Merging upstream version 1.72.1+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

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`