rust: zerocopy: update to v0.8.52

Update our vendored copy of `zerocopy` (and `zerocopy-derive`) to v0.8.52.

Most SPDX identifiers have been added upstream at our request [1]
(without parentheses -- supporting them is an issue on the kernel side,
but it does already reduce our differences). The CSS one for `rustdoc`
was added too [2], but will be picked up in a later version.

For `zerocopy`, enable `--cfg no_fp_fmt_parse`, which was added at our
request to avoid our local workaround [3]. This means one less difference,
thus indicate so in our `README.md`.

For `zerocopy-derive`, enable `--cfg zerocopy_unstable_linux`. This
allows us to use `#[derive(zerocopy_derive::most_traits)]`, a new feature
upstream added for us [4]. We noticed a minor doc render bug [5], which
will be fixed for a future version too.

The following script may be used to check for the remaining differences:

    for path in $(cd rust/zerocopy-derive/ && find . -type f ! -name README.md); do
        curl --silent --show-error --location \
            https://github.com/google/zerocopy/raw/v0.8.52/zerocopy/zerocopy-derive/src/$path |
            git diff --no-index - rust/zerocopy-derive/$path &&
            echo $path: OK
    done

    for path in $(cd rust/zerocopy/ && find . -type f ! -name README.md); do
        curl --silent --show-error --location \
            https://github.com/google/zerocopy/raw/v0.8.52/zerocopy/$path |
            git diff --no-index - rust/zerocopy/$path &&
            echo $path: OK
    done

Cc: Joshua Liebow-Feeser <joshlf@google.com>
Cc: Jack Wrenn <jswrenn@google.com>
Link: https://github.com/google/zerocopy/issues/3428 [1]
Link: https://github.com/google/zerocopy/issues/3457 [2]
Link: https://github.com/google/zerocopy/issues/3426 [3]
Link: https://github.com/google/zerocopy/pull/3416 [4]
Link: https://github.com/google/zerocopy/issues/3466 [5]
Acked-by: Nicolas Schier <n.schier@fritz.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260625231919.692444-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

20 files changed, 73 insertions, 40 deletions

diff --git a/rust/zerocopy/README.md b/rust/zerocopy/README.md
index 99e6cad0e26c..712b0317df25 100644
--- a/rust/zerocopy/README.md
+++ b/rust/zerocopy/README.md
@@ -1,14 +1,13 @@
 # `zerocopy`
 
-These source files come from the Rust `zerocopy` crate, version v0.8.50
-(released 2026-05-31), hosted in the <https://github.com/google/zerocopy>
+These source files come from the Rust `zerocopy` crate, version v0.8.52
+(released 2026-06-09), hosted in the <https://github.com/google/zerocopy>
 repository, licensed under "BSD-2-Clause OR Apache-2.0 OR MIT" and only
-modified to add the SPDX license identifiers and to remove `Display`
-for `f32` and `f64`.
+modified to tweak the SPDX license identifiers.
 
 For copyright details, please see:
 
-    https://github.com/google/zerocopy/blob/v0.8.50/README.md?plain=1
-    https://github.com/google/zerocopy/blob/v0.8.50/LICENSE-BSD
-    https://github.com/google/zerocopy/blob/v0.8.50/LICENSE-APACHE
-    https://github.com/google/zerocopy/blob/v0.8.50/LICENSE-MIT
+    https://github.com/google/zerocopy/blob/v0.8.52/README.md?plain=1
+    https://github.com/google/zerocopy/blob/v0.8.52/LICENSE-BSD
+    https://github.com/google/zerocopy/blob/v0.8.52/LICENSE-APACHE
+    https://github.com/google/zerocopy/blob/v0.8.52/LICENSE-MIT
diff --git a/rust/zerocopy/src/byte_slice.rs b/rust/zerocopy/src/byte_slice.rs
index a5ded4a18b39..b7f85098dbc4 100644
--- a/rust/zerocopy/src/byte_slice.rs
+++ b/rust/zerocopy/src/byte_slice.rs
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: (BSD-2-Clause OR Apache-2.0) OR MIT
-
+//
 // Copyright 2024 The Fuchsia Authors
 //
 // Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
diff --git a/rust/zerocopy/src/byteorder.rs b/rust/zerocopy/src/byteorder.rs
index 8f70048f1eb0..ecf95e38eebd 100644
--- a/rust/zerocopy/src/byteorder.rs
+++ b/rust/zerocopy/src/byteorder.rs
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: (BSD-2-Clause OR Apache-2.0) OR MIT
-
+//
 // Copyright 2019 The Fuchsia Authors
 //
 // Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
@@ -164,6 +164,42 @@ pub type BE = BigEndian;
 /// A type alias for [`LittleEndian`].
 pub type LE = LittleEndian;
 
