From bf6cbc675ccb9c97c1a4385c19f8ba64115e6ccd Mon Sep 17 00:00:00 2001
From: Basil Crow <me@basilcrow.com>
Date: Fri, 8 Mar 2024 10:22:25 -0800
Subject: [PATCH] [JENKINS-72833] Do not attempt to self-`exec` on systems
 without `libc`

---
 .../main/java/hudson/lifecycle/Lifecycle.java |  6 +++---
 .../java/hudson/lifecycle/UnixLifecycle.java  | 20 +++++++++----------
 .../java/jenkins/util/JavaVMArguments.java    |  5 +++--
 3 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/core/src/main/java/hudson/lifecycle/Lifecycle.java b/core/src/main/java/hudson/lifecycle/Lifecycle.java
index d6c59713f481..b6f90f2d82d3 100644
--- a/core/src/main/java/hudson/lifecycle/Lifecycle.java
+++ b/core/src/main/java/hudson/lifecycle/Lifecycle.java
@@ -120,13 +120,13 @@ public void verifyRestartable() throws RestartNotSupportedException {
                     // if run on Unix, we can do restart
                     try {
                         instance = new UnixLifecycle();
-                    } catch (final IOException e) {
-                        LOGGER.log(Level.WARNING, "Failed to install embedded lifecycle implementation", e);
+                    } catch (final Throwable t) {
+                        LOGGER.log(Level.WARNING, "Failed to install embedded lifecycle implementation", t);
                         instance = new Lifecycle() {
                             @Override
                             public void verifyRestartable() throws RestartNotSupportedException {
                                 throw new RestartNotSupportedException(
-                                        "Failed to install embedded lifecycle implementation, so cannot restart: " + e, e);
+                                        "Failed to install embedded lifecycle implementation, so cannot restart: " + t, t);
                             }
                         };
                     }
diff --git a/core/src/main/java/hudson/lifecycle/UnixLifecycle.java b/core/src/main/java/hudson/lifecycle/UnixLifecycle.java
index ca8f50b9f589..cb314465d09b 100644
--- a/core/src/main/java/hudson/lifecycle/UnixLifecycle.java
+++ b/core/src/main/java/hudson/lifecycle/UnixLifecycle.java
@@ -31,6 +31,8 @@
 
 import com.sun.jna.Native;
 import com.sun.jna.StringArray;
+import edu.umd.cs.findbugs.annotations.NonNull;
+import hudson.Functions;
 import hudson.Platform;
 import java.io.IOException;
 import java.util.List;
@@ -50,16 +52,12 @@
  * @since 1.304
  */
 public class UnixLifecycle extends Lifecycle {
+
+    @NonNull
     private List<String> args;
-    private Throwable failedToObtainArgs;
 
-    public UnixLifecycle() throws IOException {
-        try {
-            args = JavaVMArguments.current();
-        } catch (UnsupportedOperationException | LinkageError e) {
-            // can't restart / see JENKINS-3875
-            failedToObtainArgs = e;
-        }
+    public UnixLifecycle() {
+        args = JavaVMArguments.current();
     }
 
     @Override
@@ -89,6 +87,10 @@ public void restart() throws IOException, InterruptedException {
 
     @Override
     public void verifyRestartable() throws RestartNotSupportedException {
+        if (!Functions.isGlibcSupported()) {
+            throw new RestartNotSupportedException("Restart is not supported on platforms without libc");
+        }
+
         // see http://lists.apple.com/archives/cocoa-dev/2005/Oct/msg00836.html and
         // http://factor-language.blogspot.com/2007/07/execve-returning-enotsup-on-mac-os-x.html
         // on Mac, execv fails with ENOTSUP if the caller is multi-threaded, resulting in an error like
@@ -97,8 +99,6 @@ public void verifyRestartable() throws RestartNotSupportedException {
         // according to http://www.mail-archive.com/wine-devel@winehq.org/msg66797.html this now works on Snow Leopard
         if (Platform.isDarwin() && !Platform.isSnowLeopardOrLater())
             throw new RestartNotSupportedException("Restart is not supported on Mac OS X");
-        if (args == null)
-            throw new RestartNotSupportedException("Failed to obtain the command line arguments of the process", failedToObtainArgs);
     }
 
     private static final Logger LOGGER = Logger.getLogger(UnixLifecycle.class.getName());
diff --git a/core/src/main/java/jenkins/util/JavaVMArguments.java b/core/src/main/java/jenkins/util/JavaVMArguments.java
index 473849a9922e..c677df0e5827 100644
--- a/core/src/main/java/jenkins/util/JavaVMArguments.java
+++ b/core/src/main/java/jenkins/util/JavaVMArguments.java
@@ -1,6 +1,6 @@
 package jenkins.util;
 
-import com.google.common.primitives.Ints;
+import edu.umd.cs.findbugs.annotations.NonNull;
 import hudson.Functions;
 import hudson.util.ProcessTree;
 import java.lang.management.ManagementFactory;
@@ -20,6 +20,7 @@ public class JavaVMArguments {
     /**
      * Gets the process argument list of the current process.
      */
+    @NonNull
     public static List<String> current() {
         ProcessHandle.Info info = ProcessHandle.current().info();
         if (info.command().isPresent() && info.arguments().isPresent()) {
@@ -30,7 +31,7 @@ public static List<String> current() {
             return args;
         } else if (Functions.isGlibcSupported()) {
             // Native approach
-            int pid = Ints.checkedCast(ProcessHandle.current().pid());
+            int pid = Math.toIntExact(ProcessHandle.current().pid());
             ProcessTree.OSProcess process = ProcessTree.get().get(pid);
             if (process != null) {
                 List<String> args = process.getArguments();