[Qemu-devel] Re: [PATCH] Permit zero-sized qemu_malloc() & friends

[Paolo Bonzini <pbonzini@redhat.com>]

On 12/06/2009 11:22 AM, malc wrote:
> Here, i believe, you are inventing artificial restrictions on how
> malloc behaves, i don't see anything that prevents the implementor
> from setting aside a range of addresses with 31st bit set as an
> indicator of "zero" allocations, and then happily giving it to the
> user of malloc and consumming it in free.

But it has to make it a valid address anyway.  If a zero-sized read 
treats it as invalid (SIGSEGV, EFAULT, whatever), malloc has failed to 
return a valid address and is not obeying its specification.

Paolo