Justus Winter, le Sat 17 Jan 2015 18:26:46 +0100, a écrit :
> Previously, the proc server did not call `startup_essential_task'
> until it got the message port of the startup server using
> `proc_setmsgport'.
>
> Now that we have `/servers/startup', we can do this in main, before we
> start our message service loop.
>
> A complication arises because the traditional startup server is
> single-threaded. Handle this by tweaking startup not to bind itself
> to `/servers/startup' before it is ready.
Ack, thanks!
> * proc/main.c (main): Try to lookup `/servers/startup' and send the
> message here, or...
> * proc/msg.c (S_proc_setmsgport): ... fall back to the old way here.
> * proc/proc.h (startup_fallback): New variable.
> * startup/startup.c (main): Move code installing ourself on `/servers/startup'
> (install_as_translator): ... here.
> (launch_core_servers): And use it here, just before we reply to `/hurd/auth'.
> ---
> proc/main.c | 23 +++++++++++++++++++++++
> proc/msg.c | 2 +-
> proc/proc.h | 2 ++
> startup/startup.c | 44 ++++++++++++++++++++++++++++++++------------
> 4 files changed, 58 insertions(+), 13 deletions(-)
>
> diff --git a/proc/main.c b/proc/main.c
> index b4288fb..6df4141 100644
> --- a/proc/main.c
> +++ b/proc/main.c
> @@ -22,6 +22,7 @@ the Free Software Foundation, 675 Mass Ave, Cambridge, MA
> 02139, USA. */
> #include <mach.h>
> #include <hurd/hurd_types.h>
> #include <hurd.h>
> +#include <hurd/paths.h>
> #include <hurd/startup.h>
> #include <device/device.h>
> #include <assert.h>
> @@ -62,6 +63,7 @@ message_demuxer (mach_msg_header_t *inp,
> }
>
> pthread_mutex_t global_lock = PTHREAD_MUTEX_INITIALIZER;
> +int startup_fallback;
>
> error_t
> increase_priority (void)
> @@ -99,6 +101,7 @@ main (int argc, char **argv, char **envp)
> error_t err;
> void *genport;
> process_t startup_port;
> + mach_port_t startup;
> struct argp argp = { 0, 0, 0, "Hurd process server" };
>
> argp_parse (&argp, argc, argv, 0, 0, 0);
> @@ -173,6 +176,26 @@ main (int argc, char **argv, char **envp)
> mach_port_deallocate (mach_task_self (), cons);
> }
>
> + startup = file_name_lookup (_SERVERS_STARTUP, 0, 0);
> + if (MACH_PORT_VALID (startup))
> + {
> + err = startup_essential_task (startup, mach_task_self (),
> + MACH_PORT_NULL, "proc", _hurd_host_priv);
> + if (err)
> + /* Due to the single-threaded nature of /hurd/startup, it can
> + only handle requests once the core server bootstrap has
> + completed. Therefore, it does not bind itself to
> + /servers/startup until it is ready. */
> + /* Fall back to abusing the message port lookup. */
> + startup_fallback = 1;
> +
> + err = mach_port_deallocate (mach_task_self (), startup);
> + assert_perror (err);
> + }
> + else
> + /* Fall back to abusing the message port lookup. */
> + startup_fallback = 1;
> +
> while (1)
> ports_manage_port_operations_multithread (proc_bucket,
> message_demuxer,
> diff --git a/proc/msg.c b/proc/msg.c
> index 796cae3..c7bab99 100644
> --- a/proc/msg.c
> +++ b/proc/msg.c
> @@ -63,7 +63,7 @@ S_proc_setmsgport (struct proc *p,
> prociterate (check_message_return, p);
> p->p_checkmsghangs = 0;
>
> - if (p == startup_proc)
> + if (p == startup_proc && startup_fallback)
> {
> /* Init is single threaded, so we can't delay our reply for
> the essential task RPC; spawn a thread to do it. */
> diff --git a/proc/proc.h b/proc/proc.h
> index a056d18..4be1de4 100644
> --- a/proc/proc.h
> +++ b/proc/proc.h
> @@ -151,6 +151,8 @@ mach_port_t generic_port; /* messages not related to a
> specific proc */
>
> pthread_mutex_t global_lock;
>
> +extern int startup_fallback; /* (ab)use /hurd/startup's message port */
> +
> /* Forward declarations */
> void complete_wait (struct proc *, int);
> int check_uid (struct proc *, uid_t);
> diff --git a/startup/startup.c b/startup/startup.c
> index c9fe215..e01d2a8 100644
> --- a/startup/startup.c
> +++ b/startup/startup.c
> @@ -514,6 +514,32 @@ demuxer (mach_msg_header_t *inp,
> startup_server (inp, outp));
> }
>
> +error_t
> +install_as_translator (void)
> +{
> + error_t err;
> + file_t node;
> +
> + node = file_name_lookup (_SERVERS_STARTUP, O_NOTRANS, 0);
> + if (! MACH_PORT_VALID (node))
> + {
> + if (errno == ENOENT)
> + {
> + /* Degrade gracefully if the node does not exist. */
> + error (0, errno, "%s", _SERVERS_STARTUP);
> + return 0;
> + }
> + return errno;
> + }
> +
> + err = file_set_translator (node,
> + 0, FS_TRANS_SET, 0,
> + NULL, 0,
> + startup, MACH_MSG_TYPE_COPY_SEND);
> + mach_port_deallocate (mach_task_self (), node);
> + return err;
> +}
> +
> static int
> parse_opt (int key, char *arg, struct argp_state *state)
> {
> @@ -587,18 +613,6 @@ main (int argc, char **argv, char **envp)
> /* Crash if the boot filesystem task dies. */
> request_dead_name (fstask);
>
> - file_t node = file_name_lookup (_SERVERS_STARTUP, O_NOTRANS, 0);
> - if (node == MACH_PORT_NULL)
> - error (0, errno, "%s", _SERVERS_STARTUP);
> - else
> - {
> - file_set_translator (node,
> - 0, FS_TRANS_SET, 0,
> - NULL, 0,
> - startup, MACH_MSG_TYPE_COPY_SEND);
> - mach_port_deallocate (mach_task_self (), node);
> - }
> -
> /* Set up the set of ports we will pass to the programs we exec. */
> for (i = 0; i < INIT_PORT_MAX; i++)
> switch (i)
> @@ -672,6 +686,12 @@ launch_core_servers (void)
> proc_task2proc (procserver, authtask, &authproc);
> proc_mark_important (authproc);
> proc_mark_exec (authproc);
> +
> + err = install_as_translator ();
> + if (err)
> + /* Good luck. Who knows, maybe it's an old installation. */
> + error (0, err, "Failed to bind to " _SERVERS_STARTUP);
> +
> startup_authinit_reply (authreply, authreplytype, 0, authproc,
> MACH_MSG_TYPE_COPY_SEND);
> mach_port_deallocate (mach_task_self (), authproc);
> --
> 2.1.4
>
--
Samuel
* x remarque qu'avec un peu de volonté, on peut faire du code de porc
dans d'importe quel langage Turing-complet
-+- x sur #ens-mim - codons porc -+-
