Mercurial > hg > truffle
diff src/os/solaris/vm/attachListener_solaris.cpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
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children | e392695de029 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/os/solaris/vm/attachListener_solaris.cpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,682 @@ +/* + * Copyright 2005-2006 Sun Microsystems, Inc. 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 + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + +# include "incls/_precompiled.incl" +# include "incls/_attachListener_solaris.cpp.incl" + +#include <door.h> +#include <string.h> +#include <signal.h> +#include <sys/types.h> +#include <sys/socket.h> +#include <sys/stat.h> + +// stropts.h uses STR in stream ioctl defines +#undef STR +#include <stropts.h> +#undef STR +#define STR(a) #a + +// The attach mechanism on Solaris is implemented using the Doors IPC +// mechanism. The first tool to attempt to attach causes the attach +// listener thread to startup. This thread creats a door that is +// associated with a function that enqueues an operation to the attach +// listener. The door is attached to a file in the file system so that +// client (tools) can locate it. To enqueue an operation to the VM the +// client calls through the door which invokes the enqueue function in +// this process. The credentials of the client are checked and if the +// effective uid matches this process then the operation is enqueued. +// When an operation completes the attach listener is required to send the +// operation result and any result data to the client. In this implementation +// the result is returned via a UNIX domain socket. A pair of connected +// sockets (socketpair) is created in the enqueue function and the file +// descriptor for one of the sockets is returned to the client as the +// return from the door call. The other end is retained in this process. +// When the operation completes the result is sent to the client and +// the socket is closed. + +// forward reference +class SolarisAttachOperation; + +class SolarisAttachListener: AllStatic { + private: + + // the path to which we attach the door file descriptor + static char _door_path[PATH_MAX+1]; + static volatile bool _has_door_path; + + // door descriptor returned by door_create + static int _door_descriptor; + + static void set_door_path(char* path) { + if (path == NULL) { + _has_door_path = false; + } else { + strncpy(_door_path, path, PATH_MAX); + _door_path[PATH_MAX] = '\0'; // ensure it's nul terminated + _has_door_path = true; + } + } + + static void set_door_descriptor(int dd) { _door_descriptor = dd; } + + // mutex to protect operation list + static mutex_t _mutex; + + // semaphore to wakeup listener thread + static sema_t _wakeup; + + static mutex_t* mutex() { return &_mutex; } + static sema_t* wakeup() { return &_wakeup; } + + // enqueued operation list + static SolarisAttachOperation* _head; + static SolarisAttachOperation* _tail; + + static SolarisAttachOperation* head() { return _head; } + static void set_head(SolarisAttachOperation* head) { _head = head; } + + static SolarisAttachOperation* tail() { return _tail; } + static void set_tail(SolarisAttachOperation* tail) { _tail = tail; } + + // create the door + static int create_door(); + + public: + enum { + ATTACH_PROTOCOL_VER = 1 // protocol version + }; + enum { + ATTACH_ERROR_BADREQUEST = 100, // error code returned by + ATTACH_ERROR_BADVERSION = 101, // the door call + ATTACH_ERROR_RESOURCE = 102, + ATTACH_ERROR_INTERNAL = 103, + ATTACH_ERROR_DENIED = 104 + }; + + // initialize the listener + static int init(); + + static bool has_door_path() { return _has_door_path; } + static char* door_path() { return _door_path; } + static int door_descriptor() { return _door_descriptor; } + + // enqueue an operation + static void enqueue(SolarisAttachOperation* op); + + // dequeue an operation + static SolarisAttachOperation* dequeue(); +}; + + +// SolarisAttachOperation is an AttachOperation that additionally encapsulates +// a socket connection to the requesting client/tool. SolarisAttachOperation +// can additionally be held in a linked list. + +class SolarisAttachOperation: public AttachOperation { + private: + friend class SolarisAttachListener; + + // connection to client + int _socket; + + // linked list support + SolarisAttachOperation* _next; + + SolarisAttachOperation* next() { return _next; } + void set_next(SolarisAttachOperation* next) { _next = next; } + + public: + void complete(jint