forked from Minki/linux
33ea4b2427
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>
510 lines
12 KiB
C
510 lines
12 KiB
C
/*
|
|
* trace event based perf event profiling/tracing
|
|
*
|
|
* Copyright (C) 2009 Red Hat Inc, Peter Zijlstra
|
|
* Copyright (C) 2009-2010 Frederic Weisbecker <fweisbec@gmail.com>
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/kprobes.h>
|
|
#include "trace.h"
|
|
#include "trace_probe.h"
|
|
|
|
static char __percpu *perf_trace_buf[PERF_NR_CONTEXTS];
|
|
|
|
/*
|
|
* Force it to be aligned to unsigned long to avoid misaligned accesses
|
|
* suprises
|
|
*/
|
|
typedef typeof(unsigned long [PERF_MAX_TRACE_SIZE / sizeof(unsigned long)])
|
|
perf_trace_t;
|
|
|
|
/* Count the events in use (per event id, not per instance) */
|
|
static int total_ref_count;
|
|
|
|
static int perf_trace_event_perm(struct trace_event_call *tp_event,
|
|
struct perf_event *p_event)
|
|
{
|
|
if (tp_event->perf_perm) {
|
|
int ret = tp_event->perf_perm(tp_event, p_event);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* We checked and allowed to create parent,
|
|
* allow children without checking.
|
|
*/
|
|
if (p_event->parent)
|
|
return 0;
|
|
|
|
/*
|
|
* It's ok to check current process (owner) permissions in here,
|
|
* because code below is called only via perf_event_open syscall.
|
|
*/
|
|
|
|
/* The ftrace function trace is allowed only for root. */
|
|
if (ftrace_event_is_function(tp_event)) {
|
|
if (perf_paranoid_tracepoint_raw() && !capable(CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
|
|
if (!is_sampling_event(p_event))
|
|
return 0;
|
|
|
|
/*
|
|
* We don't allow user space callchains for function trace
|
|
* event, due to issues with page faults while tracing page
|
|
* fault handler and its overall trickiness nature.
|
|
*/
|
|
if (!p_event->attr.exclude_callchain_user)
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* Same reason to disable user stack dump as for user space
|
|
* callchains above.
|
|
*/
|
|
if (p_event->attr.sample_type & PERF_SAMPLE_STACK_USER)
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* No tracing, just counting, so no obvious leak */
|
|
if (!(p_event->attr.sample_type & PERF_SAMPLE_RAW))
|
|
return 0;
|
|
|
|
/* Some events are ok to be traced by non-root users... */
|
|
if (p_event->attach_state == PERF_ATTACH_TASK) {
|
|
if (tp_event->flags & TRACE_EVENT_FL_CAP_ANY)
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* ...otherwise raw tracepoint data can be a severe data leak,
|
|
* only allow root to have these.
|
|
*/
|
|
if (perf_paranoid_tracepoint_raw() && !capable(CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int perf_trace_event_reg(struct trace_event_call *tp_event,
|
|
struct perf_event *p_event)
|
|
{
|
|
struct hlist_head __percpu *list;
|
|
int ret = -ENOMEM;
|
|
int cpu;
|
|
|
|
p_event->tp_event = tp_event;
|
|
if (tp_event->perf_refcount++ > 0)
|
|
return 0;
|
|
|
|
list = alloc_percpu(struct hlist_head);
|
|
if (!list)
|
|
goto fail;
|
|
|
|
for_each_possible_cpu(cpu)
|
|
INIT_HLIST_HEAD(per_cpu_ptr(list, cpu));
|
|
|
|
tp_event->perf_events = list;
|
|
|
|
if (!total_ref_count) {
|
|
char __percpu *buf;
|
|
int i;
|
|
|
|
for (i = 0; i < PERF_NR_CONTEXTS; i++) {
|
|
buf = (char __percpu *)alloc_percpu(perf_trace_t);
|
|
if (!buf)
|
|
goto fail;
|
|
|
|
perf_trace_buf[i] = buf;
|
|
}
|
|
}
|
|
|
|
ret = tp_event->class->reg(tp_event, TRACE_REG_PERF_REGISTER, NULL);
|
|
if (ret)
|
|
goto fail;
|
|
|
|
total_ref_count++;
|
|
return 0;
|
|
|
|
fail:
|
|
if (!total_ref_count) {
|
|
int i;
|
|
|
|
for (i = 0; i < PERF_NR_CONTEXTS; i++) {
|
|
free_percpu(perf_trace_buf[i]);
|
|
perf_trace_buf[i] = NULL;
|
|
}
|
|
}
|
|
|
|
if (!--tp_event->perf_refcount) {
|
|
free_percpu(tp_event->perf_events);
|
|
tp_event->perf_events = NULL;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void perf_trace_event_unreg(struct perf_event *p_event)
|
|
{
|
|
struct trace_event_call *tp_event = p_event->tp_event;
|
|
int i;
|
|
|
|
if (--tp_event->perf_refcount > 0)
|
|
goto out;
|
|
|
|
tp_event->class->reg(tp_event, TRACE_REG_PERF_UNREGISTER, NULL);
|
|
|
|
/*
|
|
* Ensure our callback won't be called anymore. The buffers
|
|
* will be freed after that.
