8314491: Linux: jexec launched via PATH fails to find java

Reviewed-by: dholmes, rriggs

Author: Vladimir Petko

src/java.base/unix/native/launcher/jexec.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -168,7 +168,16 @@ int main(int argc, const char * argv[]) {
 
     /* Get the path to the java binary, which is in a known position relative
      * to our current position, which is in argv[0]. */
-    if (getJavaPath(argv[argi++], java, RELATIVE_DEPTH) != 0) {
+    int error = getJavaPath(argv[argi++], java, RELATIVE_DEPTH);
+#ifdef __linux__
+    /* Try to read the symbolic link to the current binary
+     * if the java path can not be resolved from argv[0]. */
+    if (error != 0) {
+        error = getJavaPath("/proc/self/exe", java, RELATIVE_DEPTH);
+    }
+#endif
+
+    if (error != 0) {
         errorExit(errno, MISSING_JAVA_MSG);
     }
     alen = (argc + 2) * (sizeof (const char *));

test/jdk/tools/launcher/Jexec.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -23,14 +23,16 @@
 
 /*
  * @test
- * @bug 8175000
+ * @bug 8175000 8314491
  * @summary test jexec
+ * @requires os.family == "linux"
  * @build TestHelper
  * @run main Jexec
  */
 
 import java.io.File;
 import java.io.IOException;
+import java.nio.file.Path;
 
 public class Jexec extends TestHelper {
     private final File testJar;
@@ -54,20 +56,12 @@ public class Jexec extends TestHelper {
     }
 
     public static void main(String... args) throws Exception {
-        // linux is the only supported platform, give the others a pass
-        if (!isLinux) {
-            System.err.println("Warning: unsupported platform test passes vacuously");
-            return;
-        }
-        // ok to run the test now
         Jexec t = new Jexec();
         t.run(null);
     }
 
-    @Test
-    void jexec() throws Exception {
-        TestResult tr = doExec(jexecCmd.getAbsolutePath(),
-                testJar.getAbsolutePath(), message);
+    private void runTest(String... cmds) throws Exception {
+        TestResult tr = doExec(cmds);
         if (!tr.isOK()) {
             System.err.println(tr);
             throw new Exception("incorrect exit value");
@@ -77,4 +71,17 @@ void jexec() throws Exception {
             throw new Exception("expected message \'" + message + "\' not found");
         }
     }
+
+    @Test
+    void jexec() throws Exception {
+        runTest(jexecCmd.getAbsolutePath(),
+                testJar.getAbsolutePath(), message);
+    }
+
+    @Test
+    void jexecInPath() throws Exception {
+        Path jexec = Path.of(jexecCmd.getAbsolutePath());
+        runTest("/bin/sh", "-c",
+                String.format("PATH=%s ; jexec %s '%s'",jexec.getParent(), testJar.getAbsolutePath(), message));
+    }
 }