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authorGary Guo <gary@garyguo.net>2023-05-31 17:44:50 +0000
committerMiguel Ojeda <ojeda@kernel.org>2023-06-13 01:24:42 +0200
commitd2e3115d717197cb2bc020dd1f06b06538474ac3 (patch)
treece25ae73636780e460a5a3a7f714ec1f3b075f16 /rust
parentd09a61024f6b78c6a08892fc916cdafd87b50365 (diff)
rust: error: `impl Debug` for `Error` with `errname()` integration
Integrate the `Error` type with `errname()` by providing a new `name()` method. Then, implement `Debug` for the type using the new method. [ Miguel: under `CONFIG_SYMBOLIC_ERRNAME=n`, `errname()` is a `static inline`, so added a helper to support that case, like we had in the `rust` branch. Also moved `#include` up and reworded commit message for clarity. ] 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> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Link: https://lore.kernel.org/r/20230531174450.3733220-1-aliceryhl@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Diffstat (limited to 'rust')
-rw-r--r--rust/bindings/bindings_helper.h1
-rw-r--r--rust/helpers.c7
-rw-r--r--rust/kernel/error.rs39
3 files changed, 47 insertions, 0 deletions
diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index 50e7a76d5455..3e601ce2548d 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -6,6 +6,7 @@
* Sorted alphabetically.
*/
+#include <linux/errname.h>
#include <linux/slab.h>
#include <linux/refcount.h>
#include <linux/wait.h>
diff --git a/rust/helpers.c b/rust/helpers.c
index 81e80261d597..bb594da56137 100644
--- a/rust/helpers.c
+++ b/rust/helpers.c
@@ -21,6 +21,7 @@
#include <linux/bug.h>
#include <linux/build_bug.h>
#include <linux/err.h>
+#include <linux/errname.h>
#include <linux/refcount.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
@@ -110,6 +111,12 @@ long rust_helper_PTR_ERR(__force const void *ptr)
}
EXPORT_SYMBOL_GPL(rust_helper_PTR_ERR);
+const char *rust_helper_errname(int err)
+{
+ return errname(err);
+}
+EXPORT_SYMBOL_GPL(rust_helper_errname);
+
struct task_struct *rust_helper_get_current(void)
{
return current;
diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs
index 7c1ce2bccd08..05fcab6abfe6 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;
@@ -133,6 +136,42 @@ 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 {