8325621: Improve jspawnhelper version checks

make/autoconf/jdk-version.m4

@@ -444,6 +444,13 @@ AC_DEFUN_ONCE([JDKVER_SETUP_JDK_VERSION_NUMBERS],
   # VERSION_NUMBER but always with exactly 4 positions, with 0 for empty positions.
   VERSION_NUMBER_FOUR_POSITIONS=$VERSION_FEATURE.$VERSION_INTERIM.$VERSION_UPDATE.$VERSION_PATCH
 
+  # VERSION_NUMBER but always with exactly 4 positions, with 0 padding for all positions.
+  VERSION_FEATURE_PADDING=$(printf "%04d" $VERSION_FEATURE)
+  VERSION_INTERIM_PADDING=$(printf "%04d" $VERSION_INTERIM)
+  VERSION_UPDATE_PADDING=$(printf "%04d" $VERSION_UPDATE)
+  VERSION_PATCH_PADDING=$(printf "%04d" $VERSION_PATCH)
+  VERSION_NUMBER_FOUR_POSITIONS_PADDING=$VERSION_FEATURE_PADDING.$VERSION_INTERIM_PADDING.$VERSION_UPDATE_PADDING.$VERSION_PATCH_PADDING
+
   # VERSION_NUMBER but always with all positions, with 0 for empty positions.
   VERSION_NUMBER_ALL_POSITIONS=$VERSION_NUMBER_FOUR_POSITIONS.$VERSION_EXTRA1.$VERSION_EXTRA2.$VERSION_EXTRA3
 
@@ -571,6 +578,7 @@ AC_DEFUN_ONCE([JDKVER_SETUP_JDK_VERSION_NUMBERS],
   AC_SUBST(VERSION_OPT)
   AC_SUBST(VERSION_NUMBER)
   AC_SUBST(VERSION_NUMBER_FOUR_POSITIONS)
+  AC_SUBST(VERSION_NUMBER_FOUR_POSITIONS_PADDING)
   AC_SUBST(VERSION_STRING)
   AC_SUBST(VERSION_SHORT)
   AC_SUBST(VERSION_IS_GA)

make/autoconf/spec.gmk.template

@@ -225,6 +225,8 @@ VERSION_OPT := @VERSION_OPT@
 VERSION_NUMBER := @VERSION_NUMBER@
 # VERSION_NUMBER but always with exactly 4 positions, with 0 for empty positions.
 VERSION_NUMBER_FOUR_POSITIONS := @VERSION_NUMBER_FOUR_POSITIONS@
+# VERSION_NUMBER but always with exactly 4 positions, with 0 padding for all positions.
+VERSION_NUMBER_FOUR_POSITIONS_PADDING := @VERSION_NUMBER_FOUR_POSITIONS_PADDING@
 # The complete version string, with additional build information
 VERSION_STRING := @VERSION_STRING@
 # The short version string, without trailing zeroes and just PRE, if present.

make/modules/java.base/Launcher.gmk

@@ -78,7 +78,7 @@ ifeq ($(call isTargetOs, macosx aix linux), true)
       NAME := jspawnhelper, \
       SRC := $(TOPDIR)/src/$(MODULE)/unix/native/jspawnhelper, \
       OPTIMIZATION := LOW, \
-      CFLAGS := $(CFLAGS_JDKEXE) -I$(TOPDIR)/src/$(MODULE)/unix/native/libjava, \
+      CFLAGS := $(CFLAGS_JDKEXE) -I$(TOPDIR)/src/$(MODULE)/unix/native/libjava -DVERSION_NUMBER_FOUR_POSITIONS_PADDING='"$(VERSION_NUMBER_FOUR_POSITIONS_PADDING)"', \
       EXTRA_OBJECT_FILES := $(SUPPORT_OUTPUTDIR)/native/$(MODULE)/libjava/childproc$(OBJ_SUFFIX), \
       LDFLAGS := $(LDFLAGS_JDKEXE), \
       OUTPUT_DIR := $(SUPPORT_OUTPUTDIR)/modules_libs/$(MODULE), \

make/modules/java.base/lib/CoreLibraries.gmk

@@ -46,7 +46,7 @@ TARGETS += $(BUILD_LIBVERIFY)
 
 ##########################################################################################
 
