Re: [Qemu-devel] ARM hosts: code_gen_alloc() maps code buffer on top of libc heap

[Peter Maydell]

On 28 October 2011 17:14, Paolo Bonzini <address@hidden> wrote:
> On 10/28/2011 04:32 PM, Peter Maydell wrote:
>>
>> I suspect we need to drop the MAP_FIXED requirement and
>> fix the TCG code to cope with emitting code for longer-range
>> branches for calls to host fns etc (calls/branches within the
>> generated code should be ok to keep using the short-range
>> branch insn I think). There is already no guarantee that
>> the generated code and the host C code are within short
>> branch range of each other...
>
> Does USE_STATIC_CODE_GEN_BUFFER fix it?

Well, it avoids the malloc abort. We seem to get stuck in an
infinite cycle of the guest trying to start grub and rebooting
before it manages to print the blue-background grub menu screen,
though, so something's still not right. Likely a different bug,
though.

> Do you know why "Currently it is
> not recommended to allocate big chunks of data in user mode"?

Don't know, but my guess is that it is or was likely to clash
with attempts to put the guest binary in the right place in
the address space.

-- PMM