--- a/src/hotspot/os/linux/os_linux.cpp	Tue Jul 02 12:24:28 2019 +0200
+++ b/src/hotspot/os/linux/os_linux.cpp	Tue Jul 02 13:45:08 2019 +0200
@@ -84,6 +84,7 @@
 # include <sys/select.h>
 # include <pthread.h>
 # include <signal.h>
+# include <endian.h>
 # include <errno.h>
 # include <dlfcn.h>
 # include <stdio.h>
@@ -1747,11 +1748,26 @@
     return NULL;
   }
 
+  if (elf_head.e_ident[EI_DATA] != LITTLE_ENDIAN_ONLY(ELFDATA2LSB) BIG_ENDIAN_ONLY(ELFDATA2MSB)) {
+    // handle invalid/out of range endianness values
+    if (elf_head.e_ident[EI_DATA] == 0 || elf_head.e_ident[EI_DATA] > 2) {
+      return NULL;
+    }
+
+#if defined(VM_LITTLE_ENDIAN)
+    // VM is LE, shared object BE
+    elf_head.e_machine = be16toh(elf_head.e_machine);
+#else
+    // VM is BE, shared object LE
+    elf_head.e_machine = le16toh(elf_head.e_machine);
+#endif
+  }
+
   typedef struct {
     Elf32_Half    code;         // Actual value as defined in elf.h
     Elf32_Half    compat_class; // Compatibility of archs at VM's sense
     unsigned char elf_class;    // 32 or 64 bit
-    unsigned char endianess;    // MSB or LSB
+    unsigned char endianness;   // MSB or LSB
     char*         name;         // String representation
   } arch_t;
 
@@ -1778,8 +1794,9 @@
     {EM_PPC64,       EM_PPC64,   ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
     {EM_SH,          EM_SH,      ELFCLASS32, ELFDATA2MSB, (char*)"SuperH BE"},
 #endif
-    {EM_ARM,         EM_ARM,     ELFCLASS32,   ELFDATA2LSB, (char*)"ARM"},
-    {EM_S390,        EM_S390,    ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
+    {EM_ARM,         EM_ARM,     ELFCLASS32, ELFDATA2LSB, (char*)"ARM"},
+    // we only support 64 bit z architecture
+    {EM_S390,        EM_S390,    ELFCLASS64, ELFDATA2MSB, (char*)"IBM System/390"},
     {EM_ALPHA,       EM_ALPHA,   ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
     {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
     {EM_MIPS,        EM_MIPS,    ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
@@ -1825,7 +1842,7 @@
         AARCH64, ALPHA, ARM, AMD64, IA32, IA64, M68K, MIPS, MIPSEL, PARISC, __powerpc__, __powerpc64__, S390, SH, __sparc
 #endif
 
-  // Identify compatability class for VM's architecture and library's architecture
+  // Identify compatibility class for VM's architecture and library's architecture
   // Obtain string descriptions for architectures
 
   arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
@@ -1849,29 +1866,35 @@
     return NULL;
   }
 
-  if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
-    ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
-    return NULL;
-  }
-
-#ifndef S390
-  if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
-    ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
-    return NULL;
-  }
-#endif // !S390
-
   if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
-    if (lib_arch.name!=NULL) {
+    if (lib_arch.name != NULL) {
       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
-                 " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
+                 " (Possible cause: can't load %s .so on a %s platform)",
                  lib_arch.name, arch_array[running_arch_index].name);
     } else {
       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
-                 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
-                 lib_arch.code,
-                 arch_array[running_arch_index].name);
+                 " (Possible cause: can't load this .so (machine code=0x%x) on a %s platform)",
+                 lib_arch.code, arch_array[running_arch_index].name);
     }
+    return NULL;
+  }
+
+  if (lib_arch.endianness != arch_array[running_arch_index].endianness) {
+    ::snprintf(diag_msg_buf, diag_msg_max_length-1, " (Possible cause: endianness mismatch)");
+    return NULL;
+  }
+
+  // ELF file class/capacity : 0 - invalid, 1 - 32bit, 2 - 64bit
+  if (lib_arch.elf_class > 2 || lib_arch.elf_class < 1) {
+    ::snprintf(diag_msg_buf, diag_msg_max_length-1, " (Possible cause: invalid ELF file class)");
+    return NULL;
+  }
+
+  if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
+    ::snprintf(diag_msg_buf, diag_msg_max_length-1,
+               " (Possible cause: architecture word width mismatch, can't load %d-bit .so on a %d-bit platform)",
+               (int) lib_arch.elf_class * 32, arch_array[running_arch_index].elf_class * 32);
+    return NULL;
   }
 
   return NULL;

