Re: [Qemu-devel] [PATCH] linux-user: Fix stale tbs after mmap

[Peter Maydell <peter.maydell@linaro.org>]

On 7 May 2012 10:30, Alexander Graf <agraf@suse.de> wrote:
> @@ -587,6 +587,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
>     page_dump(stdout);
>     printf("\n");
>  #endif
> +    tb_invalidate_phys_page_range(start, start + len, 0);
>     mmap_unlock();
>     return start;

The comment at the top of tb_invalidate_phys_page_range() says
"start and end must refer to the same physical page" -- is it
out of date or does that not apply to user-mode?

Do you need to also invalidate the range on munmap() and
mprotect-to-not-executable in order to correctly fault on
the case of:
  map something
  execute it
  unmap it
  try to execute it again

? (haven't tested that case but it seems like it might be an issue)

-- PMM