Mercurial > hg > graal-compiler
diff agent/src/os/linux/ps_proc.c @ 8058:2394a89e89f4
8008088: SA can hang the VM
Reviewed-by: mgronlun, sla, dholmes
author | rbackman |
---|---|
date | Wed, 13 Feb 2013 09:46:19 +0100 |
parents | 0a8e0d4345b3 |
children | f2512d89ad0c |
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--- a/agent/src/os/linux/ps_proc.c Wed Feb 13 11:23:46 2013 +0100 +++ b/agent/src/os/linux/ps_proc.c Wed Feb 13 09:46:19 2013 +0100 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it @@ -25,6 +25,7 @@ #include <stdio.h> #include <stdlib.h> #include <string.h> +#include <signal.h> #include <errno.h> #include <sys/ptrace.h> #include "libproc_impl.h" @@ -142,46 +143,71 @@ } +static bool ptrace_continue(pid_t pid, int signal) { + // pass the signal to the process so we don't swallow it + if (ptrace(PTRACE_CONT, pid, NULL, signal) < 0) { + print_debug("ptrace(PTRACE_CONT, ..) failed for %d\n", pid); + return false; + } + return true; +} + +// waits until the ATTACH has stopped the process +// by signal SIGSTOP +static bool ptrace_waitpid(pid_t pid) { + int ret; + int status; + while (true) { + // Wait for debuggee to stop. + ret = waitpid(pid, &status, 0); + if (ret == -1 && errno == ECHILD) { + // try cloned process. + ret = waitpid(pid, &status, __WALL); + } + if (ret >= 0) { + if (WIFSTOPPED(status)) { + // Any signal will stop the thread, make sure it is SIGSTOP. Otherwise SIGSTOP + // will still be pending and delivered when the process is DETACHED and the process + // will go to sleep. + if (WSTOPSIG(status) == SIGSTOP) { + // Debuggee stopped by SIGSTOP. + return true; + } + if (!ptrace_continue(pid, WSTOPSIG(status))) { + print_error("Failed to correctly attach to VM. VM might HANG! [PTRACE_CONT failed, stopped by %d]\n", WSTOPSIG(status)); + return false; + } + } else { + print_debug("waitpid(): Child process exited/terminated (status = 0x%x)\n", status); + return false; + } + } else { + switch (errno) { + case EINTR: + continue; + break; + case ECHILD: + print_debug("waitpid() failed. Child process pid (%d) does not exist \n", pid); + break; + case EINVAL: + print_debug("waitpid() failed. Invalid options argument.\n"); + break; + default: + print_debug("waitpid() failed. Unexpected error %d\n",errno); + break; + } + return false; + } + } +} + // attach to a process/thread specified by "pid" static bool ptrace_attach(pid_t pid) { if (ptrace(PTRACE_ATTACH, pid, NULL, NULL) < 0) { print_debug("ptrace(PTRACE_ATTACH, ..) failed for %d\n", pid); return false; } else { - int ret; - int status; - do { - // Wait for debuggee to stop. - ret = waitpid(pid, &status, 0); - if (ret == -1 && errno == ECHILD) { - // try cloned process. - ret = waitpid(pid, &status, __WALL); - } - if (ret >= 0) { - if (WIFSTOPPED(status)) { - // Debuggee stopped. - return true; - } else { - print_debug("waitpid(): Child process exited/terminated (status = 0x%x)\n", status); - return false; - } - } else { - switch (errno) { - case EINTR: - continue; - break; - case ECHILD: - print_debug("waitpid() failed. Child process pid (%d) does not exist \n", pid); - break; - case EINVAL: - print_debug("waitpid() failed. Invalid options argument.\n"); - break; - default: - print_debug("waitpid() failed. Unexpected error %d\n",errno); - } - return false; - } - } while(true); + return ptrace_waitpid(pid); } }