[PATCH] make CALLER_ADDRx overwriteable

Uwe Kleine-König
2009-02-26T22:11:47Z

The current definition of CALLER_ADDRx isn't suitable for all platforms.
E.g. for ARM __builtin_return_address(N) doesn't work for N > 0 and
AFAIK for powerpc there are no frame pointers needed to have a working
__builtin_return_address. This patch allows defining the CALLER_ADDRx
macros in <asm/ftrace.h> and let these take precedence.

Because now <asm/ftrace.h> is included unconditionally in
<linux/ftrace.h> all archs that don't already had this include get an
empty one for free.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
--
Hello,

as Steven suggested I added empty <asm/ftrace.h> files since the last
version of this patch.

@Ingo: I assume this update doesn't invalidate your Acked-by:, but to
be on the save side I didn't add it here.

Best regards
Uwe

---
arch/alpha/include/asm/ftrace.h | 1 +
arch/avr32/include/asm/ftrace.h | 1 +
arch/blackfin/include/asm/ftrace.h | 1 +
arch/cris/include/asm/ftrace.h | 1 +
arch/h8300/include/asm/ftrace.h | 1 +
arch/m68k/include/asm/ftrace.h | 1 +
arch/mips/include/asm/ftrace.h | 1 +
arch/parisc/include/asm/ftrace.h | 1 +
arch/um/include/asm/ftrace.h | 1 +
arch/xtensa/include/asm/ftrace.h | 1 +
include/asm-frv/ftrace.h | 1 +
include/asm-m32r/ftrace.h | 1 +
include/asm-mn10300/ftrace.h | 1 +
include/linux/ftrace.h | 41 ++++++++++++++++++-----------------
14 files changed, 34 insertions(+), 20 deletions(-)

diff --git a/arch/alpha/include/asm/ftrace.h b/arch/alpha/include/asm/ftrace.h
new file mode 100644
index 0000000..40a8c17
--- /dev/null
+++ b/arch/alpha/include/asm/ftrace.h
@@ -0,0 +1 @@
+/* empty */
diff --git a/arch/avr32/include/asm/ftrace.h b/arch/avr32/include/asm/ftrace.h
new file mode 100644
index 0000000..40a8c17
--- /dev/null
+++ b/arch/avr32/include/asm/ftrace.h
@@ -0,0 +1 @@
+/* empty */
diff --git a/arch/blackfin/include/asm/ftrace.h b/arch/blackfin/include/asm/ftrace.h
new file mode 100644
index 0000000..40a8c17
--- /dev/null
+++ b/arch/blackfin/include/asm/ftrace.h
@@ -0,0 +1 @@
+/* empty */
diff --git a/arch/cris/include/asm/ftrace.h b/arch/cris/include/asm/ftrace.h
new file mode 100644
index 0000000..40a8c17
--- /dev/null
+++ b/arch/cris/include/asm/ftrace.h
@@ -0,0 +1 @@
+/* empty */
diff --git a/arch/h8300/include/asm/ftrace.h b/arch/h8300/include/asm/ftrace.h
new file mode 100644
index 0000000..40a8c17
--- /dev/null
+++ b/arch/h8300/include/asm/ftrace.h
@@ -0,0 +1 @@
+/* empty */
diff --git a/arch/m68k/include/asm/ftrace.h b/arch/m68k/include/asm/ftrace.h
new file mode 100644
index 0000000..40a8c17
--- /dev/null
+++ b/arch/m68k/include/asm/ftrace.h
@@ -0,0 +1 @@
+/* empty */
diff --git a/arch/mips/include/asm/ftrace.h b/arch/mips/include/asm/ftrace.h
new file mode 100644
index 0000000..40a8c17
--- /dev/null
+++ b/arch/mips/include/asm/ftrace.h
@@ -0,0 +1 @@
+/* empty */
diff --git a/arch/parisc/include/asm/ftrace.h b/arch/parisc/include/asm/ftrace.h
new file mode 100644
index 0000000..40a8c17
--- /dev/null
+++ b/arch/parisc/include/asm/ftrace.h
@@ -0,0 +1 @@
+/* empty */
diff --git a/arch/um/include/asm/ftrace.h b/arch/um/include/asm/ftrace.h
new file mode 100644
index 0000000..40a8c17
--- /dev/null
+++ b/arch/um/include/asm/ftrace.h
@@ -0,0 +1 @@
+/* empty */
diff --git a/arch/xtensa/include/asm/ftrace.h b/arch/xtensa/include/asm/ftrace.h
new file mode 100644
index 0000000..40a8c17
--- /dev/null
+++ b/arch/xtensa/include/asm/ftrace.h
@@ -0,0 +1 @@
+/* empty */
diff --git a/include/asm-frv/ftrace.h b/include/asm-frv/ftrace.h
new file mode 100644
index 0000000..40a8c17
--- /dev/null
+++ b/include/asm-frv/ftrace.h
@@ -0,0 +1 @@
+/* empty */
diff --git a/include/asm-m32r/ftrace.h b/include/asm-m32r/ftrace.h
new file mode 100644
index 0000000..40a8c17
--- /dev/null
+++ b/include/asm-m32r/ftrace.h
@@ -0,0 +1 @@
+/* empty */
diff --git a/include/asm-mn10300/ftrace.h b/include/asm-mn10300/ftrace.h
new file mode 100644
index 0000000..40a8c17
--- /dev/null
+++ b/include/asm-mn10300/ftrace.h
@@ -0,0 +1 @@
+/* empty */
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 847bb3c..9d8d362 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -11,6 +11,8 @@
#include <linux/bitops.h>
#include <linux/sched.h>

+#include <asm/ftrace.h>
+
#ifdef CONFIG_FUNCTION_TRACER

extern int ftrace_enabled;
@@ -103,8 +105,6 @@ struct ftrace_func_command {
};

#ifdef CONFIG_DYNAMIC_FTRACE
-/* asm/ftrace.h must be defined for archs supporting dynamic ftrace */
-#include <asm/ftrace.h>

int ftrace_arch_code_modify_prepare(void);
int ftrace_arch_code_modify_post_process(void);
@@ -282,24 +282,25 @@ static inline void __ftrace_enabled_restore(int enabled)
#endif
}

-#ifdef CONFIG_FRAME_POINTER
-/* TODO: need to fix this for ARM */
-# define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
-# define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
-# define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
-# define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
-# define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
-# define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
-# define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
-#else
-# define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
-# define CALLER_ADDR1 0UL
-# define CALLER_ADDR2 0UL
-# define CALLER_ADDR3 0UL
-# define CALLER_ADDR4 0UL
-# define CALLER_ADDR5 0UL
-# define CALLER_ADDR6 0UL
-#endif
+#ifndef CALLER_ADDR0
+# ifdef CONFIG_FRAME_POINTER
+# define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
+# define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
+# define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
+# define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
+# define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
+# define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
+# define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
+# else
+# define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
+# define CALLER_ADDR1 0UL
+# define CALLER_ADDR2 0UL
+# define CALLER_ADDR3 0UL
+# define CALLER_ADDR4 0UL
+# define CALLER_ADDR5 0UL
+# define CALLER_ADDR6 0UL
+# endif
+#endif /* ifndef CALLER_ADDR0 */

#ifdef CONFIG_IRQSOFF_TRACER
extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
--
tg: (db50eec..) t/ftrace/make_CALLER_ADDRx_overwriteable (depends on: tip/master)