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perf scripts python: Support Arm CoreSight trace data disassembly
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This commit adds python script to parse CoreSight tracing event and
print out source line and disassembly, it generates readable program
execution flow for easier humans inspecting.

The script receives CoreSight tracing packet with below format:

                +------------+------------+------------+
  packet(n):    |    addr    |    ip      |    cpu     |
                +------------+------------+------------+
  packet(n+1):  |    addr    |    ip      |    cpu     |
                +------------+------------+------------+

packet::addr presents the start address of the coming branch sample, and
packet::ip is the last address of the branch smple.  Therefore, a code
section between branches starts from packet(n)::addr and it stops at
packet(n+1)::ip.  As results we combines the two continuous packets to
generate the address range for instructions:

  [ sample(n)::addr .. sample(n+1)::ip ]

The script supports both objdump or llvm-objdump for disassembly with
specifying option '-d'.  If doesn't specify option '-d', the script
simply outputs source lines and symbols.

Below shows usages with llvm-objdump or objdump to output disassembly.

  # perf script -s scripts/python/arm-cs-trace-disasm.py -- -d llvm-objdump-11 -k ./vmlinux
  ARM CoreSight Trace Data Assembler Dump
  	ffff800008eb3198 <etm4_enable_hw>:
  	ffff800008eb3310: c0 38 00 35  	cbnz	w0, 0xffff800008eb3a28 <etm4_enable_hw+0x890>
  	ffff800008eb3314: 9f 3f 03 d5  	dsb	sy
  	ffff800008eb3318: df 3f 03 d5  	isb
  	ffff800008eb331c: f5 5b 42 a9  	ldp	x21, x22, [sp, #32]
  	ffff800008eb3320: fb 73 45 a9  	ldp	x27, x28, [sp, #80]
  	ffff800008eb3324: e0 82 40 39  	ldrb	w0, [x23, #32]
  	ffff800008eb3328: 60 00 00 34  	cbz	w0, 0xffff800008eb3334 <etm4_enable_hw+0x19c>
  	ffff800008eb332c: e0 03 19 aa  	mov	x0, x25
  	ffff800008eb3330: 8c fe ff 97  	bl	0xffff800008eb2d60 <etm4_cs_lock.isra.0.part.0>
              main  6728/6728  [0004]         0.000000000  etm4_enable_hw+0x198                    [kernel.kallsyms]
  	ffff800008eb2d60 <etm4_cs_lock.isra.0.part.0>:
  	ffff800008eb2d60: 1f 20 03 d5  	nop
  	ffff800008eb2d64: 1f 20 03 d5  	nop
  	ffff800008eb2d68: 3f 23 03 d5  	hint	#25
  	ffff800008eb2d6c: 00 00 40 f9  	ldr	x0, [x0]
  	ffff800008eb2d70: 9f 3f 03 d5  	dsb	sy
  	ffff800008eb2d74: 00 c0 3e 91  	add	x0, x0, #4016
  	ffff800008eb2d78: 1f 00 00 b9  	str	wzr, [x0]
  	ffff800008eb2d7c: bf 23 03 d5  	hint	#29
  	ffff800008eb2d80: c0 03 5f d6  	ret
              main  6728/6728  [0004]         0.000000000  etm4_cs_lock.isra.0.part.0+0x20

  # perf script -s scripts/python/arm-cs-trace-disasm.py -- -d objdump -k ./vmlinux
  ARM CoreSight Trace Data Assembler Dump
  	ffff800008eb3310 <etm4_enable_hw+0x178>:
  	ffff800008eb3310:	350038c0 	cbnz	w0, ffff800008eb3a28 <etm4_enable_hw+0x890>
  	ffff800008eb3314:	d5033f9f 	dsb	sy
  	ffff800008eb3318:	d5033fdf 	isb
  	ffff800008eb331c:	a9425bf5 	ldp	x21, x22, [sp, #32]
  	ffff800008eb3320:	a94573fb 	ldp	x27, x28, [sp, #80]
  	ffff800008eb3324:	394082e0 	ldrb	w0, [x23, #32]
  	ffff800008eb3328:	34000060 	cbz	w0, ffff800008eb3334 <etm4_enable_hw+0x19c>
  	ffff800008eb332c:	aa1903e0 	mov	x0, x25
  	ffff800008eb3330:	97fffe8c 	bl	ffff800008eb2d60 <etm4_cs_lock.isra.0.part.0>
              main  6728/6728  [0004]         0.000000000  etm4_enable_hw+0x198                    [kernel.kallsyms]
  	ffff800008eb2d60 <etm4_cs_lock.isra.0.part.0>:
  	ffff800008eb2d60:	d503201f 	nop
  	ffff800008eb2d64:	d503201f 	nop
  	ffff800008eb2d68:	d503233f 	paciasp
  	ffff800008eb2d6c:	f9400000 	ldr	x0, [x0]
  	ffff800008eb2d70:	d5033f9f 	dsb	sy
  	ffff800008eb2d74:	913ec000 	add	x0, x0, #0xfb0
  	ffff800008eb2d78:	b900001f 	str	wzr, [x0]
  	ffff800008eb2d7c:	d50323bf 	autiasp
  	ffff800008eb2d80:	d65f03c0 	ret
              main  6728/6728  [0004]         0.000000000  etm4_cs_lock.isra.0.part.0+0x20

