diff options
| author | Wu Zhangjin <[email protected]> | 2009-11-20 20:34:35 +0800 |
|---|---|---|
| committer | Ralf Baechle <[email protected]> | 2009-12-17 01:57:25 +0000 |
| commit | e17ff5fec65a0213416efbe7ceae5f2f9887dda2 (patch) | |
| tree | 9f315fcacb075e4e1828fd9e0bd2133e11ec47b2 | |
| parent | 29c5d3462f7c8f17bb9e0a29f0a299036468074d (diff) | |
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 <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Nicholas Mc Guire <[email protected]>
Cc: [email protected]
Cc: Wu Zhangjin <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: [email protected]
Cc: [email protected]
Patchwork: http://patchwork.linux-mips.org/patch/678/
Signed-off-by: Ralf Baechle <[email protected]>
| -rw-r--r-- | arch/mips/kernel/ftrace.c | 21 | ||||
| -rw-r--r-- | arch/mips/kernel/mcount.S | 14 |
2 files changed, 33 insertions, 2 deletions
diff --git a/arch/mips/kernel/ftrace.c b/arch/mips/kernel/ftrace.c index 65a3f8a89927..e981a497c98f 100644 --- a/arch/mips/kernel/ftrace.c +++ b/arch/mips/kernel/ftrace.c @@ -115,6 +115,27 @@ int __init ftrace_dyn_arch_init(void *data) #ifdef CONFIG_FUNCTION_GRAPH_TRACER +#ifdef CONFIG_DYNAMIC_FTRACE + +extern void ftrace_graph_call(void); +#define JMP 0x08000000 /* jump to target directly */ +#define CALL_FTRACE_GRAPH_CALLER \ + jump_insn_encode(JMP, (unsigned long)(&ftrace_graph_caller)) +#define FTRACE_GRAPH_CALL_IP ((unsigned long)(&ftrace_graph_call)) + +int ftrace_enable_ftrace_graph_caller(void) +{ + return ftrace_modify_code(FTRACE_GRAPH_CALL_IP, + CALL_FTRACE_GRAPH_CALLER); +} + +int ftrace_disable_ftrace_graph_caller(void) +{ + return ftrace_modify_code(FTRACE_GRAPH_CALL_IP, ftrace_nop); +} + +#endif /* !CONFIG_DYNAMIC_FTRACE */ + #define S_RA_SP (0xafbf << 16) /* s{d,w} ra, offset(sp) */ #define S_R_SP (0xafb0 << 16) /* s{d,w} R, offset(sp) */ #define OFFSET_MASK 0xffff /* stack offset range: 0 ~ PT_SIZE */ diff --git a/arch/mips/kernel/mcount.S b/arch/mips/kernel/mcount.S index b50e38d828c4..98d469032506 100644 --- a/arch/mips/kernel/mcount.S +++ b/arch/mips/kernel/mcount.S @@ -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 */ |