continue.c revision 8fd04b8338ed5093ec2d1e668fa620b7de44c177
/*
* 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 2010 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* interface to continue a target process (DIRECT_MODE) and helper
* functions needed by this routine.
*/
#include "tnfctl_int.h"
#include "prb_proc.h"
#include "dbg.h"
#include <stdlib.h>
#include <errno.h>
static tnfctl_errcode_t _tnfctl_continue(tnfctl_handle_t *hndl,
tnfctl_event_t *evt, sigset_t *oldmask, boolean_t watch_forks);
static tnfctl_errcode_t enable_target_state(tnfctl_handle_t *hndl,
boolean_t watch_forks);
static tnfctl_errcode_t disable_target_state(tnfctl_handle_t *hndl);
/*
* continue the target process and return the evt it stopped on.
* If child_hndl is set and we see a fork, return a handle on child
* process.
*/
tnfctl_errcode_t
tnfctl_continue(tnfctl_handle_t *hndl, tnfctl_event_t *evt,
tnfctl_handle_t **child_hndl)
{
tnfctl_errcode_t prexstat;
prb_status_t prbstat;
boolean_t lmapok = B_FALSE;
boolean_t watch_forks;
/* set my_evt to something other than TNFCTL_EVENT_TARGGONE */
tnfctl_event_t my_evt = TNFCTL_EVENT_EINTR;
enum event_op_t dl_evt;
sigset_t newmask, oldmask;
prb_proc_ctl_t *proc_p;
prgreg_t reg0, reg1;
/* this interface only works for DIRECT_MODE clients */
if (hndl->mode != DIRECT_MODE)
return (TNFCTL_ERR_BADARG);
proc_p = hndl->proc_p;
if (sigfillset(&newmask) == -1)
return (tnfctl_status_map(errno));
watch_forks = (child_hndl != NULL);
/*
* XXXX block all signals. Synchronous signals like SEGV that
* the user could catch and handle will now result in a core dump.
* But, this is very unlikely for 2 reasons - most users don't try
* to handle synchronous signals - it usually just aborts the process.
* And, secondly, the code until we return the original mask is the
* place where this synchronous signal would be generated - and, it
* is not very much code.
*/
if (sigprocmask(SIG_BLOCK, &newmask, &oldmask) == -1)
return (tnfctl_status_map(errno));
/*
* Target is stopped on entry because tnfctl_continue()
* only returns with a stopped target.
*/
/* target process shouldn't be stopped when link maps are incosistent */
while (lmapok == B_FALSE) {
prexstat = _tnfctl_continue(hndl, &my_evt, &oldmask,
watch_forks);
if (prexstat) {
if (my_evt == TNFCTL_EVENT_TARGGONE ||
my_evt == TNFCTL_EVENT_EXIT) {
/*
* target exited - free obj list and probe
* list so that we keep our internal state
* correct, else probe control interfaces will
* have wrong information.
*/
DBG(fprintf(stderr, "target is gone\n"));
_tnfctl_free_objs_and_probes(hndl);
*evt = my_evt;
return (TNFCTL_ERR_NONE);
} else if (my_evt == TNFCTL_EVENT_EXEC) {
*evt = my_evt;
return (TNFCTL_ERR_NONE);
} else if (prexstat == TNFCTL_ERR_FILENOTFOUND) {
return (TNFCTL_ERR_NOPROCESS);
} else {
return (prexstat);
}
}
if (my_evt == TNFCTL_EVENT_FORK) {
/*
* sanity check. we should only get here if child_hndl is set
*/
if (child_hndl) {
*evt = my_evt;
prbstat = prb_proc_get_r0_r1(proc_p,
&reg0, &reg1);
if (prbstat) {
prexstat = _tnfctl_map_to_errcode(prbstat);
return (prexstat);
}
prexstat = tnfctl_pid_open((pid_t)reg0,
child_hndl);
disable_target_state(*child_hndl);
return (prexstat);
}
return (TNFCTL_ERR_NONE);
}
/*
* update state in handle
* REMIND: Only need to call _tnfctl_refresh_process on
* dlopen or dlclose. Need to take out other functionality
* of refresh_process into a separate function that should
* be called here.
*/
prexstat = _tnfctl_refresh_process(hndl, &lmapok, &dl_evt);
if (prexstat && (lmapok == B_TRUE))
return (prexstat);
prexstat = TNFCTL_ERR_NONE;
}
*evt = my_evt;
/* see if we have more detail about the event */
if (dl_evt == EVT_OPEN)
*evt = TNFCTL_EVENT_DLOPEN;
else if (dl_evt == EVT_CLOSE)
*evt = TNFCTL_EVENT_DLCLOSE;
return (TNFCTL_ERR_NONE);
}
/*
* Continues target and waits for it to stop.
* warning: This routine returns TNFCTL_EVENT_DLOPEN for any kind of
* dl activity. Up to the caller to determine the actual DL event.