Signed-off-by: Leo Yan <[email protected]>
Co-authored-by: Al Grant <[email protected]>
Co-authored-by: Mathieu Poirier <[email protected]>
Co-authored-by: Tor Jeremiassen <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Eelco Chaudron <[email protected]>
Cc: German Gomez <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: James Clark <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephen Brennan <[email protected]>
Cc: Tanmay Jagdale <[email protected]>
Cc: [email protected]
Cc: zengshun . wu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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4 people authored and acmel committed May 27, 2022
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272 changes: 272 additions & 0 deletions tools/perf/scripts/python/arm-cs-trace-disasm.py
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# SPDX-License-Identifier: GPL-2.0
# arm-cs-trace-disasm.py: ARM CoreSight Trace Dump With Disassember
#
# Author: Tor Jeremiassen <[email protected]>
# Mathieu Poirier <[email protected]>
# Leo Yan <[email protected]>
# Al Grant <[email protected]>

from __future__ import print_function
import os
from os import path
import sys
import re
from subprocess import *
from optparse import OptionParser, make_option

from perf_trace_context import perf_set_itrace_options, \
perf_sample_insn, perf_sample_srccode

# Below are some example commands for using this script.
#
# Output disassembly with objdump:
# perf script -s scripts/python/arm-cs-trace-disasm.py \
# -- -d objdump -k path/to/vmlinux
# Output disassembly with llvm-objdump:
# perf script -s scripts/python/arm-cs-trace-disasm.py \
# -- -d llvm-objdump-11 -k path/to/vmlinux
# Output only source line and symbols:
# perf script -s scripts/python/arm-cs-trace-disasm.py

# Command line parsing.
option_list = [
# formatting options for the bottom entry of the stack
make_option("-k", "--vmlinux", dest="vmlinux_name",
help="Set path to vmlinux file"),
make_option("-d", "--objdump", dest="objdump_name",
help="Set path to objdump executable file"),
make_option("-v", "--verbose", dest="verbose",
action="store_true", default=False,
help="Enable debugging log")
]

parser = OptionParser(option_list=option_list)
(options, args) = parser.parse_args()

# Initialize global dicts and regular expression
disasm_cache = dict()
cpu_data = dict()
disasm_re = re.compile("^\s*([0-9a-fA-F]+):")
disasm_func_re = re.compile("^\s*([0-9a-fA-F]+)\s.*:")
cache_size = 64*1024

glb_source_file_name = None
glb_line_number = None
glb_dso = None

def get_optional(perf_dict, field):
if field in perf_dict:
return perf_dict[field]
return "[unknown]"

def get_offset(perf_dict, field):
if field in perf_dict:
return f"+0x{perf_dict[field]:x}"
return ""

def get_dso_file_path(dso_name, dso_build_id):
if (dso_name == "[kernel.kallsyms]" or dso_name == "vmlinux"):
if (options.vmlinux_name):
return options.vmlinux_name;
else:
return dso_name

if (dso_name == "[vdso]") :
append = "/vdso"
else:
append = "/elf"

dso_path = f"{os.environ['PERF_BUILDID_DIR']}/{dso_name}/{dso_build_id}{append}"
# Replace duplicate slash chars to single slash char
dso_path = dso_path.replace('//', '/', 1)
return dso_path

def read_disam(dso_fname, dso_start, start_addr, stop_addr):
addr_range = str(start_addr) + ":" + str(stop_addr) + ":" + dso_fname

# Don't let the cache get too big, clear it when it hits max size
if (len(disasm_cache) > cache_size):
disasm_cache.clear();

if addr_range in disasm_cache:
disasm_output = disasm_cache[addr_range];
else:
start_addr = start_addr - dso_start;
stop_addr = stop_addr - dso_start;
disasm = [ options.objdump_name, "-d", "-z",
f"--start-address=0x{start_addr:x}",
f"--stop-address=0x{stop_addr:x}" ]
disasm += [ dso_fname ]
disasm_output = check_output(disasm).decode('utf-8').split('\n')
disasm_cache[addr_range] = disasm_output

return disasm_output

def print_disam(dso_fname, dso_start, start_addr, stop_addr):
for line in read_disam(dso_fname, dso_start, start_addr, stop_addr):
m = disasm_func_re.search(line)
if m is None:
m = disasm_re.search(line)
if m is None:
continue
print(f"\t{line}")

def print_sample(sample):
print(f"Sample = {{ cpu: {sample['cpu']:04} addr: 0x{sample['addr']:016x} " \
f"phys_addr: 0x{sample['phys_addr']:016x} ip: 0x{sample['ip']:016x} " \
f"pid: {sample['pid']} tid: {sample['tid']} period: {sample['period']} time: {sample['time']} }}")

def trace_begin():
print('ARM CoreSight Trace Data Assembler Dump')

def trace_end():
print('End')

def trace_unhandled(event_name, context, event_fields_dict):
print(' '.join(['%s=%s'%(k,str(v))for k,v in sorted(event_fields_dict.items())]))

def common_start_str(comm, sample):
sec = int(sample["time"] / 1000000000)
ns = sample["time"] % 1000000000
cpu = sample["cpu"]
pid = sample["pid"]
tid = sample["tid"]
return f"{comm:>16} {pid:>5}/{tid:<5} [{cpu:04}] {sec:9}.{ns:09} "

# This code is copied from intel-pt-events.py for printing source code
# line and symbols.
def print_srccode(comm, param_dict, sample, symbol, dso):
ip = sample["ip"]
if symbol == "[unknown]":
start_str = common_start_str(comm, sample) + ("%x" % ip).rjust(16).ljust(40)
else:
offs = get_offset(param_dict, "symoff")
start_str = common_start_str(comm, sample) + (symbol + offs).ljust(40)

global glb_source_file_name
global glb_line_number
global glb_dso

source_file_name, line_number, source_line = perf_sample_srccode(perf_script_context)
if source_file_name:
if glb_line_number == line_number and glb_source_file_name == source_file_name:
src_str = ""
else:
if len(source_file_name) > 40:
src_file = ("..." + source_file_name[-37:]) + " "
else:
src_file = source_file_name.ljust(41)

if source_line is None:
src_str = src_file + str(line_number).rjust(4) + " <source not found>"
else:
src_str = src_file + str(line_number).rjust(4) + " " + source_line
glb_dso = None
elif dso == glb_dso:
src_str = ""
else:
src_str = dso
glb_dso = dso

glb_line_number = line_number
glb_source_file_name = source_file_name

print(f"{start_str}{src_str}")

def process_event(param_dict):
global cache_size
global options

sample = param_dict["sample"]
comm = param_dict["comm"]

name = param_dict["ev_name"]
dso = get_optional(param_dict, "dso")
dso_bid = get_optional(param_dict, "dso_bid")
dso_start = get_optional(param_dict, "dso_map_start")
dso_end = get_optional(param_dict, "dso_map_end")
symbol = get_optional(param_dict, "symbol")

if (options.verbose == True):
print(f"Event type: {name}")
print_sample(sample)

# If cannot find dso so cannot dump assembler, bail out
if (dso == '[unknown]'):
return

# Validate dso start and end addresses
if ((dso_start == '[unknown]') or (dso_end == '[unknown]')):
print(f"Failed to find valid dso map for dso {dso}")
return

if (name[0:12] == "instructions"):
print_srccode(comm, param_dict, sample, symbol, dso)
return

# Don't proceed if this event is not a branch sample, .
if (name[0:8] != "branches"):
return

cpu = sample["cpu"]
ip = sample["ip"]
addr = sample["addr"]

# Initialize CPU data if it's empty, and directly return back
# if this is the first tracing event for this CPU.
if (cpu_data.get(str(cpu) + 'addr') == None):
cpu_data[str(cpu) + 'addr'] = addr
return

# The format for packet is:
#
# +------------+------------+------------+
# sample_prev: | addr | ip | cpu |
# +------------+------------+------------+
# sample_next: | addr | ip | cpu |
# +------------+------------+------------+
#
# We need to combine the two continuous packets to get the instruction
# range for sample_prev::cpu:
#
# [ sample_prev::addr .. sample_next::ip ]
#
# For this purose, sample_prev::addr is stored into cpu_data structure
# and read back for 'start_addr' when the new packet comes, and we need
# to use sample_next::ip to calculate 'stop_addr', plusing extra 4 for
# 'stop_addr' is for the sake of objdump so the final assembler dump can
# include last instruction for sample_next::ip.
start_addr = cpu_data[str(cpu) + 'addr']
stop_addr = ip + 4

# Record for previous sample packet
cpu_data[str(cpu) + 'addr'] = addr

# Handle CS_ETM_TRACE_ON packet if start_addr=0 and stop_addr=4
if (start_addr == 0 and stop_addr == 4):
print(f"CPU{cpu}: CS_ETM_TRACE_ON packet is inserted")
return

if (start_addr < int(dso_start) or start_addr > int(dso_end)):
print(f"Start address 0x{start_addr:x} is out of range [ 0x{dso_start:x} .. 0x{dso_end:x} ] for dso {dso}")
return

if (stop_addr < int(dso_start) or stop_addr > int(dso_end)):
print(f"Stop address 0x{stop_addr:x} is out of range [ 0x{dso_start:x} .. 0x{dso_end:x} ] for dso {dso}")
return

if (options.objdump_name != None):
# It doesn't need to decrease virtual memory offset for disassembly
# for kernel dso, so in this case we set vm_start to zero.
if (dso == "[kernel.kallsyms]"):
dso_vm_start = 0
else:
dso_vm_start = int(dso_start)

dso_fname = get_dso_file_path(dso, dso_bid)
if path.exists(dso_fname):
print_disam(dso_fname, dso_vm_start, start_addr, stop_addr)
else:
print(f"Failed to find dso {dso} for address range [ 0x{start_addr:x} .. 0x{stop_addr:x} ]")

print_srccode(comm, param_dict, sample, symbol, dso)

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