res, bufferedStream* st); + + int socket() const { return _socket; } + void set_socket(int s) { _socket = s; } + + SolarisAttachOperation(char* name) : AttachOperation(name) { + set_socket(-1); + set_next(NULL); + } +}; + +// statics +char SolarisAttachListener::_door_path[PATH_MAX+1]; +volatile bool SolarisAttachListener::_has_door_path; +int SolarisAttachListener::_door_descriptor = -1; +mutex_t SolarisAttachListener::_mutex; +sema_t SolarisAttachListener::_wakeup; +SolarisAttachOperation* SolarisAttachListener::_head = NULL; +SolarisAttachOperation* SolarisAttachListener::_tail = NULL; + +// Supporting class to help split a buffer into individual components +class ArgumentIterator : public StackObj { + private: + char* _pos; + char* _end; + public: + ArgumentIterator(char* arg_buffer, size_t arg_size) { + _pos = arg_buffer; + _end = _pos + arg_size - 1; + } + char* next() { + if (*_pos == '\0') { + return NULL; + } + char* res = _pos; + char* next_pos = strchr(_pos, '\0'); + if (next_pos < _end) { + next_pos++; + } + _pos = next_pos; + return res; + } +}; + +// Calls from the door function to check that the client credentials +// match this process. Returns 0 if credentials okay, otherwise -1. +static int check_credentials() { + door_cred_t cred_info; + + // get client credentials + if (door_cred(&cred_info) == -1) { + return -1; // unable to get them + } + + // get our euid/eguid (probably could cache these) + uid_t euid = geteuid(); + gid_t egid = getegid(); + + // check that the effective uid/gid matches - discuss this with Jeff. + if (cred_info.dc_euid == euid && cred_info.dc_egid == egid) { + return 0; // okay + } else { + return -1; // denied + } +} + + +// Parses the argument buffer to create an AttachOperation that we should +// enqueue to the attach listener. +// The buffer is expected to be formatted as follows: +// <ver>0<cmd>0<arg>0<arg>0<arg>0 +// where <ver> is the version number (must be "1"), <cmd> is the command +// name ("load, "datadump", ...) and <arg> is an argument. +// +static SolarisAttachOperation* create_operation(char* argp, size_t arg_size, int* err) { + // assume bad request until parsed + *err = SolarisAttachListener::ATTACH_ERROR_BADREQUEST; + + if (arg_size < 2 || argp[arg_size-1] != '\0') { + return NULL; // no ver or not null terminated + } + + // Use supporting class to iterate over the buffer + ArgumentIterator args(argp, arg_size); + + // First check the protocol version + char* ver = args.next(); + if (ver == NULL) { + return NULL; + } + if (atoi(ver) != SolarisAttachListener::ATTACH_PROTOCOL_VER) { + *err = SolarisAttachListener::ATTACH_ERROR_BADVERSION; + return NULL; + } + + // Get command name and create the operation + char* name = args.next(); + if (name == NULL || strlen(name) > AttachOperation::name_length_max) { + return NULL; + } + SolarisAttachOperation* op = new SolarisAttachOperation(name); + + // Iterate over the arguments + for (int i=0; i<AttachOperation::arg_count_max; i++) { + char* arg = args.next(); + if (arg == NULL) { + op->set_arg(i, NULL); + } else { + if (strlen(arg) > AttachOperation::arg_length_max) { + delete op; + return NULL; + } + op->set_arg(i, arg); + } + } + + // return operation + *err = 0; + return op; +} + +// create special operation to indicate all clients have detached +static SolarisAttachOperation* create_detachall_operation() { + return new SolarisAttachOperation(AttachOperation::detachall_operation_name()); +} + +// This is door function which the client executes via a door_call. +extern "C" { + static void enqueue_proc(void* cookie, char* argp, size_t arg_size, + door_desc_t* dt, uint_t n_desc) + { + int return_fd = -1; + SolarisAttachOperation* op = NULL; + + // no listener + jint res = 0; + if (!AttachListener::is_initialized()) { + // how did we get here? + debug_only(warning("door_call when not enabled")); + res = (jint)SolarisAttachListener::ATTACH_ERROR_INTERNAL; + } + + // check client credentials + if (res == 0) { + if (check_credentials() != 0) { + res = (jint)SolarisAttachListener::ATTACH_ERROR_DENIED; + } + } + + // if we are stopped at ShowMessageBoxOnError then maybe we can + // load a diagnostic library + if (res == 0 && is_error_reported()) { + if (ShowMessageBoxOnError) { + // TBD - support loading of diagnostic library here + } + + // can't enqueue operation after fatal error + res = (jint)SolarisAttachListener::ATTACH_ERROR_RESOURCE; + } + + // create the operation + if (res == 0) { + int err; + op = create_operation(argp, arg_size, &err); + res = (op == NULL) ? (jint)err : 