8345782: Refining the cases that libjsig deprecation warning is issued

Reviewed-by: dholmes, kevinw

Author: jaokim

src/java.base/unix/native/libjsig/jsig.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2025, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2012, 2015 SAP SE. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -47,6 +47,7 @@
 #define MAX_SIGNALS NSIG
 
 static struct sigaction sact[MAX_SIGNALS]; /* saved signal handlers */
+static bool deprecated_usage[MAX_SIGNALS]; /* usage of signal/sigset */
 
 static sigset_t jvmsigs; /* Signals used by jvm. */
 
@@ -69,6 +70,7 @@ static sigaction_t os_sigaction = 0; /* os's version of sigaction() */
 
 static bool jvm_signal_installing = false;
 static bool jvm_signal_installed = false;
+static bool warning_printed = false;
 
 
 static void signal_lock() {
@@ -89,15 +91,20 @@ static void signal_unlock() {
   pthread_mutex_unlock(&mutex);
 }
 
+static void print_deprecation_warning() {
+  if (!warning_printed) {
+    warning_printed = true;
+    fprintf(stderr, HOTSPOT_VM_DISTRO " VM warning: the use of signal() and sigset() "
+            "for signal chaining was deprecated in version 16.0 and will "
+            "be removed in a future release. Use sigaction() instead.\n");
+  }
+}
+
 static sa_handler_t call_os_signal(int sig, sa_handler_t disp,
                                    bool is_sigset) {
   sa_handler_t res;
 
   if (os_signal == NULL) {
-    // Deprecation warning first time through
-    fprintf(stderr, HOTSPOT_VM_DISTRO " VM warning: the use of signal() and sigset() "
-            "for signal chaining was deprecated in version 16.0 and will "
-            "be removed in a future release. Use sigaction() instead.\n");
     if (!is_sigset) {
       os_signal = (signal_function_t)dlsym(RTLD_NEXT, "signal");
     } else {
@@ -140,8 +147,11 @@ static sa_handler_t set_signal(int sig, sa_handler_t disp, bool is_sigset) {
 
   signal_lock();
 
+  deprecated_usage[sig] = true;
+
   sigused = sigismember(&jvmsigs, sig);
   if (jvm_signal_installed && sigused) {
+    print_deprecation_warning();
     /* jvm has installed its signal handler for this signal. */
     /* Save the handler. Don't really install it. */
     if (is_sigset) {
@@ -250,6 +260,9 @@ JNIEXPORT int sigaction(int sig, const struct sigaction *act, struct sigaction *
      * within the JVM_begin_signal_setting-JVM_end_signal_setting-window. There can be any number of non-modifying
      * calls, but they will only return the expected preexisting handler if executed before the modifying call.
      */
+    if (deprecated_usage[sig] == true) {
+      print_deprecation_warning();
+    }
     res = call_os_sigaction(sig, act, &oldAct);
     if (res == 0) {
       if (act != NULL) {

test/hotspot/jtreg/runtime/signal/README

@@ -1,4 +1,4 @@
-Copyright (c) 2008, 2020, Oracle and/or its affiliates. All rights reserved.
+Copyright (c) 2008, 2025, 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
@@ -41,6 +41,9 @@ Also 2 different ways of setting signal handlers are tested: sigaction, sigset.
 
 For 'postpre' and 'postpro' libjsig.so is used to chain signal handlers behind VM installed ones.
 
+When libjsig.so is used, the warning for deprecated usage of signal/sigset is checked. For this
+purpose, all scenarios are also run once with libjsig preloaded.
+
 => Current tests cover the following cases (don't count 'nojvm' scenario):
 1. Support for pre-installed signal handlers when the HotSpot VM is created.
 2. Support for signal handler installation after the HotSpot VM is created inside JNI code

test/hotspot/jtreg/runtime/signal/SigTestDriver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2007, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2007, 2025, 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
@@ -91,12 +91,16 @@ public static void main(String[] args) {
                             .subList(1, args.length);
         cmd.addAll(argList);
 
