1*387f9dfdSAndroid Build Coastguard Worker#!/usr/bin/env bcc-lua 2*387f9dfdSAndroid Build Coastguard Worker--[[ 3*387f9dfdSAndroid Build Coastguard WorkerCopyright 2016 GitHub, Inc 4*387f9dfdSAndroid Build Coastguard Worker 5*387f9dfdSAndroid Build Coastguard WorkerLicensed under the Apache License, Version 2.0 (the "License"); 6*387f9dfdSAndroid Build Coastguard Workeryou may not use this file except in compliance with the License. 7*387f9dfdSAndroid Build Coastguard WorkerYou may obtain a copy of the License at 8*387f9dfdSAndroid Build Coastguard Worker 9*387f9dfdSAndroid Build Coastguard Workerhttp://www.apache.org/licenses/LICENSE-2.0 10*387f9dfdSAndroid Build Coastguard Worker 11*387f9dfdSAndroid Build Coastguard WorkerUnless required by applicable law or agreed to in writing, software 12*387f9dfdSAndroid Build Coastguard Workerdistributed under the License is distributed on an "AS IS" BASIS, 13*387f9dfdSAndroid Build Coastguard WorkerWITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14*387f9dfdSAndroid Build Coastguard WorkerSee the License for the specific language governing permissions and 15*387f9dfdSAndroid Build Coastguard Workerlimitations under the License. 16*387f9dfdSAndroid Build Coastguard Worker]] 17*387f9dfdSAndroid Build Coastguard Worker 18*387f9dfdSAndroid Build Coastguard Workerassert(arg[1], "usage: strlen_count PID") 19*387f9dfdSAndroid Build Coastguard Worker 20*387f9dfdSAndroid Build Coastguard Workerlocal program = string.gsub([[ 21*387f9dfdSAndroid Build Coastguard Worker#include <uapi/linux/ptrace.h> 22*387f9dfdSAndroid Build Coastguard Workerint printarg(struct pt_regs *ctx) { 23*387f9dfdSAndroid Build Coastguard Worker if (!PT_REGS_PARM1(ctx)) 24*387f9dfdSAndroid Build Coastguard Worker return 0; 25*387f9dfdSAndroid Build Coastguard Worker u32 pid = bpf_get_current_pid_tgid(); 26*387f9dfdSAndroid Build Coastguard Worker if (pid != PID) 27*387f9dfdSAndroid Build Coastguard Worker return 0; 28*387f9dfdSAndroid Build Coastguard Worker char str[128] = {}; 29*387f9dfdSAndroid Build Coastguard Worker bpf_probe_read_user(&str, sizeof(str), (void *)PT_REGS_PARM1(ctx)); 30*387f9dfdSAndroid Build Coastguard Worker bpf_trace_printk("strlen(\"%s\")\n", &str); 31*387f9dfdSAndroid Build Coastguard Worker return 0; 32*387f9dfdSAndroid Build Coastguard Worker}; 33*387f9dfdSAndroid Build Coastguard Worker]], "PID", arg[1]) 34*387f9dfdSAndroid Build Coastguard Worker 35*387f9dfdSAndroid Build Coastguard Workerreturn function(BPF) 36*387f9dfdSAndroid Build Coastguard Worker local b = BPF:new{text=program, debug=0} 37*387f9dfdSAndroid Build Coastguard Worker b:attach_uprobe{name="c", sym="strlen", fn_name="printarg"} 38*387f9dfdSAndroid Build Coastguard Worker 39*387f9dfdSAndroid Build Coastguard Worker local pipe = b:pipe() 40*387f9dfdSAndroid Build Coastguard Worker while true do 41*387f9dfdSAndroid Build Coastguard Worker local task, pid, cpu, flags, ts, msg = pipe:trace_fields() 42*387f9dfdSAndroid Build Coastguard Worker print("%-18.9f %-16s %-6d %s" % {ts, task, pid, msg}) 43*387f9dfdSAndroid Build Coastguard Worker end 44*387f9dfdSAndroid Build Coastguard Workerend 45