lib/libtnfctl/util.c

	util.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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 (c) 1994, by Sun Microsytems, Inc.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * Utility functions to initialize tnfctl handle, find functions that
 * can be plugged into probes, find trace file information, and create
 * a trace file for process tracing.
 */

#ifndef DEBUG
#define NDEBUG  1
#endif

#include "tnfctl_int.h"
#include "dbg.h"

#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/param.h>

#include "tnf_buf.h"
/*
 * Defines - Project private interfaces in libtnfprobe.so
 */

#define TRACEFILE_NAME      "tnf_trace_file_name"
#define TRACEFILE_SIZE      "tnf_trace_file_size"
#define TRACEFILE_MIN       "tnf_trace_file_min"
#define TRACE_ERROR     "_tnfw_b_control"

#define TRACE_ALLOC     "tnf_trace_alloc"
#define TRACE_COMMIT        "tnf_trace_commit"
#define TRACE_ROLLBACK      "tnf_trace_rollback"
#define DEBUG_ENTRY     "tnf_probe_debug"

#define PROBE_LIST_HEAD     "__tnf_probe_list_head"
#define PROBE_LIST_VALID    "__tnf_probe_list_valid"

#define NONTHREAD_TEST      "tnf_non_threaded_test_addr"
#define THREAD_TEST     "tnf_threaded_test_addr"
#define PROBE_THR_SYNC      "__tnf_probe_thr_sync"

#define MEMSEG_PTR      "__tnf_probe_memseg_p"

/* Project private interfaces in libthread.so */
#define LIBTHREAD_PRESENT   "thr_probe_getfunc_addr"

/*
 * Local declarations
 */

static tnfctl_errcode_t find_test_func(tnfctl_handle_t *hndl);
static tnfctl_errcode_t find_target_syms(tnfctl_handle_t *hndl);
static tnfctl_errcode_t find_trace_file_info(tnfctl_handle_t *hndl);
static tnfctl_errcode_t check_trace_error(tnfctl_handle_t *hndl);

/*
 * _tnfctl_refresh_process() - search for new shared objects.  If any
 * found, discover probes in new shared objects.
 *  NOT to be called in kernel mode.
 */

tnfctl_errcode_t
_tnfctl_refresh_process(tnfctl_handle_t *hndl, boolean_t *lmap_ok,
            enum event_op_t *dl_evt)
{
    tnfctl_errcode_t    prexstat = TNFCTL_ERR_NONE;
    boolean_t   release_lock;

    assert(hndl->mode != KERNEL_MODE);

    /*LINTED statement has no consequent: else*/
    LOCK(hndl, prexstat, release_lock);

    prexstat = check_trace_error(hndl);
    if (prexstat)
        goto finish_func;

    /*
     * update the link map. caller decides what to do on
     * inconsistent link map
     */
    prexstat = _tnfctl_lmap_update(hndl, lmap_ok, dl_evt);
    if (prexstat)
        goto finish_func;

    /* link map is ok now */
    prexstat = find_test_func(hndl);
    if (prexstat)
        goto finish_func;
    if (*dl_evt != EVT_NONE) {
        prexstat = _tnfctl_find_all_probes(hndl);
        if (prexstat)
            goto finish_func;
    }

finish_func:
    /*LINTED statement has no consequent: else*/
    UNLOCK(hndl, release_lock);

    return (prexstat);
}

/*
 * initialize tnfctl handle for a new target
 */
tnfctl_errcode_t
_tnfctl_set_state(tnfctl_handle_t *hndl)
{
    tnfctl_errcode_t    prexstat = TNFCTL_ERR_NONE;
    boolean_t   lmap_ok;
    enum event_op_t dl_evt;
    boolean_t   release_lock;

    hndl->targ_pid = hndl->p_getpid(hndl->proc_p);

    /*LINTED statement has no consequent: else*/
    LOCK(hndl, prexstat, release_lock);

    /*
     * initialize the link map table. If link map is not ok, it is an
     * error.
     */
    prexstat = _tnfctl_lmap_update(hndl, &lmap_ok, &dl_evt);
    if (prexstat)
        goto end_func;

