diff src/os/solaris/dtrace/jvm_dtrace.c @ 0:a61af66fc99e

Initial load
author duke
date Sat, 01 Dec 2007 00:00:00 +0000
parents
children c18cbe5936b8
line wrap: on
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/os/solaris/dtrace/jvm_dtrace.c	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,565 @@
+/*
+ * Copyright 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 <door.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <poll.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <thread.h>
+#include <unistd.h>
+#include "jvm_dtrace.h"
+
+// NOTE: These constants are used in JVM code as well.
+// KEEP JVM CODE IN SYNC if you are going to change these...
+
+#define DTRACE_ALLOC_PROBES   0x1
+#define DTRACE_METHOD_PROBES  0x2
+#define DTRACE_MONITOR_PROBES 0x4
+#define DTRACE_ALL_PROBES     -1
+
+// generic error messages
+#define JVM_ERR_OUT_OF_MEMORY            "out of memory (native heap)"
+#define JVM_ERR_INVALID_PARAM            "invalid input parameter(s)"
+#define JVM_ERR_NULL_PARAM               "input paramater is NULL"
+
+// error messages for attach
+#define JVM_ERR_CANT_OPEN_DOOR           "cannot open door file"
+#define JVM_ERR_CANT_CREATE_ATTACH_FILE  "cannot create attach file"
+#define JVM_ERR_DOOR_FILE_PERMISSION     "door file is not secure"
+#define JVM_ERR_CANT_SIGNAL              "cannot send SIGQUIT to target"
+
+// error messages for enable probe
+#define JVM_ERR_DOOR_CMD_SEND            "door command send failed"
+#define JVM_ERR_DOOR_CANT_READ_STATUS    "cannot read door command status"
+#define JVM_ERR_DOOR_CMD_STATUS          "door command error status"
+
+// error message for detach
+#define JVM_ERR_CANT_CLOSE_DOOR          "cannot close door file"
+
+#define RESTARTABLE(_cmd, _result) do { \
+    do { \
+        _result = _cmd; \
+    } while((_result == -1) && (errno == EINTR)); \
+} while(0)
+
+struct _jvm_t {
+    pid_t pid;
+    int door_fd;
+};
+
+static int libjvm_dtrace_debug;
+static void print_debug(const char* fmt,...) {
+    if (libjvm_dtrace_debug) {
+        va_list alist;
+        va_start(alist, fmt);
+        fputs("libjvm_dtrace DEBUG: ", stderr);
+        vfprintf(stderr, fmt, alist);
+        va_end(alist);
+    }
+}
+
+/* Key for thread local error message */
+static thread_key_t jvm_error_key;
+
+/* init function for this library */
+static void init_jvm_dtrace() {
+    /* check for env. var for debug mode */
+    libjvm_dtrace_debug = getenv("LIBJVM_DTRACE_DEBUG") != NULL;
+    /* create key for thread local error message */
+    if (thr_keycreate(&jvm_error_key, NULL) != 0) {
+        print_debug("can't create thread_key_t for jvm error key\n");
+        // exit(1); ?
+    }
+}
+
+#pragma init(init_jvm_dtrace)
+
+/* set thread local error message */
+static void set_jvm_error(const char* msg) {
+    thr_setspecific(jvm_error_key, (void*)msg);
+}
+
+/* clear thread local error message */
+static void clear_jvm_error() {
+    thr_setspecific(jvm_error_key, NULL);
+}
+
+/* file handling functions that can handle interrupt */
+
+static int file_open(const char* path, int flag) {
+    int ret;
+    RESTARTABLE(open(path, flag), ret);
+    return ret;
+}
+
+static int file_close(int fd) {
+    int ret;
+    RESTARTABLE(close(fd), ret);
+    return ret;
+}
+
+static int file_read(int fd, char* buf, int len) {
+    int ret;
+    RESTARTABLE(read(fd, buf, len), ret);
+    return ret;
+}
+
+/* send SIGQUIT signal to given process */
+static int send_sigquit(pid_t pid) {
+    int ret;
+    RESTARTABLE(kill(pid, SIGQUIT), ret);
+    return ret;
+}
+
+/* called to check permissions on attach file */
+static int check_permission(const char* path) {
+    struct stat64 sb;
+    uid_t uid, gid;
+    int res;
+
+    /*
+     * Check that the path is owned by the effective uid/gid of this
+     * process. Also check that group/other access is not allowed.
