From: Alice Ryhl <aliceryhl@google.com>
To: rust-for-linux@vger.kernel.org
Cc: "Miguel Ojeda" <ojeda@kernel.org>,
"Wedson Almeida Filho" <wedsonaf@gmail.com>,
"Alex Gaynor" <alex.gaynor@gmail.com>,
"Boqun Feng" <boqun.feng@gmail.com>,
"Gary Guo" <gary@garyguo.net>,
"Björn Roy Baron" <bjorn3_gh@protonmail.com>,
"Benno Lossin" <benno.lossin@proton.me>,
"Alice Ryhl" <aliceryhl@google.com>,
linux-kernel@vger.kernel.org, patches@lists.linux.dev,
"Wedson Almeida Filho" <walmeida@microsoft.com>,
"Sven Van Asbroeck" <thesven73@gmail.com>
Subject: [PATCH v1] rust: error: integrate Rust error type with `errname`
Date: Wed, 31 May 2023 17:44:50 +0000 [thread overview]
Message-ID: <20230531174450.3733220-1-aliceryhl@google.com> (raw)
From: Gary Guo <gary@garyguo.net>
This integrates the `Error` type with the `errname` by making it
accessible via the `name` method or via the `Debug` trait.
Co-Developed-by: Wedson Almeida Filho <walmeida@microsoft.com>
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Co-Developed-by: Sven Van Asbroeck <thesven73@gmail.com>
Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
---
rust/bindings/bindings_helper.h | 1 +
rust/kernel/error.rs | 39 +++++++++++++++++++++++++++++++++
2 files changed, 40 insertions(+)
diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index 50e7a76d5455..dc8691f83253 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -10,6 +10,7 @@
#include <linux/refcount.h>
#include <linux/wait.h>
#include <linux/sched.h>
+#include <linux/errname.h>
/* `bindgen` gets confused at certain things. */
const gfp_t BINDINGS_GFP_KERNEL = GFP_KERNEL;
diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs
index 5f4114b30b94..59ff362028d0 100644
--- a/rust/kernel/error.rs
+++ b/rust/kernel/error.rs
@@ -4,12 +4,15 @@
//!
//! C header: [`include/uapi/asm-generic/errno-base.h`](../../../include/uapi/asm-generic/errno-base.h)
+use crate::str::CStr;
+
use alloc::{
alloc::{AllocError, LayoutError},
collections::TryReserveError,
};
use core::convert::From;
+use core::fmt;
use core::num::TryFromIntError;
use core::str::Utf8Error;
@@ -113,6 +116,42 @@ impl Error {
// SAFETY: self.0 is a valid error due to its invariant.
unsafe { bindings::ERR_PTR(self.0.into()) as *mut _ }
}
+
+ /// Returns a string representing the error, if one exists.
+ #[cfg(not(testlib))]
+ pub fn name(&self) -> Option<&'static CStr> {
+ // SAFETY: Just an FFI call, there are no extra safety requirements.
+ let ptr = unsafe { bindings::errname(-self.0) };
+ if ptr.is_null() {
+ None
+ } else {
+ // SAFETY: The string returned by `errname` is static and `NUL`-terminated.
+ Some(unsafe { CStr::from_char_ptr(ptr) })
+ }
+ }
+
+ /// Returns a string representing the error, if one exists.
+ ///
+ /// When `testlib` is configured, this always returns `None` to avoid the dependency on a
+ /// kernel function so that tests that use this (e.g., by calling [`Result::unwrap`]) can still
+ /// run in userspace.
+ #[cfg(testlib)]
+ pub fn name(&self) -> Option<&'static CStr> {
+ None
+ }
+}
+
+impl fmt::Debug for Error {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ match self.name() {
+ // Print out number if no name can be found.
+ None => f.debug_tuple("Error").field(&-self.0).finish(),
+ // SAFETY: These strings are ASCII-only.
+ Some(name) => f
+ .debug_tuple(unsafe { core::str::from_utf8_unchecked(name) })
+ .finish(),
+ }
+ }
}
impl From<AllocError> for Error {
base-commit: ac9a78681b921877518763ba0e89202254349d1b
--
2.41.0.rc0.172.g3f132b7071-goog
next reply other threads:[~2023-05-31 17:45 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-31 17:44 Alice Ryhl [this message]
[not found] ` <CAGngYiW_3HfebWZO5S=RXFqhNnsbnix-NaA0UGYRnRLd4SK65w@mail.gmail.com>
2023-06-12 19:04 ` [PATCH v1] rust: error: integrate Rust error type with `errname` Miguel Ojeda
2023-06-12 23:36 ` Miguel Ojeda
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20230531174450.3733220-1-aliceryhl@google.com \
--to=aliceryhl@google.com \
--cc=alex.gaynor@gmail.com \
--cc=benno.lossin@proton.me \
--cc=bjorn3_gh@protonmail.com \
--cc=boqun.feng@gmail.com \
--cc=gary@garyguo.net \
--cc=linux-kernel@vger.kernel.org \
--cc=ojeda@kernel.org \
--cc=patches@lists.linux.dev \
--cc=rust-for-linux@vger.kernel.org \
--cc=thesven73@gmail.com \
--cc=walmeida@microsoft.com \
--cc=wedsonaf@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).