/* Support for tracing forked processes */
struct tcb *parent; /* Parent of this process */
int nchildren; /* # of traced children */
- int waitpid; /* pid(s) this process is waiting for */
int nzombies; /* # of formerly traced children now dead */
#ifdef LINUX
int nclone_threads; /* # of nchildren with CLONE_THREAD */
- int nclone_waiting; /* clone threads in wait4 (TCB_SUSPENDED) */
#endif
/* (1st arg of wait4()) */
long baddr; /* `Breakpoint' address */
extern int change_syscall(struct tcb *, int);
extern int internal_fork(struct tcb *);
extern int internal_exec(struct tcb *);
-extern int internal_wait(struct tcb *, int);
extern int internal_exit(struct tcb *);
#ifdef LINUX
extern int handle_new_child(struct tcb *, int, int);
return 0;
}
-int
-internal_wait(struct tcb *tcp, int flagarg)
-{
- int got_kids;
-
-#ifdef TCB_CLONE_THREAD
- if (tcp->flags & TCB_CLONE_THREAD)
- /* The children we wait for are our parent's children. */
- got_kids = (tcp->parent->nchildren
- > tcp->parent->nclone_threads);
- else
- got_kids = (tcp->nchildren > tcp->nclone_threads);
-#else
- got_kids = tcp->nchildren > 0;
-#endif
-
- if (entering(tcp) && got_kids) {
- /* There are children that this parent should block for.
- But ptrace made us the parent of the traced children
- and the real parent will get ECHILD from the wait call.
-
- XXX If we attached with strace -f -p PID, then there
- may be untraced dead children the parent could be reaping
- now, but we make him block. */
-
- /* ??? WTA: fix bug with hanging children */
-
- if (!(tcp->u_arg[flagarg] & WNOHANG)) {
- /*
- * There are traced children. We'll make the parent
- * block to avoid a false ECHILD error due to our
- * ptrace having stolen the children. However,
- * we shouldn't block if there are zombies to reap.
- * XXX doesn't handle pgrp matches (u_arg[0]==0,<-1)
- */
- struct tcb *child = NULL;
- if (tcp->nzombies > 0 &&
- (tcp->u_arg[0] == -1 ||
- (child = pid2tcb(tcp->u_arg[0])) == NULL))
- return 0;
- if (tcp->u_arg[0] > 0) {
- /*
- * If the parent waits for a specified child
- * PID, then it must get ECHILD right away
- * if that PID is not one of its children.
- * Make sure that the requested PID matches
- * one of the parent's children that we are
- * tracing, and don't suspend it otherwise.
- */
- if (child == NULL)
- child = pid2tcb(tcp->u_arg[0]);
- if (child == NULL || child->parent != (
-#ifdef TCB_CLONE_THREAD
- (tcp->flags & TCB_CLONE_THREAD)
- ? tcp->parent :
-#endif
- tcp) ||
- (child->flags & TCB_EXITING))
- return 0;
- }
- tcp->flags |= TCB_SUSPENDED;
- tcp->waitpid = tcp->u_arg[0];
-#ifdef TCB_CLONE_THREAD
- if (tcp->flags & TCB_CLONE_THREAD)
- tcp->parent->nclone_waiting++;
-#endif
- }
- }
- if (exiting(tcp) && tcp->u_error == ECHILD && got_kids) {
- if (tcp->u_arg[flagarg] & WNOHANG) {
- /* We must force a fake result of 0 instead of
- the ECHILD error. */
- return force_result(tcp, 0, 0);
- }
- }
- else if (exiting(tcp) && tcp->u_error == 0 && tcp->u_rval > 0 &&
- tcp->nzombies > 0 && pid2tcb(tcp->u_rval) == NULL) {
- /*
- * We just reaped a child we don't know about,
- * presumably a zombie we already droptcb'd.