0; + } + + // create a pair of connected sockets. Store the file descriptor + // for one end in the operation and enqueue the operation. The + // file descriptor for the other end wil be returned to the client. + if (res == 0) { + int s[2]; + if (socketpair(PF_UNIX, SOCK_STREAM, 0, s) < 0) { + delete op; + res = (jint)SolarisAttachListener::ATTACH_ERROR_RESOURCE; + } else { + op->set_socket(s[0]); + return_fd = s[1]; + SolarisAttachListener::enqueue(op); + } + } + + // Return 0 (success) + file descriptor, or non-0 (error) + if (res == 0) { + door_desc_t desc; + desc.d_attributes = DOOR_DESCRIPTOR; + desc.d_data.d_desc.d_descriptor = return_fd; + door_return((char*)&res, sizeof(res), &desc, 1); + } else { + door_return((char*)&res, sizeof(res), NULL, 0); + } + } +} + +// atexit hook to detach the door and remove the file +extern "C" { + static void listener_cleanup() { + static int cleanup_done; + if (!cleanup_done) { + cleanup_done = 1; + int dd = SolarisAttachListener::door_descriptor(); + if (dd >= 0) { + ::close(dd); + } + if (SolarisAttachListener::has_door_path()) { + char* path = SolarisAttachListener::door_path(); + ::fdetach(path); + ::unlink(path); + } + } + } +} + +// Create the door +int SolarisAttachListener::create_door() { + char door_path[PATH_MAX+1]; + int fd, res; + + // register exit function + ::atexit(listener_cleanup); + + // create the door descriptor + int dd = ::door_create(enqueue_proc, NULL, 0); + if (dd < 0) { + return -1; + } + + sprintf(door_path, "%s/.java_pid%d", os::get_temp_directory(), os::current_process_id()); + RESTARTABLE(::creat(door_path, S_IRUSR | S_IWUSR), fd); + + if (fd == -1) { + debug_only(warning("attempt to create %s failed", door_path)); + return -1; + } + assert(fd >= 0, "bad file descriptor"); + set_door_path(door_path); + RESTARTABLE(::close(fd), res); + + // attach the door descriptor to the file + if ((res = ::fattach(dd, door_path)) == -1) { + // if busy then detach and try again + if (errno == EBUSY) { + ::fdetach(door_path); + res = ::fattach(dd, door_path); + } + if (res == -1) { + ::door_revoke(dd); + dd = -1; + } + } + if (dd >= 0) { + set_door_descriptor(dd); + } else { + // unable to create door or attach it to the file + ::unlink(door_path); + set_door_path(NULL); + return -1; + } + + return 0; +} + +// Initialization - create the door, locks, and other initialization +int SolarisAttachListener::init() { + if (create_door()) { + return -1; + } + + int status = os::Solaris::mutex_init(&_mutex); + assert_status(status==0, status, "mutex_init"); + + status = ::sema_init(&_wakeup, 0, NULL, NULL); + assert_status(status==0, status, "sema_init"); + + set_head(NULL); + set_tail(NULL); + + return 0; +} + +// Dequeue an operation +SolarisAttachOperation* SolarisAttachListener::dequeue() { + for (;;) { + int res; + + // wait for somebody to enqueue something + while ((res = ::sema_wait(wakeup())) == EINTR) + ; + if (res) { + warning("sema_wait failed: %s", strerror(res)); + return NULL; + } + + // lock the list + res = os::Solaris::mutex_lock(mutex()); + assert(res == 0, "mutex_lock failed"); + + // remove the head of the list + SolarisAttachOperation* op = head(); + if (op != NULL) { + set_head(op->next()); + if (head() == NULL) { + set_tail(NULL); + } + } + + // unlock + os::Solaris::mutex_unlock(mutex()); + + // if we got an operation when return it. + if (op != NULL) { + return op; + } + } +} + +// Enqueue an operation +void SolarisAttachListener::enqueue(SolarisAttachOperation* op) { + // lock list + int res = os::Solaris::mutex_lock(mutex()); + assert(res == 0, "mutex_lock failed"); + + // enqueue at tail + op->set_next(NULL); + if (head() == NULL) { + set_head(op); + } else { + tail()->set_next(op); + } + set_tail(op); + + // wakeup the attach listener + RESTARTABLE(::sema_post(wakeup()), res); + assert(res == 0, "sema_post failed"); + + // unlock + os::Solaris::mutex_unlock(mutex()); +} + + +// support function - writes the (entire) buffer to a socket +static int write_fully(int s, char* buf, int len) { + do { + int n = ::write(s, buf, len); + if (n == -1) { + if (errno != EINTR) return -1; + } else { + buf += n; + len -= n; + } + } + while (len > 0); + return 0; +} + +// Complete an operation by sending the operation result and any result +// output to the client. At this time the socket is in blocking mode so +// potentially we can block if there is a lot of data and the client is +// non-responsive. For most operations this is a non-issue because the +// default send buffer is sufficient to buffer everything. In