Programming with X32VM and DMC 8.33 I install an exception
handler using  _x32_fault_intercept().

Then in my handler I longjmp() out to a main exception handler
(in case the stack was screwed up before my handler got called).
Before I call _exit(), I print the registers and call only critical exit
handlers.

Q: Is it safe to use longjmp()?

--gv

In article <b87cpd$r9l$1@digitaldaemon.com>, Gisle Vanem (gvanem@eunet.no) says...
> Programming with X32VM and DMC 8.33 I install an exception
> handler using  _x32_fault_intercept().
> 
> Then in my handler I longjmp() out to a main exception handler
> (in case the stack was screwed up before my handler got called).
> Before I call _exit(), I print the registers and call only critical exit
> handlers.
> 
> Q: Is it safe to use longjmp()?

Once memory has been corrupted by
stray writes thru bad pointers, (such
as would "screw up" the stack), then
longjump's data structure may also
have been hit and the longjump() may
fail.  However, understanding that any
stack unwinding (dtor calls) will be
bypassed by a longjump(), it is among
the safer things you can do other than
just terminating the process.

If it was crucial, you could add some
redundancy to the longjump struct and
validate it before the longjump().

-- 
-Larry Brasfield
(address munged, s/sn/h/ to reply)

"Larry Brasfield" <larry_brasfield@snotmail.com> wrote:

> Once memory has been corrupted by
> stray writes thru bad pointers, (such
> as would "screw up" the stack), then
> longjump's data structure may also
> have been hit and the longjump() may
> fail.  However, understanding that any
> stack unwinding (dtor calls) will be
> bypassed by a longjump(), it is among
> the safer things you can do other than
> just terminating the process.

Thanks for the info. I was a bit uncertain if
_x32_fault_intercept() required the handler to
return to do some internal house-keeping.
But some test convinced m it's not needed.

--gv