/* * Class: sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal * Method: resume0 * Signature: ()V */ JNIEXPORT void JNICALL Java_sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal_resume0 (JNIEnv *env, jobject this_obj) { jlong p_ps_prochandle = env->GetLongField(this_obj, p_ps_prochandle_ID); // for now don't check return value. revisit this again. Psetrun((struct ps_prochandle*) p_ps_prochandle, 0, PRCFAULT|PRSTOP); }
/* * Main loop for all victim process control threads. We initialize all the * appropriate /proc control mechanisms, and then enter a loop waiting for * the process to stop on an event or die. We process any events by calling * appropriate subroutines, and exit when the victim dies or we lose control. * * The control thread synchronizes the use of dpr_proc with other libdtrace * threads using dpr_lock. We hold the lock for all of our operations except * waiting while the process is running: this is accomplished by writing a * PCWSTOP directive directly to the underlying /proc/<pid>/ctl file. If the * libdtrace client wishes to exit or abort our wait, SIGCANCEL can be used. */ static void * dt_proc_control(void *arg) { dt_proc_control_data_t *datap = arg; dtrace_hdl_t *dtp = datap->dpcd_hdl; dt_proc_t *dpr = datap->dpcd_proc; dt_proc_hash_t *dph = dpr->dpr_hdl->dt_procs; struct ps_prochandle *P = dpr->dpr_proc; #if defined(sun) int pfd = Pctlfd(P); const long wstop = PCWSTOP; #endif int notify = B_FALSE; /* * We disable the POSIX thread cancellation mechanism so that the * client program using libdtrace can't accidentally cancel our thread. * dt_proc_destroy() uses SIGCANCEL explicitly to simply poke us out * of PCWSTOP with EINTR, at which point we will see dpr_quit and exit. */ (void) pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL); dpr->dpr_pid = proc_getpid(P); int pid = dpr->dpr_pid; /* * Set up the corresponding process for tracing by libdtrace. We want * to be able to catch breakpoints and efficiently single-step over * them, and we need to enable librtld_db to watch libdl activity. */ do_ptrace(__func__, PTRACE_ATTACH, dpr->dpr_pid, 0, 0); (void) pthread_mutex_lock(&dpr->dpr_lock); (void) Punsetflags(P, PR_ASYNC); /* require synchronous mode */ (void) Psetflags(P, PR_BPTADJ); /* always adjust eip on x86 */ (void) Punsetflags(P, PR_FORK); /* do not inherit on fork */ (void) Pfault(P, FLTBPT, B_TRUE); /* always trace breakpoints */ (void) Pfault(P, FLTTRACE, B_TRUE); /* always trace single-step */ /* * We must trace exit from exec() system calls so that if the exec is * successful, we can reset our breakpoints and re-initialize libproc. */ (void) Psysexit(P, SYS_exec, B_TRUE); (void) Psysexit(P, SYS_execve, B_TRUE); /* * We must trace entry and exit for fork() system calls in order to * disable our breakpoints temporarily during the fork. We do not set * the PR_FORK flag, so if fork succeeds the child begins executing and * does not inherit any other tracing behaviors or a control thread. */ (void) Psysentry(P, SYS_vfork, B_TRUE); (void) Psysexit(P, SYS_vfork, B_TRUE); (void) Psysentry(P, SYS_fork1, B_TRUE); (void) Psysexit(P, SYS_fork1, B_TRUE); (void) Psysentry(P, SYS_forkall, B_TRUE); (void) Psysexit(P, SYS_forkall, B_TRUE); (void) Psysentry(P, SYS_forksys, B_TRUE); (void) Psysexit(P, SYS_forksys, B_TRUE); Psync(P); /* enable all /proc changes */ dt_proc_attach(dpr, B_FALSE); /* enable rtld breakpoints */ /* * If PR_KLC is set, we created the process; otherwise we grabbed it. * Check for an appropriate stop request and wait for dt_proc_continue. */ dpr->dpr_stop |= DT_PROC_STOP_CREATE; if (Pstatus(P)->pr_flags & PR_KLC) dt_proc_stop(dpr, DT_PROC_STOP_CREATE); else dt_proc_stop(dpr, DT_PROC_STOP_GRAB); if (Psetrun(P, 0, 0) == -1) { dt_dprintf("pid %d: failed to set running: %s\n", (int)dpr->dpr_pid, strerror(errno)); } (void) pthread_mutex_unlock(&dpr->dpr_lock); /* * Wait for the process corresponding to this control thread to stop, * process the event, and then set it running again. We want to sleep * with dpr_lock *unheld* so that other parts of libdtrace can use the * ps_prochandle in the meantime (e.g. ustack()). To do this, we write * a PCWSTOP directive directly to the underlying /proc/<pid>/ctl file. * Once the process stops, we wake up, grab dpr_lock, and then call * Pwait() (which will return immediately) and do our processing. */ //printf("%s: waiting to quit\n", __func__); while (!dpr->dpr_quit) { const lwpstatus_t *psp; #if defined(sun) if (write(pfd, &wstop, sizeof (wstop)) == -1 && errno == EINTR) continue; /* check dpr_quit and continue waiting */ #else /* Wait for the process to report status. */ proc_wait(P); #endif (void) pthread_mutex_lock(&dpr->dpr_lock); pwait_locked: if (Pstopstatus(P, PCNULL, 0) == -1 && errno == EINTR) { //printf("%s stopstatus (loop) pr_pid pid=%d\n", __func__, Pstatus(dpr->dpr_proc)->pr_pid); (void) pthread_mutex_unlock(&dpr->dpr_lock); continue; /* check dpr_quit and continue waiting */ } switch (Pstate(P)) { case PS_STOP: psp = &Pstatus(P)->pr_lwp; dt_dprintf("pid %d: proc stopped showing %d/%d\n", pid, psp->pr_why, psp->pr_what); #if defined(sun) /* * If the process stops showing PR_REQUESTED, then the * DTrace stop() action was applied to it or another * debugging utility (e.g. pstop(1)) asked it to stop. * In either case, the user's intention is for the * process to remain stopped until another external * mechanism (e.g. prun(1)) is applied. So instead of * setting the process running ourself, we wait for * someone else to do so. Once that happens, we return * to our normal loop waiting for an event of interest. */ if (psp->pr_why == PR_REQUESTED) { dt_proc_waitrun(dpr); (void) pthread_mutex_unlock(&dpr->dpr_lock); continue; } /* * If the process stops showing one of the events that * we are tracing, perform the appropriate response. * Note that we ignore PR_SUSPENDED, PR_CHECKPOINT, and * PR_JOBCONTROL by design: if one of these conditions * occurs, we will fall through to Psetrun() but the * process will remain stopped in the kernel by the * corresponding mechanism (e.g. job control stop). */ if (psp->pr_why == PR_FAULTED && psp->pr_what == FLTBPT) dt_proc_bpmatch(dtp, dpr); else if (psp->pr_why == PR_SYSENTRY && IS_SYS_FORK(psp->pr_what)) dt_proc_bpdisable(dpr); else if (psp->pr_why == PR_SYSEXIT && IS_SYS_FORK(psp->pr_what)) dt_proc_bpenable(dpr); else if (psp->pr_why == PR_SYSEXIT && IS_SYS_EXEC(psp->pr_what)) dt_proc_attach(dpr, B_TRUE); #endif //printf("In PS_STOP dpr_stop=%x\n", dpr->dpr_stop); break; case PS_LOST: //printf("in PS_LOST\n"); if (Preopen(P) == 0) goto pwait_locked; dt_dprintf("pid %d: proc lost: %s\n", pid, strerror(errno)); dpr->dpr_quit = B_TRUE; notify = B_TRUE; break; case PS_UNDEAD: case PS_DEAD: dt_dprintf("pid %d: proc died\n", pid); dpr->dpr_quit = B_TRUE; notify = B_TRUE; break; } if (Pstate(P) != PS_UNDEAD && Psetrun(P, 0, 0) == -1) { dt_dprintf("pid %d: failed to set running: %s\n", (int)dpr->dpr_pid, strerror(errno)); } (void) pthread_mutex_unlock(&dpr->dpr_lock); } /* * If the control thread detected PS_UNDEAD or PS_LOST, then enqueue * the dt_proc_t structure on the dt_proc_hash_t notification list. */ if (notify) dt_proc_notify(dtp, dph, dpr, NULL); /* * Destroy and remove any remaining breakpoints, set dpr_done and clear * dpr_tid to indicate the control thread has exited, and notify any * waiting thread in dt_proc_destroy() that we have succesfully exited. */ (void) pthread_mutex_lock(&dpr->dpr_lock); dt_proc_bpdestroy(dpr, B_TRUE); dpr->dpr_done = B_TRUE; dpr->dpr_tid = 0; (void) pthread_cond_broadcast(&dpr->dpr_cv); (void) pthread_mutex_unlock(&dpr->dpr_lock); return (NULL); }
int main(int argc, char **argv) { int opt, exit; pid_t pid; struct siginfo info; int status; int gret; struct ps_prochandle *Pr; if ((command = strrchr(argv[0], '/')) != NULL) command++; else command = argv[0]; while ((opt = getopt(argc, argv, "Fhmp:")) != EOF) { switch (opt) { case 'F': /* force grabbing (no O_EXCL) */ Fflag = PGRAB_FORCE; break; case 'm': /* microstate accounting */ mflag = 1; break; case 'p': pflag = 1; pidarg = optarg; break; default: errflg = 1; break; } } argc -= optind; argv += optind; if (((pidarg != NULL) ^ (argc < 1)) || errflg) { (void) fprintf(stderr, "usage:\t%s [-mh] [-p pidlist | command [ args ... ]]\n", command); (void) fprintf(stderr, " (time a command using microstate accounting)\n"); return (1); } if (pflag) { char *pp; exit = 0; (void) signal(SIGINT, SIG_IGN); (void) signal(SIGQUIT, SIG_IGN); pp = strtok(pidarg, ", "); if (pp == NULL) { (void) fprintf(stderr, "%s: invalid argument for -p\n", command); return (1); } exit = ptime_pid(pp); while ((pp = strtok(NULL, ", ")) != NULL) { exit |= ptime_pid(pp); } return (exit); } if ((Pr = Pcreate(argv[0], &argv[0], &gret, NULL, 0)) == NULL) { (void) fprintf(stderr, "%s: failed to exec %s: %s\n", command, argv[0], Pcreate_error(gret)); return (1); } if (Psetrun(Pr, 0, 0) == -1) { (void) fprintf(stderr, "%s: failed to set running %s: " "%s\n", command, argv[0], strerror(errno)); return (1); } pid = Pstatus(Pr)->pr_pid; (void) sprintf(procname, "%d", (int)pid); /* for perr() */ (void) signal(SIGINT, SIG_IGN); (void) signal(SIGQUIT, SIG_IGN); (void) waitid(P_PID, pid, &info, WEXITED | WNOWAIT); (void) look(pid); (void) waitpid(pid, &status, 0); if (WIFEXITED(status)) return (WEXITSTATUS(status)); if (WIFSIGNALED(status)) { int sig = WTERMSIG(status); char name[SIG2STR_MAX]; (void) fprintf(stderr, "%s: command terminated " "abnormally by %s\n", command, proc_signame(sig, name, sizeof (name))); } return (status | WCOREFLG); /* see time(1) */ }