From mboxrd@z Thu Jan  1 00:00:00 1970
From: Erik Hensema <erik.hensema@group2000.nl>
To: 'Pthreads-win32' <pthreads-win32@sourceware.cygnus.com>
Subject: Bug in pthread_setcancelstate()?
Date: Thu, 28 Oct 1999 09:40:00 -0000
Message-id: <A01E735D4940D311A3850090275559330BA993@NTSRV02>
X-SW-Source: 1999/msg00114.html

Hi,

>From the pthread_setcancelstate() from SunOS 5.5.1:

 pthread_setcancelstate
     pthread_setcancelstate()  automically   sets   the   calling
     thread's  cancellation  state to the specified state and, if
     oldstate is not NULL, stores the previous cancellation state
     in oldstate.

In cancel.c:

 if (((self = pthread_self ()) != NULL) &&
     (state == PTHREAD_CANCEL_ENABLE ||
      state == PTHREAD_CANCEL_DISABLE))
   {

     *oldstate = self->cancelState;     <---- crash if oldstate==NULL
     self->cancelState = state;
     result = 0;

   }

As you can see, it will crash if oldstate==NULL.

The obvious fix is to add the line " if(oldstate!=NULL)" above the
"*oldstate=".

ps. I haven't checked this with the Posix standard, so it can also be a
deviation from the standard by Sun; however, I think the code is more robust
this way.

-- 
Erik Hensema
Work: erik.hensema@group2000.nl
Home: erik@hensema.xs4all.nl