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 <mhiramat@redhat.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <20090910235329.22412.94731.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
This commit is contained in:
Masami Hiramatsu
2009-09-10 19:53:30 -04:00
committed by Frederic Weisbecker
parent 4a846b443b
commit e08d1c657f
2 changed files with 111 additions and 3 deletions

View File

@@ -28,6 +28,7 @@
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/ptrace.h>
#include <linux/perf_counter.h>
#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) {