uname: Map machine architecture to processor type (rebased)

docs/src/extensions.md

@@ -1,4 +1,4 @@
-<!-- spell-checker:ignore hhhhp armv7 cccccccccccccccccccccccccccccccdp ccccccccccccccd ccccccccccccccdp fffffffp -->
+<!-- spell-checker:ignore hhhhp armv7 cccccccccccccccccccccccccccccccdp ccccccccccccccd ccccccccccccccdp fffffffp kdump ppc64le mipsel mips64el riscv powerpc sparc sysinfo armv -->
 
 # Extensions over GNU
 
@@ -205,3 +205,33 @@ With `-U`/`--no-utf8`, you can interpret input files as 8-bit ASCII rather than
 ## `install`
 
 `install` offers FreeBSD's `-U` unprivileged option to not change the owner, the group, or the file flags of the destination.
+
+## `uname`
+
+GNU coreutils uses platform-specific mechanisms to determine processor type on modern
+systems (e.g., `sysinfo(SI_ARCHITECTURE)` on Solaris, `sysctl()` on BSD, compile-time
+architecture detection on macOS). On Linux systems without these mechanisms, it returns
+"unknown" for `uname -p`.
+
+uutils takes a different approach: it maps machine architecture strings (from `uname -m`)
+to processor types. This provides consistent, useful output on all platforms for packages
+that depend on processor type information (e.g., kdump-tools).
+
+**Current mappings:**
+
+| Machine (`uname -m`) | Processor (`uname -p`) |
+| -------------------- | ---------------------- |
+| arm64, aarch64, arm, armv7l, armv8l, armv7, armv8 | arm |
+| x86_64, amd64 | x86_64 |
+| i386, i486, i586, i686 | i386 |
+| ppc, ppc64, ppc64le, ppc32 | powerpc |
+| riscv32, riscv64 | riscv |
+| sparc, sparc64 | sparc |
+| mips, mipsel, mips64, mips64el | mips |
+| (other) | unknown |
+
+**Differences from GNU:**
+
+* uutils uses runtime string matching rather than compile-time detection (e.g., `__arm__`, `__x86_64__` macros on macOS)
+* uutils does not use `sysinfo(SI_ARCHITECTURE)` or `sysctl()` fallbacks available on some platforms
+* The mapping is based on `uname -m` output rather than platform-specific system calls

src/uu/uname/src/uname.rs

@@ -3,7 +3,7 @@
 // For the full copyright and license information, please view the LICENSE
 // file that was distributed with this source code.
 
-// spell-checker:ignore (API) nodename osname sysname (options) mnrsv mnrsvo
+// spell-checker:ignore (API) nodename osname sysname (options) mnrsv mnrsvo armv kdump ppc64le mipsel mips64el riscv
 
 use std::ffi::{OsStr, OsString};
 
@@ -28,6 +28,40 @@ pub mod options {
     pub static OS: &str = "operating-system";
 }
 
+/// Map machine architecture string to processor type.
+///
+/// This provides GNU coreutils-compatible processor type mappings from machine
+/// architecture strings. Previously returned "unknown" causing regressions in
+/// packages like kdump-tools.
+///
+/// Mapping table:
+/// - arm64, aarch64 → "arm"
+/// - x86_64, amd64 → "x86_64"
+/// - i386, i486, i586, i686 → "i386"
+/// - ppc, ppc64, ppc64le → "powerpc"
+/// - riscv32, riscv64 → "riscv"
+/// - arm, armv7l, armv8l → "arm"
+/// - (other) → "unknown"
+fn map_processor(machine: &str) -> String {
+    match machine {
+        // ARM architectures
+        "arm64" | "aarch64" => "arm".to_string(),
+        "arm" | "armv7l" | "armv8l" | "armv7" | "armv8" => "arm".to_string(),
+        // x86 architectures
+        "x86_64" | "amd64" => "x86_64".to_string(),
+        "i386" | "i486" | "i586" | "i686" => "i386".to_string(),
+        // PowerPC architectures (matches GNU coreutils on Apple)
+        "ppc" | "ppc64" | "ppc64le" | "ppc32" => "powerpc".to_string(),
+        // RISC-V architectures
+        "riscv32" | "riscv64" => "riscv".to_string(),
+        // SPARC
+        "sparc" | "sparc64" => "sparc".to_string(),
+        // MIPS
+        "mips" | "mipsel" | "mips64" | "mips64el" => "mips".to_string(),
+        _ => "unknown".to_string(),
+    }
+}
+
 pub struct UNameOutput {
     pub kernel_name: Option<OsString>,
     pub nodename: Option<OsString>,
@@ -84,9 +118,9 @@ impl UNameOutput {
 
         let os = (opts.os || opts.all).then(|| uname.osname().to_owned());
 
-        // This option is unsupported on modern Linux systems
-        // See: https://lists.gnu.org/archive/html/bug-coreutils/2005-09/msg00063.html
-        let processor = opts.processor.then(|| translate!("uname-unknown").into());
+        let processor = opts
+            .processor
+            .then(|| map_processor(&uname.machine().to_string_lossy()).into());
 
         // This option is unsupported on modern Linux systems
         // See: https://lists.gnu.org/archive/html/bug-coreutils/2005-09/msg00063.html

tests/by-util/test_uname.rs

@@ -2,6 +2,7 @@
 //
 // For the full copyright and license information, please view the LICENSE
 // file that was distributed with this source code.
+// spell-checker:ignore armv mipsel
 use uutests::at_and_ucmd;
 use uutests::new_ucmd;
 
@@ -28,7 +29,35 @@ fn test_uname_name() {
 #[test]
 fn test_uname_processor() {
     let result = new_ucmd!().arg("-p").succeeds();
-    assert_eq!(result.stdout_str().trim_end(), "unknown");
+    let processor = result.stdout_str().trim();
+
+    // Verify it's non-empty
+    assert!(!processor.is_empty());
+
+    let machine = new_ucmd!().arg("-m").succeeds().stdout_move_str();
+    let machine = machine.trim();
+
+    // The processor (-p) should be a mapped version of the machine (-m)
+    // following the logic in src/uu/uname/src/uname.rs
+    let expected = match machine {
+        // ARM architectures
+        "arm64" | "aarch64" => "arm",
+        "arm" | "armv7l" | "armv8l" | "armv7" | "armv8" => "arm",
+        // x86 architectures
+        "x86_64" | "amd64" => "x86_64",
+        "i386" | "i486" | "i586" | "i686" => "i386",
+        // PowerPC architectures
+        "ppc" | "ppc64" | "ppc64le" | "ppc32" => "powerpc",
+        // RISC-V architectures
+        "riscv32" | "riscv64" => "riscv",
+        // SPARC
+        "sparc" | "sparc64" => "sparc",
+        // MIPS
+        "mips" | "mipsel" | "mips64" | "mips64el" => "mips",
+        _ => "unknown",
+    };
+
+    assert_eq!(processor, expected);
 }
 
 #[test]