+macro_rules! impl_dbg_trait {
+    ($name:ident, $native:ident) => {
+        impl<O: ByteOrder> Debug for $name<O> {
+            #[inline]
+            fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+                // This results in a format like "U16(42)".
+                f.debug_tuple(stringify!($name)).field(&self.get()).finish()
+            }
+        }
+    };
+}
+
+macro_rules! impl_dbg_traits {
+    ($name:ident, $native:ident, "floating point number") => {
+        #[cfg(not(no_fp_fmt_parse))]
+        impl_dbg_trait!($name, $native);
+
+        #[cfg(no_fp_fmt_parse)]
+        impl<O: ByteOrder> Debug for $name<O> {
+            #[inline]
+            fn fmt(&self, _f: &mut Formatter<'_>) -> fmt::Result {
+                panic!("floating point support is turned off");
+            }
+        }
+    };
+    ($name:ident, $native:ident, "unsigned integer") => {
+        impl_dbg_traits!($name, $native, @all_types);
+    };
+    ($name:ident, $native:ident, "signed integer") => {
+        impl_dbg_traits!($name, $native, @all_types);
+    };
+    ($name:ident, $native:ident, @all_types) => {
+        impl_dbg_trait!($name, $native);
+    };
+}
+
 macro_rules! impl_fmt_trait {
     ($name:ident, $native:ident, $trait:ident) => {
         impl<O: ByteOrder> $trait for $name<O> {
@@ -177,6 +213,8 @@ macro_rules! impl_fmt_trait {
 
 macro_rules! impl_fmt_traits {
     ($name:ident, $native:ident, "floating point number") => {
+        #[cfg(not(no_fp_fmt_parse))]
+        impl_fmt_trait!($name, $native, Display);
     };
     ($name:ident, $native:ident, "unsigned integer") => {
         impl_fmt_traits!($name, $native, @all_types);
@@ -687,16 +725,9 @@ example of how it can be used for parsing UDP packets.
             }
         }
 
+        impl_dbg_traits!($name, $native, $number_kind);
         impl_fmt_traits!($name, $native, $number_kind);
         impl_ops_traits!($name, $native, $number_kind);
-
-        impl<O: ByteOrder> Debug for $name<O> {
-            #[inline]
-            fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-                // This results in a format like "U16(42)".
-                f.debug_tuple(stringify!($name)).field(&self.get()).finish()
-            }
-        }
     };
 }
 
diff --git a/rust/zerocopy/src/deprecated.rs b/rust/zerocopy/src/deprecated.rs
index 24bafbf9adeb..59ddd35c77c6 100644
--- a/rust/zerocopy/src/deprecated.rs
+++ b/rust/zerocopy/src/deprecated.rs
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: (BSD-2-Clause OR Apache-2.0) OR MIT
-
+//
 // Copyright 2024 The Fuchsia Authors
 //
 // Licensed under the 2-Clause BSD License <LICENSE-BSD or
diff --git a/rust/zerocopy/src/error.rs b/rust/zerocopy/src/error.rs
index 7cb08c31d452..5eb30de934f3 100644
--- a/rust/zerocopy/src/error.rs
+++ b/rust/zerocopy/src/error.rs
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: (BSD-2-Clause OR Apache-2.0) OR MIT
-
+//
 // Copyright 2024 The Fuchsia Authors
 //
 // Licensed under the 2-Clause BSD License <LICENSE-BSD or
diff --git a/rust/zerocopy/src/impls.rs b/rust/zerocopy/src/impls.rs
index 22fd6c3d5d94..62e234c5202b 100644
--- a/rust/zerocopy/src/impls.rs
+++ b/rust/zerocopy/src/impls.rs
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: (BSD-2-Clause OR Apache-2.0) OR MIT
-
+//
 // Copyright 2024 The Fuchsia Authors
 //
 // Licensed under the 2-Clause BSD License <LICENSE-BSD or
@@ -1359,7 +1359,7 @@ mod simd {
         #[cfg(not(no_zerocopy_aarch64_simd_1_59_0))]
         simd_arch_mod!(
             #[cfg(all(
-                target_arch = "aarch64", 
+                target_arch = "aarch64",
                 any(
                     target_endian = "little",
                     not(no_zerocopy_aarch64_simd_be_1_87_0)
diff --git a/rust/zerocopy/src/layout.rs b/rust/zerocopy/src/layout.rs
index 6015d0f2de52..942d35db8957 100644
--- a/rust/zerocopy/src/layout.rs
+++ b/rust/zerocopy/src/layout.rs
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: (BSD-2-Clause OR Apache-2.0) OR MIT
-
+//
 // Copyright 2024 The Fuchsia Authors
 //
 // Licensed under the 2-Clause BSD License <LICENSE-BSD or
diff --git a/rust/zerocopy/src/lib.rs b/rust/zerocopy/src/lib.rs
index 3302d67602ab..700fece1b728 100644
--- a/rust/zerocopy/src/lib.rs
+++ b/rust/zerocopy/src/lib.rs
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: (BSD-2-Clause OR Apache-2.0) OR MIT
-
+//
 // Copyright 2018 The Fuchsia Authors
 //
 // Licensed under the 2-Clause BSD License <LICENSE-BSD or
@@ -12,7 +12,7 @@
 // After updating the following doc comment, make sure to run the following
 // command to update `README.md` based on its contents:
 //
-//   cargo -q run --manifest-path tools/Cargo.toml -p generate-readme > README.md
+//   (cd .. && cargo -q run --manifest-path tools/Cargo.toml -p generate-readme) > README.md
 
