diff --git a/hotspot/agent/src/os/linux/LinuxDebuggerLocal.c b/hotspot/agent/src/os/linux/LinuxDebuggerLocal.c
index 1d3c3bbd02..b39bea9576 100644
--- a/hotspot/agent/src/os/linux/LinuxDebuggerLocal.c
+++ b/hotspot/agent/src/os/linux/LinuxDebuggerLocal.c
@@ -23,6 +23,7 @@
  */
 
 #include <jni.h>
+#include <stdlib.h>
 #include "libproc.h"
 
 #if defined(x86_64) && !defined(amd64)
@@ -73,7 +74,7 @@ JNIEXPORT void JNICALL Java_sun_jvm_hotspot_debugger_linux_LinuxDebuggerLocal_in
   (JNIEnv *env, jclass cls) {
   jclass listClass;
 
-  if (init_libproc(getenv("LIBSAPROC_DEBUG")) != true) {
+  if (init_libproc(getenv("LIBSAPROC_DEBUG") != NULL) != true) {
      THROW_NEW_DEBUGGER_EXCEPTION("can't initialize libproc");
   }
 
diff --git a/hotspot/agent/src/os/linux/ps_proc.c b/hotspot/agent/src/os/linux/ps_proc.c
index 61f08692ca..61923a2552 100644
--- a/hotspot/agent/src/os/linux/ps_proc.c
+++ b/hotspot/agent/src/os/linux/ps_proc.c
@@ -27,6 +27,8 @@
 #include <string.h>
 #include <signal.h>
 #include <errno.h>
+#include <sys/types.h>
+#include <sys/wait.h>
 #include <sys/ptrace.h>
 #include "libproc_impl.h"
 
diff --git a/hotspot/agent/src/os/linux/salibelf.c b/hotspot/agent/src/os/linux/salibelf.c
index 9634da8be5..4c860a0fe0 100644
--- a/hotspot/agent/src/os/linux/salibelf.c
+++ b/hotspot/agent/src/os/linux/salibelf.c
@@ -25,6 +25,7 @@
 #include "salibelf.h"
 #include <stdlib.h>
 #include <unistd.h>
+#include <string.h>
 
 extern void print_debug(const char*,...);
 
diff --git a/hotspot/agent/src/os/linux/symtab.c b/hotspot/agent/src/os/linux/symtab.c
index bea59e3782..f9fc33f14e 100644
--- a/hotspot/agent/src/os/linux/symtab.c
+++ b/hotspot/agent/src/os/linux/symtab.c
@@ -305,7 +305,7 @@ static struct symtab* build_symtab_from_build_id(Elf64_Nhdr *note)
 
   unsigned char *bytes
     = (unsigned char*)(note+1) + note->n_namesz;
-  unsigned char *filename
+  char *filename
     = (build_id_to_debug_filename (note->n_descsz, bytes));
 
   fd = pathmap_open(filename);
diff --git a/hotspot/src/cpu/x86/vm/assembler_x86.cpp b/hotspot/src/cpu/x86/vm/assembler_x86.cpp
index 94f21349dc..d2a409d839 100644
--- a/hotspot/src/cpu/x86/vm/assembler_x86.cpp
+++ b/hotspot/src/cpu/x86/vm/assembler_x86.cpp
@@ -4713,7 +4713,7 @@ void Assembler::adcq(Register dst, Address src) {
 }
 
 void Assembler::adcq(Register dst, Register src) {
-  (int) prefixq_and_encode(dst->encoding(), src->encoding());
+  (void) prefixq_and_encode(dst->encoding(), src->encoding());
   emit_arith(0x13, 0xC0, dst, src);
 }
 
@@ -4768,7 +4768,7 @@ void Assembler::andq(Register dst, Address src) {
 }
 
 void Assembler::andq(Register dst, Register src) {
-  (int) prefixq_and_encode(dst->encoding(), src->encoding());
+  (void) prefixq_and_encode(dst->encoding(), src->encoding());
   emit_arith(0x23, 0xC0, dst, src);
 }