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/* Pseudo implementation of waitid.
Copyright (C) 1997-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Zack Weinberg <zack@rabi.phys.columbia.edu>, 1997.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <assert.h>
#include <errno.h>
#include <signal.h>
#define __need_NULL
#include <stddef.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <sysdep-cancel.h>
#ifdef DO_WAITID
# define OUR_WAITID DO_WAITID
#elif !defined NO_DO_WAITID
# define OUR_WAITID do_waitid
#endif
#ifdef OUR_WAITID
static int
OUR_WAITID (idtype_t idtype, id_t id, siginfo_t *infop, int options)
{
pid_t pid, child;
int status;
switch (idtype)
{
case P_PID:
if(id <= 0)
goto invalid;
pid = (pid_t) id;
break;
case P_PGID:
if (id < 0 || id == 1)
goto invalid;
pid = (pid_t) -id;
break;
case P_ALL:
pid = -1;
break;
default:
invalid:
__set_errno (EINVAL);
return -1;
}
/* Technically we're supposed to return EFAULT if infop is bogus,
but that would involve mucking with signals, which is
too much hassle. User will have to deal with SIGSEGV/SIGBUS.
We just check for a null pointer. */
if (infop == NULL)
{
__set_errno (EFAULT);
return -1;
}
/* This emulation using waitpid cannot support the waitid modes in which
we do not reap the child, or match only stopped and not dead children. */
if (0
#ifdef WNOWAIT
|| (options & WNOWAIT)
#endif
#ifdef WEXITED
|| ((options & (WEXITED|WSTOPPED|WCONTINUED))
!= (WEXITED | (options & WSTOPPED)))
#endif
)
{
__set_errno (ENOTSUP);
return -1;
}
/* Note the waitid() is a cancellation point. But since we call
waitpid() which itself is a cancellation point we do not have
to do anything here. */
child = __waitpid (pid, &status,
options
#ifdef WEXITED
&~ WEXITED
#endif
);
if (child == -1)
/* `waitpid' set `errno' for us. */
return -1;
if (child == 0)
{
/* The WHOHANG bit in OPTIONS is set and there are children available
but none has a status for us. The XPG docs do not mention this
case so we clear the `siginfo_t' struct and return successfully. */
infop->si_signo = 0;
infop->si_code = 0;
return 0;
}
/* Decode the status field and set infop members... */
infop->si_signo = SIGCHLD;
infop->si_pid = child;
infop->si_errno = 0;
if (WIFEXITED (status))
{
infop->si_code = CLD_EXITED;
infop->si_status = WEXITSTATUS (status);
}
else if (WIFSIGNALED (status))
{
infop->si_code = WCOREDUMP (status) ? CLD_DUMPED : CLD_KILLED;
infop->si_status = WTERMSIG (status);
}
else if (WIFSTOPPED (status))
{
infop->si_code = CLD_STOPPED;
infop->si_status = WSTOPSIG (status);
}
#ifdef WIFCONTINUED
else if (WIFCONTINUED (status))
{
infop->si_code = CLD_CONTINUED;
infop->si_status = SIGCONT;
}
#endif
else
/* Can't happen. */
assert (! "What?");
return 0;
}
#endif
int
__waitid (idtype_t idtype, id_t id, siginfo_t *infop, int options)
{
/* __waitpid should be a cancellation point. */
return do_waitid (idtype, id, infop, options);
}
weak_alias (__waitid, waitid)
strong_alias (__waitid, __libc_waitid)
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