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author | Zong Li <zong@andestech.com> | 2018-08-15 10:53:04 +0800 |
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committer | Greentime Hu <greentime@andestech.com> | 2018-09-04 14:45:17 +0800 |
commit | 1e9b14c0d92b61a0979fd5ee24d5e7f080f11030 (patch) | |
tree | afca1e8776b080ac31d2803990e691bb9f9bf58b /arch/nds32/kernel | |
parent | a18082575c664847d36c6ca030b09ce8d93aec2f (diff) | |
download | linux-stable-1e9b14c0d92b61a0979fd5ee24d5e7f080f11030.tar.gz linux-stable-1e9b14c0d92b61a0979fd5ee24d5e7f080f11030.tar.bz2 linux-stable-1e9b14c0d92b61a0979fd5ee24d5e7f080f11030.zip |
nds32/ftrace: Support static function graph tracer
This patch contains implementation of static function graph tracer.
Signed-off-by: Zong Li <zong@andestech.com>
Acked-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
Diffstat (limited to 'arch/nds32/kernel')
-rw-r--r-- | arch/nds32/kernel/ftrace.c | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/arch/nds32/kernel/ftrace.c b/arch/nds32/kernel/ftrace.c index 563f64c070b3..707fce76522e 100644 --- a/arch/nds32/kernel/ftrace.c +++ b/arch/nds32/kernel/ftrace.c @@ -6,6 +6,8 @@ extern void (*ftrace_trace_function)(unsigned long, unsigned long, struct ftrace_ops*, struct pt_regs*); +extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace); +extern void ftrace_graph_caller(void); noinline void __naked ftrace_stub(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct pt_regs *regs) @@ -23,6 +25,73 @@ noinline void _mcount(unsigned long parent_ip) ftrace_trace_function(ip - MCOUNT_INSN_SIZE, parent_ip, NULL, NULL); +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + if (ftrace_graph_return != (trace_func_graph_ret_t)ftrace_stub + || ftrace_graph_entry != ftrace_graph_entry_stub) + ftrace_graph_caller(); +#endif + /* restore all state by the compiler epilogue */ } EXPORT_SYMBOL(_mcount); + +#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; + + trace.func = self_addr; + trace.depth = current->curr_ret_stack + 1; + + /* Only trace if the calling function expects to */ + if (!ftrace_graph_entry(&trace)) + return; + + err = ftrace_push_return_trace(old, self_addr, &trace.depth, + frame_pointer, NULL); + + if (err == -EBUSY) + return; + + *parent = return_hooker; +} + +noinline void ftrace_graph_caller(void) +{ + unsigned long *parent_ip = + (unsigned long *)(__builtin_frame_address(2) - 4); + + unsigned long selfpc = + (unsigned long)(__builtin_return_address(1) - MCOUNT_INSN_SIZE); + + unsigned long frame_pointer = + (unsigned long)__builtin_frame_address(3); + + prepare_ftrace_return(parent_ip, selfpc, frame_pointer); +} + +extern unsigned long ftrace_return_to_handler(unsigned long frame_pointer); +void __naked return_to_handler(void) +{ + __asm__ __volatile__ ( + /* save state needed by the ABI */ + "smw.adm $r0,[$sp],$r1,#0x0 \n\t" + + /* get original return address */ + "move $r0, $fp \n\t" + "bal ftrace_return_to_handler\n\t" + "move $lp, $r0 \n\t" + + /* restore state nedded by the ABI */ + "lmw.bim $r0,[$sp],$r1,#0x0 \n\t"); +} +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |