Le 13/12/2019 à 03:29, Xinyu Li a écrit :
> In init_guest_space, we need to mmap guest space. If the return address
> of first mmap is not aligned with align, which was set to MAX(SHMLBA,
> qemu_host_page_size), we need unmap and a new mmap(space is larger than
> first size). The new size is named real_size, which is aligned_size +
> qemu_host_page_size. alugned_size is the guest space size. And add a
> qemu_host_page_size to avoid memory error when we align real_start
> manually (ROUND_UP(real_start, align)). But when SHMLBA >
> qemu_host_page_size, the added size will smaller than the size to align,
> which can make a mistake(in a mips machine, it appears). So change
> real_size from aligned_size +qemu_host_page_size
> to aligned_size + align will solve it.
>
> Signed-off-by: Xinyu Li <preci...@mail.ustc.edu.cn>
> ---
> linux-user/elfload.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/linux-user/elfload.c b/linux-user/elfload.c
> index f6693e5760..312ded0779 100644
> --- a/linux-user/elfload.c
> +++ b/linux-user/elfload.c
> @@ -2189,7 +2189,7 @@ unsigned long init_guest_space(unsigned long host_start,
> * to where we need to put the commpage.
> */
> munmap((void *)real_start, host_size);
> - real_size = aligned_size + qemu_host_page_size;
> + real_size = aligned_size + align;
> real_start = (unsigned long)
> mmap((void *)real_start, real_size, PROT_NONE, flags, -1, 0);
> if (real_start == (unsigned long)-1) {
>
Your change seems correct to me.
Richard did you miss this in your patch
30ab9ef2967d ("linux-user: Fix shmat emulation by honoring host SHMLBA")
or was it voluntary to keep it?
Thanks,
Laurent
