diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 0e613e7..6edc1d3 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -43,3 +43,25 @@ void arch_task_cache_init(void)
 				  __alignof__(union thread_xstate),
 				  SLAB_PANIC, NULL);
 }
+
+
+/*
+ * Used to check if we can recurse without risking stack overflow
+ * Rules are :
+ *   32 bits and 4K stacks (separate irq stacks) : can use up to 25% of stack
+ *   64 bits, 8K stacks (separate irq stacks)    : can use up to 25% of stack
+ *   32 bits and 8K stacks (no irq stacks)       : can use up to 50% of stack
+ */
+#if defined(CONFIG_4KSTACKS) || defined(CONFIG_X86_64)
+# define STACK_RECURSE_LIMIT (THREAD_SIZE/4)
+#else
+# define STACK_RECURSE_LIMIT (THREAD_SIZE/2)
+#endif
+
+int arch_stack_can_recurse()
+{
+	unsigned long offset_stack = current_stack_pointer & (THREAD_SIZE - 1);
+	unsigned long avail_stack = offset_stack - sizeof(struct thread_info);
+
+	return avail_stack >= STACK_RECURSE_LIMIT;
+}
diff --git a/include/asm-x86/thread_info_64.h b/include/asm-x86/thread_info_64.h
index f23fefc..9a913c4 100644
--- a/include/asm-x86/thread_info_64.h
+++ b/include/asm-x86/thread_info_64.h
@@ -60,6 +60,9 @@ struct thread_info {
 #define init_thread_info	(init_thread_union.thread_info)
 #define init_stack		(init_thread_union.stack)
 
+/* how to get the current stack pointer from C */
+register unsigned long current_stack_pointer asm("rsp") __used;
+
 static inline struct thread_info *current_thread_info(void)
 {
 	struct thread_info *ti;
diff --git a/include/linux/sched.h b/include/linux/sched.h
index ca720f0..445b8da 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1600,6 +1600,8 @@ union thread_union {
 	unsigned long stack[THREAD_SIZE/sizeof(long)];
 };
 
+extern int arch_stack_can_recurse(void);
+
 #ifndef __HAVE_ARCH_KSTACK_END
 static inline int kstack_end(void *addr)
 {
diff --git a/kernel/fork.c b/kernel/fork.c
index a19df75..cd5d1e1 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -136,6 +136,11 @@ void __attribute__((weak)) arch_task_cache_init(void)
 {
 }
 
+int __attribute__((weak)) arch_stack_can_recurse(void)
+{
+	return 0;
+}
+
 void __init fork_init(unsigned long mempages)
 {
 #ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR