Author: ed Date: Thu Jul 9 12:04:45 2015 New Revision: 285312 URL: https://svnweb.freebsd.org/changeset/base/285312
Log: Don't clobber td->td_retval[0] in proc_reap(). While writing tests for CloudABI, I noticed that close() on process descriptors returns the process ID of the child process. This is interesting, as close() is only allowed to return 0 or -1. It turns out that we clobber td->td_retval[0] in proc_reap(), so that wait*() properly returns the process ID. Change proc_reap() to leave td->td_retval[0] alone. Set the return value in kern_wait6() instead, by keeping track of the PID before we (potentially) reap the process. Differential Revision: https://reviews.freebsd.org/D3032 Reviewed by: kib Modified: head/sys/kern/kern_exit.c Modified: head/sys/kern/kern_exit.c ============================================================================== --- head/sys/kern/kern_exit.c Thu Jul 9 11:32:29 2015 (r285311) +++ head/sys/kern/kern_exit.c Thu Jul 9 12:04:45 2015 (r285312) @@ -839,7 +839,6 @@ proc_reap(struct thread *td, struct proc q = td->td_proc; PROC_SUNLOCK(p); - td->td_retval[0] = p->p_pid; if (status) *status = p->p_xstat; /* convert to int */ if (options & WNOWAIT) { @@ -1153,6 +1152,7 @@ kern_wait6(struct thread *td, idtype_t i int options, struct __wrusage *wrusage, siginfo_t *siginfo) { struct proc *p, *q; + pid_t pid; int error, nfound, ret; AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */ @@ -1191,14 +1191,17 @@ loop: nfound = 0; sx_xlock(&proctree_lock); LIST_FOREACH(p, &q->p_children, p_sibling) { + pid = p->p_pid; ret = proc_to_reap(td, p, idtype, id, status, options, wrusage, siginfo, 0); if (ret == 0) continue; else if (ret == 1) nfound++; - else + else { + td->td_retval[0] = pid; return (0); + } PROC_LOCK(p); PROC_SLOCK(p); @@ -1212,7 +1215,6 @@ loop: if ((options & WNOWAIT) == 0) p->p_flag |= P_WAITED; sx_xunlock(&proctree_lock); - td->td_retval[0] = p->p_pid; if (status != NULL) *status = W_STOPCODE(p->p_xstat); @@ -1231,6 +1233,7 @@ loop: p->p_pid, W_STOPCODE(p->p_xstat), p->p_xstat, p->p_xthread != NULL ? p->p_xthread->td_tid : -1); PROC_UNLOCK(p); + td->td_retval[0] = pid; return (0); } if ((options & WUNTRACED) != 0 && @@ -1241,7 +1244,6 @@ loop: if ((options & WNOWAIT) == 0) p->p_flag |= P_WAITED; sx_xunlock(&proctree_lock); - td->td_retval[0] = p->p_pid; if (status != NULL) *status = W_STOPCODE(p->p_xstat); @@ -1256,13 +1258,13 @@ loop: } PROC_UNLOCK(p); + td->td_retval[0] = pid; return (0); } PROC_SUNLOCK(p); if ((options & WCONTINUED) != 0 && (p->p_flag & P_CONTINUED) != 0) { sx_xunlock(&proctree_lock); - td->td_retval[0] = p->p_pid; if ((options & WNOWAIT) == 0) { p->p_flag &= ~P_CONTINUED; PROC_LOCK(q); @@ -1277,6 +1279,7 @@ loop: siginfo->si_status = SIGCONT; siginfo->si_code = CLD_CONTINUED; } + td->td_retval[0] = pid; return (0); } PROC_UNLOCK(p); _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "[email protected]"
