diff src/os_cpu/linux_x86/vm/os_linux_x86.hpp @ 4956:418fb371f2b9

8023956: Provide a work-around to broken Linux 32 bit "Exec Shield" using CS for NX emulation (crashing with SI_KERNEL) Summary: Execute some code at a high virtual address value, and keep mapped Reviewed-by: coleenp, zgu
author dsimms
date Wed, 25 Sep 2013 13:58:13 +0200
parents 7ab5f6318694
children
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--- a/src/os_cpu/linux_x86/vm/os_linux_x86.hpp	Fri Feb 14 01:52:08 2014 -0800
+++ b/src/os_cpu/linux_x86/vm/os_linux_x86.hpp	Wed Sep 25 13:58:13 2013 +0200
@@ -36,4 +36,17 @@
   // Note: Currently only used in 64 bit Windows implementations
   static bool register_code_area(char *low, char *high) { return true; }
 
+  /*
+   * Work-around for broken NX emulation using CS limit, Red Hat patch "Exec-Shield"
+   * (IA32 only).
+   *
+   * Map and execute at a high VA to prevent CS lazy updates race with SMP MM
+   * invalidation.Further code generation by the JVM will no longer cause CS limit
+   * updates.
+   *
+   * Affects IA32: RHEL 5 & 6, Ubuntu 10.04 (LTS), 10.10, 11.04, 11.10, 12.04.
+   * @see JDK-8023956
+   */
+  static void workaround_expand_exec_shield_cs_limit();
+
 #endif // OS_CPU_LINUX_X86_VM_OS_LINUX_X86_HPP