From e08d1c657f70bcaca11401cd6ac5c8fe59bd2bb7 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 10 Sep 2009 19:53:30 -0400 Subject: [PATCH] tracing/kprobes: Add event profiling support Add *probe_profile_enable/disable to support kprobes raw events sampling from perf counters, like other ftrace events, when CONFIG_PROFILE_EVENT=y. Signed-off-by: Masami Hiramatsu Cc: Jim Keniston Cc: Ananth N Mavinakayanahalli Cc: Andi Kleen Cc: Christoph Hellwig Cc: Frank Ch. Eigler Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Jason Baron Cc: K.Prasad Cc: Lai Jiangshan Cc: Li Zefan Cc: Peter Zijlstra Cc: Srikar Dronamraju Cc: Steven Rostedt Cc: Tom Zanussi LKML-Reference: <20090910235329.22412.94731.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Frederic Weisbecker --- Documentation/trace/kprobetrace.txt | 4 +- kernel/trace/trace_kprobe.c | 110 +++++++++++++++++++++++++++- 2 files changed, 111 insertions(+), 3 deletions(-) diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt index db553186564..8f882ebd136 100644 --- a/Documentation/trace/kprobetrace.txt +++ b/Documentation/trace/kprobetrace.txt @@ -62,13 +62,15 @@ enabled: You can enable/disable the probe by writing 1 or 0 on it. format: - It shows the format of this probe event. It also shows aliases of arguments + This shows the format of this probe event. It also shows aliases of arguments which you specified to kprobe_events. filter: You can write filtering rules of this event. And you can use both of aliase names and field names for describing filters. +id: + This shows the id of this probe event. Event Profiling --------------- diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 4ce728ca1b1..730e992d28d 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -28,6 +28,7 @@ #include #include #include +#include #include "trace.h" #include "trace_output.h" @@ -280,6 +281,7 @@ static struct trace_probe *alloc_trace_probe(const char *event, } else tp->rp.kp.addr = addr; + /* Set handler here for checking whether this probe is return or not. */ if (is_return) tp->rp.handler = kretprobe_trace_func; else @@ -929,10 +931,13 @@ static int probe_event_enable(struct ftrace_event_call *call) { struct trace_probe *tp = (struct trace_probe *)call->data; - if (probe_is_return(tp)) + if (probe_is_return(tp)) { + tp->rp.handler = kretprobe_trace_func; return enable_kretprobe(&tp->rp); - else + } else { + tp->rp.kp.pre_handler = kprobe_trace_func; return enable_kprobe(&tp->rp.kp); + } } static void probe_event_disable(struct ftrace_event_call *call) @@ -1105,6 +1110,101 @@ static int kretprobe_event_show_format(struct ftrace_event_call *call, "func, ret_ip"); } +#ifdef CONFIG_EVENT_PROFILE + +/* Kprobe profile handler */ +static __kprobes int kprobe_profile_func(struct kprobe *kp, + struct pt_regs *regs) +{ + struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp); + struct ftrace_event_call *call = &tp->call; + struct kprobe_trace_entry *entry; + int size, i, pc; + unsigned long irq_flags; + + local_save_flags(irq_flags); + pc = preempt_count(); + + size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args); + + do { + char raw_data[size]; + struct trace_entry *ent; + + *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL; + entry = (struct kprobe_trace_entry *)raw_data; + ent = &entry->ent; + + tracing_generic_entry_update(ent, irq_flags, pc); + ent->type = call->id; + entry->nargs = tp->nr_args; + entry->ip = (unsigned long)kp->addr; + for (i = 0; i < tp->nr_args; i++) + entry->args[i] = call_fetch(&tp->args[i], regs); + perf_tpcounter_event(call->id, entry->ip, 1, entry, size); + } while (0); + return 0; +} + +/* Kretprobe profile handler */ +static __kprobes int kretprobe_profile_func(struct kretprobe_instance *ri, + struct pt_regs *regs) +{ + struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp); + struct ftrace_event_call *call = &tp->call; + struct kretprobe_trace_entry *entry; + int size, i, pc; + unsigned long irq_flags; + + local_save_flags(irq_flags); + pc = preempt_count(); + + size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args); + + do { + char raw_data[size]; + struct trace_entry *ent; + + *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL; + entry = (struct kretprobe_trace_entry *)raw_data; + ent = &entry->ent; + + tracing_generic_entry_update(ent, irq_flags, pc); + ent->type = call->id; + entry->nargs = tp->nr_args; + entry->func = (unsigned long)tp->rp.kp.addr; + entry->ret_ip = (unsigned long)ri->ret_addr; + for (i = 0; i < tp->nr_args; i++) + entry->args[i] = call_fetch(&tp->args[i], regs); + perf_tpcounter_event(call->id, entry->ret_ip, 1, entry, size); + } while (0); + return 0; +} + +static int probe_profile_enable(struct ftrace_event_call *call) +{ + struct trace_probe *tp = (struct trace_probe *)call->data; + + if (atomic_inc_return(&call->profile_count)) + return 0; + + if (probe_is_return(tp)) { + tp->rp.handler = kretprobe_profile_func; + return enable_kretprobe(&tp->rp); + } else { + tp->rp.kp.pre_handler = kprobe_profile_func; + return enable_kprobe(&tp->rp.kp); + } +} + +static void probe_profile_disable(struct ftrace_event_call *call) +{ + if (atomic_add_negative(-1, &call->profile_count)) + probe_event_disable(call); +} + +#endif /* CONFIG_EVENT_PROFILE */ + static int register_probe_event(struct trace_probe *tp) { struct ftrace_event_call *call = &tp->call; @@ -1130,6 +1230,12 @@ static int register_probe_event(struct trace_probe *tp) call->enabled = 1; call->regfunc = probe_event_enable; call->unregfunc = probe_event_disable; + +#ifdef CONFIG_EVENT_PROFILE + atomic_set(&call->profile_count, -1); + call->profile_enable = probe_profile_enable; + call->profile_disable = probe_profile_disable; +#endif call->data = tp; ret = trace_add_event_call(call); if (ret) { -- 2.39.2