    /* find the needed target symbols */
    prexstat = find_target_syms(hndl);
    if (prexstat) {
        /* is libtnfprobe.so loaded in target ? */
        goto end_func;
    }

    prexstat = find_trace_file_info(hndl);
    if (prexstat)
        goto end_func;

    prexstat = find_test_func(hndl);
    if (prexstat)
        goto end_func;

    prexstat = _tnfctl_find_all_probes(hndl);
    if (prexstat)
        goto end_func;

    prexstat = check_trace_error(hndl);
    /* fall into end_func */

end_func:
    /*LINTED statement has no consequent: else*/
    UNLOCK(hndl, release_lock);

    return (prexstat);
}

/*
 * find the test function for a probe.  The test function could change
 * with time, so we have to repeatedly check for the test function to use
 */
static tnfctl_errcode_t
find_test_func(tnfctl_handle_t *hndl)
{
    long        thr_sync;
    int     miscstat;

    if (hndl->mt_target == B_FALSE) {
        /* no libthread linked in */
        hndl->testfunc = hndl->nonthread_test;
    } else {
        /*
         * check whether libthread/libtnfw have synced up.
         * If not yet synced up, use non-threaded test function
         */

        /* assume we are going to use threaded test */
        hndl->testfunc = hndl->thread_test;
        miscstat = hndl->p_read(hndl->proc_p, hndl->thread_sync,
            &thr_sync, sizeof (thr_sync));
        if (miscstat != 0)
            return (TNFCTL_ERR_INTERNAL);
        /* if not yet synced up, change test func to non-threaded one */
        if (thr_sync == 0) {
            hndl->testfunc = hndl->nonthread_test;
        }
    }

    /*
     * Note: the testfunc in the target can change underneath us because
     * in an MT program the init section of libthread changes all the
     * test functions from the non-threaded one to the threaded one.
     * So, every time we write out a probe, we have to make sure that
     * we are using the correct test function by not trusting the test
     * function in our copy of the probe.  A more fool-proof solution
     * which will allow other fields in the probe to change internally
     * is to refresh every probe on a _tnfctl_refresh_process()
     */
    return (TNFCTL_ERR_NONE);
}

/*
 * check_trace_error() - checks whether there was an error in tracing
 *  side effects trace_buf_state and trace_state in hndl
 *  note: call this function only after trace_file_name is set up
 *  in hndl
 */
tnfctl_errcode_t
check_trace_error(tnfctl_handle_t *hndl)
{
    int     miscstat;
    uintptr_t   trace_error_ptr;
    TNFW_B_CONTROL  trace_error_rec;

    /* read in the value of the control structure pointer */
    miscstat = hndl->p_read(hndl->proc_p, hndl->trace_error,
        &trace_error_ptr, sizeof (trace_error_ptr));
    if (miscstat != 0)
        return (TNFCTL_ERR_INTERNAL);

    /* read in the value of the control structure */
    miscstat = hndl->p_read(hndl->proc_p, trace_error_ptr, &trace_error_rec,
        sizeof (trace_error_rec));
    if (miscstat != 0)
        return (TNFCTL_ERR_INTERNAL);

    if (trace_error_rec.tnf_state == TNFW_B_NOBUFFER) {
        /*
         * massage into correct state for caller - the target might
         * not have hit the first probe and hence we got "no buffer".
         * So, if the user had given a file name, return BUF_OK.
         */
        if (hndl->trace_file_name == NULL)
            hndl->trace_buf_state = TNFCTL_BUF_NONE;
        else
            hndl->trace_buf_state = TNFCTL_BUF_OK;
    } else if (trace_error_rec.tnf_state == TNFW_B_BROKEN) {
        hndl->trace_buf_state = TNFCTL_BUF_BROKEN;
    } else {
        hndl->trace_buf_state = TNFCTL_BUF_OK;
    }

    if (TNFW_B_IS_STOPPED(trace_error_rec.tnf_state))
        hndl->trace_state = B_FALSE;
    else
        hndl->trace_state = B_TRUE;

    return (TNFCTL_ERR_NONE);

}               /* end find_alloc_func */

/*
 * find_target_syms() - finds needed target functions
 *  sideffects allocfunc, commitfunc, endfunc, rollbackfunc in hndl
 */
static tnfctl_errcode_t
find_target_syms(tnfctl_handle_t *hndl)
{
    tnfctl_errcode_t    prexstat;
    uintptr_t       temp_addr;
    int         miscstat;

    prexstat = _tnfctl_sym_find(hndl, TRACE_ALLOC, &hndl->allocfunc);
    if (prexstat)
        goto end_of_func;

    prexstat = _tnfctl_sym_find(hndl, TRACE_COMMIT, &hndl->commitfunc);
    if (prexstat)
        goto end_of_func;

    prexstat = _tnfctl_sym_find(hndl, TRACE_END_FUNC, &hndl->endfunc);
    if (prexstat)
        goto end_of_func;

