From 09272b3c77464dad9cff9b8b30b59111d8b1b3cb Mon Sep 17 00:00:00 2001
From: mmc <codeberg.wilder850@simplelogin.com>
Date: Fri, 7 Aug 2026 12:09:47 -0500
Subject: [PATCH] lscpu: accept -1 as physical package id

The kernel falls back to -1 in
/sys/devices/system/cpu/cpuN/topology/physical_package_id when the
architecture does not expose physical package information:
https://www.kernel.org/doc/html/latest/admin-guide/cputopology.html

Issue #495 reports exactly this on ppc64, where parsing the value as
usize made lscpu panic. Parse it as i64 instead, so unknown ids
collapse into a single socket bucket, matching the Socket(s): 1 that
util-linux lscpu is observed to report there.

Fixes #495
---
 src/uu/lscpu/src/sysfs.rs | 31 +++++++++++++++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/src/uu/lscpu/src/sysfs.rs b/src/uu/lscpu/src/sysfs.rs
index e8a8e1a1..81ec12bb 100644
--- a/src/uu/lscpu/src/sysfs.rs
+++ b/src/uu/lscpu/src/sysfs.rs
@@ -18,7 +18,9 @@ pub struct CpuTopology {
 #[derive(Debug)]
 pub struct Cpu {
     _index: usize,
-    pub pkg_id: usize,
+    // i64 rather than usize: the kernel reports -1 when the architecture
+    // does not expose physical package information
+    pub pkg_id: i64,
     pub core_id: usize,
     pub caches: Vec<CpuCache>,
 }
@@ -53,7 +55,7 @@ impl CpuTopology {
             let pkg_id = fs::read_to_string(cpu_dir.join("topology/physical_package_id"))
                 .unwrap()
                 .trim()
-                .parse::<usize>()
+                .parse::<i64>()
                 .unwrap();
 
             let core_id = fs::read_to_string(cpu_dir.join("topology/core_id"))
@@ -276,6 +278,31 @@ fn test_print_cache_size() {
     );
 }
 
+#[test]
+fn test_socket_count_with_unknown_package_id() {
+    // The kernel reports physical_package_id as -1 when the architecture does
+    // not expose package information (e.g. some ppc64 machines, see #495).
+    // All-unknown ids collapse into a single socket bucket.
+    let topology = CpuTopology {
+        cpus: vec![
+            Cpu {
+                _index: 0,
+                pkg_id: -1,
+                core_id: 0,
+                caches: vec![],
+            },
+            Cpu {
+                _index: 1,
+                pkg_id: -1,
+                core_id: 1,
+                caches: vec![],
+            },
+        ],
+    };
+    assert_eq!(topology.socket_count(), 1);
+    assert_eq!(topology.core_count(), 2);
+}
+
 #[test]
 fn test_parse_cpu_list() {
     assert_eq!(parse_cpu_list(""), Vec::<usize>::new());