numam-spdk/scripts/bpf/gen.py
Konrad Sztyber 143aa5cb1f scripts/bpftrace: use SO names in bpftrace scripts
If an USDT probe is defined within a shared object, bpftrace expects the
path to that shared object instead of an executable.  This means that we
need to replace __EXE__ in the bpftrace scripts differently, depending
on whether the application was linked statically or dynamically.

This is now done by the `scripts/bpf/gen.py` script.  It lists all
available probes, along with their locations, of a process.  Then, it
matches them to those described in a bpftrace script replacing the
__EXE__ markers with the listed location (either a path to the
executable or a shared library).  If a bpftrace script uses a probe that
isn't listed, its __EXE__ will be replaced by a path to the executable.

Signed-off-by: Konrad Sztyber <konrad.sztyber@intel.com>
Change-Id: I7c323d5f7d948ea57cf8d4d3132e4d59a2de594f
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/9807
Community-CI: Broadcom CI <spdk-ci.pdl@broadcom.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
2021-10-20 23:39:59 +00:00

54 lines
1.9 KiB
Python
Executable File

#!/usr/bin/env python3
from argparse import ArgumentParser
import os
import re
import subprocess
import sys
class TraceProcess:
def __init__(self, pid):
self._path = os.readlink(f'/proc/{pid}/exe')
self._pid = pid
self._probes = self._init_probes()
def _init_probes(self):
lines = subprocess.check_output(['bpftrace', '-l', '-p', str(self._pid)], text=True)
probes = {}
for line in lines.split('\n'):
parts = line.split(':')
if len(parts) < 3:
continue
ptype, path, function = parts[0], parts[1], parts[-1]
probes[(ptype, function)] = path
return probes
def fixup(self, script):
pregs = [re.compile(r'({}):__EXE__:(\w+)'.format(ptype)) for ptype in ['usdt', 'uprobe']]
with open(script, 'r') as file:
lines = file.readlines()
result = ''
for line in lines:
for regex in pregs:
match = regex.match(line)
if match is not None:
ptype, function = match.groups()
path = self._probes.get((ptype, function), self._path)
line = line.replace('__EXE__', path)
break
result += line.replace('__EXE__', self._path).replace('__PID__', str(self._pid))
return result
if __name__ == '__main__':
parser = ArgumentParser(description='bpftrace script generator replacing special ' +
'variables in the scripts with appropriate values')
parser.add_argument('-p', '--pid', type=int, required=True, help='PID of a traced process')
parser.add_argument('scripts', metavar='SCRIPTS', type=str, nargs='+',
help='bpftrace scripts to process')
args = parser.parse_args(sys.argv[1:])
proc = TraceProcess(args.pid)
for script in args.scripts:
print(proc.fixup(script))