MIPS: Tracing: Add dynamic function graph tracer for MIPS

This patch make function graph tracer work with dynamic function tracer.

To share the source code of dynamic function tracer(MCOUNT_SAVE_REGS),
and avoid restoring the whole saved registers, we need to restore the ra
register from the stack.

(NOTE: This not work with 32bit! need to ensure why!)

Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Nicholas Mc Guire <der.herr@hofr.at>
Cc: zhangfx@lemote.com
Cc: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/678/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Wu Zhangjin
2009-11-20 20:34:35 +08:00
committed by Ralf Baechle
parent 29c5d3462f
commit e17ff5fec6
2 changed files with 33 additions and 2 deletions

View File

@@ -77,6 +77,13 @@ ftrace_call:
nop /* a placeholder for the call to a real tracing function */
move a1, AT /* arg2: the caller's next ip, parent */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
.globl ftrace_graph_call
ftrace_graph_call:
nop
nop
#endif
MCOUNT_RESTORE_REGS
.globl ftrace_stub
ftrace_stub:
@@ -124,10 +131,13 @@ ftrace_stub:
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
NESTED(ftrace_graph_caller, PT_SIZE, ra)
#ifdef CONFIG_DYNAMIC_FTRACE
PTR_L a1, PT_R31(sp) /* load the original ra from the stack */
#else
MCOUNT_SAVE_REGS
PTR_LA a0, PT_R1(sp) /* arg1: &AT -> a0 */
move a1, ra /* arg2: next ip, selfaddr */
#endif
PTR_LA a0, PT_R1(sp) /* arg1: &AT -> a0 */
jal prepare_ftrace_return
move a2, fp /* arg3: frame pointer */