    prexstat = _tnfctl_sym_find(hndl, TRACE_ROLLBACK, &hndl->rollbackfunc);
    if (prexstat)
        goto end_of_func;

    prexstat = _tnfctl_sym_find(hndl, PROBE_LIST_HEAD,
                    &hndl->probelist_head);
    if (prexstat)
        goto end_of_func;

    prexstat = _tnfctl_sym_find(hndl, TRACE_ERROR, &hndl->trace_error);
    if (prexstat)
        goto end_of_func;

    prexstat = _tnfctl_sym_find(hndl, MEMSEG_PTR, &temp_addr);
    if (prexstat)
        goto end_of_func;

    /* dereference to get the actual address of structure */
    miscstat = hndl->p_read(hndl->proc_p, temp_addr, &hndl->memseg_p,
            sizeof (hndl->memseg_p));
    if (miscstat != 0)
        return (TNFCTL_ERR_INTERNAL);

    prexstat = _tnfctl_sym_find(hndl, PROBE_LIST_VALID,
                    &hndl->probelist_valid);
    if (prexstat)
        goto end_of_func;

    prexstat = _tnfctl_sym_find(hndl, NONTHREAD_TEST, &temp_addr);
    if (prexstat)
        goto end_of_func;

    /* dereference to get the actual function address */
    miscstat = hndl->p_read(hndl->proc_p, temp_addr, &hndl->nonthread_test,
            sizeof (hndl->nonthread_test));
    if (miscstat != 0)
        return (TNFCTL_ERR_INTERNAL);

    prexstat = _tnfctl_sym_find(hndl, THREAD_TEST, &temp_addr);
    if (prexstat)
        goto end_of_func;

    /* dereference to get the actual function address */
    miscstat = hndl->p_read(hndl->proc_p, temp_addr, &hndl->thread_test,
            sizeof (hndl->thread_test));
    if (miscstat != 0)
        return (TNFCTL_ERR_INTERNAL);

    prexstat = _tnfctl_sym_find(hndl, PROBE_THR_SYNC, &hndl->thread_sync);
    if (prexstat)
        goto end_of_func;

    prexstat = _tnfctl_sym_find(hndl, LIBTHREAD_PRESENT, &temp_addr);
    if (prexstat) {
        if (prexstat == TNFCTL_ERR_BADARG) {
            /* no libthread linked in */
            hndl->mt_target = B_FALSE;
            /* this is not an error condition */
            prexstat = TNFCTL_ERR_NONE;
        } else {
            return (prexstat);
        }
    } else {
        hndl->mt_target = B_TRUE;
    }

end_of_func:
    if (prexstat == TNFCTL_ERR_BADARG)
        prexstat = TNFCTL_ERR_NOLIBTNFPROBE;

    return (prexstat);
}

/*
 * _tnfctl_create_tracefile() - initializes tracefile, sets the tracefile name
 *  and size
 *  side effects trace_file_name and trace_buf_size in hndl
 */

#define ZBUFSZ      (64 * 1024)

tnfctl_errcode_t
_tnfctl_create_tracefile(tnfctl_handle_t *hndl, const char *trace_file_name,
            uint_t trace_file_size)
{
    char        *preexisting;
    tnfctl_errcode_t    prexstat;
    int     miscstat;
    char        path[MAXPATHLEN];
    uintptr_t   name_addr, size_addr;
    uint_t      outsize;
    char        zerobuf[ZBUFSZ];
    int     fd, sz, i;

    /* find the neccessary symbols in the target */
    prexstat = _tnfctl_sym_find(hndl, TRACEFILE_NAME, &name_addr);
    if (prexstat) {
        if (prexstat == TNFCTL_ERR_BADARG)
            prexstat = TNFCTL_ERR_INTERNAL;
        return (prexstat);
    }
    prexstat = _tnfctl_sym_find(hndl, TRACEFILE_SIZE, &size_addr);
    if (prexstat) {
        if (prexstat == TNFCTL_ERR_BADARG)
            prexstat = TNFCTL_ERR_INTERNAL;
        return (prexstat);
    }

    /* Double check that a file name doesn't already exist */
    preexisting = NULL;
    prexstat = _tnfctl_readstr_targ(hndl, name_addr, &preexisting);
    if (prexstat) {
        if (preexisting)
            free(preexisting);
        return (prexstat);
    }

    /* There better not be a file name there yet */
    assert(preexisting[0] == '\0');