 //! ***<span style="font-size: 140%">Fast, safe, <span
 //! style="color:red;">compile error</span>. Pick two.</span>***
@@ -174,7 +174,7 @@
 //!
 //! [Miri]: https://github.com/rust-lang/miri
 //! [Kani]: https://github.com/model-checking/kani
-//! [soundness policy]: https://github.com/google/zerocopy/blob/main/POLICIES.md#soundness
+//! [soundness policy]: https://github.com/google/zerocopy/blob/main/zerocopy/POLICIES.md#soundness
 //!
 //! # Relationship to Project Safe Transmute
 //!
@@ -203,7 +203,7 @@
 //!
 //! See our [MSRV policy].
 //!
-//! [MSRV policy]: https://github.com/google/zerocopy/blob/main/POLICIES.md#msrv
+//! [MSRV policy]: https://github.com/google/zerocopy/blob/main/zerocopy/POLICIES.md#msrv
 //!
 //! # Changelog
 //!
@@ -435,6 +435,9 @@ const _: () = {
     WARNING
 };
 
+#[doc(hidden)]
+#[cfg(all(any(feature = "derive", test), zerocopy_unstable_linux))]
+pub use zerocopy_derive::most_traits;
 /// Implements [`KnownLayout`].
 ///
 /// This derive analyzes various aspects of a type's layout that are needed for
@@ -2832,7 +2835,7 @@ pub unsafe trait TryFromBytes {
     /// ```
     ///
     /// [`try_mut_from_bytes`]: TryFromBytes::try_mut_from_bytes
-    ///  
+    ///
     #[doc = codegen_header!("h5", "try_mut_from_bytes_with_elems")]
     ///
     /// See [`TryFromBytes::try_ref_from_bytes_with_elems`](#method.try_ref_from_bytes_with_elems.codegen).
diff --git a/rust/zerocopy/src/macros.rs b/rust/zerocopy/src/macros.rs
index b801d86a8fa6..ec67c03a44fc 100644
--- a/rust/zerocopy/src/macros.rs
+++ b/rust/zerocopy/src/macros.rs
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: (BSD-2-Clause OR Apache-2.0) OR MIT
-
+//
 // Copyright 2024 The Fuchsia Authors
 //
 // Licensed under the 2-Clause BSD License <LICENSE-BSD or
diff --git a/rust/zerocopy/src/pointer/inner.rs b/rust/zerocopy/src/pointer/inner.rs
index 5db08080141f..949b60a3f83e 100644
--- a/rust/zerocopy/src/pointer/inner.rs
+++ b/rust/zerocopy/src/pointer/inner.rs
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: (BSD-2-Clause OR Apache-2.0) OR MIT
-
+//
 // Copyright 2024 The Fuchsia Authors
 //
 // Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
diff --git a/rust/zerocopy/src/pointer/invariant.rs b/rust/zerocopy/src/pointer/invariant.rs
index 1802d23563db..7ff0d43dad5e 100644
--- a/rust/zerocopy/src/pointer/invariant.rs
+++ b/rust/zerocopy/src/pointer/invariant.rs
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: (BSD-2-Clause OR Apache-2.0) OR MIT
-
+//
 // Copyright 2024 The Fuchsia Authors
 //
 // Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
diff --git a/rust/zerocopy/src/pointer/mod.rs b/rust/zerocopy/src/pointer/mod.rs
index 3461f7f5ca80..d6eacc52febe 100644
--- a/rust/zerocopy/src/pointer/mod.rs
+++ b/rust/zerocopy/src/pointer/mod.rs
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: (BSD-2-Clause OR Apache-2.0) OR MIT
-
+//
 // Copyright 2023 The Fuchsia Authors
 //
 // Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
diff --git a/rust/zerocopy/src/pointer/ptr.rs b/rust/zerocopy/src/pointer/ptr.rs
