6 files changed, 154 insertions, 10 deletions

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index ccdd8de3c558..e122d241f17d 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -111,6 +111,7 @@ config PPC
         select HAVE_FTRACE_MCOUNT_RECORD
         select HAVE_DYNAMIC_FTRACE
         select HAVE_FUNCTION_TRACER
+        select HAVE_FUNCTION_GRAPH_TRACER if !DYNAMIC_FTRACE && PPC64
         select ARCH_WANT_OPTIONAL_GPIOLIB
         select HAVE_IDE
         select HAVE_IOREMAP_PROT
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)