    /* paranoia - for optimized compilation */
    if (preexisting[0] != '\0')
        return (TNFCTL_ERR_BUFEXISTS);

    /* free memory in preexisting string */
    if (preexisting)
        free(preexisting);

    if (trace_file_size < hndl->trace_min_size) {
        return (TNFCTL_ERR_SIZETOOSMALL);
    }

    /* do we have an absolute, relative or no pathname specified? */
    if (trace_file_name == NULL) {
        return (TNFCTL_ERR_BADARG);
    }
    if (trace_file_name[0] == '/') {
        /* absolute path to tracefile specified */
        if ((strlen(trace_file_name) + 1) > (size_t) MAXPATHLEN) {
            /* directory specification too long */
            return (TNFCTL_ERR_BADARG);
        }
        (void) strcpy(path, trace_file_name);
    } else {
        char           *cwd;

        /* relative path to tracefile specified */
        cwd = getcwd(NULL, MAXPATHLEN);
        if (!cwd) {
            return (tnfctl_status_map(errno));
        }
        if ((strlen(cwd) + 1 + strlen(trace_file_name) + 1) >
            (size_t) MAXPATHLEN) {
            /* path name too long */
            return (TNFCTL_ERR_BADARG);
        }
        (void) sprintf(path, "%s/%s", cwd, trace_file_name);

        free(cwd);
    }

    outsize = trace_file_size;

    DBG_TNF_PROBE_2(_tnfctl_create_tracefile_1, "libtnfctl",
        "sunw%verbosity 1; sunw%debug 'setting trace file name'",
        tnf_string, tracefile_name, path,
        tnf_long, tracefile_size, outsize);

    /* unlink a previous tracefile (if one exists) */
    (void) unlink(path);

    /* create the new tracefile */
    fd = open(path, O_CREAT | O_RDWR | O_TRUNC, 0644);
    if (fd < 0) {
        return (tnfctl_status_map(errno));
    }

    /* zero fill the file */
    (void) memset(zerobuf, 0, ZBUFSZ);
    sz = ZBUFSZ;
    for (i = 0; i < outsize; i += sz) {
        ulong_t     retval;

        sz = ((outsize - i) > ZBUFSZ) ? ZBUFSZ : (outsize - i);
        retval = write(fd, zerobuf, sz);
        if (retval != sz) {
            /* trouble zeroing tracefile */
            return (tnfctl_status_map(errno));
        }
    }

    /* close the file */
    (void) close(fd);

    /* write the tracefile name and size into the target process */
    miscstat = hndl->p_write(hndl->proc_p, name_addr, path,
                    strlen(path) + 1);
    if (miscstat != 0)
        return (TNFCTL_ERR_INTERNAL);
    miscstat = hndl->p_write(hndl->proc_p, size_addr, &outsize,
                    sizeof (outsize));
    if (miscstat != 0)
        return (TNFCTL_ERR_INTERNAL);

    hndl->trace_file_name = strdup(path);
    if (hndl->trace_file_name == NULL)
        return (TNFCTL_ERR_ALLOCFAIL);
    hndl->trace_buf_size = outsize;
    hndl->trace_buf_state = TNFCTL_BUF_OK;
    return (TNFCTL_ERR_NONE);
}               /* end _tnfctl_create_tracefile */

/*
 * find_trace_file_info()
 *  finds out information about the trace file.
 *  side effects trace_buf_size, trace_min_size, trace_file_name in hndl
 */

static tnfctl_errcode_t
find_trace_file_info(tnfctl_handle_t *hndl)
{
    tnfctl_errcode_t    prexstat;
    int     miscstat;
    char        *preexisting;
    uintptr_t   name_addr, size_addr, min_addr;
    uint_t      outsize, minoutsize;

    /* find the neccessary symbols in the target */
    prexstat = _tnfctl_sym_find(hndl, TRACEFILE_NAME, &name_addr);
    if (prexstat) {
        if (prexstat == TNFCTL_ERR_BADARG)
            prexstat = TNFCTL_ERR_INTERNAL;
        return (prexstat);
    }
    prexstat = _tnfctl_sym_find(hndl, TRACEFILE_SIZE, &size_addr);
    if (prexstat) {
        if (prexstat == TNFCTL_ERR_BADARG)
            prexstat = TNFCTL_ERR_INTERNAL;
        return (prexstat);
    }
    prexstat = _tnfctl_sym_find(hndl, TRACEFILE_MIN, &min_addr);
    if (prexstat) {
        if (prexstat == TNFCTL_ERR_BADARG)
            prexstat = TNFCTL_ERR_INTERNAL;
        return (prexstat);
    }