-LIBJAVA_CFLAGS := -DARCHPROPNAME='"$(OPENJDK_TARGET_CPU_OSARCH)"'
+LIBJAVA_CFLAGS := -DARCHPROPNAME='"$(OPENJDK_TARGET_CPU_OSARCH)"' -DVERSION_NUMBER_FOUR_POSITIONS_PADDING='"$(VERSION_NUMBER_FOUR_POSITIONS_PADDING)"'
 
 ifeq ($(call isTargetOs, macosx), true)
   BUILD_LIBJAVA_java_props_md.c_CFLAGS := -x objective-c

src/java.base/unix/native/jspawnhelper/jspawnhelper.c

@@ -29,6 +29,7 @@
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -50,6 +51,10 @@ extern int errno;
 #define ERR_PIPE 2
 #define ERR_ARGS 3
 
+#ifndef VERSION_NUMBER_FOUR_POSITIONS_PADDING
+#error VERSION_NUMBER_FOUR_POSITIONS_PADDING must be defined
+#endif
+
 void error (int fd, int err) {
     if (write (fd, &err, sizeof(err)) != sizeof(err)) {
         /* Not sure what to do here. I have no one to speak to. */
@@ -134,6 +139,11 @@ void initChildStuff (int fdin, int fdout, ChildStuff *c) {
 }
 
 int main(int argc, char *argv[]) {
+    if (argc == 2 && strcmp(argv[1], "-version") == 0) {
+        fprintf(stdout, "%s\n", VERSION_NUMBER_FOUR_POSITIONS_PADDING);
+        exit (0);
+    }
+
     ChildStuff c;
     struct stat buf;
     /* argv[1] contains the fd number to read all the child info */

src/java.base/unix/native/libjava/ProcessImpl_md.c

@@ -43,6 +43,7 @@
 #include <sys/wait.h>
 #include <signal.h>
 #include <string.h>
+#include <stdio.h>
 
 #include <spawn.h>
 
@@ -609,6 +610,10 @@ startChild(JNIEnv *env, jobject process, ChildStuff *c, const char *helperpath)
     }
 }
 
+#ifndef VERSION_NUMBER_FOUR_POSITIONS_PADDING
+#error VERSION_NUMBER_FOUR_POSITIONS_PADDING must be defined
+#endif
+
 JNIEXPORT jint JNICALL
 Java_java_lang_ProcessImpl_forkAndExec(JNIEnv *env,
                                        jobject process,
@@ -631,6 +636,12 @@ Java_java_lang_ProcessImpl_forkAndExec(JNIEnv *env,
     const char *penvBlock = NULL;
     ChildStuff *c;
 
+    char *phelperpathversion = NULL;
+    FILE *stream = NULL;
+
+    const int version_length = 20;
+    char version_data[version_length];
+
     in[0] = in[1] = out[0] = out[1] = err[0] = err[1] = fail[0] = fail[1] = -1;
     childenv[0] = childenv[1] = -1;
     // Reset errno to protect against bogus error messages
@@ -655,6 +666,19 @@ Java_java_lang_ProcessImpl_forkAndExec(JNIEnv *env,
     c->argc = argc + 2;
     initVectorFromBlock(c->argv+1, pargBlock, argc);
 
+    // Check that jspawnhelper is correct version
+    const char *dash_version = " -version";
+    if ((phelperpathversion = NEW(char, strlen(phelperpath) + strlen(dash_version) + 1)) == NULL) goto Catch;
+    strcpy(phelperpathversion, phelperpath);
+    strcat(phelperpathversion, dash_version);
+
+    stream = popen(phelperpathversion, "r");
+    fgets(version_data, version_length, stream);
+
+    if (strcmp(VERSION_NUMBER_FOUR_POSITIONS_PADDING, version_data) != 0) {
+        throwIOException(env, errno, "Incorrect jspawnhelper version");
+    }
+
     if (envBlock != NULL) {
         /* Convert envBlock into a char ** envv */
         if ((penvBlock = getBytes(env, envBlock))   == NULL) goto Catch;
@@ -787,6 +811,11 @@ Java_java_lang_ProcessImpl_forkAndExec(JNIEnv *env,
     free(c->argv);
     free(c->envv);
     free(c);
+    free(phelperpathversion);
+
+    if (stream) {
+        pclose(stream);
+    }
 
     if (fds != NULL)
         (*env)->ReleaseIntArrayElements(env, std_fds, fds, 0);