the future +// if there are operations that involves a very big reply then it the +// socket could be made non-blocking and a timeout could be used. + +void SolarisAttachOperation::complete(jint res, bufferedStream* st) { + if (this->socket() >= 0) { + JavaThread* thread = JavaThread::current(); + ThreadBlockInVM tbivm(thread); + + thread->set_suspend_equivalent(); + // cleared by handle_special_suspend_equivalent_condition() or + // java_suspend_self() via check_and_wait_while_suspended() + + // write operation result + char msg[32]; + sprintf(msg, "%d\n", res); + int rc = write_fully(this->socket(), msg, strlen(msg)); + + // write any result data + if (rc == 0) { + write_fully(this->socket(), (char*) st->base(), st->size()); + ::shutdown(this->socket(), 2); + } + + // close socket and we're done + RESTARTABLE(::close(this->socket()), rc); + + // were we externally suspended while we were waiting? + thread->check_and_wait_while_suspended(); + } + delete this; +} + + +// AttachListener functions + +AttachOperation* AttachListener::dequeue() { + JavaThread* thread = JavaThread::current(); + ThreadBlockInVM tbivm(thread); + + thread->set_suspend_equivalent(); + // cleared by handle_special_suspend_equivalent_condition() or + // java_suspend_self() via check_and_wait_while_suspended() + + AttachOperation* op = SolarisAttachListener::dequeue(); + + // were we externally suspended while we were waiting? + thread->check_and_wait_while_suspended(); + + return op; +} + +int AttachListener::pd_init() { + JavaThread* thread = JavaThread::current(); + ThreadBlockInVM tbivm(thread); + + thread->set_suspend_equivalent(); + // cleared by handle_special_suspend_equivalent_condition() or + // java_suspend_self() + + int ret_code = SolarisAttachListener::init(); + + // were we externally suspended while we were waiting? + thread->check_and_wait_while_suspended(); + + return ret_code; +} + +// Attach Listener is started lazily except in the case when +// +ReduseSignalUsage is used +bool AttachListener::init_at_startup() { + if (ReduceSignalUsage) { + return true; + } else { + return false; + } +} + +// If the file .attach_pid<pid> exists in the working directory +// or /tmp then this is the trigger to start the attach mechanism +bool AttachListener::is_init_trigger() { + if (init_at_startup() || is_initialized()) { + return false; // initialized at startup or already initialized + } + char fn[32]; + sprintf(fn, ".attach_pid%d", os::current_process_id()); + int ret; + struct stat64 st; + RESTARTABLE(::stat64(fn, &st), ret); + if (ret == -1) { + sprintf(fn, "/tmp/.attach_pid%d", os::current_process_id()); + RESTARTABLE(::stat64(fn, &st), ret); + } + if (ret == 0) { + // simple check to avoid starting the attach mechanism when + // a bogus user creates the file + if (st.st_uid == geteuid()) { + init(); + return true; + } + } + return false; +} + +// if VM aborts then detach/cleanup +void AttachListener::abort() { + listener_cleanup(); +} + +void AttachListener::pd_data_dump() { + os::signal_notify(SIGQUIT); +} + +static jint enable_dprobes(AttachOperation* op, outputStream* out) { + const char* probe = op->arg(0); + if (probe == NULL || probe[0] == '\0') { + out->print_cr("No probe specified"); + return JNI_ERR; + } else { + int probe_typess = atoi(probe); + if (errno) { + out->print_cr("invalid probe type"); + return JNI_ERR; + } else { + DTrace::enable_dprobes(probe_typess); + return JNI_OK; + } + } +} + +// platform specific operations table +static AttachOperationFunctionInfo funcs[] = { + { "enabledprobes", enable_dprobes }, + { NULL, NULL } +}; + +AttachOperationFunctionInfo* AttachListener::pd_find_operation(const char* name) { + int i; + for (i = 0; funcs[i].name != NULL; i++) { + if (strcmp(funcs[i].name, name) == 0) { + return &funcs[i]; + } + } + return NULL; +} + +// Solaris specific global flag set. Currently, we support only +// changing ExtendedDTraceProbes flag. +jint AttachListener::pd_set_flag(AttachOperation* op, outputStream* out) { + const char* name = op->arg(0); + assert(name != NULL, "flag name should not be null"); + bool flag = true; + const char* arg1; + if ((arg1 = op->arg(1)) != NULL) { + flag = (atoi(arg1) != 0); + if (errno) { + out->print_cr("flag value has to be an integer"); + return JNI_ERR; + } + } + + if (strcmp(name, "ExtendedDTraceProbes") != 0) { + out->print_cr("flag '%s' cannot be changed", name); + return JNI_ERR; + } + + DTrace::set_extended_dprobes(flag); + return JNI_OK; +} + +void AttachListener::pd_detachall() { + DTrace::detach_all_clients(); +}