    /* read file name */
    preexisting = NULL;
    prexstat = _tnfctl_readstr_targ(hndl, name_addr, &preexisting);
    if (prexstat) {
        if (preexisting)
            free(preexisting);
        return (prexstat);
    }

    /* read the minimum file size from the target */
    miscstat = hndl->p_read(hndl->proc_p, min_addr, &minoutsize,
                            sizeof (minoutsize));
    if (miscstat != 0)
        return (TNFCTL_ERR_INTERNAL);
    hndl->trace_min_size = minoutsize;

    /* if there is no filename, we are done */
    if (preexisting[0] == '\0') {
        hndl->trace_file_name = NULL;
        hndl->trace_buf_size = 0;
    } else {
        hndl->trace_file_name = preexisting;
        /* read size of file */
        miscstat = hndl->p_read(hndl->proc_p, size_addr,
                &outsize, sizeof (outsize));
        if (miscstat != 0)
            return (TNFCTL_ERR_INTERNAL);
        hndl->trace_buf_size = outsize;
    }

    return (TNFCTL_ERR_NONE);
}               /* end find_trace_file_info */

/*
 * wrapper functions over native /proc functions implemented by proc
 * layer
 */
int
_tnfctl_read_targ(void *proc_p, uintptr_t addr, void *buf, size_t size)
{
    return (prb_proc_read(proc_p, addr, buf, size));
}

int
_tnfctl_write_targ(void *proc_p, uintptr_t addr, void *buf, size_t size)
{
    return (prb_proc_write(proc_p, addr, buf, size));
}

int
_tnfctl_loadobj_iter(void *proc_p, tnfctl_ind_obj_f *func, void *client_data)
{
    prb_loadobj_f *same_func = (prb_loadobj_f *) func;

    return (prb_loadobj_iter(proc_p, same_func, client_data));
}

pid_t
_tnfctl_pid_get(void *proc_p)
{
    return (prb_proc_pid_get(proc_p));
}

/*
 * _tnfctl_readstr_targ() - dereferences a string in the target
 *  NOTE: There is a similar routine called prb_proc_readstr()
 *        used by proc layer.  It would be better if there was only
 *        one of these functions defined.
 */

#define BUFSZ   256

tnfctl_errcode_t
_tnfctl_readstr_targ(tnfctl_handle_t *hndl, uintptr_t addr, char **outstr_pp)
{
    int     retstat;
    int     bufsz = BUFSZ;
    char        buffer[BUFSZ + 1];
    offset_t    offset;
    char        *ptr, *orig_ptr;

    *outstr_pp = NULL;
    offset = 0;

    /* allocate an inital return buffer */
    ptr = (char *) malloc(BUFSZ);
    if (!ptr) {
        DBG((void) fprintf(stderr,
            "_tnfctl_readstr_targ: malloc failed\n"));
        return (TNFCTL_ERR_ALLOCFAIL);
    }
    /*LINTED constant in conditional context*/
    while (1) {
        int          i;

        /* read a chunk into our buffer */
        retstat = hndl->p_read(hndl->proc_p, addr + offset, buffer,
                                bufsz);
        if (retstat != 0) {

            /*
             * if we get into trouble with a large read, try again
             * with a single byte.  Subsequent failiure is real ...
             */
            if (bufsz > 1) {
                bufsz = 1;
                continue;
            }

            DBG((void) fprintf(stderr,
                "_tnfctl_readstr_targ: target read failed: \n"));
            free(ptr);
            return (TNFCTL_ERR_INTERNAL);
        }
        /* copy the chracters into the return buffer */
        for (i = 0; i < bufsz; i++) {
            char            c = buffer[i];

            ptr[offset + i] = c;
            if (c == '\0') {
                /* hooray! we saw the end of the string */
                *outstr_pp = ptr;
                return (TNFCTL_ERR_NONE);
            }
        }

        /* bummer, need to grab another bufsz characters */
        offset += bufsz;
        orig_ptr = ptr;
        ptr = (char *) realloc(ptr, offset + bufsz);
        if (!ptr) {
            free(orig_ptr);
            DBG((void) fprintf(stderr,
                "_tnfctl_readstr_targ: realloc failed\n"));
            return (TNFCTL_ERR_ALLOCFAIL);
        }
    }

#if defined(lint)
    return (TNFCTL_ERR_NONE);
#endif

}