cvs commit: src/sys/kern uipc_socket.c

[John Baldwin]

On Tuesday 29 November 2005 02:47 pm, Bjoern A. Zeeb wrote:
> On Mon, 28 Nov 2005, Robert Watson wrote:
> > rwatson     2005-11-28 18:09:03 UTC
> >
> >  FreeBSD src repository
> >
> >  Modified files:
> >    sys/kern             uipc_socket.c
> >  Log:
> >  Break out functionality in sosend() responsible for building mbuf
> >  chains and copying in mbufs from the body of the send logic, creating
> >  a new function sosend_copyin().  This changes makes sosend() almost
> >  readable, and will allow the same logic to be used by tailored socket
> >  send routines.
> >
> >  MFC after:      1 month
> >  Reviewed by:    andre, glebius
> >
> >  Revision  Changes    Path
> >  1.253     +170 -141  src/sys/kern/uipc_socket.c
>
> there seems to be some locking problem. I can easily reproduce that
> with a dmesg of a bootverbose boot on a ssh connection:
>
> System call write returning with the following locks held:
> exclusive sleep mutex so_snd r = 0 (0xffffff0094a78670) locked @
> /local/building/freebsd/HEAD/sys/kern/uipc_socket.c:884 panic: witness_warn
> KDB: enter: panic
> [thread pid 523 tid 100061 ]
> Stopped at      kdb_enter+0x31: leave

Try this patch:

Index: uipc_socket.c
===================================================================
RCS file: /usr/cvs/src/sys/kern/uipc_socket.c,v
retrieving revision 1.254
diff -u -r1.254 uipc_socket.c
--- uipc_socket.c       28 Nov 2005 21:45:36 -0000      1.254
+++ uipc_socket.c       29 Nov 2005 21:28:16 -0000
@@ -716,7 +716,7 @@
 }

 #define        SBLOCKWAIT(f)   (((f) & MSG_DONTWAIT) ? M_NOWAIT : M_WAITOK)
-#define        snderr(errno)   { error = (errno); goto out; }
+#define        snderr(errno)   { error = (errno); goto release; }

 /*
  * Send on a socket.

-- 
John Baldwin <jhb at FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve"  =  http://www.FreeBSD.org