Re: [Qemu-devel] [PATCH 14/17] Revived GUEST_BASE support for usermode emulation targets.

[Paul Brook <paul@codesourcery.com>]

On Tuesday 31 March 2009, riku.voipio@iki.fi wrote:
> +           "You can use -B option to load target binary into different\n"
> +           "address that is specified in elf headers.  This can be
> useful\n" +           "when target binary would be loaded to low addresses
> and\n" +           "/proc/sys/vm/mmap_min_addr is set to higher.  For
> example\n" +           "     qemu-" TARGET_ARCH " -B 0x100000 ...\n"
> +           "loads target binary starting from the first meg.\n"

This is wrong. -B is completely transparent to the guest application and 
offsets the whole guest address space. 

> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index c6b0b74..ef2bf55 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -2413,6 +2413,8 @@ static inline abi_long do_shmat(int shmid, abi_ulong
> shmaddr, int shmflg, }
>      }
>  
> +    *raddr = h2g(*raddr);
> +

This is wrong. host and guest addresses are different sizes.
This sort of bugfix should also be separated from the host support. Especially 
as the bogus code comes from one of your earlier patches.

Paul