Date: Sat, 29 Nov 2003 12:21:38 -0800 From: Alfred Perlstein <bright@mu.org> To: Daniel Eischen <eischen@vigrid.com> Cc: current@freebsd.org Subject: Re: [PATCH] please review. file descriptor passing for libc_r. Message-ID: <20031129202138.GU35957@elvis.mu.org> In-Reply-To: <Pine.GSO.4.10.10311222342030.18080-100000@pcnet5.pcnet.com> References: <20031123023649.GG35957@elvis.mu.org> <Pine.GSO.4.10.10311222342030.18080-100000@pcnet5.pcnet.com>
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* Daniel Eischen <eischen@vigrid.com> [031122 20:46] wrote:
> On Sat, 22 Nov 2003, Alfred Perlstein wrote:
>
> > This should make things work properly for apps that are linked
> > against libc_r and use filedescriptor passing.
> >
> > Can someone review and approve it please?
>
> This isn't needed. Any time a file descriptor is used, a call
> should first be made to _FD_LOCK() which ends up calling
> _thread_fd_lock() which then calls _thread_fd_table_init()
> for the file descriptor.
>
> If there's a reason that this is necessary, then I think it
> is just covering up another problem. I think I made this
> same comment a couple of years ago ;-)
Sorry for the long delay here, I was in Vegas for my sister's
birthday.
Actually there is a problem here. :(
Descriptor's passed can't be closed because the uthread kernel does this:
int
_close(int fd)
{
int flags;
int ret;
struct stat sb;
struct fd_table_entry *entry;
if ((fd < 0) || (fd >= _thread_dtablesize) ||
(fd == _thread_kern_pipe[0]) || (fd == _thread_kern_pipe[1]) ||
(_thread_fd_table[fd] == NULL)) {
/*
* Don't allow silly programs to close the kernel pipe
* and non-active descriptors.
*/
errno = EBADF;
ret = -1;
}
...
So basically, if the entry is not initialized we can't close descriptors.
What do you suggest we do?
--
- Alfred Perlstein
- Research Engineering Development Inc.
- email: bright@mu.org cell: 408-480-4684
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