1 files changed, 31 insertions, 34 deletions

diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 70139d9d2e01..cace6e8d7cc7 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -25,6 +25,7 @@
 #include <linux/memory.h>
 #include <linux/vmalloc.h>
 #include <linux/set_memory.h>
+#include <linux/execmem.h>
 
 #include <trace/syscall.h>
 
@@ -260,25 +261,14 @@ void arch_ftrace_update_code(int command)
 /* Currently only x86_64 supports dynamic trampolines */
 #ifdef CONFIG_X86_64
 
-#ifdef CONFIG_MODULES
-#include <linux/moduleloader.h>
-/* Module allocation simplifies allocating memory for code */
 static inline void *alloc_tramp(unsigned long size)
 {
-	return module_alloc(size);
+	return execmem_alloc(EXECMEM_FTRACE, size);
 }
 static inline void tramp_free(void *tramp)
 {
-	module_memfree(tramp);
+	execmem_free(tramp);
 }
-#else
-/* Trampolines can only be created if modules are supported */
-static inline void *alloc_tramp(unsigned long size)
-{
-	return NULL;
-}
-static inline void tramp_free(void *tramp) { }
-#endif
 
 /* Defined as markers to the end of the ftrace default trampolines */
 extern void ftrace_regs_caller_end(void);
@@ -615,16 +605,8 @@ int ftrace_disable_ftrace_graph_caller(void)
 }
 #endif /* CONFIG_DYNAMIC_FTRACE && !CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */
 
-/*
- * Hook the return address and push it in the stack of return addrs
- * in current thread info.
- */
-void prepare_ftrace_return(unsigned long ip, unsigned long *parent,
-			   unsigned long frame_pointer)
+static inline bool skip_ftrace_return(void)
 {
-	unsigned long return_hooker = (unsigned long)&return_to_handler;
-	int bit;
-
 	/*
 	 * When resuming from suspend-to-ram, this function can be indirectly
 	 * called from early CPU startup code while the CPU is in real mode,
@@ -634,33 +616,48 @@ void prepare_ftrace_return(unsigned long ip, unsigned long *parent,
 	 * This check isn't as accurate as virt_addr_valid(), but it should be
 	 * good enough for this purpose, and it's fast.
 	 */
-	if (unlikely((long)__builtin_frame_address(0) >= 0))
-		return;
+	if ((long)__builtin_frame_address(0) >= 0)
+		return true;
 
-	if (unlikely(ftrace_graph_is_dead()))
-		return;
+	if (ftrace_graph_is_dead())
+		return true;
 
-	if (unlikely(atomic_read(&current->tracing_graph_pause)))
-		return;
+	if (atomic_read(&current->tracing_graph_pause))
+		return true;
+	return false;
+}
 
-	bit = ftrace_test_recursion_trylock(ip, *parent);
-	if (bit < 0)
+/*
+ * Hook the return address and push it in the stack of return addrs
+ * in current thread info.
+ */
+void prepare_ftrace_return(unsigned long ip, unsigned long *parent,
+			   unsigned long frame_pointer)
+{
+	unsigned long return_hooker = (unsigned long)&return_to_handler;
+
+	if (unlikely(skip_ftrace_return()))
 		return;
 
 	if (!function_graph_enter(*parent, ip, frame_pointer, parent))
 		*parent = return_hooker;
-
-	ftrace_test_recursion_unlock(bit);
 }
 
 #ifdef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
 void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
 		       struct ftrace_ops *op, struct ftrace_regs *fregs)
 {
-	struct pt_regs *regs = &fregs->regs;
+	struct pt_regs *regs = &arch_ftrace_regs(fregs)->regs;
 	unsigned long *stack = (unsigned long *)kernel_stack_pointer(regs);
+	unsigned long return_hooker = (unsigned long)&return_to_handler;
+	unsigned long *parent = (unsigned long *)stack;
 
-	prepare_ftrace_return(ip, (unsigned long *)stack, 0);
+	if (unlikely(skip_ftrace_return()))
+		return;
+
+
+	if (!function_graph_enter_regs(*parent, ip, 0, parent, fregs))
+		*parent = return_hooker;
 }
 #endif