More On Solaris ADDRESS_SPACE_LIMIT

[Robert Lunnon]

In dlls/ntdlls/virtual.c around line 1033 in NtAllocateVirtualMemory:

NTSTATUS res=anon_mmap_aligned( &base, size,VIRTUAL_GetUnixProt( vprot ), 0 );
            if (res) return res;

Why is mmap used here rather than just a malloc/calloc to the OS ? If I can 
convert this call to a calloc then the ADDRESS_SPACE_LIMIT test will pass on 
Solaris.

Can someone give me some insight here ?

Bob

[Alexandre Julliard]

Robert Lunnon  writes:
> In dlls/ntdlls/virtual.c around line 1033 in NtAllocateVirtualMemory:
>
> NTSTATUS res=anon_mmap_aligned( &base, size,VIRTUAL_GetUnixProt( vprot ), 0 );
>             if (res) return res;
>
> Why is mmap used here rather than just a malloc/calloc to the OS ? If I can 
> convert this call to a calloc then the ADDRESS_SPACE_LIMIT test will pass on 
> Solaris.

No, you need an mmap. What you have to do is write a routine that
allocates (with mmap) all available memory above ADDRESS_SPACE_LIMIT
to make sure following mmap calls can't allocate there; and that
routine can then be called the first time mmap returns such an
address, so that it will work for all platforms that may have that
problem.