which can't be modified. | -| LoongArch | `$r2` or `$tp` | This is reserved for TLS. | -| LoongArch | `$r21` | This is reserved by the ABI. | -| LoongArch | `$r31` or `$s8` | This is used internally by LLVM. | ## Template modifiers @@ -150,8 +137,6 @@ This feature tracks `asm!` and `global_asm!` support for the following architect | PowerPC | `reg` | None | `0` | None | | PowerPC | `reg_nonzero` | None | `3` | `b` | | PowerPC | `freg` | None | `0` | None | -| LoongArch | `reg` | None | `$r2` | None | -| LoongArch | `freg` | None | `$f0` | None | | s390x | `reg` | None | `%r0` | None | | s390x | `freg` | None | `%f0` | None | diff --git a/src/doc/unstable-book/src/language-features/const-eval-limit.md b/src/doc/unstable-book/src/language-features/const-eval-limit.md deleted file mode 100644 index df68e83bc..000000000 --- a/src/doc/unstable-book/src/language-features/const-eval-limit.md +++ /dev/null @@ -1,7 +0,0 @@ -# `const_eval_limit` - -The tracking issue for this feature is: [#67217] - -[#67217]: https://github.com/rust-lang/rust/issues/67217 - -The `const_eval_limit` allows someone to limit the evaluation steps the CTFE undertakes to evaluate a `const fn`. diff --git a/src/doc/unstable-book/src/language-features/lang-items.md b/src/doc/unstable-book/src/language-features/lang-items.md index 6adb3506e..f4bc18bc7 100644 --- a/src/doc/unstable-book/src/language-features/lang-items.md +++ b/src/doc/unstable-book/src/language-features/lang-items.md @@ -11,8 +11,8 @@ it exists. The marker is the attribute `#[lang = "..."]` and there are various different values of `...`, i.e. various different 'lang items'. -For example, `Box` pointers require two lang items, one for allocation -and one for deallocation. A freestanding program that uses the `Box` +For example, `Box` pointers require a lang item for allocation. +A freestanding program that uses the `Box` sugar for dynamic allocations via `malloc` and `free`: ```rust,ignore (libc-is-finicky) @@ -48,9 +48,10 @@ unsafe fn allocate(size: usize, _align: usize) -> *mut u8 { p } -#[lang = "box_free"] -unsafe fn box_free<T: ?Sized>(ptr: *mut T) { - libc::free(ptr as *mut libc::c_void) +impl<T> Drop for Box<T> { + fn drop(&mut self) { + libc::free(self.0.0.0 as *mut libc::c_void) + } } #[start] @@ -84,8 +85,8 @@ Other features provided by lang items include: `contravariant_lifetime`, etc. Lang items are loaded lazily by the compiler; e.g. if one never uses -`Box` then there is no need to define functions for `exchange_malloc` -and `box_free`. `rustc` will emit an error when an item is needed +`Box` then there is no need to define a function for `exchange_malloc`. +`rustc` will emit an error when an item is needed but not found in the current crate or any that it depends on. Most lang items are defined by `libcore`, but if you're trying to build @@ -250,7 +251,6 @@ the source code. - Allocations - `owned_box`: `liballoc/boxed.rs` - `exchange_malloc`: `liballoc/heap.rs` - - `box_free`: `liballoc/heap.rs` - Operands - `not`: `libcore/ops/bit.rs` - `bitand`: `libcore/ops/bit.rs` |