--- a/src/hotspot/os/solaris/os_solaris.cpp	Tue Jul 02 12:24:28 2019 +0200
+++ b/src/hotspot/os/solaris/os_solaris.cpp	Tue Jul 02 13:45:08 2019 +0200
@@ -1520,6 +1520,13 @@
   }
 }
 
+static void change_endianness(Elf32_Half& val) {
+  unsigned char *ptr = (unsigned char *)&val;
+  unsigned char swp = ptr[0];
+  ptr[0] = ptr[1];
+  ptr[1] = swp;
+}
+
 // Loads .dll/.so and
 // in case of error it checks if .dll/.so was built for the
 // same architecture as Hotspot is running on
@@ -1570,6 +1577,14 @@
     return NULL;
   }
 
+  if (elf_head.e_ident[EI_DATA] != LITTLE_ENDIAN_ONLY(ELFDATA2LSB) BIG_ENDIAN_ONLY(ELFDATA2MSB)) {
+    // handle invalid/out of range endianness values
+    if (elf_head.e_ident[EI_DATA] == 0 || elf_head.e_ident[EI_DATA] > 2) {
+      return NULL;
+    }
+    change_endianness(elf_head.e_machine);
+  }
+
   typedef struct {
     Elf32_Half    code;         // Actual value as defined in elf.h
     Elf32_Half    compat_class; // Compatibility of archs at VM's sense
@@ -1588,7 +1603,10 @@
     {EM_SPARCV9,     EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
     {EM_PPC,         EM_PPC,     ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
     {EM_PPC64,       EM_PPC64,   ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
-    {EM_ARM,         EM_ARM,     ELFCLASS32, ELFDATA2LSB, (char*)"ARM 32"}
+    {EM_ARM,         EM_ARM,     ELFCLASS32, ELFDATA2LSB, (char*)"ARM"},
+    // we only support 64 bit z architecture
+    {EM_S390,        EM_S390,    ELFCLASS64, ELFDATA2MSB, (char*)"IBM System/390"},
+    {EM_AARCH64,     EM_AARCH64, ELFCLASS64, ELFDATA2LSB, (char*)"AARCH64"}
   };
 
 #if  (defined IA32)
@@ -1612,7 +1630,7 @@
        IA32, AMD64, IA64, __sparc, __powerpc__, ARM, ARM
 #endif
 
-  // Identify compatability class for VM's architecture and library's architecture
+  // Identify compatibility class for VM's architecture and library's architecture
   // Obtain string descriptions for architectures
 
   arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
@@ -1636,29 +1654,37 @@
     return NULL;
   }
 
+  if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
+    if (lib_arch.name != NULL) {
+      ::snprintf(diag_msg_buf, diag_msg_max_length-1,
+                 " (Possible cause: can't load %s .so on a %s platform)",
+                 lib_arch.name, arch_array[running_arch_index].name);
+    } else {
+      ::snprintf(diag_msg_buf, diag_msg_max_length-1,
+                 " (Possible cause: can't load this .so (machine code=0x%x) on a %s platform)",
+                 lib_arch.code, arch_array[running_arch_index].name);
+    }
+    return NULL;
+  }
+
   if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
     return NULL;
   }
 
+  // ELF file class/capacity : 0 - invalid, 1 - 32bit, 2 - 64bit
+  if (lib_arch.elf_class > 2 || lib_arch.elf_class < 1) {
+    ::snprintf(diag_msg_buf, diag_msg_max_length-1, " (Possible cause: invalid ELF file class)");
+    return NULL;
+  }
+
   if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
-    ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
+    ::snprintf(diag_msg_buf, diag_msg_max_length-1,
+               " (Possible cause: architecture word width mismatch, can't load %d-bit .so on a %d-bit platform)",
+               (int) lib_arch.elf_class * 32, arch_array[running_arch_index].elf_class * 32);
     return NULL;
   }
 
-  if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
-    if (lib_arch.name!=NULL) {
-      ::snprintf(diag_msg_buf, diag_msg_max_length-1,
-                 " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
-                 lib_arch.name, arch_array[running_arch_index].name);
-    } else {
-      ::snprintf(diag_msg_buf, diag_msg_max_length-1,
-                 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
-                 lib_arch.code,
-                 arch_array[running_arch_index].name);
-    }
-  }
-
   return NULL;
 }