From 181f817eaaca4c1f8a9c265d339d2b96de8b245d Mon Sep 17 00:00:00 2001
From: =?utf8?q?Uwe=20Kleine-K=C3=B6nig?= <u.kleine-koenig@pengutronix.de>
Date: Thu, 13 Aug 2009 20:38:16 +0200
Subject: [PATCH] [ARM] support tracing when using newer compilers
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Since gcc 4.4 the name and calling convention for function profiling
on ARM changed. With this patch both types are supported.
See http://sourceware.org/ml/libc-ports/2008-04/msg00009.html for some
details.
Lightly-Tested-by: Anand Gadiyar <gadiyar@ti.com>
Tested-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
arch/arm/include/asm/ftrace.h | 1 +
arch/arm/kernel/armksyms.c | 1 +
arch/arm/kernel/entry-common.S | 19 +++++++++++++++++++
3 files changed, 21 insertions(+)
diff --git a/arch/arm/include/asm/ftrace.h b/arch/arm/include/asm/ftrace.h
index 39c8bc1a006a..0d4c478e01b6 100644
--- a/arch/arm/include/asm/ftrace.h
+++ b/arch/arm/include/asm/ftrace.h
@@ -7,6 +7,7 @@
#ifndef __ASSEMBLY__
extern void mcount(void);
+extern void __gnu_mcount_nc(void);
#endif
#endif
diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c
index 531e1860e546..0e627705f746 100644
--- a/arch/arm/kernel/armksyms.c
+++ b/arch/arm/kernel/armksyms.c
@@ -186,4 +186,5 @@ EXPORT_SYMBOL(_find_next_bit_be);
#ifdef CONFIG_FUNCTION_TRACER
EXPORT_SYMBOL(mcount);
+EXPORT_SYMBOL(__gnu_mcount_nc);
#endif
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 366e5097a41a..99208728d48f 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -132,6 +132,25 @@ ftrace_call:
#else
+ENTRY(__gnu_mcount_nc)
+ stmdb sp!, {r0-r3, lr}
+ ldr r0, =ftrace_trace_function
+ ldr r2, [r0]
+ adr r0, ftrace_stub
+ cmp r0, r2
+ bne gnu_trace
+ ldmia sp!, {r0-r3, ip, lr}
+ bx ip
+
+gnu_trace:
+ ldr r1, [sp, #20] @ lr of instrumented routine
+ mov r0, lr
+ sub r0, r0, #MCOUNT_INSN_SIZE
+ mov lr, pc
+ mov pc, r2
+ ldmia sp!, {r0-r3, ip, lr}
+ bx ip
+
ENTRY(mcount)
stmdb sp!, {r0-r3, lr}
ldr r0, =ftrace_trace_function
--
2.34.1