diff options
| author | Tim Bird <tim.bird@am.sony.com> | 2010-10-09 22:24:38 +0530 |
|---|---|---|
| committer | Rabin Vincent <rabin@rab.in> | 2010-11-19 21:43:27 +0530 |
| commit | 376cfa8730c08c0394d0aa1d4a80fd8c9971f323 (patch) | |
| tree | f1384eb77981241b1ab1028a50b94382c2c6e723 /arch/arm/kernel/ftrace.c | |
| parent | d3b9dc9dd2b994f396741f7086ffe7a48bacb165 (diff) | |
ARM: ftrace: function graph tracer support
Cc: Tim Bird <tim.bird@am.sony.com>
[rabin@rab.in: rebase on top of latest code,
keep code in ftrace.c instead of separate file,
check for ftrace_graph_entry also]
Signed-off-by: Rabin Vincent <rabin@rab.in>
Diffstat (limited to 'arch/arm/kernel/ftrace.c')
| -rw-r--r-- | arch/arm/kernel/ftrace.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c index 971ac8c36ea7..7a702a502871 100644 --- a/arch/arm/kernel/ftrace.c +++ b/arch/arm/kernel/ftrace.c @@ -24,6 +24,7 @@ #define NOP 0xe8bd4000 /* pop {lr} */ #endif +#ifdef CONFIG_DYNAMIC_FTRACE #ifdef CONFIG_OLD_MCOUNT #define OLD_MCOUNT_ADDR ((unsigned long) mcount) #define OLD_FTRACE_ADDR ((unsigned long) ftrace_caller_old) @@ -193,3 +194,36 @@ int __init ftrace_dyn_arch_init(void *data) return 0; } +#endif /* CONFIG_DYNAMIC_FTRACE */ + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr, + unsigned long frame_pointer) +{ + unsigned long return_hooker = (unsigned long) &return_to_handler; + struct ftrace_graph_ent trace; + unsigned long old; + int err; + + if (unlikely(atomic_read(¤t->tracing_graph_pause))) + return; + + old = *parent; + *parent = return_hooker; + + err = ftrace_push_return_trace(old, self_addr, &trace.depth, + frame_pointer); + if (err == -EBUSY) { + *parent = old; + return; + } + + trace.func = self_addr; + + /* Only trace if the calling function expects to */ + if (!ftrace_graph_entry(&trace)) { + current->curr_ret_stack--; + *parent = old; + } +} +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |