On Fri, Mar 24, 2006 at 01:37:54AM +0100, Blaisorblade wrote:
> Yep, it seems it looks good. But 1 bug still and two suggestions.
> See also attached patch (it misses one of the suggestions because it's late
> and I'm going to sleep).
I merged that patch.
> If possible (there should be such array constructors) this shouldn't be
> redundant / duplicated with the initial declarations.
>
> Like write_sigio_fds = (int[]) {-1,-1} and having a common macro like
>
> #define SIGIO_FDS_INIT {-1,-1}
>
> static int write_sigio_fds[2] = SIGIO_FDS_INIT;
> ...
> write_sigio_fds = (int[]) SIGIO_FDS_INIT
I tried this - I couldn't get anything like that to compile. I always
got an "incompatible types in assignment" error.
Below is the latest version.
Jeff
# This fixes a race in the starting of write_sigio_thread.
# Previously, some of the data needed by the thread was initialized
# after the clone. If the thread ean immediately, it would see the
# uninitialized data, including an empty pollfds, which would cause it
# to hang.
# We move the data initialization to before the clone, and adjust the
# error paths and cleanup accordingly.
#
# Signed-off-by: Jeff Dike <[EMAIL PROTECTED]>
Index: linux-2.6.16/arch/um/os-Linux/sigio.c
===================================================================
--- linux-2.6.16.orig/arch/um/os-Linux/sigio.c 2006-03-23 17:30:27.000000000
-0500
+++ linux-2.6.16/arch/um/os-Linux/sigio.c 2006-03-23 17:44:11.000000000
-0500
@@ -270,42 +270,40 @@ void write_sigio_workaround(void)
/* Did we race? Don't try to optimize this, please, it's not so likely
* to happen, and no more than once at the boot. */
if(write_sigio_pid != -1)
- goto out_unlock;
+ goto out_free;
- write_sigio_pid = run_helper_thread(write_sigio_thread, NULL,
- CLONE_FILES | CLONE_VM, &stack, 0);
-
- if (write_sigio_pid < 0)
- goto out_clear;
+ current_poll = ((struct pollfds) { .poll = p,
+ .used = 1,
+ .size = 1 });
if (write_sigio_irq(l_write_sigio_fds[0]))
- goto out_kill;
+ goto out_free;
- /* Success, finally. */
memcpy(write_sigio_fds, l_write_sigio_fds, sizeof(l_write_sigio_fds));
memcpy(sigio_private, l_sigio_private, sizeof(l_sigio_private));
- current_poll = ((struct pollfds) { .poll = p,
- .used = 1,
- .size = 1 });
+ write_sigio_pid = run_helper_thread(write_sigio_thread, NULL,
+ CLONE_FILES | CLONE_VM, &stack, 0);
- sigio_unlock();
- return;
+ if (write_sigio_pid < 0)
+ goto out_clear;
- out_kill:
- l_write_sigio_pid = write_sigio_pid;
- write_sigio_pid = -1;
sigio_unlock();
- /* Going to call waitpid, avoid holding the lock. */
- os_kill_process(l_write_sigio_pid, 1);
- goto out_free;
+ return;
out_clear:
write_sigio_pid = -1;
- out_unlock:
- sigio_unlock();
+ current_poll = ((struct pollfds) { .poll = NULL,
+ .size = 0,
+ .used = 0 });
+ write_sigio_fds[0] = -1;
+ write_sigio_fds[1] = -1;
+
+ sigio_private[0] = -1;
+ sigio_private[1] = -1;
out_free:
kfree(p);
+ sigio_unlock();
out_close2:
close(l_sigio_private[0]);
close(l_sigio_private[1]);
