diff options
author | Song Liu <songliubraving@fb.com> | 2017-12-07 01:45:16 +0300 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2018-02-06 13:29:28 +0300 |
commit | 33ea4b24277b06dbc55d7f5772a46f029600255e (patch) | |
tree | f80ea7a788b1ec87c6bab4d15bbe09c9dd5d978e /kernel/trace | |
parent | e12f03d7031a977356e3d7b75a68c2185ff8d155 (diff) | |
download | linux-33ea4b24277b06dbc55d7f5772a46f029600255e.tar.xz |
perf/core: Implement the 'perf_uprobe' PMU
This patch adds perf_uprobe support with similar pattern as previous
patch (for kprobe).
Two functions, create_local_trace_uprobe() and
destroy_local_trace_uprobe(), are created so a uprobe can be created
and attached to the file descriptor created by perf_event_open().
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/20171206224518.3598254-7-songliubraving@fb.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/trace')
-rw-r--r-- | kernel/trace/trace_event_perf.c | 53 | ||||
-rw-r--r-- | kernel/trace/trace_probe.h | 4 | ||||
-rw-r--r-- | kernel/trace/trace_uprobe.c | 86 |
3 files changed, 135 insertions, 8 deletions
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index 779baade9114..2c416509b834 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -286,6 +286,59 @@ void perf_kprobe_destroy(struct perf_event *p_event) } #endif /* CONFIG_KPROBE_EVENTS */ +#ifdef CONFIG_UPROBE_EVENTS +int perf_uprobe_init(struct perf_event *p_event, bool is_retprobe) +{ + int ret; + char *path = NULL; + struct trace_event_call *tp_event; + + if (!p_event->attr.uprobe_path) + return -EINVAL; + path = kzalloc(PATH_MAX, GFP_KERNEL); + if (!path) + return -ENOMEM; + ret = strncpy_from_user( + path, u64_to_user_ptr(p_event->attr.uprobe_path), PATH_MAX); + if (ret < 0) + goto out; + if (path[0] == '\0') { + ret = -EINVAL; + goto out; + } + + tp_event = create_local_trace_uprobe( + path, p_event->attr.probe_offset, is_retprobe); + if (IS_ERR(tp_event)) { + ret = PTR_ERR(tp_event); + goto out; + } + + /* + * local trace_uprobe need to hold event_mutex to call + * uprobe_buffer_enable() and uprobe_buffer_disable(). + * event_mutex is not required for local trace_kprobes. + */ + mutex_lock(&event_mutex); + ret = perf_trace_event_init(tp_event, p_event); + if (ret) + destroy_local_trace_uprobe(tp_event); + mutex_unlock(&event_mutex); +out: + kfree(path); + return ret; +} + +void perf_uprobe_destroy(struct perf_event *p_event) +{ + mutex_lock(&event_mutex); + perf_trace_event_close(p_event); + perf_trace_event_unreg(p_event); + mutex_unlock(&event_mutex); + destroy_local_trace_uprobe(p_event->tp_event); +} +#endif /* CONFIG_UPROBE_EVENTS */ + int perf_trace_add(struct perf_event *p_event, int flags) { struct trace_event_call *tp_event = p_event->tp_event; diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index e3d940a49dcd..27de3174050a 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -410,4 +410,8 @@ extern struct trace_event_call * create_local_trace_kprobe(char *func, void *addr, unsigned long offs, bool is_return); extern void destroy_local_trace_kprobe(struct trace_event_call *event_call); + +extern struct trace_event_call * +create_local_trace_uprobe(char *name, unsigned long offs, bool is_return); +extern void destroy_local_trace_uprobe(struct trace_event_call *event_call); #endif diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 40592e7b3568..e3cbae702a53 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -1292,16 +1292,25 @@ static struct trace_event_functions uprobe_funcs = { .trace = print_uprobe_event }; -static int register_uprobe_event(struct trace_uprobe *tu) +static inline void init_trace_event_call(struct trace_uprobe *tu, + struct trace_event_call *call) { - struct trace_event_call *call = &tu->tp.call; - int ret; - - /* Initialize trace_event_call */ INIT_LIST_HEAD(&call->class->fields); call->event.funcs = &uprobe_funcs; call->class->define_fields = uprobe_event_define_fields; + call->flags = TRACE_EVENT_FL_UPROBE; + call->class->reg = trace_uprobe_register; + call->data = tu; +} + +static int register_uprobe_event(struct trace_uprobe *tu) +{ + struct trace_event_call *call = &tu->tp.call; + int ret = 0; + + init_trace_event_call(tu, call); + if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) return -ENOMEM; @@ -1311,9 +1320,6 @@ static int register_uprobe_event(struct trace_uprobe *tu) return -ENODEV; } - call->flags = TRACE_EVENT_FL_UPROBE; - call->class->reg = trace_uprobe_register; - call->data = tu; ret = trace_add_event_call(call); if (ret) { @@ -1339,6 +1345,70 @@ static int unregister_uprobe_event(struct trace_uprobe *tu) return 0; } +#ifdef CONFIG_PERF_EVENTS +struct trace_event_call * +create_local_trace_uprobe(char *name, unsigned long offs, bool is_return) +{ + struct trace_uprobe *tu; + struct inode *inode; + struct path path; + int ret; + + ret = kern_path(name, LOOKUP_FOLLOW, &path); + if (ret) + return ERR_PTR(ret); + + inode = igrab(d_inode(path.dentry)); + path_put(&path); + + if (!inode || !S_ISREG(inode->i_mode)) { + iput(inode); + return ERR_PTR(-EINVAL); + } + + /* + * local trace_kprobes are not added to probe_list, so they are never + * searched in find_trace_kprobe(). Therefore, there is no concern of + * duplicated name "DUMMY_EVENT" here. + */ + tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0, + is_return); + + if (IS_ERR(tu)) { + pr_info("Failed to allocate trace_uprobe.(%d)\n", + (int)PTR_ERR(tu)); + return ERR_CAST(tu); + } + + tu->offset = offs; + tu->inode = inode; + tu->filename = kstrdup(name, GFP_KERNEL); + init_trace_event_call(tu, &tu->tp.call); + + if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) { + ret = -ENOMEM; + goto error; + } + + return &tu->tp.call; +error: + free_trace_uprobe(tu); + return ERR_PTR(ret); +} + +void destroy_local_trace_uprobe(struct trace_event_call *event_call) +{ + struct trace_uprobe *tu; + + tu = container_of(event_call, struct trace_uprobe, tp.call); + + kfree(tu->tp.call.print_fmt); + tu->tp.call.print_fmt = NULL; + + free_trace_uprobe(tu); +} +#endif /* CONFIG_PERF_EVENTS */ + /* Make a trace interface for controling probe points */ static __init int init_uprobe_trace(void) { |