*/
static tnfctl_errcode_t
_tnfctl_continue(tnfctl_handle_t *hndl, tnfctl_event_t *evt, sigset_t *oldmask,
boolean_t watch_forks)
{
tnfctl_errcode_t prexstat;
tnfctl_errcode_t ret_prexstat = TNFCTL_ERR_NONE;
prb_status_t prbstat, prbstat2;
prb_proc_ctl_t *proc_p;
prb_proc_state_t state;
proc_p = hndl->proc_p;
/* set up state before we run process */
prexstat = enable_target_state(hndl, watch_forks);
if (prexstat)
return (prexstat);
again:
/* resume target */
prbstat = prb_proc_cont(proc_p);
if (prbstat) {
ret_prexstat = _tnfctl_map_to_errcode(prbstat);
goto end_of_func;
}
/* wait on target to stop (standby) */
prbstat = prb_proc_wait(proc_p, B_TRUE, oldmask);
if (prbstat) {
if (prbstat == EINTR) {
*evt = TNFCTL_EVENT_EINTR;
prbstat2 = prb_proc_stop(proc_p);
if (prbstat2) {
ret_prexstat = _tnfctl_map_to_errcode(prbstat2);
goto end_of_func;
}
} else if (prbstat == ENOENT) {
/* target process finished */
if (hndl->called_exit)
*evt = TNFCTL_EVENT_EXIT;
else
*evt = TNFCTL_EVENT_TARGGONE;
/* return directly - process no longer around */
return (TNFCTL_ERR_INTERNAL);
} else {
ret_prexstat = _tnfctl_map_to_errcode(prbstat);
goto end_of_func;
}
}
prbstat = prb_proc_state(proc_p, &state);
if (prbstat) {
ret_prexstat = _tnfctl_map_to_errcode(prbstat);
goto end_of_func;
}
if (state.ps_isbptfault) {
/* dlopen or dlclose */
prbstat = prb_rtld_advance(proc_p);
if (prbstat) {
ret_prexstat = _tnfctl_map_to_errcode(prbstat);
goto end_of_func;
}
/*
* actually don't know if it is a dlopen or dlclose yet.
* But, we return dlopen here. Up to the caller to determine
* which one it actually is.
*/
*evt = TNFCTL_EVENT_DLOPEN;
} else
if (state.ps_issysentry) {
switch (state.ps_syscallnum) {
case SYS_execve:
*evt = TNFCTL_EVENT_EXEC;
ret_prexstat = TNFCTL_ERR_INTERNAL;
break;
case SYS_exit:
hndl->called_exit = B_TRUE;
goto again;
default:
break;
}
} else if (state.ps_issysexit) {
switch (state.ps_syscallnum) {
case SYS_vfork:
case SYS_forksys:
*evt = TNFCTL_EVENT_FORK;
break;
default:
break;
}
}
end_of_func:
/*
* disable all our sycall tracing and bpt setup in process when it
* is stopped, so that even if the controlling process aborts,
* the target could continue running
*/
prexstat = disable_target_state(hndl);
if (prexstat)
return (prexstat);
return (ret_prexstat);
}
/*
* enable the system call tracing and dl activity tracing
*/
static tnfctl_errcode_t
enable_target_state(tnfctl_handle_t *hndl, boolean_t watch_forks)
{
prb_status_t prbstat;
prb_proc_ctl_t *proc_p;
proc_p = hndl->proc_p;
/* trace exec */
prbstat = prb_proc_entry(proc_p, SYS_execve, PRB_SYS_ADD);
if (prbstat)
return (_tnfctl_map_to_errcode(prbstat));
/* trace exit */
prbstat = prb_proc_entry(proc_p, SYS_exit, PRB_SYS_ADD);
if (prbstat)
return (_tnfctl_map_to_errcode(prbstat));
/* trace fork if the caller requests */
if (watch_forks) {
prbstat = prb_proc_exit(proc_p, SYS_vfork, PRB_SYS_ADD);
if (prbstat)
return (_tnfctl_map_to_errcode(prbstat));
prbstat = prb_proc_exit(proc_p, SYS_forksys, PRB_SYS_ADD);
if (prbstat)
return (_tnfctl_map_to_errcode(prbstat));
prbstat = prb_proc_setfork(proc_p, B_TRUE);
if (prbstat)
return (_tnfctl_map_to_errcode(prbstat));
}
/*
* tracing flags for fork and exec will get unset when
* process stops. see disable_target_state()
*/
/* setup process to stop during dlopen() or dlclose() */
prbstat = prb_rtld_stalk(proc_p);
return (_tnfctl_map_to_errcode(prbstat));
}
/*
* disable the system call tracing and dl activity tracing
*/
static tnfctl_errcode_t
disable_target_state(tnfctl_handle_t *hndl)
{
prb_status_t prbstat;
prb_proc_ctl_t *proc_p;
proc_p = hndl->proc_p;
/* remove the stalking breakpoint while the process is stopped */
prbstat = prb_rtld_unstalk(proc_p);
if (prbstat)
return (_tnfctl_map_to_errcode(prbstat));
/* remove the exec, exit and fork tracing while stopped */
prbstat = prb_proc_entry(proc_p, SYS_execve, PRB_SYS_DEL);
if (prbstat)
return (_tnfctl_map_to_errcode(prbstat));
prbstat = prb_proc_entry(proc_p, SYS_exit, PRB_SYS_DEL);
if (prbstat)
return (_tnfctl_map_to_errcode(prbstat));
prbstat = prb_proc_exit(proc_p, SYS_vfork, PRB_SYS_DEL);
if (prbstat)
return (_tnfctl_map_to_errcode(prbstat));
prbstat = prb_proc_exit(proc_p, SYS_forksys, PRB_SYS_DEL);
if (prbstat)
return (_tnfctl_map_to_errcode(prbstat));
prbstat = prb_proc_setfork(proc_p, B_FALSE);
if (prbstat)
return (_tnfctl_map_to_errcode(prbstat));
return (TNFCTL_ERR_NONE);
}