+        String failureMessage = null;
         boolean passed = true;
 
         for (String mode : new String[] {"sigset", "sigaction"}) {
-            for (String scenario : new String[] {"nojvm", "prepre", "prepost", "postpre", "postpost"}) {
+            // Scenarios postpre and postpost requires libjsig.
+            // The other scenarios are run with libjsig to validate the deprecation warning.
+            for (String scenario : new String[] {"nojvm", "prepre", "prepost", "postpre#libjsig", "postpost#libjsig",
+                    "nojvm#libjsig", "prepre#libjsig", "prepost#libjsig", }) {
                 cmd.set(modeIdx, mode);
-                cmd.set(scenarioIdx, scenario);
+                cmd.set(scenarioIdx, scenario.replace("#libjsig", ""));
                 System.out.printf("START TESTING: SIGNAL = %s, MODE = %s, SCENARIO=%s%n", signame, mode, scenario);
                 System.out.printf("Do execute: %s%n", cmd.toString());
 
@@ -105,32 +109,54 @@ public static void main(String[] args) {
                         (x, y) -> y + File.pathSeparator + x);
                 pb.environment().put("CLASSPATH", Utils.TEST_CLASS_PATH);
 
-                switch (scenario) {
-                    case "postpre":
-                    case "postpost": {
-                        pb.environment().merge("LD_PRELOAD", libjsig().toString(),
-                                (x, y) -> y + File.pathSeparator + x);
-                    }
+                boolean useLibjsig = scenario.endsWith("#libjsig");
+                if (useLibjsig) {
+                    pb.environment().merge("LD_PRELOAD", libjsig().toString(),
+                            (x, y) -> y + File.pathSeparator + x);
                 }
 
                 try {
                     OutputAnalyzer oa = ProcessTools.executeProcess(pb);
                     oa.reportDiagnosticSummary();
                     int exitCode = oa.getExitValue();
                     if (exitCode == 0) {
-                        System.out.println("PASSED with exit code 0");
+                        // Skip deprecation warning check on MacOSX (see JDK-8346381)
+                        if (useLibjsig && !Platform.isOSX()) {
+                            // verify that deprecation warning for sigset/signal is printed
+                            // only in the correct scenarios
+                            boolean deprecatedSigFunctionUsed = mode.equals("sigset");
+                            boolean jvmInvolved = !scenario.contains("nojvm");
+                            boolean warningPrinted = oa.contains("VM warning");
+                            boolean sigUsedByJVM = sigIsUsedByJVM(signame);
+                            if (deprecatedSigFunctionUsed && jvmInvolved && sigUsedByJVM) {
+                                if (!warningPrinted) {
+                                    failureMessage = "FAILED: Missing deprecation warning for mode " + mode +
+                                                     ", scenario: "+ scenario + ", signal " + signame;
+                                    passed = false;
+                                }
+                            } else if (warningPrinted) {
+                                failureMessage = "FAILED: Deprecation warning shouldn't be printed for mode " + mode +
+                                                 ", scenario: "+ scenario + ", signal " + signame;
+                                passed = false;
+                            }
+                        } else {
+                            System.out.println("PASSED with exit code 0");
+                        }
                     } else {
-                        System.out.println("FAILED with exit code " + exitCode);
+                        failureMessage = "FAILED with exit code " + exitCode;
                         passed = false;
                     }
+                    if (!passed) {
+                        System.out.println(failureMessage);
+                    }
                 } catch (Exception e) {
                     throw new Error("execution failed", e);
                 }
             }
         }
 
         if (!passed) {
-            throw new Error("test failed");
+            throw new Error(failureMessage != null ? failureMessage : "test failed");
         }
     }
 
@@ -146,4 +172,26 @@ private static List<String> vmargs() {
     private static Path libjsig() {
         return Platform.jvmLibDir().resolve(Platform.buildSharedLibraryName("jsig"));
     }
+
+    /**
+     * Return true for the chainable signals that are used by the JVM.
+     * See src/hotspot/os/posix/signals_posix.cpp
+     * @param signame
+     * @return true if signal is used by JVM, false otherwise
+     */
+    private static boolean sigIsUsedByJVM(String signame) {
+        switch(signame) {
+            case "SIGSEGV":
+            case "SIGPIPE":
+            case "SIGBUS":
+            case "SIGILL":
+            case "SIGFPE":
+            case "SIGXFSZ":
+                return true;
+            case "SIGTRAP":
+                return Platform.isPPC();
+            default:
+                return false;
+        }
+    }
 }