1.1 --- a/agent/src/os/bsd/ps_proc.c Wed Feb 13 11:23:46 2013 +0100
1.2 +++ b/agent/src/os/bsd/ps_proc.c Wed Feb 13 09:46:19 2013 +0100
1.3 @@ -1,5 +1,5 @@
1.4 /*
1.5 - * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
1.6 + * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
1.7 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.8 *
1.9 * This code is free software; you can redistribute it and/or modify it
1.10 @@ -129,42 +129,66 @@
1.11 return (errno == 0)? true: false;
1.12 }
1.13
1.14 +static bool ptrace_continue(pid_t pid, int signal) {
1.15 + // pass the signal to the process so we don't swallow it
1.16 + if (ptrace(PTRACE_CONT, pid, NULL, signal) < 0) {
1.17 + print_debug("ptrace(PTRACE_CONT, ..) failed for %d\n", pid);
1.18 + return false;
1.19 + }
1.20 + return true;
1.21 +}
1.22 +
1.23 +// waits until the ATTACH has stopped the process
1.24 +// by signal SIGSTOP
1.25 +static bool ptrace_waitpid(pid_t pid) {
1.26 + int ret;
1.27 + int status;
1.28 + do {
1.29 + // Wait for debuggee to stop.
1.30 + ret = waitpid(pid, &status, 0);
1.31 + if (ret >= 0) {
1.32 + if (WIFSTOPPED(status)) {
1.33 + // Any signal will stop the thread, make sure it is SIGSTOP. Otherwise SIGSTOP
1.34 + // will still be pending and delivered when the process is DETACHED and the process
1.35 + // will go to sleep.
1.36 + if (WSTOPSIG(status) == SIGSTOP) {
1.37 + // Debuggee stopped by SIGSTOP.
1.38 + return true;
1.39 + }
1.40 + if (!ptrace_continue(pid, WSTOPSIG(status))) {
1.41 + print_error("Failed to correctly attach to VM. VM might HANG! [PTRACE_CONT failed, stopped by %d]\n", WSTOPSIG(status));
1.42 + return false;
1.43 + }
1.44 + } else {
1.45 + print_debug("waitpid(): Child process exited/terminated (status = 0x%x)\n", status);
1.46 + return false;
1.47 + }
1.48 + } else {
1.49 + switch (errno) {
1.50 + case EINTR:
1.51 + continue;
1.52 + break;
1.53 + case ECHILD:
1.54 + print_debug("waitpid() failed. Child process pid (%d) does not exist \n", pid);
1.55 + break;
1.56 + case EINVAL:
1.57 + print_debug("waitpid() failed. Invalid options argument.\n");
1.58 + break;
1.59 + default:
1.60 + print_debug("waitpid() failed. Unexpected error %d\n",errno);
1.61 + }
1.62 + return false;
1.63 + }
1.64 + } while(true);
1.65 +}
1.66 +
1.67 // attach to a process/thread specified by "pid"
1.68 static bool ptrace_attach(pid_t pid) {
1.69 if (ptrace(PT_ATTACH, pid, NULL, 0) < 0) {
1.70 print_debug("ptrace(PTRACE_ATTACH, ..) failed for %d\n", pid);
1.71 return false;
1.72 } else {
1.73 - int ret;
1.74 - int status;
1.75 - do {
1.76 - // Wait for debuggee to stop.
1.77 - ret = waitpid(pid, &status, 0);
1.78 - if (ret >= 0) {
1.79 - if (WIFSTOPPED(status)) {
1.80 - // Debuggee stopped.
1.81 - return true;
1.82 - } else {
1.83 - print_debug("waitpid(): Child process exited/terminated (status = 0x%x)\n", status);
1.84 - return false;
1.85 - }
1.86 - } else {
1.87 - switch (errno) {
1.88 - case EINTR:
1.89 - continue;
1.90 - break;
1.91 - case ECHILD:
1.92 - print_debug("waitpid() failed. Child process pid (%d) does not exist \n", pid);
1.93 - break;
1.94 - case EINVAL:
1.95 - print_debug("waitpid() failed. Invalid options argument.\n");
1.96 - break;
1.97 - default:
1.98 - print_debug("waitpid() failed. Unexpected error %d\n",errno);
1.99 - }
1.100 - return false;
1.101 - }
1.102 - } while(true);
1.103 + return ptrace_waitpid(pid);
1.104 }
1.105 }
1.106