+     */
+    uid = geteuid();
+    gid = getegid();
+
+    res = stat64(path, &sb);
+    if (res != 0) {
+        print_debug("stat failed for %s\n", path);
+        return -1;
+    }
+
+    if ((sb.st_uid != uid) || (sb.st_gid != gid) ||
+        ((sb.st_mode & (S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH)) != 0)) {
+        print_debug("well-known file %s is not secure\n", path);
+        return -1;
+    }
+    return 0;
+}
+
+#define ATTACH_FILE_PATTERN "/tmp/.attach_pid%d"
+
+/* fill-in the name of attach file name in given buffer */
+static void fill_attach_file_name(char* path, int len, pid_t pid) {
+    memset(path, 0, len);
+    sprintf(path, ATTACH_FILE_PATTERN, pid);
+}
+
+#define DOOR_FILE_PATTERN "/tmp/.java_pid%d"
+
+/* open door file for the given JVM */
+static int open_door(pid_t pid) {
+    char path[PATH_MAX + 1];
+    int fd;
+
+    sprintf(path, DOOR_FILE_PATTERN, pid);
+    fd = file_open(path, O_RDONLY);
+    if (fd < 0) {
+        set_jvm_error(JVM_ERR_CANT_OPEN_DOOR);
+        print_debug("cannot open door file %s\n", path);
+        return -1;
+    }
+    print_debug("opened door file %s\n", path);
+    if (check_permission(path) != 0) {
+        set_jvm_error(JVM_ERR_DOOR_FILE_PERMISSION);
+        print_debug("check permission failed for %s\n", path);
+        file_close(fd);
+        fd = -1;
+    }
+    return fd;
+}
+
+/* create attach file for given process */
+static int create_attach_file(pid_t pid) {
+    char path[PATH_MAX + 1];
+    int fd;
+    fill_attach_file_name(path, sizeof(path), pid);
+    fd = file_open(path, O_CREAT | O_RDWR);
+    if (fd < 0) {
+        set_jvm_error(JVM_ERR_CANT_CREATE_ATTACH_FILE);
+        print_debug("cannot create file %s\n", path);
+    } else {
+        print_debug("created attach file %s\n", path);
+    }
+    return fd;
+}
+
+/* delete attach file for given process */
+static void delete_attach_file(pid_t pid) {
+    char path[PATH_MAX + 1];
+    fill_attach_file_name(path, sizeof(path), pid);
+    int res = unlink(path);
+    if (res) {
+        print_debug("cannot delete attach file %s\n", path);
+    } else {
+        print_debug("deleted attach file %s\n", path);
+    }
+}
+
+/* attach to given JVM */
+jvm_t* jvm_attach(pid_t pid) {
+    jvm_t* jvm;
+    int door_fd, attach_fd, i;
+
+    jvm = (jvm_t*) calloc(1, sizeof(jvm_t));
+    if (jvm == NULL) {
+        set_jvm_error(JVM_ERR_OUT_OF_MEMORY);
+        print_debug("calloc failed in %s at %d\n", __FILE__, __LINE__);
+        return NULL;
+    }
+    jvm->pid = pid;
+    attach_fd = -1;
+
+    door_fd = open_door(pid);
+    if (door_fd < 0) {
+        print_debug("trying to create attach file\n");
+        if ((attach_fd = create_attach_file(pid)) < 0) {
+            goto quit;
+        }
+
+        /* send QUIT signal to the target so that it will
+         * check for the attach file.
+         */
+        if (send_sigquit(pid) != 0) {
+            set_jvm_error(JVM_ERR_CANT_SIGNAL);
+            print_debug("sending SIGQUIT failed\n");
+            goto quit;
+        }
+
+        /* give the target VM time to start the attach mechanism */
+        do {
+            int res;
+            RESTARTABLE(poll(0, 0, 200), res);
+            door_fd = open_door(pid);
+            i++;
+        } while (i <= 50 && door_fd == -1);
+        if (door_fd < 0) {
+            print_debug("Unable to open door to process %d\n", pid);
+            goto quit;
+        }
+    }
+
+quit:
+    if (attach_fd >= 0) {
+        file_close(attach_fd);
+        delete_attach_file(jvm->pid);
+    }
+    if (door_fd >= 0) {
+        jvm->door_fd = door_fd;
+        clear_jvm_error();
+    } else {
+        free(jvm);
+        jvm = NULL;
+    }
+    return jvm;
+}
+
+/* return the last thread local error message */
+const char* jvm_get_last_error() {
+    const char* res = NULL;
+    thr_getspecific(jvm_error_key, (void**)&res);
+    return res;
+}
+
+/* detach the givenb JVM */
+int jvm_detach(jvm_t* jvm) {
+    if (jvm) {
+        int res;
+        if (jvm->door_fd != -1) {
+            if (file_close(jvm->door_fd) != 0) {
+                set_jvm_error(JVM_ERR_CANT_CLOSE_DOOR);
+                res = -1;
+            } else {
+                clear_jvm_error();
+                res = 0;
+            }
+        }
+        free(jvm);
+        return res;
+    } else {
+        set_jvm_error(JVM_ERR_NULL_PARAM);
+        print_debug("jvm_t* is NULL\n");
+        return -1;
+    }
+}
+
+/*
+ * A simple table to translate some known errors into reasonable
+ * error messages
+ */
+static struct {
+    int err;
+    const char* msg;
+} const error_messages[] = {
+    { 100,      "Bad request" },
+    { 101,      "Protocol mismatch" },
+    { 102,      "Resource failure" },
+    { 103,      "Internal error" },
+    { 104,      "Permission denied" },
+};
+
+/*
+ * Lookup the given error code and return the appropriate
+ * message. If not found return NULL.
