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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* Includes
*/
#ifndef DEBUG
#define NDEBUG 1
#endif
#include <assert.h>
#include <limits.h>
#include <values.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <dlfcn.h>
#include <sys/mman.h>
#include <sys/param.h>
#include <thread.h>
#include <sys/lwp.h>
#include <errno.h>
#include "tnf_trace.h"
/*
* Defines
*/
#define TNF_FILE_MODE (S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH)
/*
* Declarations
*/
extern void thr_probe_setup(void *);
#pragma weak thr_probe_setup
/*
* Globals
*/
static TNFW_B_CONTROL __tnfw_b_control_local = {
TNFW_B_NOBUFFER,
NULL,
_tnf_trace_initialize,
_tnf_fork_thread_setup,
NULL
};
TNFW_B_CONTROL *_tnfw_b_control = &__tnfw_b_control_local;
static char *file_start;
/*
* Two Project Private Interfaces between prex and libtnfprobe -
* tnf_trace_file_name and tnf_trace_file_size (three now ...)
*/
char tnf_trace_file_name[MAXPATHLEN] = "";
uint_t tnf_trace_file_size = 4194304; /* 4 Meg */
uint_t tnf_trace_file_min = (128 * 1024);
tnf_ops_t tnf_trace_initial_tpd = {
TNF_ALLOC_REUSABLE, /* mode */
tnfw_b_alloc, /* alloc */
tnfw_b_xcommit, /* commit */
tnfw_b_xabort, /* rollback */
{
B_FALSE /* tnfw_w_initialized */
/* rest of struct is null */
},
0 /* busy */
};
/*
* tnf_process_enable: exported API to turn on tracing for the process
* (on by default).
*/
void
tnf_process_enable(void)
{
TNFW_B_UNSET_STOPPED(_tnfw_b_control->tnf_state);
}
/*
* tnf_process_disable: exported API to turn off tracing for the process.
*/
void
tnf_process_disable(void)
{
TNFW_B_SET_STOPPED(_tnfw_b_control->tnf_state);
}
/*
* _tnf_trace_initialize
* prex is responsible for creating and zeroing the trace file. So,
* this routine expects the file to be there. It does try to handle
* the case where prex (run as root) for probing a setuid root program
* created the trace file as root. But, by the time the first probe is
* hit (and this function is called), the program has reduced it's
* privilege to its real user id - so the open fails. In this case,
* this function unlinks the trace file and creates it again with its
* current user id. The unlink can fail if the user does not have
* write permission in the directory where the trace file is - if so,
* tracing is set to broken.
*/
int
_tnf_trace_initialize(void)
{
int fd;
int created_file = 0;
static mutex_t init_mutex = DEFAULTMUTEX;
/*
* if this is a MT program and the primordial thread hasn't been
* setup yet, can't start tracing yet - THREAD_REG hasn't been
* initialized, so we can't call open() in libthread.
*/
/*
* Use dlsym to check for the present of thr_probe_setup.
*/
if ((((int(*)())dlsym(RTLD_DEFAULT, "thr_probe_setup")) != NULL) &&
(thr_main() == -1)) {
return (0);
}
/*
* lock is needed to to prevent multiple threads from
* mmapping the file.
*/
mutex_lock(&init_mutex);
if (_tnfw_b_control->tnf_state != TNFW_B_NOBUFFER) {
mutex_unlock(&init_mutex);
return (1);
}
_tnfw_b_control->tnf_pid = getpid();
assert(tnf_trace_file_name[0] != '\0');
fd = open(tnf_trace_file_name, O_RDWR, TNF_FILE_MODE);
if (fd < 0) {
if (errno == EACCES) {
/*
* fix for bug 1197494: permission denied when
* trying to open the file - happens for setuid root
* programs - prex creates the file with root ownership
*/
if (unlink(tnf_trace_file_name) == -1) {
goto SetBroken;
}
/* try creating it rather than opening it */
fd = open(tnf_trace_file_name,
O_CREAT | O_RDWR | O_TRUNC, TNF_FILE_MODE);
if (fd < 0) {
goto SetBroken;
}
/*
* expand file to needed size - ftruncate is not
* portable, hence using lseek + write.
*/
if (lseek(fd, tnf_trace_file_size-1, SEEK_SET) == -1) {
goto SetBroken;
}
if (write(fd, "", 1) != 1) {
goto SetBroken;
}
created_file = 1;
} else {
goto SetBroken;
}
}
/* mmap the file */
if ((file_start = mmap(0, tnf_trace_file_size,
PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0)) == (caddr_t)-1) {
goto SetBroken;
}
if (created_file == 1) {
/* explicitly zero the file XXX - performance problem */
(void) memset(file_start, 0, tnf_trace_file_size);
}
_tnfw_b_control->tnf_buffer = file_start;
if (tnfw_b_init_buffer(file_start, tnf_trace_file_size / TNF_BLOCK_SIZE,
TNF_BLOCK_SIZE, B_TRUE) != TNFW_B_OK) {
goto SetBroken;
}
/* successful return */
_tnfw_b_control->tnf_state = TNFW_B_RUNNING;
mutex_unlock(&init_mutex);
return (1);
SetBroken:
_tnfw_b_control->tnf_state = TNFW_B_BROKEN;
mutex_unlock(&init_mutex);
return (0);
}
/*
* _tnf_sched_init
*/
void
_tnf_sched_init(tnf_schedule_t *sched, hrtime_t t)
{
thread_t tid = 0;
sched->time_base = t;
/* thr_self() is stubbed out by libc for a non-threaded pgm */
tid = thr_self();
sched->tid = tid;
sched->lwpid = _lwp_self();
sched->pid = getpid();
}
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