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authorSven Van Asbroeck <thesven73@gmail.com>2023-04-03 18:48:14 +0900
committerMiguel Ojeda <ojeda@kernel.org>2023-04-12 18:41:04 +0200
commit752417b3f0e7721f1d630f40da22d57e0dae043e (patch)
tree5baa8b2da6389cb02f89b4e58ac3957c8f9b0274 /rust/helpers.c
parent086fbfa3b328901fa8b369093ba468864e20544e (diff)
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rust: error: Add a helper to convert a C ERR_PTR to a `Result`
Some kernel C API functions return a pointer which embeds an optional `errno`. Callers are supposed to check the returned pointer with `IS_ERR()` and if this returns `true`, retrieve the `errno` using `PTR_ERR()`. Create a Rust helper function to implement the Rust equivalent: transform a `*mut T` to `Result<*mut T>`. Lina: Imported from rust-for-linux/linux, with subsequent refactoring and contributions squashed in and attributed below. Renamed the function to from_err_ptr(). Co-developed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Co-developed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Co-developed-by: Fox Chen <foxhlchen@gmail.com> Signed-off-by: Fox Chen <foxhlchen@gmail.com> Co-developed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Gary Guo <gary@garyguo.net> Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Asahi Lina <lina@asahilina.net> Link: https://lore.kernel.org/r/20230224-rust-error-v3-5-03779bddc02b@asahilina.net [ Add a removal of `#[allow(dead_code)]`. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Diffstat (limited to 'rust/helpers.c')
-rw-r--r--rust/helpers.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/rust/helpers.c b/rust/helpers.c
index 89f4cd1e0df3..04b9be46e887 100644
--- a/rust/helpers.c
+++ b/rust/helpers.c
@@ -53,6 +53,18 @@ __force void *rust_helper_ERR_PTR(long err)
}
EXPORT_SYMBOL_GPL(rust_helper_ERR_PTR);
+bool rust_helper_IS_ERR(__force const void *ptr)
+{
+ return IS_ERR(ptr);
+}
+EXPORT_SYMBOL_GPL(rust_helper_IS_ERR);
+
+long rust_helper_PTR_ERR(__force const void *ptr)
+{
+ return PTR_ERR(ptr);
+}
+EXPORT_SYMBOL_GPL(rust_helper_PTR_ERR);
+
/*
* We use `bindgen`'s `--size_t-is-usize` option to bind the C `size_t` type
* as the Rust `usize` type, so we can use it in contexts where Rust