Wolf, Josef <[EMAIL PROTECTED]> wrote: > I've just checked uClibc. It uses alloca only when a MMU is available. > If there's no MMU, it falls back to mmap().
That's a bit of a problem surely as you can't free the mappings later. > Now I'm somewhat confused. What's wrong with alloca in the vfork > context? The only problem I can think of is that alloca() allocates from the stack, and with NOMMU-mode you've got a limited stack space and no hope of expanding it if you don't have enough. > Maybe the problem is coupled with setjmp implementations > of vfork? I found http://gcc.gnu.org/ml/gcc/2005-06/msg01265.html but > that discusses vfork implementation. That's a totally different thing > from exec* implementation since the exec* functions have their own > stack frames Using alloca() should just require the function using it to use a frame pointer. alloca() allocates simply by subtracting (or adding, depending on your CPU) from the stack pointer. > > > > > malloc/free _can_ be safe, too _if_ _exactly_ the malloc'ed > > > > > areas are freed. But how do you call free() after (v)forking? > > Ugh. I think that's one of those "not recommended" things. > > You mean the double-vfrok? I'd consider this to be one of the > "forbidden" things. Yes. David _______________________________________________ uClinux-dev mailing list uClinux-dev@uclinux.org http://mailman.uclinux.org/mailman/listinfo/uclinux-dev This message was resent by uclinux-dev@uclinux.org To unsubscribe see: http://mailman.uclinux.org/mailman/options/uclinux-dev