+ */
+static const char* translate_error(int err) {
+    int table_size = sizeof(error_messages) / sizeof(error_messages[0]);
+    int i;
+
+    for (i=0; i<table_size; i++) {
+        if (err == error_messages[i].err) {
+            return error_messages[i].msg;
+        }
+    }
+    return NULL;
+}
+
+/*
+ * Current protocol version
+ */
+static const char* PROTOCOL_VERSION = "1";
+
+#define RES_BUF_SIZE 128
+
+/*
+ * Enqueue attach-on-demand command to the given JVM
+ */
+static
+int enqueue_command(jvm_t* jvm, const char* cstr, int arg_count, const char** args) {
+    size_t size;
+    door_arg_t door_args;
+    char res_buffer[RES_BUF_SIZE];
+    int rc, i;
+    char* buf = NULL;
+    int result = -1;
+
+    /*
+     * First we get the command string and create the start of the
+     * argument string to send to the target VM:
+     * <ver>\0<cmd>\0
+     */
+    if (cstr == NULL) {
+        print_debug("command name is NULL\n");
+        goto quit;
+    }
+    size = strlen(PROTOCOL_VERSION) + strlen(cstr) + 2;
+    buf = (char*)malloc(size);
+    if (buf != NULL) {
+        char* pos = buf;
+        strcpy(buf, PROTOCOL_VERSION);
+        pos += strlen(PROTOCOL_VERSION)+1;
+        strcpy(pos, cstr);
+    } else {
+        set_jvm_error(JVM_ERR_OUT_OF_MEMORY);
+        print_debug("malloc failed at %d in %s\n", __LINE__, __FILE__);
+        goto quit;
+    }
+
+    /*
+     * Next we iterate over the arguments and extend the buffer
+     * to include them.
+     */
+    for (i=0; i<arg_count; i++) {
+        cstr = args[i];
+        if (cstr != NULL) {
+            size_t len = strlen(cstr);
+            char* newbuf = (char*)realloc(buf, size+len+1);
+            if (newbuf == NULL) {
+                set_jvm_error(JVM_ERR_OUT_OF_MEMORY);
+                print_debug("realloc failed in %s at %d\n", __FILE__, __LINE__);
+                goto quit;
+            }
+            buf = newbuf;
+            strcpy(buf+size, cstr);
+            size += len+1;
+        }
+    }
+
+    /*
+     * The arguments to the door function are in 'buf' so we now
+     * do the door call
+     */
+    door_args.data_ptr = buf;
+    door_args.data_size = size;
+    door_args.desc_ptr = NULL;
+    door_args.desc_num = 0;
+    door_args.rbuf = (char*)&res_buffer;
+    door_args.rsize = sizeof(res_buffer);
+
+    RESTARTABLE(door_call(jvm->door_fd, &door_args), rc);
+
+    /*
+     * door_call failed
+     */
+    if (rc == -1) {
+        print_debug("door_call failed\n");
+    } else {
+        /*
+         * door_call succeeded but the call didn't return the the expected jint.