|
|
*/
|
|
tracepoint_synchronize_unregister();
|
|
|
|
free_percpu(tp_event->perf_events);
|
|
tp_event->perf_events = NULL;
|
|
|
|
if (!--total_ref_count) {
|
|
for (i = 0; i < PERF_NR_CONTEXTS; i++) {
|
|
free_percpu(perf_trace_buf[i]);
|
|
perf_trace_buf[i] = NULL;
|
|
}
|
|
}
|
|
out:
|
|
module_put(tp_event->mod);
|
|
}
|
|
|
|
static int perf_trace_event_open(struct perf_event *p_event)
|
|
{
|
|
struct trace_event_call *tp_event = p_event->tp_event;
|
|
return tp_event->class->reg(tp_event, TRACE_REG_PERF_OPEN, p_event);
|
|
}
|
|
|
|
static void perf_trace_event_close(struct perf_event *p_event)
|
|
{
|
|
struct trace_event_call *tp_event = p_event->tp_event;
|
|
tp_event->class->reg(tp_event, TRACE_REG_PERF_CLOSE, p_event);
|
|
}
|
|
|
|
static int perf_trace_event_init(struct trace_event_call *tp_event,
|
|
struct perf_event *p_event)
|
|
{
|
|
int ret;
|
|
|
|
ret = perf_trace_event_perm(tp_event, p_event);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = perf_trace_event_reg(tp_event, p_event);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = perf_trace_event_open(p_event);
|
|
if (ret) {
|
|
perf_trace_event_unreg(p_event);
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int perf_trace_init(struct perf_event *p_event)
|
|
{
|
|
struct trace_event_call *tp_event;
|
|
u64 event_id = p_event->attr.config;
|
|
int ret = -EINVAL;
|
|
|
|
mutex_lock(&event_mutex);
|
|
list_for_each_entry(tp_event, &ftrace_events, list) {
|
|
if (tp_event->event.type == event_id &&
|
|
tp_event->class && tp_event->class->reg &&
|
|
try_module_get(tp_event->mod)) {
|
|
ret = perf_trace_event_init(tp_event, p_event);
|
|
if (ret)
|
|
module_put(tp_event->mod);
|
|
break;
|
|
}
|
|
}
|
|
mutex_unlock(&event_mutex);
|
|
|
|
return ret;
|
|
}
|
|
|
|
void perf_trace_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);
|
|
}
|
|
|
|
#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 */
|
|
|
|
#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;
|
|
|
|
if (!(flags & PERF_EF_START))
|
|
p_event->hw.state = PERF_HES_STOPPED;
|
|
|
|
/*
|
|
* If TRACE_REG_PERF_ADD returns false; no custom action was performed
|
|
* and we need to take the default action of enqueueing our event on
|
|
* the right per-cpu hlist.
|
|
*/
|
|
if (!tp_event->class->reg(tp_event, TRACE_REG_PERF_ADD, p_event)) {
|
|
struct hlist_head __percpu *pcpu_list;
|
|
struct hlist_head *list;
|
|
|
|
pcpu_list = tp_event->perf_events;
|
|
if (WARN_ON_ONCE(!pcpu_list))
|
|
return -EINVAL;
|
|
|
|
list = this_cpu_ptr(pcpu_list);
|
|
hlist_add_head_rcu(&p_event->hlist_entry, list);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void perf_trace_del(struct perf_event *p_event, int flags)
|
|
{
|
|
struct trace_event_call *tp_event = p_event->tp_event;
|
|
|
|
/*
|
|
* If TRACE_REG_PERF_DEL returns false; no custom action was performed
|
|
* and we need to take the default action of dequeueing our event from
|
|
* the right per-cpu hlist.
