> From: [email protected] (Jeremie Courreges-Anglas)
> Date: Mon, 27 Jun 2016 20:13:54 +0200
>
> Some time ago someone reported a wird behavior in the shells/zsh ports.
>
> http://marc.info/?l=openbsd-misc&m=146101806918986&w=2
>
> The latter relies on kill(zombie, 0) to succeed, instead we return -1.
> This is because zombie processes aren't looked up in sys_kill().
>
> A potential fix was suggested, which involved stopping using a reaper
> process and let processes clean up after themselves. However such
> a change doesn't look trivial, especially late in this development
> cycle.
>
> So here's a bit of band-aid. Worth it?
ok kettenis@
> Index: kern/kern_proc.c
> ===================================================================
> RCS file: /cvs/src/sys/kern/kern_proc.c,v
> retrieving revision 1.66
> diff -u -p -r1.66 kern_proc.c
> --- kern/kern_proc.c 4 Mar 2016 14:09:37 -0000 1.66
> +++ kern/kern_proc.c 27 Jun 2016 18:02:01 -0000
> @@ -205,6 +205,20 @@ pgfind(pid_t pgid)
> }
>
> /*
> + * Locate a zombie process
> + */
> +struct process *
> +zombiefind(pid_t pid)
> +{
> + struct process *pr;
> +
> + LIST_FOREACH(pr, &zombprocess, ps_list)
> + if (pr->ps_mainproc->p_pid == pid)
> + return (pr);
> + return (NULL);
> +}
> +
> +/*
> * Move p to a new or existing process group (and session)
> * Caller provides a pre-allocated pgrp and session that should
> * be freed if they are not used.
> Index: kern/kern_sig.c
> ===================================================================
> RCS file: /cvs/src/sys/kern/kern_sig.c,v
> retrieving revision 1.199
> diff -u -p -r1.199 kern_sig.c
> --- kern/kern_sig.c 27 Jun 2016 16:49:45 -0000 1.199
> +++ kern/kern_sig.c 27 Jun 2016 18:02:01 -0000
> @@ -627,19 +627,24 @@ sys_kill(struct proc *cp, void *v, regis
> int pid = SCARG(uap, pid);
> int signum = SCARG(uap, signum);
> int error;
> + int zombie = 0;
>
> if ((error = pledge_kill(cp, pid)) != 0)
> return (error);
> if (((u_int)signum) >= NSIG)
> return (EINVAL);
> if (pid > 0) {
> - if ((pr = prfind(pid)) == NULL)
> - return (ESRCH);
> + if ((pr = prfind(pid)) == NULL) {
> + if ((pr = zombiefind(pid)) == NULL)
> + return (ESRCH);
> + else
> + zombie = 1;
> + }
> if (!cansignal(cp, pr, signum))
> return (EPERM);
>
> /* kill single process */
> - if (signum)
> + if (signum && !zombie)
> prsignal(pr, signum);
> return (0);
> }
> Index: sys/proc.h
> ===================================================================
> RCS file: /cvs/src/sys/sys/proc.h,v
> retrieving revision 1.223
> diff -u -p -r1.223 proc.h
> --- sys/proc.h 30 May 2016 21:31:27 -0000 1.223
> +++ sys/proc.h 27 Jun 2016 18:02:01 -0000
> @@ -482,6 +482,7 @@ pid_t allocpid(void);
> void freepid(pid_t);
>
> struct process *prfind(pid_t); /* Find process by id. */
> +struct process *zombiefind(pid_t); /* Find zombie process by id. */
> struct proc *pfind(pid_t); /* Find thread by id. */
> struct pgrp *pgfind(pid_t); /* Find process group by id. */
> void proc_printit(struct proc *p, const char *modif,
>
>
> --
> jca | PGP: 0x1524E7EE / 5135 92C1 AD36 5293 2BDF DDCC 0DFA 74AE 1524 E7EE
>
>
