lkml.org 
[lkml]   [2001]   [Sep]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH]Fix bug in msgsnd
It would be nice, if you could send the test cases you used to test these
fixes or
their outputs before and after the fix, showing the problem and then the
problem
going away.

Thanks,
Balbir Singh.

Mingming cao wrote:

> Hello linus & Alan,
>
> This patch fixes a bug in msgsnd. If a message is sent via
> pipelined_send(), the q_lrpid field of the associated message queue
> (last pid receive) is not updated correctly. The existing code
> (apparently by mistake) updates the lspid field instead. The second
> problem is that, for the pipelinesend case, q_lstime(last msgsnd time)
> is set AFTER q_lrtime(last msgrcv time), yielding a negative time delta.
>
> This patch is against kernel 2.4.9 and has been tested. Please
> apply.
>
> Please CC your feedback to me also, thanks.
>
> --
> Mingming Cao
> IBM Linux Technology Center
>
> diff -urN -X dontdiff linux/ipc/msg.c linux-tk/ipc/msg.c
> --- linux/ipc/msg.c Tue Sep 11 16:21:42 2001
> +++ linux-tk/ipc/msg.c Tue Sep 11 16:21:31 2001
> @@ -613,7 +613,7 @@
> wake_up_process(msr->r_tsk);
> } else {
> msr->r_msg = msg;
> - msq->q_lspid = msr->r_tsk->pid;
> + msq->q_lrpid = msr->r_tsk->pid;
> msq->q_rtime = CURRENT_TIME;
> wake_up_process(msr->r_tsk);
> return 1;
> @@ -683,6 +683,9 @@
> goto retry;
> }
>
> + msq->q_lspid = current->pid;
> + msq->q_stime = CURRENT_TIME;
> +
> if(!pipelined_send(msq,msg)) {
> /* noone is waiting for this message, enqueue it */
> list_add_tail(&msg->m_list,&msq->q_messages);
> @@ -694,8 +697,6 @@
>
> err = 0;
> msg = NULL;
> - msq->q_lspid = current->pid;
> - msq->q_stime = CURRENT_TIME;
>
> out_unlock_free:
> msg_unlock(msqid);
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/

-------------------------------------------------------------------------------------------------------------------------
Information transmitted by this E-MAIL is proprietary to Wipro and/or its Customers and
is intended for use only by the individual or entity to which it is
addressed, and may contain information that is privileged, confidential or
exempt from disclosure under applicable law. If you are not the intended
recipient or it appears that this mail has been forwarded to you without
proper authority, you are notified that any use or dissemination of this
information in any manner is strictly prohibited. In such cases, please
notify us immediately at mailto:mailadmin@wipro.com and delete this mail
from your records.
----------------------------------------------------------------------------------------------------------------------
\
 
 \ /
  Last update: 2005-03-22 13:17    [W:0.047 / U:4.856 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site