7 files changed, 60 insertions, 73 deletions

diff --git a/arch/sh/Kconfig.debug b/arch/sh/Kconfig.debug
index 52a132c24aab..b440fd936714 100644
--- a/arch/sh/Kconfig.debug
+++ b/arch/sh/Kconfig.debug
@@ -61,12 +61,14 @@ config EARLY_PRINTK
           select both the EARLY_SCIF_CONSOLE and SH_STANDARD_BIOS, using
           the kernel command line option to toggle back and forth.
 
-config DEBUG_STACKOVERFLOW
+config STACK_DEBUG
         bool "Check for stack overflows"
         depends on DEBUG_KERNEL && SUPERH32
         help
           This option will cause messages to be printed if free stack space
-          drops below a certain limit.
+          drops below a certain limit. Saying Y here will add overhead to
+          every function call and will therefore incur a major
+          performance hit. Most users should say N.
 
 config DEBUG_STACK_USAGE
         bool "Stack utilization instrumentation"
@@ -123,15 +125,9 @@ config SH64_SR_WATCH
         bool "Debug: set SR.WATCH to enable hardware watchpoints and trace"
         depends on SUPERH64
 
-config STACK_DEBUG
-        bool "Enable diagnostic checks of the kernel stack"
-        depends on FUNCTION_TRACER
-        select DEBUG_STACKOVERFLOW
-        default n
-        help
-          This option allows checks to be performed on the kernel stack
-          at runtime. Saying Y here will add overhead to every function
-          call and will therefore incur a major performance hit. Most
-          users should say N.
+config MCOUNT
+        def_bool y
+        depends on SUPERH32
+        depends on STACK_DEBUG || FUNCTION_TRACER
 
 endmenu
diff --git a/arch/sh/Makefile b/arch/sh/Makefile
index 75d049b03f7e..52c34bf56962 100644
--- a/arch/sh/Makefile
+++ b/arch/sh/Makefile
@@ -186,6 +186,10 @@ KBUILD_CFLAGS		+= -pipe $(cflags-y)
 KBUILD_CPPFLAGS         += $(cflags-y)
 KBUILD_AFLAGS           += $(cflags-y)
 
+ifeq ($(CONFIG_MCOUNT),y)
+  KBUILD_CFLAGS += -pg
+endif
+
 libs-$(CONFIG_SUPERH32)         := arch/sh/lib/ $(libs-y)
 libs-$(CONFIG_SUPERH64)         := arch/sh/lib64/ $(libs-y)
 
diff --git a/arch/sh/boot/compressed/Makefile b/arch/sh/boot/compressed/Makefile
index 3324019e207e..59e2937caa2f 100644
--- a/arch/sh/boot/compressed/Makefile
+++ b/arch/sh/boot/compressed/Makefile
@@ -24,7 +24,7 @@ IMAGE_OFFSET	:= $(shell /bin/bash -c 'printf "0x%08x" \
 
 LIBGCC  := $(shell $(CC) $(KBUILD_CFLAGS) -print-libgcc-file-name)
 
-ifeq ($(CONFIG_FUNCTION_TRACER),y)
+ifeq ($(CONFIG_MCOUNT),y)
 ORIG_CFLAGS := $(KBUILD_CFLAGS)
 KBUILD_CFLAGS = $(subst -pg, , $(ORIG_CFLAGS))
 endif
diff --git a/arch/sh/kernel/irq.c b/arch/sh/kernel/irq.c
index 3d09062f4682..278c68c60488 100644
--- a/arch/sh/kernel/irq.c
+++ b/arch/sh/kernel/irq.c
@@ -114,23 +114,6 @@ asmlinkage int do_IRQ(unsigned int irq, struct pt_regs *regs)
 #endif
 
         irq_enter();
-
-#ifdef CONFIG_DEBUG_STACKOVERFLOW
-        /* Debugging check for stack overflow: is there less than 1KB free? */
-        {
-                long sp;
-
-                __asm__ __volatile__ ("and r15, %0" :
-                                        "=r" (sp) : "0" (THREAD_SIZE - 1));
-
-                if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
-                        printk("do_IRQ: stack overflow: %ld\n",
-                               sp - sizeof(struct thread_info));
-                        dump_stack();
-                }
-        }
-#endif
-
         irq = irq_demux(intc_evt2irq(irq));
 
 #ifdef CONFIG_IRQSTACKS
diff --git a/arch/sh/kernel/sh_ksyms_32.c b/arch/sh/kernel/sh_ksyms_32.c
index fcc5de31f83b..cec610888e28 100644
--- a/arch/sh/kernel/sh_ksyms_32.c
+++ b/arch/sh/kernel/sh_ksyms_32.c
@@ -106,8 +106,8 @@ EXPORT_SYMBOL(flush_dcache_page);
 EXPORT_SYMBOL(clear_user_page);
 #endif
 
-#ifdef CONFIG_FUNCTION_TRACER
-EXPORT_SYMBOL(mcount);
+#ifdef CONFIG_MCOUNT
+DECLARE_EXPORT(mcount);
 #endif
 EXPORT_SYMBOL(csum_partial);
 EXPORT_SYMBOL(csum_partial_copy_generic);
diff --git a/arch/sh/lib/Makefile b/arch/sh/lib/Makefile
index 19328d90a2d1..c2b28d8b2dd1 100644
--- a/arch/sh/lib/Makefile
+++ b/arch/sh/lib/Makefile
@@ -24,8 +24,7 @@ memcpy-y			:= memcpy.o
 memcpy-$(CONFIG_CPU_SH4)        := memcpy-sh4.o
 
 lib-$(CONFIG_MMU)               += copy_page.o clear_page.o
-lib-$(CONFIG_FUNCTION_TRACER)   += mcount.o
-lib-$(CONFIG_FUNCTION_GRAPH_TRACER) += mcount.o
+lib-$(CONFIG_MCOUNT)            += mcount.o
 lib-y                           += $(memcpy-y) $(udivsi3-y)
 
 EXTRA_CFLAGS += -Werror
diff --git a/arch/sh/lib/mcount.S b/arch/sh/lib/mcount.S
index bd3ec648becc..84a57761f17e 100644
--- 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
@@ -192,6 +195,10 @@ ftrace_call:
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 #endif /* CONFIG_DYNAMIC_FTRACE */
 
+        .align 2
+.Lfunction_trace_stop:
+        .long   function_trace_stop
+
 /*
  * NOTE: From here on the locations of the .Lftrace_stub label and
  * ftrace_stub itself are fixed. Adding additional data here will skew
@@ -199,7 +206,6 @@ ftrace_call:
  * Place new labels either after the ftrace_stub body, or before
  * ftrace_caller. You have been warned.
  */
-        .align 2
 .Lftrace_stub:
         .long   ftrace_stub
 
@@ -208,40 +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
-.Lfunction_trace_stop:
-        .long   function_trace_stop
-.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:
@@ -303,3 +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 */