index b7c4ea56d2b2..7213f6f4a04e 100644
--- a/rust/zerocopy/src/pointer/ptr.rs
+++ b/rust/zerocopy/src/pointer/ptr.rs
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: (BSD-2-Clause OR Apache-2.0) OR MIT
-
+//
 // Copyright 2023 The Fuchsia Authors
 //
 // Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
diff --git a/rust/zerocopy/src/pointer/transmute.rs b/rust/zerocopy/src/pointer/transmute.rs
index a534984b70d3..ef9836698203 100644
--- a/rust/zerocopy/src/pointer/transmute.rs
+++ b/rust/zerocopy/src/pointer/transmute.rs
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: (BSD-2-Clause OR Apache-2.0) OR MIT
-
+//
 // Copyright 2025 The Fuchsia Authors
 //
 // Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
diff --git a/rust/zerocopy/src/ref.rs b/rust/zerocopy/src/ref.rs
index 860066d75196..e49f2a887ffa 100644
--- a/rust/zerocopy/src/ref.rs
+++ b/rust/zerocopy/src/ref.rs
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: (BSD-2-Clause OR Apache-2.0) OR MIT
-
+//
 // Copyright 2024 The Fuchsia Authors
 //
 // Licensed under the 2-Clause BSD License <LICENSE-BSD or
diff --git a/rust/zerocopy/src/split_at.rs b/rust/zerocopy/src/split_at.rs
index 9a67d5acbb0d..d7778425a31d 100644
--- a/rust/zerocopy/src/split_at.rs
+++ b/rust/zerocopy/src/split_at.rs
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: (BSD-2-Clause OR Apache-2.0) OR MIT
-
+//
 // Copyright 2025 The Fuchsia Authors
 //
 // Licensed under the 2-Clause BSD License <LICENSE-BSD or
diff --git a/rust/zerocopy/src/util/macro_util.rs b/rust/zerocopy/src/util/macro_util.rs
index 1abb0fbeb46e..ceeb80432b0b 100644
--- a/rust/zerocopy/src/util/macro_util.rs
+++ b/rust/zerocopy/src/util/macro_util.rs
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: (BSD-2-Clause OR Apache-2.0) OR MIT
-
+//
 // Copyright 2022 The Fuchsia Authors
 //
 // Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
diff --git a/rust/zerocopy/src/util/macros.rs b/rust/zerocopy/src/util/macros.rs
index 43e4fd64ee15..7e63e3a54fc4 100644
--- a/rust/zerocopy/src/util/macros.rs
+++ b/rust/zerocopy/src/util/macros.rs
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: (BSD-2-Clause OR Apache-2.0) OR MIT
-
+//
 // Copyright 2023 The Fuchsia Authors
 //
 // Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
diff --git a/rust/zerocopy/src/util/mod.rs b/rust/zerocopy/src/util/mod.rs
index d6d4c6c2fcd9..f8affbbd336c 100644
--- a/rust/zerocopy/src/util/mod.rs
+++ b/rust/zerocopy/src/util/mod.rs
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: (BSD-2-Clause OR Apache-2.0) OR MIT
-
+//
 // Copyright 2023 The Fuchsia Authors
 //
 // Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
diff --git a/rust/zerocopy/src/wrappers.rs b/rust/zerocopy/src/wrappers.rs
index 266aec25fa58..1a8cf2b41d55 100644
--- a/rust/zerocopy/src/wrappers.rs
+++ b/rust/zerocopy/src/wrappers.rs
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: (BSD-2-Clause OR Apache-2.0) OR MIT
-
+//
 // Copyright 2023 The Fuchsia Authors
 //
 // Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0