From a0d3e66522e8f6119f002cf31e5d92d7ae73b409 Mon Sep 17 00:00:00 2001 From: Michal Simek Date: Mon, 16 Nov 2009 10:32:10 +0100 Subject: microblaze: ftrace: add function graph support For more information look at Documentation/trace folder. Signed-off-by: Michal Simek --- arch/microblaze/Kconfig | 1 + arch/microblaze/kernel/ftrace.c | 58 +++++++++++++++++++++++++++++++++++++++++ arch/microblaze/kernel/mcount.S | 41 +++++++++++++++++++++++++++++ 3 files changed, 100 insertions(+) (limited to 'arch') diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig index 102d73aa1063..e297802b8321 100644 --- a/arch/microblaze/Kconfig +++ b/arch/microblaze/Kconfig @@ -8,6 +8,7 @@ config MICROBLAZE select HAVE_LMB select HAVE_FUNCTION_TRACER select HAVE_FUNCTION_TRACE_MCOUNT_TEST + select HAVE_FUNCTION_GRAPH_TRACER select HAVE_DYNAMIC_FTRACE select HAVE_FTRACE_MCOUNT_RECORD select USB_ARCH_HAS_EHCI diff --git a/arch/microblaze/kernel/ftrace.c b/arch/microblaze/kernel/ftrace.c index c1889b101cb8..0952a8b52c35 100644 --- a/arch/microblaze/kernel/ftrace.c +++ b/arch/microblaze/kernel/ftrace.c @@ -14,6 +14,64 @@ #include #include +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +/* + * Hook the return address and push it in the stack of return addrs + * in current thread info. + */ +void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr) +{ + unsigned long old; + int faulted, err; + struct ftrace_graph_ent trace; + unsigned long return_hooker = (unsigned long) + &return_to_handler; + + if (unlikely(atomic_read(¤t->tracing_graph_pause))) + return; + + /* + * Protect against fault, even if it shouldn't + * happen. This tool is too much intrusive to + * ignore such a protection. + */ + asm volatile(" 1: lwi %0, %2, 0; \ + 2: swi %3, %2, 0; \ + addik %1, r0, 0; \ + 3: \ + .section .fixup, \"ax\"; \ + 4: brid 3b; \ + addik %1, r0, 1; \ + .previous; \ + .section __ex_table,\"a\"; \ + .word 1b,4b; \ + .word 2b,4b; \ + .previous;" \ + : "=&r" (old), "=r" (faulted) + : "r" (parent), "r" (return_hooker) + ); + + if (unlikely(faulted)) { + ftrace_graph_stop(); + WARN_ON(1); + return; + } + + err = ftrace_push_return_trace(old, self_addr, &trace.depth, 0); + 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 */ + #ifdef CONFIG_DYNAMIC_FTRACE /* save value to addr - it is save to do it in asm */ static int ftrace_modify_code(unsigned long addr, unsigned int value) diff --git a/arch/microblaze/kernel/mcount.S b/arch/microblaze/kernel/mcount.S index 30aaf8fb55b2..84a19458c74d 100644 --- a/arch/microblaze/kernel/mcount.S +++ b/arch/microblaze/kernel/mcount.S @@ -96,6 +96,27 @@ ENTRY(ftrace_caller) bneid r5, end; nop; /* MS: HAVE_FUNCTION_TRACE_MCOUNT_TEST end of checking */ +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + lwi r5, r0, ftrace_graph_return; + addik r6, r0, ftrace_stub; /* asm implementation */ + cmpu r5, r5, r6; /* ftrace_graph_return != ftrace_stub */ + beqid r5, end_graph_tracer; + nop; + + lwi r6, r0, ftrace_graph_entry; + addik r5, r0, ftrace_graph_entry_stub; /* implemented in C */ + cmpu r5, r5, r6; /* ftrace_graph_entry != ftrace_graph_entry_stub */ + beqid r5, end_graph_tracer; + nop; + addik r5, r1, 120; /* MS: load parent addr */ + addik r6, r15, 0; /* MS: load current function addr */ + bralid r15, prepare_ftrace_return; + nop; + /* MS: graph was taken that's why - can jump over function trace */ + brid end; + nop; +end_graph_tracer: +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ #ifndef CONFIG_DYNAMIC_FTRACE /* MS: test function trace if is taken or not */ lwi r20, r0, ftrace_trace_function; @@ -121,3 +142,23 @@ end: rtsd r15, 8; /* MS: jump back */ nop; + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +ENTRY(return_to_handler) + nop; /* MS: just barrier for rtsd r15, 8 */ + nop; + SAVE_REGS + swi r15, r1, 0; + + /* MS: find out returning address */ + bralid r15, ftrace_return_to_handler; + nop; + + /* MS: return value from ftrace_return_to_handler is my returning addr + * must be before restore regs because I have to restore r3 content */ + addik r15, r3, 0; + RESTORE_REGS + + rtsd r15, 8; /* MS: jump back */ + nop; +#endif /* CONFIG_FUNCTION_TRACER */ -- cgit v1.2.3