Blob Blame Raw
diff --git openjdk/src/hotspot/os/linux/os_linux.cpp openjdk/src/hotspot/os/linux/os_linux.cpp
--- openjdk/src/hotspot/os/linux/os_linux.cpp
+++ openjdk/src/hotspot/os/linux/os_linux.cpp
@@ -107,6 +107,8 @@
 # include <inttypes.h>
 # include <sys/ioctl.h>
 
+#include <sys/prctl.h>
+
 #ifndef _GNU_SOURCE
   #define _GNU_SOURCE
   #include <sched.h>
@@ -4984,6 +4986,48 @@
 extern void report_error(char* file_name, int line_no, char* title,
                          char* format, ...);
 
+/* Per task speculation control */
+#ifndef PR_GET_SPECULATION_CTRL
+# define PR_GET_SPECULATION_CTRL    52
+#endif
+#ifndef PR_SET_SPECULATION_CTRL
+# define PR_SET_SPECULATION_CTRL    53
+#endif
+/* Speculation control variants */
+#ifndef PR_SPEC_STORE_BYPASS
+# define PR_SPEC_STORE_BYPASS          0
+#endif
+/* Return and control values for PR_SET/GET_SPECULATION_CTRL */
+
+#ifndef PR_SPEC_NOT_AFFECTED
+# define PR_SPEC_NOT_AFFECTED          0
+#endif
+#ifndef PR_SPEC_PRCTL
+# define PR_SPEC_PRCTL                 (1UL << 0)
+#endif
+#ifndef PR_SPEC_ENABLE
+# define PR_SPEC_ENABLE                (1UL << 1)
+#endif
+#ifndef PR_SPEC_DISABLE
+# define PR_SPEC_DISABLE               (1UL << 2)
+#endif
+#ifndef PR_SPEC_FORCE_DISABLE
+# define PR_SPEC_FORCE_DISABLE         (1UL << 3)
+#endif
+#ifndef PR_SPEC_DISABLE_NOEXEC
+# define PR_SPEC_DISABLE_NOEXEC        (1UL << 4)
+#endif
+
+static void set_speculation() __attribute__((constructor));
+static void set_speculation() {
+  if ( prctl(PR_SET_SPECULATION_CTRL,
+             PR_SPEC_STORE_BYPASS,
+             PR_SPEC_DISABLE_NOEXEC, 0, 0) == 0 ) {
+    return;
+  }
+  prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_STORE_BYPASS, PR_SPEC_DISABLE, 0, 0);
+}
+
 // this is called _before_ most of the global arguments have been parsed
 void os::init(void) {
   char dummy;   // used to get a guess on initial stack address