Fix windows build (this is now used from the java library)

[simgrid.git] / src / simix / smx_context.c

diff --git a/src/simix/smx_context.c b/src/simix/smx_context.c
index 12552da..f222f62 100644 (file)
--- a/src/simix/smx_context.c
+++ b/src/simix/smx_context.c
@@ -13,6 +13,25 @@
 #include "smx_private.h"
 #include "simgrid/sg_config.h"
 #include "internal_config.h"
+#include "simgrid/modelchecker.h"
+
+
+#ifdef _WIN32
+#include <windows.h>
+#else
+#include <sys/mman.h>
+#endif
+
+#ifdef __MINGW32__ 
+#define _aligned_malloc __mingw_aligned_malloc 
+#define _aligned_free  __mingw_aligned_free 
+#endif //MINGW
+
+
+
+#ifdef HAVE_VALGRIND_VALGRIND_H
+# include <valgrind/valgrind.h>
+#endif
 
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_context, simix,
                                 "Context switching mechanism");
@@ -21,6 +40,8 @@ char* smx_context_factory_name = NULL; /* factory name specified by --cfg=contex
 smx_ctx_factory_initializer_t smx_factory_initializer_to_use = NULL;
 int smx_context_stack_size;
 int smx_context_stack_size_was_set = 0;
+int smx_context_guard_size;
+int smx_context_guard_size_was_set = 0;
 #ifdef HAVE_THREAD_LOCAL_STORAGE
 static __thread smx_context_t smx_current_context_parallel;
 #else
@@ -101,11 +122,85 @@ void SIMIX_context_mod_exit(void)
 
 void *SIMIX_context_stack_new(void)
 {
-  return xbt_malloc0(smx_context_stack_size);
+  void *stack;
+
+  /* FIXME: current code for stack overflow protection assumes that stacks are
+   * growing downward (PTH_STACKGROWTH == -1).  Protected pages need to be put
+   * after the stack when PTH_STACKGROWTH == 1. */
+
+  if (smx_context_guard_size > 0 && !MC_is_active()) {
+
+#if defined(_XBT_WIN32) || (PTH_STACKGROWTH != -1)
+    static int warned_once = 0;
+    if (!warned_once) {
+      XBT_WARN("Stack overflow protection is known to be broken on your system.  Either you're on Windows or PTH_STACKGROWTH != -1 (current value is %d).",
+               PTH_STACKGROWTH);
+      warned_once = 1;
+    }
+#endif
+
+    size_t size = smx_context_stack_size + smx_context_guard_size;
+#ifdef HAVE_MC
+    /* Cannot use posix_memalign when HAVE_MC. Align stack by hand, and save the
+     * pointer returned by xbt_malloc0. */
+    char *alloc = xbt_malloc0(size + xbt_pagesize);
+    stack = alloc - ((uintptr_t)alloc & (xbt_pagesize - 1)) + xbt_pagesize;
+    *((void **)stack - 1) = alloc;
+#elif !defined(_XBT_WIN32)
+    if (posix_memalign(&stack, xbt_pagesize, size) != 0)
+      xbt_die("Failed to allocate stack.");
+#else
+    stack = _aligned_malloc(size, xbt_pagesize);
+#endif
+
+#ifndef _XBT_WIN32
+    if (mprotect(stack, smx_context_guard_size, PROT_NONE) == -1) {
+      XBT_WARN("Failed to protect stack: %s", strerror(errno));
+      /* That's not fatal, pursue anyway. */
+    }
+#endif
+    stack = (char *)stack + smx_context_guard_size;
+  } else {
+    stack = xbt_malloc0(smx_context_stack_size);
+  }
+
+#ifdef HAVE_VALGRIND_VALGRIND_H
+  unsigned int valgrind_stack_id =
+    VALGRIND_STACK_REGISTER(stack, (char *)stack + smx_context_stack_size);
+  memcpy((char *)stack + smx_context_usable_stack_size, &valgrind_stack_id,
+         sizeof valgrind_stack_id);
+#endif
+
+  return stack;
 }
 
 void SIMIX_context_stack_delete(void *stack)
 {
+  if (!stack)
+    return;
+
+#ifdef HAVE_VALGRIND_VALGRIND_H
+  unsigned int valgrind_stack_id;
+  memcpy(&valgrind_stack_id, (char *)stack + smx_context_usable_stack_size,
+         sizeof valgrind_stack_id);
+  VALGRIND_STACK_DEREGISTER(valgrind_stack_id);
+#endif
+
+#ifndef WIN32
+  if (smx_context_guard_size > 0 && !MC_is_active()) {
+    stack = (char *)stack - smx_context_guard_size;
+    if (mprotect(stack, smx_context_guard_size,
+                 PROT_READ | PROT_WRITE | PROT_EXEC) == -1) {
+      XBT_WARN("Failed to remove page protection: %s", strerror(errno));
+      /* try to pursue anyway */
+    }
+#ifdef HAVE_MC
+    /* Retrieve the saved pointer.  See SIMIX_context_stack_new above. */
+    stack = *((void **)stack - 1);
+#endif
+  }
+#endif
+
   xbt_free(stack);
 }