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perf/core: Implement the 'perf_kprobe' PMU

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A new PMU type, perf_kprobe is added. Based on attr from perf_event_open(),
perf_kprobe creates a kprobe (or kretprobe) for the perf_event. This
kprobe is private to this perf_event, and thus not added to global
lists, and not available in tracefs.

Two functions, create_local_trace_kprobe() and
destroy_local_trace_kprobe()  are added to created and destroy these
local trace_kprobe.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Yonghong Song <yhs@fb.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Cc: <daniel@iogearbox.net>
Cc: <davem@davemloft.net>
Cc: <kernel-team@fb.com>
Cc: <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20171206224518.3598254-6-songliubraving@fb.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Song Liu
2017-12-06 14:45:15 -08:00
committed by Ingo Molnar
parent 0d8dd67be0
commit e12f03d703
5 changed files with 250 additions and 43 deletions
Download Patch File Download Diff File Expand all files Collapse all files

49
kernel/trace/trace_event_perf.c
View File

@@ -8,6 +8,7 @@
#include <linux/module.h>
#include <linux/kprobes.h>
#include "trace.h"
#include "trace_probe.h"
static char __percpu *perf_trace_buf[PERF_NR_CONTEXTS];
@@ -237,6 +238,54 @@ void perf_trace_destroy(struct perf_event *p_event)
mutex_unlock(&event_mutex);
}
#ifdef CONFIG_KPROBE_EVENTS
int perf_kprobe_init(struct perf_event *p_event, bool is_retprobe)
{
int ret;
char *func = NULL;
struct trace_event_call *tp_event;
if (p_event->attr.kprobe_func) {
func = kzalloc(KSYM_NAME_LEN, GFP_KERNEL);
if (!func)
return -ENOMEM;
ret = strncpy_from_user(
func, u64_to_user_ptr(p_event->attr.kprobe_func),
KSYM_NAME_LEN);
if (ret < 0)
goto out;
if (func[0] == '\0') {
kfree(func);
func = NULL;
}
}
tp_event = create_local_trace_kprobe(
func, (void *)(unsigned long)(p_event->attr.kprobe_addr),
p_event->attr.probe_offset, is_retprobe);
if (IS_ERR(tp_event)) {
ret = PTR_ERR(tp_event);
goto out;
}
ret = perf_trace_event_init(tp_event, p_event);
if (ret)
destroy_local_trace_kprobe(tp_event);
out:
kfree(func);
return ret;
}
void perf_kprobe_destroy(struct perf_event *p_event)
{
perf_trace_event_close(p_event);
perf_trace_event_unreg(p_event);
destroy_local_trace_kprobe(p_event->tp_event);
}
#endif /* CONFIG_KPROBE_EVENTS */
int perf_trace_add(struct perf_event *p_event, int flags)
{
struct trace_event_call *tp_event = p_event->tp_event;