Le 28/12/2017 à 19:08, Luke Shumaker a écrit :
> From: Luke Shumaker
>
> If the ensure-alignment code gets triggered, then the
> "if (host_start && real_start != current_start)" check will always trigger,
> so save 2 syscalls and put that check first.
>
> Note that we can't just switch to using MAP_FIXED for that check, because
> then we couldn't differentiate between a failure because "there isn't
> enough space" and "there isn't enough space *here*".
>
> Signed-off-by: Luke Shumaker
> ---
> linux-user/elfload.c | 10 +-
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/linux-user/elfload.c b/linux-user/elfload.c
> index 5c0ad65611..1b7583d659 100644
> --- a/linux-user/elfload.c
> +++ b/linux-user/elfload.c
> @@ -1871,6 +1871,11 @@ unsigned long init_guest_space(unsigned long
> host_start,
> return (unsigned long)-1;
> }
>
> +/* Check to see if the address is valid. */
> +if (host_start && real_start != current_start) {
> +goto try_again;
> +}
> +
> /* Ensure the address is properly aligned. */
> if (real_start & ~qemu_host_page_mask) {
> /* Ideally, we adjust like
> @@ -1905,11 +1910,6 @@ unsigned long init_guest_space(unsigned long
> host_start,
> aligned_start = real_start;
> }
>
> -/* Check to see if the address is valid. */
> -if (host_start && aligned_start != current_start) {
> -goto try_again;
> -}
> -
> #if defined(TARGET_ARM) && !defined(TARGET_AARCH64)
> /* On 32-bit ARM, we need to also be able to map the commpage. */
> int valid = init_guest_commpage(aligned_start - guest_start,
>
Applied to my 'linux-user-for-2.12' branch.
Thanks,
Laurent