diff -r eecfc14e66ee src/os/linux/vm/os_linux.cpp
--- openjdk/hotspot/src/os/linux/vm/os_linux.cpp Mon Jan 22 16:25:24 2018 +0000
+++ openjdk/hotspot/src/os/linux/vm/os_linux.cpp Wed Feb 21 13:52:31 2018 +0000
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 1999, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -674,6 +674,10 @@
}
}
+void os::Linux::expand_stack_to(address bottom) {
+ _expand_stack_to(bottom);
+}
+
bool os::Linux::manually_expand_stack(JavaThread * t, address addr) {
assert(t!=NULL, "just checking");
assert(t->osthread()->expanding_stack(), "expand should be set");
diff -r eecfc14e66ee src/os/linux/vm/os_linux.hpp
--- openjdk/hotspot/src/os/linux/vm/os_linux.hpp Mon Jan 22 16:25:24 2018 +0000
+++ openjdk/hotspot/src/os/linux/vm/os_linux.hpp Wed Feb 21 13:52:31 2018 +0000
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -245,6 +245,8 @@
static int safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime);
private:
+ static void expand_stack_to(address bottom);
+
typedef int (*sched_getcpu_func_t)(void);
typedef int (*numa_node_to_cpus_func_t)(int node, unsigned long *buffer, int bufferlen);
typedef int (*numa_max_node_func_t)(void);
diff -r eecfc14e66ee src/os_cpu/linux_x86/vm/os_linux_x86.cpp
--- openjdk/hotspot/src/os_cpu/linux_x86/vm/os_linux_x86.cpp Mon Jan 22 16:25:24 2018 +0000
+++ openjdk/hotspot/src/os_cpu/linux_x86/vm/os_linux_x86.cpp Wed Feb 21 13:52:31 2018 +0000
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 1999, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -892,6 +892,25 @@
void os::workaround_expand_exec_shield_cs_limit() {
#if defined(IA32)
size_t page_size = os::vm_page_size();
+
+ /*
+ * JDK-8197429
+ *
+ * Expand the stack mapping to the end of the initial stack before
+ * attempting to install the codebuf. This is needed because newer
+ * Linux kernels impose a distance of a megabyte between stack
+ * memory and other memory regions. If we try to install the
+ * codebuf before expanding the stack the installation will appear
+ * to succeed but we'll get a segfault later if we expand the stack
+ * in Java code.
+ *
+ */
+ if (os::Linux::is_initial_thread()) {
+ address limit = Linux::initial_thread_stack_bottom();
+ limit += (StackYellowPages + StackRedPages) * page_size;
+ os::Linux::expand_stack_to(limit);
+ }
+
/*
* Take the highest VA the OS will give us and exec
*
@@ -910,6 +929,16 @@
char* hint = (char*) (Linux::initial_thread_stack_bottom() -
((StackYellowPages + StackRedPages + 1) * page_size));
char* codebuf = os::attempt_reserve_memory_at(page_size, hint);
+
+ if (codebuf == NULL) {
+ // JDK-8197429: There may be a stack gap of one megabyte between
+ // the limit of the stack and the nearest memory region: this is a
+ // Linux kernel workaround for CVE-2017-1000364. If we failed to
+ // map our codebuf, try again at an address one megabyte lower.
+ hint -= 1 * M;
+ codebuf = os::attempt_reserve_memory_at(page_size, hint);
+ }
+
if ( (codebuf == NULL) || (!os::commit_memory(codebuf, page_size, true)) ) {
return; // No matter, we tried, best effort.
}