sh: Fix up stack overflow check with ftrace disabled.

Presently the STACK_CHECK() code is called in to multiple times, although
it's only necessary from the mcount entry. The code still attempts to
treat the nop case as an ftrace path resulting in superfluous code flow
for the case where ftrace is disabled. And finally, this also fixes up
references to a few undefined symbols when FUNCTION_TRACER=n.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

diff --git a/arch/sh/lib/mcount.S b/arch/sh/lib/mcount.S
index 9e397aa..84a5776 100644 (file)
--- a/arch/sh/lib/mcount.S
+++ b/arch/sh/lib/mcount.S
@@ -1,7 +1,7 @@
 /*
  * arch/sh/lib/mcount.S
  *
- *  Copyright (C) 2008  Paul Mundt
+ *  Copyright (C) 2008, 2009  Paul Mundt
  *  Copyright (C) 2008, 2009  Matt Fleming
  *
  * This file is subject to the terms and conditions of the GNU General Public
@@ -86,13 +86,18 @@
        .type   mcount,@function
 _mcount:
 mcount:
+       STACK_CHECK()
+
+#ifndef CONFIG_FUNCTION_TRACER
+       rts
+        nop
+#else
 #ifndef CONFIG_DYNAMIC_FTRACE
        mov.l   .Lfunction_trace_stop, r0
        mov.l   @r0, r0
        tst     r0, r0
        bf      ftrace_stub
 #endif
-       STACK_CHECK()
 
        MCOUNT_ENTER()
 
@@ -174,8 +179,6 @@ ftrace_caller:
        tst     r0, r0
        bf      ftrace_stub
 
-       STACK_CHECK()
-
        MCOUNT_ENTER()
 
        .globl ftrace_call
@@ -211,38 +214,6 @@ ftrace_stub:
        rts
         nop
 
-#ifdef CONFIG_STACK_DEBUG
-       .globl  stack_panic
-stack_panic:
-       mov.l   .Ldump_stack, r0
-       jsr     @r0
-        nop
-
-       mov.l   .Lpanic, r0
-       jsr     @r0
-        mov.l  .Lpanic_s, r4
-
-       rts
-        nop
-
-       .align 2
-.L_ebss:
-       .long   _ebss
-.L_init_thread_union:
-       .long   init_thread_union
-.Lpanic:
-       .long   panic
-.Lpanic_s:
-       .long   .Lpanic_str
-.Ldump_stack:
-       .long   dump_stack
-
-       .section        .rodata
-       .align 2
-.Lpanic_str:
-       .string "Stack error"
-#endif /* CONFIG_STACK_DEBUG */
-
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
        .globl  ftrace_graph_caller
 ftrace_graph_caller:
@@ -304,3 +275,36 @@ return_to_handler:
 .Lftrace_return_to_handler:
        .long   ftrace_return_to_handler
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+#endif /* CONFIG_FUNCTION_TRACER */
+
+#ifdef CONFIG_STACK_DEBUG
+       .globl  stack_panic
+stack_panic:
+       mov.l   .Ldump_stack, r0
+       jsr     @r0
+        nop
+
+       mov.l   .Lpanic, r0
+       jsr     @r0
+        mov.l  .Lpanic_s, r4
+
+       rts
+        nop
+
+       .align 2
+.L_ebss:
+       .long   _ebss
+.L_init_thread_union:
+       .long   init_thread_union
+.Lpanic:
+       .long   panic
+.Lpanic_s:
+       .long   .Lpanic_str
+.Ldump_stack:
+       .long   dump_stack
+
+       .section        .rodata
+       .align 2
+.Lpanic_str:
+       .string "Stack error"
+#endif /* CONFIG_STACK_DEBUG */