- */
- tcp->nzombies--;
- }
- return 0;
-}
-
#ifdef SVR4
int
tcp->nzombies = 0;
#ifdef TCB_CLONE_THREAD
tcp->nclone_threads = 0;
- tcp->nclone_waiting = 0;
#endif
tcp->flags = TCB_INUSE | TCB_STARTUP;
tcp->outf = outf; /* Initialise to current out file */
tcp->outf = 0;
}
-#ifndef USE_PROCFS
-
-static int
-resume(struct tcb *tcp)
-{
- if (tcp == NULL)
- return -1;
-
- if (!(tcp->flags & TCB_SUSPENDED)) {
- fprintf(stderr, "PANIC: pid %u not suspended\n", tcp->pid);
- return -1;
- }
- tcp->flags &= ~TCB_SUSPENDED;
-#ifdef TCB_CLONE_THREAD
- if (tcp->flags & TCB_CLONE_THREAD)
- tcp->parent->nclone_waiting--;
-#endif
-
- if (ptrace_restart(PTRACE_SYSCALL, tcp, 0) < 0)
- return -1;
-
- if (!qflag)
- fprintf(stderr, "Process %u resumed\n", tcp->pid);
- return 0;
-}
-
-static int
-resume_from_tcp(struct tcb *tcp)
-{
- int error = 0;
- int resumed = 0;
-
- /* XXX This won't always be quite right (but it never was).
- A waiter with argument 0 or < -1 is waiting for any pid in
- a particular pgrp, which this child might or might not be
- in. The waiter will only wake up if it's argument is -1
- or if it's waiting for tcp->pid's pgrp. It makes a
- difference to wake up a waiter when there might be more
- traced children, because it could get a false ECHILD
- error. OTOH, if this was the last child in the pgrp, then
- it ought to wake up and get ECHILD. We would have to
- search the system for all pid's in the pgrp to be sure.
-
- && (t->waitpid == -1 ||
- (t->waitpid == 0 && getpgid (tcp->pid) == getpgid (t->pid))
- || (t->waitpid < 0 && t->waitpid == -getpid (t->pid)))
- */
-
- if (tcp->parent &&
- (tcp->parent->flags & TCB_SUSPENDED) &&
- (tcp->parent->waitpid <= 0 || tcp->parent->waitpid == tcp->pid)) {
- error = resume(tcp->parent);
- ++resumed;
- }
-#ifdef TCB_CLONE_THREAD
- if (tcp->parent && tcp->parent->nclone_waiting > 0) {
- /* Some other threads of our parent are waiting too. */
- unsigned int i;
-
- /* Resume all the threads that were waiting for this PID. */
- for (i = 0; i < tcbtabsize; i++) {
- struct tcb *t = tcbtab[i];
- if (t->parent == tcp->parent && t != tcp
- && ((t->flags & (TCB_CLONE_THREAD|TCB_SUSPENDED))
- == (TCB_CLONE_THREAD|TCB_SUSPENDED))
- && t->waitpid == tcp->pid) {
- error |= resume(t);
- ++resumed;
- }
- }
- if (resumed == 0)
- /* Noone was waiting for this PID in particular,
- so now we might need to resume some wildcarders. */
- for (i = 0; i < tcbtabsize; i++) {
- struct tcb *t = tcbtab[i];
- if (t->parent == tcp->parent && t != tcp
- && ((t->flags
- & (TCB_CLONE_THREAD|TCB_SUSPENDED))
- == (TCB_CLONE_THREAD|TCB_SUSPENDED))
- && t->waitpid <= 0
- ) {
- error |= resume(t);
- break;
- }
- }
- }
-#endif
-
- return error;
-}
-
-#endif /* !USE_PROCFS */
-
/* detach traced process; continue with sig
Never call DETACH twice on the same process as both unattached and
attached-unstopped processes give the same ESRCH. For unattached process we
error = ptrace_restart(PTRACE_DETACH, tcp, sig);
#endif /* SUNOS4 */
-#ifndef USE_PROCFS
- error |= resume_from_tcp(tcp);
-#endif
-
if (!qflag)
fprintf(stderr, "Process %u detached\n", tcp->pid);
tcp->pid, leader ? leader->pid : -1);
}
/* TCP no longer exists therefore you must not detach() it. */
-#ifndef USE_PROCFS
- resume_from_tcp(tcp);
-#endif
droptcb(tcp); /* Already died. */
}
else {
)
return internal_exec(tcp);
- if ( sys_waitpid == func
- || sys_wait4 == func
-#if defined(SVR4) || defined(FREEBSD) || defined(SUNOS4)
- || sys_wait == func
-#endif
-#ifdef ALPHA
- || sys_osf_wait4 == func
-#endif
- )
- return internal_wait(tcp, 2);
-
-#if defined(LINUX) || defined(SVR4)
- if (sys_waitid == func)
- return internal_wait(tcp, 3);
-#endif
-
return 0;
}
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