|
|
*/
|
|
if (!tp_event->class->reg(tp_event, TRACE_REG_PERF_DEL, p_event))
|
|
hlist_del_rcu(&p_event->hlist_entry);
|
|
}
|
|
|
|
void *perf_trace_buf_alloc(int size, struct pt_regs **regs, int *rctxp)
|
|
{
|
|
char *raw_data;
|
|
int rctx;
|
|
|
|
BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(unsigned long));
|
|
|
|
if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
|
|
"perf buffer not large enough"))
|
|
return NULL;
|
|
|
|
*rctxp = rctx = perf_swevent_get_recursion_context();
|
|
if (rctx < 0)
|
|
return NULL;
|
|
|
|
if (regs)
|
|
*regs = this_cpu_ptr(&__perf_regs[rctx]);
|
|
raw_data = this_cpu_ptr(perf_trace_buf[rctx]);
|
|
|
|
/* zero the dead bytes from align to not leak stack to user */
|
|
memset(&raw_data[size - sizeof(u64)], 0, sizeof(u64));
|
|
return raw_data;
|
|
}
|
|
EXPORT_SYMBOL_GPL(perf_trace_buf_alloc);
|
|
NOKPROBE_SYMBOL(perf_trace_buf_alloc);
|
|
|
|
void perf_trace_buf_update(void *record, u16 type)
|
|
{
|
|
struct trace_entry *entry = record;
|
|
int pc = preempt_count();
|
|
unsigned long flags;
|
|
|
|
local_save_flags(flags);
|
|
tracing_generic_entry_update(entry, flags, pc);
|
|
entry->type = type;
|
|
}
|
|
NOKPROBE_SYMBOL(perf_trace_buf_update);
|
|
|
|
#ifdef CONFIG_FUNCTION_TRACER
|
|
static void
|
|
perf_ftrace_function_call(unsigned long ip, unsigned long parent_ip,
|
|
struct ftrace_ops *ops, struct pt_regs *pt_regs)
|
|
{
|
|
struct ftrace_entry *entry;
|
|
struct perf_event *event;
|
|
struct hlist_head head;
|
|
struct pt_regs regs;
|
|
int rctx;
|
|
|
|
if ((unsigned long)ops->private != smp_processor_id())
|
|
return;
|
|
|
|
event = container_of(ops, struct perf_event, ftrace_ops);
|
|
|
|
/*
|
|
* @event->hlist entry is NULL (per INIT_HLIST_NODE), and all
|
|
* the perf code does is hlist_for_each_entry_rcu(), so we can
|
|
* get away with simply setting the @head.first pointer in order
|
|
* to create a singular list.
|
|
*/
|
|
head.first = &event->hlist_entry;
|
|
|
|
#define ENTRY_SIZE (ALIGN(sizeof(struct ftrace_entry) + sizeof(u32), \
|
|
sizeof(u64)) - sizeof(u32))
|
|
|
|
BUILD_BUG_ON(ENTRY_SIZE > PERF_MAX_TRACE_SIZE);
|
|
|
|
memset(®s, 0, sizeof(regs));
|
|
perf_fetch_caller_regs(®s);
|
|
|
|
entry = perf_trace_buf_alloc(ENTRY_SIZE, NULL, &rctx);
|
|
if (!entry)
|
|
return;
|
|
|
|
entry->ip = ip;
|
|
entry->parent_ip = parent_ip;
|
|
perf_trace_buf_submit(entry, ENTRY_SIZE, rctx, TRACE_FN,
|
|
1, ®s, &head, NULL);
|
|
|
|
#undef ENTRY_SIZE
|
|
}
|
|
|
|
static int perf_ftrace_function_register(struct perf_event *event)
|
|
{
|
|
struct ftrace_ops *ops = &event->ftrace_ops;
|
|
|
|
ops->flags = FTRACE_OPS_FL_RCU;
|
|
ops->func = perf_ftrace_function_call;
|
|
ops->private = (void *)(unsigned long)nr_cpu_ids;
|
|
|
|
return register_ftrace_function(ops);
|
|
}
|
|
|
|
static int perf_ftrace_function_unregister(struct perf_event *event)
|
|
{
|
|
struct ftrace_ops *ops = &event->ftrace_ops;
|
|
int ret = unregister_ftrace_function(ops);
|
|
ftrace_free_filter(ops);
|
|
return ret;
|
|
}
|
|
|
|
int perf_ftrace_event_register(struct trace_event_call *call,
|
|
enum trace_reg type, void *data)
|
|
{
|
|
struct perf_event *event = data;
|
|
|
|
switch (type) {
|
|
case TRACE_REG_REGISTER:
|
|
case TRACE_REG_UNREGISTER:
|
|
break;
|
|
case TRACE_REG_PERF_REGISTER:
|
|
case TRACE_REG_PERF_UNREGISTER:
|
|
return 0;
|
|
case TRACE_REG_PERF_OPEN:
|
|
return perf_ftrace_function_register(data);
|
|
case TRACE_REG_PERF_CLOSE:
|
|
return perf_ftrace_function_unregister(data);
|
|
case TRACE_REG_PERF_ADD:
|
|
event->ftrace_ops.private = (void *)(unsigned long)smp_processor_id();
|
|
return 1;
|
|
case TRACE_REG_PERF_DEL:
|
|
event->ftrace_ops.private = (void *)(unsigned long)nr_cpu_ids;
|
|
return 1;
|
|
}
|
|
|
|
return -EINVAL;
|
|
}
|
|
#endif /* CONFIG_FUNCTION_TRACER */
|