[ARM] support tracing when using newer compilers
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>
diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c
index 531e186..0e62770 100644
--- a/arch/arm/kernel/armksyms.c
+++ b/arch/arm/kernel/armksyms.c
@@ -186,4 +186,5 @@
#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 366e509..9920872 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -132,6 +132,25 @@
#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