# Copyright 2016 Sasha Goldshtein
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import ctypes as ct
import os
from .utils import get_online_cpus
class _sample_period_union(ct.Union):
_fields_ = [
('sample_period', ct.c_ulong),
('sample_freq', ct.c_ulong),
]
class _wakeup_events_union(ct.Union):
_fields_ = [
('wakeup_events', ct.c_uint),
('wakeup_watermark', ct.c_uint),
]
class _bp_addr_union(ct.Union):
_fields_ = [
('bp_addr', ct.c_ulong),
('kprobe_func', ct.c_ulong),
('uprobe_path', ct.c_ulong),
('config1', ct.c_ulong),
]
class _bp_len_union(ct.Union):
_fields_ = [
('bp_len', ct.c_ulong),
('kprobe_addr', ct.c_ulong),
('probe_offset', ct.c_ulong),
('config2', ct.c_ulong),
]
class Perf(object):
class perf_event_attr(ct.Structure):
_anonymous_ = [
"_sample_period_union",
"_wakeup_events_union",
"_bp_addr_union",
"_bp_len_union"
]
_fields_ = [
('type', ct.c_uint),
('size', ct.c_uint),
('config', ct.c_ulong),
('_sample_period_union', _sample_period_union), # ct.c_ulong
('sample_type', ct.c_ulong),
('read_format', ct.c_ulong),
('disabled', ct.c_uint, 1),
('inherit', ct.c_uint, 1),
('pinned', ct.c_uint, 1),
('exclusive', ct.c_uint, 1),
('exclude_user', ct.c_uint, 1),
('exclude_kernel', ct.c_uint, 1),
('exclude_hv', ct.c_uint, 1),
('exclude_idle', ct.c_uint, 1),
('mmap', ct.c_uint, 1),
('comm', ct.c_uint, 1),
('freq', ct.c_uint, 1),
('inherit_stat', ct.c_uint, 1),
('enable_on_exec', ct.c_uint, 1),
('task', ct.c_uint, 1),
('watermark', ct.c_uint, 1),
('precise_ip', ct.c_uint, 2),
('mmap_data', ct.c_uint, 1),
('sample_id_all', ct.c_uint, 1),
('exclude_host', ct.c_uint, 1),
('exclude_guest', ct.c_uint, 1),
('exclude_callchain_kernel', ct.c_uint, 1),
('exclude_callchain_user', ct.c_uint, 1),
('mmap2', ct.c_uint, 1),
('comm_exec', ct.c_uint, 1),
('use_clockid', ct.c_uint, 1),
('context_switch', ct.c_uint, 1),
('write_backward', ct.c_uint, 1),
('namespaces', ct.c_uint, 1),
('ksymbol', ct.c_uint, 1),
('bpf_event', ct.c_uint, 1),
('aux_output', ct.c_uint, 1),
('cgroup', ct.c_uint, 1),
('text_poke', ct.c_uint, 1),
('__reserved_1', ct.c_uint, 30),
('_wakeup_events_union', _wakeup_events_union), # ct.c_uint
('bp_type', ct.c_uint),
('_bp_addr_union', _bp_addr_union), # ct.c_ulong
('_bp_len_union', _bp_len_union), # ct.c_ulong
('branch_sample_type', ct.c_ulong),
('sample_regs_user', ct.c_ulong),
('sample_stack_user', ct.c_uint),
('clockid', ct.c_int),
('sample_regs_intr', ct.c_ulong),
('aux_watermark', ct.c_uint),
('sample_max_stack', ct.c_uint16),
('__reserved_2', ct.c_uint16),
('aux_sample_size', ct.c_uint),
('__reserved_3', ct.c_uint),
]
def __init__(self):
self.size = 120 # PERF_ATTR_SIZE_VER6
self.ctype_fields = [item[0] for item in self._fields_]
self.ctype_fields.extend([item[0] for item in _sample_period_union._fields_])
self.ctype_fields.extend([item[0] for item in _wakeup_events_union._fields_])
self.ctype_fields.extend([item[0] for item in _bp_addr_union._fields_])
self.ctype_fields.extend([item[0] for item in _bp_len_union._fields_])
def __setattr__(self, key, value):
if hasattr(self, 'ctype_fields') and key not in self.ctype_fields:
print("Warning: Setting field {} on perf_event_attr that isn't part of the ctype - {} won't make it to perf_event_open".format(key, key))
super(Perf.perf_event_attr, self).__setattr__(key, value)
# x86 specific, from arch/x86/include/generated/uapi/asm/unistd_64.h
NR_PERF_EVENT_OPEN = 298
#
# Selected constants from include/uapi/linux/perf_event.h.
# Values copied during Linux 4.7 series.
#
# perf_type_id
PERF_TYPE_HARDWARE = 0
PERF_TYPE_SOFTWARE = 1
PERF_TYPE_TRACEPOINT = 2
PERF_TYPE_HW_CACHE = 3
# perf_event_sample_format
PERF_SAMPLE_RAW = 1024 # it's a u32; could also try zero args
# perf_event.h
PERF_FLAG_FD_CLOEXEC = 8
PERF_EVENT_IOC_SET_FILTER = 1074275334
PERF_EVENT_IOC_ENABLE = 9216
# fetch syscall routines
libc = ct.CDLL('libc.so.6', use_errno=True)
syscall = libc.syscall # not declaring vararg types
ioctl = libc.ioctl # not declaring vararg types
@staticmethod
def _open_for_cpu(cpu, attr):
pfd = Perf.syscall(Perf.NR_PERF_EVENT_OPEN, ct.byref(attr),
attr.pid, cpu, -1,
Perf.PERF_FLAG_FD_CLOEXEC)
if pfd < 0:
errno_ = ct.get_errno()
raise OSError(errno_, os.strerror(errno_))
if attr.type == Perf.PERF_TYPE_TRACEPOINT:
if Perf.ioctl(pfd, Perf.PERF_EVENT_IOC_SET_FILTER,
"common_pid == -17") < 0:
errno_ = ct.get_errno()
raise OSError(errno_, os.strerror(errno_))
# we don't setup the perf ring buffers, as we won't read them
if Perf.ioctl(pfd, Perf.PERF_EVENT_IOC_ENABLE, 0) < 0:
errno_ = ct.get_errno()
raise OSError(errno_, os.strerror(errno_))
@staticmethod
def perf_event_open(tpoint_id, pid=-1, ptype=PERF_TYPE_TRACEPOINT,
freq=0):
attr = Perf.perf_event_attr()
attr.config = tpoint_id
attr.pid = pid
attr.type = ptype
attr.sample_type = Perf.PERF_SAMPLE_RAW
if freq > 0:
# setup sampling
attr.freq = 1 # no mmap or comm
attr.sample_period = freq
else:
attr.sample_period = 1
attr.wakeup_events = 9999999 # don't wake up
for cpu in get_online_cpus():
Perf._open_for_cpu(cpu, attr)