5 files changed, 153 insertions, 10 deletions

diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index d15992119085..583ba6493a62 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -18,12 +18,10 @@ CFLAGS_REMOVE_cputable.o = -pg -mno-sched-epilog
 CFLAGS_REMOVE_prom_init.o = -pg -mno-sched-epilog
 CFLAGS_REMOVE_btext.o = -pg -mno-sched-epilog
 CFLAGS_REMOVE_prom.o = -pg -mno-sched-epilog
-
-ifdef CONFIG_DYNAMIC_FTRACE
-# dynamic ftrace setup.
+# do not trace tracer code
 CFLAGS_REMOVE_ftrace.o = -pg -mno-sched-epilog
-endif
-
+# timers used by tracing
+CFLAGS_REMOVE_time.o = -pg -mno-sched-epilog
 endif
 
 obj-y				:= cputable.o ptrace.o syscalls.o \
@@ -95,6 +93,7 @@ obj-$(CONFIG_AUDIT)		+= audit.o
 obj64-$(CONFIG_AUDIT)		+= compat_audit.o
 
 obj-$(CONFIG_DYNAMIC_FTRACE)	+= ftrace.o
+obj-$(CONFIG_FUNCTION_GRAPH_TRACER)	+= ftrace.o
 
 obj-$(CONFIG_8XX_MINIMAL_FPEMU) += softemu8xx.o
 
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 383ed6eb0085..a32699e74c3c 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -931,13 +931,65 @@ _GLOBAL(_mcount)
 	ld	r5,0(r5)
 	mtctr	r5
 	bctrl
-
 	nop
+
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+	b	ftrace_graph_caller
+#endif
 	ld	r0, 128(r1)
 	mtlr	r0
 	addi	r1, r1, 112
 _GLOBAL(ftrace_stub)
 	blr
 
-#endif
-#endif
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ftrace_graph_caller:
+	/* load r4 with local address */
+	ld	r4, 128(r1)
+	subi	r4, r4, MCOUNT_INSN_SIZE
+
+	/* get the parent address */
+	ld	r11, 112(r1)
+	addi	r3, r11, 16
+
+	bl	.prepare_ftrace_return
+	nop
+
+	ld	r0, 128(r1)
+	mtlr	r0
+	addi	r1, r1, 112
+	blr
+
+_GLOBAL(return_to_handler)
+	/* need to save return values */
+	std	r4,  -32(r1)
+	std	r3,  -24(r1)
+	/* save TOC */
+	std	r2,  -16(r1)
+	std	r31, -8(r1)
+	mr	r31, r1
+	stdu	r1, -112(r1)
+
+	/* update the TOC */
+	LOAD_REG_IMMEDIATE(r4,ftrace_return_to_handler)
+	ld	r2, 8(r4)
+
+	bl	.ftrace_return_to_handler
+	nop
+
+	/* return value has real return address */
+	mtlr	r3
+
+	ld	r1, 0(r1)
+	ld	r4,  -32(r1)
+	ld	r3,  -24(r1)
+	ld	r2,  -16(r1)
+	ld	r31, -8(r1)
+
+	/* Jump back to real return address */
+	blr
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+#endif /* CONFIG_FUNCTION_TRACER */
diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c
index 4112175183d3..c9b1547f65a5 100644
--- a/arch/powerpc/kernel/ftrace.c
+++ b/arch/powerpc/kernel/ftrace.c
@@ -5,6 +5,9 @@
  *
  * Thanks goes out to P.A. Semi, Inc for supplying me with a PPC64 box.
  *
+ * Added function graph tracer code, taken from x86 that was written
+ * by Frederic Weisbecker, and ported to PPC by Steven Rostedt.
+ *
  */
 
 #include <linux/spinlock.h>
@@ -20,8 +23,6 @@
 #include <asm/code-patching.h>
 #include <asm/ftrace.h>
 
-static unsigned int ftrace_nop = PPC_NOP_INSTR;
-
 #ifdef CONFIG_PPC32
 # define GET_ADDR(addr) addr
 #else
@@ -29,6 +30,8 @@ static unsigned int ftrace_nop = PPC_NOP_INSTR;
 # define GET_ADDR(addr) (*(unsigned long *)addr)
 #endif
 