+         */
+        if (door_args.data_size < sizeof(int)) {
+            print_debug("Enqueue error - reason unknown as result is truncated!");
+        } else {
+            int* res = (int*)(door_args.data_ptr);
+            if (*res != 0) {
+                const char* msg = translate_error(*res);
+                if (msg == NULL) {
+                    print_debug("Unable to enqueue command to target VM: %d\n", *res);
+                } else {
+                    print_debug("Unable to enqueue command to target VM: %s\n", msg);
+                }
+            } else {
+                /*
+                 * The door call should return a file descriptor to one end of
+                 * a socket pair
+                 */
+                if ((door_args.desc_ptr != NULL) &&
+                    (door_args.desc_num == 1) &&
+                    (door_args.desc_ptr->d_attributes & DOOR_DESCRIPTOR)) {
+                    result = door_args.desc_ptr->d_data.d_desc.d_descriptor;
+                } else {
+                    print_debug("Reply from enqueue missing descriptor!\n");
+                }
+            }
+        }
+    }
+
+quit:
+    if (buf) free(buf);
+    return result;
+}
+
+/* read status code for a door command */
+static int read_status(int fd) {
+    char ch, buf[16];
+    int index = 0;
+
+    while (1) {
+        if (file_read(fd, &ch, sizeof(ch)) != sizeof(ch)) {
+            set_jvm_error(JVM_ERR_DOOR_CANT_READ_STATUS);
+            print_debug("door cmd status: read status failed\n");
+            return -1;
+        }
+        buf[index++] = ch;
+        if (ch == '\n') {
+            buf[index - 1] = '\0';
+            return atoi(buf);
+        }
+        if (index == sizeof(buf)) {
+            set_jvm_error(JVM_ERR_DOOR_CANT_READ_STATUS);
+            print_debug("door cmd status: read status overflow\n");
+            return -1;
+        }
+    }
+}
+
+static const char* ENABLE_DPROBES_CMD = "enabledprobes";
+
+/* enable one or more DTrace probes for a given JVM */
+int jvm_enable_dtprobes(jvm_t* jvm, int num_probe_types, const char** probe_types) {
+    int fd, status = 0;
+    char ch;
+    const char* args[1];
+    char buf[16];
+    int probe_type = 0, index;
+    int count = 0;
+
+    if (jvm == NULL) {
+        set_jvm_error(JVM_ERR_NULL_PARAM);
+        print_debug("jvm_t* is NULL\n");
+        return -1;
+    }
+
+    if (num_probe_types == 0 || probe_types == NULL ||
+        probe_types[0] == NULL) {
+        set_jvm_error(JVM_ERR_INVALID_PARAM);
+        print_debug("invalid probe type argument(s)\n");
+        return -1;
+    }
+
+    for (index = 0; index < num_probe_types; index++) {
+        const char* p = probe_types[index];
+        if (strcmp(p, JVM_DTPROBE_OBJECT_ALLOC) == 0) {
+            probe_type |= DTRACE_ALLOC_PROBES;
+            count++;
+        } else if (strcmp(p, JVM_DTPROBE_METHOD_ENTRY) == 0 ||
+                   strcmp(p, JVM_DTPROBE_METHOD_RETURN) == 0) {
+            probe_type |= DTRACE_METHOD_PROBES;
+            count++;
+        } else if (strcmp(p, JVM_DTPROBE_MONITOR_ENTER) == 0   ||
+                   strcmp(p, JVM_DTPROBE_MONITOR_ENTERED) == 0 ||
+                   strcmp(p, JVM_DTPROBE_MONITOR_EXIT) == 0    ||
+                   strcmp(p, JVM_DTPROBE_MONITOR_WAIT) == 0    ||
+                   strcmp(p, JVM_DTPROBE_MONITOR_WAITED) == 0  ||
+                   strcmp(p, JVM_DTPROBE_MONITOR_NOTIFY) == 0  ||
+                   strcmp(p, JVM_DTPROBE_MONITOR_NOTIFYALL) == 0) {
+            probe_type |= DTRACE_MONITOR_PROBES;
+            count++;
+        } else if (strcmp(p, JVM_DTPROBE_ALL) == 0) {
+            probe_type |= DTRACE_ALL_PROBES;
+            count++;
+        }
+    }
+
+    if (count == 0) {
+        return count;
+    }
+    sprintf(buf, "%d", probe_type);
+    args[0] = buf;
+
+    fd = enqueue_command(jvm, ENABLE_DPROBES_CMD, 1, args);
+    if (fd < 0) {
+        set_jvm_error(JVM_ERR_DOOR_CMD_SEND);
+        return -1;
+    }
+
+    status = read_status(fd);
+    // non-zero status is error
+    if (status) {
+        set_jvm_error(JVM_ERR_DOOR_CMD_STATUS);
+        print_debug("%s command failed (status: %d) in target JVM\n",
+                    ENABLE_DPROBES_CMD, status);
+        file_close(fd);
+        return -1;
+    }
+    // read from stream until EOF
+    while (file_read(fd, &ch, sizeof(ch)) == sizeof(ch)) {
+        if (libjvm_dtrace_debug) {
+            printf("%c", ch);
+        }
+    }
+
+    file_close(fd);
+    clear_jvm_error();
+    return count;
+}