Body=1 with no Fuz1 or Fuz2

Gary Mills mills@cc.umanitoba.ca
Wed Jan 31 01:58:01 UTC 2007


On Sat, Jan 27, 2007 at 04:05:40PM -0700, Vernon Schryver wrote:
> > From: Gary Mills 
> 
> > When I checked the DCC log, it was a typical multipart/alternative
> > MIME message with a text/plain and a text/html portion.  Why would
> > there be no Fuz1 and Fuz2 checksums in this case?  Could they be
> > using funny MIME headers?  Here's how they look:
> 
> This problem turned out to be a very old bug.  The states of the MIME
> boundary strings matchers were not being sufficiently cleared at the
> starts of MIME parts.  When the previous mail message handled by a dccm
> or dccifd thread had broken MIME encapsulation, the MIME boundaries
> of the next message would might not be matched. 

I wonder if this bug is related to a problem I've been seeing recently?
Normally, dccm only uses a small portion of the CPU, but when this
problem strikes, the CPU usage gradually rises to become dominant.
When I stop and restart dccm, the CPU usage goes back to normal, at
least for a while.  I'm assuming that a few copies of a malformed
message have put the parser into a loop.

This evening, I found dccm running with two constantly active threads,
as shown by `pstack'.  All of the other threads were in various wait
states.  The active threads were both in the dcc_ck_body() function.

Here are the stack traces, taken a few minutes apart:

-----------------  lwp# 3086 / thread# 3086  --------------------
 000294e4 dcc_ck_body (122f88, b31058, 39d2, 1a7c, b32aa1, 1231eb) + 184
 0001981c dccm_body (affed8, b31058, 39d2, affed8, 197e8, 121db0) + 34
 0002385c mi_engine (affed8, 9, ffffffff, b31058, 92f64, 92fb0) + 28c
 00021d68 mi_handle_session (affed8, ff021634, 0, 0, 0, ffffffff) + 44
 0002142c mi_thread_handle_wrapper (affed8, 0, 0, 0, 0, 0) + 4
 ff0657b4 _lwp_start (0, 0, 0, 0, 0, 0)
-----------------  lwp# 3197 / thread# 3197  --------------------
 000294dc dcc_ck_body (11a5f4, b34b68, dd2e, 1ce0, b36832, 11a857) + 17c
 0001981c dccm_body (af4720, b34b68, dd2e, af4720, 197e8, 11941c) + 34
 0002385c mi_engine (af4720, 9, ffffffff, b34b68, 92f64, 92fb0) + 28c
 00021d68 mi_handle_session (af4720, ff171e34, 0, 0, 0, ffffffff) + 44
 0002142c mi_thread_handle_wrapper (af4720, 0, 0, 0, 0, 0) + 4
 ff0657b4 _lwp_start (0, 0, 0, 0, 0, 0)

-----------------  lwp# 3086 / thread# 3086  --------------------
 00029818 dcc_ck_body (122f88, b31058, 39d2, 1a7c, b32aa1, 12324d) + 4b8
 0001981c dccm_body (affed8, b31058, 39d2, affed8, 197e8, 121db0) + 34
 0002385c mi_engine (affed8, 9, ffffffff, b31058, 92f64, 92fb0) + 28c
 00021d68 mi_handle_session (affed8, ff021634, 0, 0, 0, ffffffff) + 44
 0002142c mi_thread_handle_wrapper (affed8, 0, 0, 0, 0, 0) + 4
 ff0657b4 _lwp_start (0, 0, 0, 0, 0, 0)
-----------------  lwp# 3197 / thread# 3197  --------------------
 00029818 dcc_ck_body (11a5f4, b34b68, dd2e, 1ce0, b36832, 11a8b9) + 4b8
 0001981c dccm_body (af4720, b34b68, dd2e, af4720, 197e8, 11941c) + 34
 0002385c mi_engine (af4720, 9, ffffffff, b34b68, 92f64, 92fb0) + 28c
 00021d68 mi_handle_session (af4720, ff171e34, 0, 0, 0, ffffffff) + 44
 0002142c mi_thread_handle_wrapper (af4720, 0, 0, 0, 0, 0) + 4
 ff0657b4 _lwp_start (0, 0, 0, 0, 0, 0)

-- 
-Gary Mills-    -Unix Support-    -U of M Academic Computing and Networking-



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