Re: [Qemu-devel] [PATCH] semaphore syscalls - refresh

[Stuart Anderson]

On Sat, 31 Mar 2007, Thiemo Seufer wrote:

> > +    switch( cmd ) {
> > +       case GETALL:
> > +       case SETALL:
> > +       case IPC_STAT:
> > +       case IPC_SET:
> > +           lock_user_struct(target_su, target_addr, 1);
> > +          target_to_host_semid_ds(ds,target_su->buf);
> > +          host_su->buf = ds;
> > +           unlock_user_struct(target_su, target_addr, 0);
> > +          break;
>
> I don't see how this can work with target_su being an uninitialized pointer.

#define lock_user_struct(host_ptr, guest_addr, copy) \
    host_ptr = lock_user(guest_addr, sizeof(*host_ptr), copy)

target_su is the left hand side of the assignment. The macro just hides it.


                                Stuart

Stuart R. Anderson                               address@hidden
Network & Software Engineering                   http://www.netsweng.com/
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