+#ifdef CONFIG_DYNAMIC_FTRACE
+static unsigned int ftrace_nop = PPC_NOP_INSTR;
 
 static unsigned int ftrace_calc_offset(long ip, long addr)
 {
@@ -525,3 +528,75 @@ int __init ftrace_dyn_arch_init(void *data)
 
 	return 0;
 }
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+
+/*
+ * Hook the return address and push it in the stack of return addrs
+ * in current thread info.
+ */
+void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
+{
+	unsigned long old;
+	unsigned long long calltime;
+	int faulted;
+	struct ftrace_graph_ent trace;
+	unsigned long return_hooker = (unsigned long)
+				&return_to_handler;
+
+	if (unlikely(atomic_read(&current->tracing_graph_pause)))
+		return;
+
+	return_hooker = GET_ADDR(return_hooker);
+
+	/*
+	 * Protect against fault, even if it shouldn't
+	 * happen. This tool is too much intrusive to
+	 * ignore such a protection.
+	 */
+	asm volatile(
+		"1: " PPC_LL "%[old], 0(%[parent])\n"
+		"2: " PPC_STL "%[return_hooker], 0(%[parent])\n"
+		"   li %[faulted], 0\n"
+		"3:"
+
+		".section .fixup, \"ax\"\n"
+		"4: li %[faulted], 1\n"
+		"   b 3b\n"
+		".previous\n"
+
+		".section __ex_table,\"a\"\n"
+			PPC_LONG_ALIGN "\n"
+			PPC_LONG "1b,4b\n"
+			PPC_LONG "2b,4b\n"
+		".previous"
+
+		: [old] "=r" (old), [faulted] "=r" (faulted)
+		: [parent] "r" (parent), [return_hooker] "r" (return_hooker)
+		: "memory"
+	);
+
+	if (unlikely(faulted)) {
+		ftrace_graph_stop();
+		WARN_ON(1);
+		return;
+	}
+
+	calltime = cpu_clock(raw_smp_processor_id());
+
+	if (ftrace_push_return_trace(old, calltime,
+				self_addr, &trace.depth) == -EBUSY) {
+		*parent = old;
+		return;
+	}
+
+	trace.func = self_addr;
+
+	/* Only trace if the calling function expects to */
+	if (!ftrace_graph_entry(&trace)) {
+		current->curr_ret_stack--;
+		*parent = old;
+	}
+}
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index fb7049c054c0..8ede428e76c0 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -33,6 +33,7 @@
 #include <linux/mqueue.h>
 #include <linux/hardirq.h>
 #include <linux/utsname.h>
+#include <linux/ftrace.h>
 #include <linux/kernel_stat.h>
 
 #include <asm/pgtable.h>
@@ -1008,6 +1009,14 @@ void show_stack(struct task_struct *tsk, unsigned long *stack)
 	unsigned long sp, ip, lr, newsp;
 	int count = 0;
 	int firstframe = 1;
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+	int curr_frame = current->curr_ret_stack;
+	extern void return_to_handler(void);
+	unsigned long addr = (unsigned long)return_to_handler;
+#ifdef CONFIG_PPC64
+	addr = *(unsigned long*)addr;
+#endif
+#endif
 
 	sp = (unsigned long) stack;
 	if (tsk == NULL)
@@ -1030,6 +1039,13 @@ void show_stack(struct task_struct *tsk, unsigned long *stack)
 		ip = stack[STACK_FRAME_LR_SAVE];
 		if (!firstframe || ip != lr) {
 			printk("["REG"] ["REG"] %pS", sp, ip, (void *)ip);
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+			if (ip == addr && curr_frame >= 0) {
+				printk(" (%pS)",
+				       (void *)current->ret_stack[curr_frame].ret);
+				curr_frame--;
+			}
+#endif
 			if (firstframe)
 				printk(" (unreliable)");
 			printk("\n");
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 161b9b9691f0..895af44bf1f4 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -58,6 +58,7 @@ SECTIONS
 		SCHED_TEXT
 		LOCK_TEXT
 		KPROBES_TEXT
+		IRQENTRY_TEXT
 
 #ifdef CONFIG_PPC32
 		*(.got1)