Le 28/12/2017 à 19:08, Luke Shumaker a écrit :
> From: Luke Shumaker <luke...@parabola.nu>
>
> Instead of doing
>
> if (check1) {
> if (check2) {
> success;
> }
> }
>
> retry;
>
> Do a clearer
>
> if (!check1) {
> goto try_again;
> }
>
> if (!check2) {
> goto try_again;
> }
>
> success;
>
> try_again:
> retry;
>
> Besides being clearer, this makes it easier to insert more checks that
> need to trigger a retry on check failure, or rearrange them, or anything
> like that.
>
> Because some indentation is changing, "ignore space change" may be useful
> for viewing this patch.
>
> Signed-off-by: Luke Shumaker <luke...@parabola.nu>
> ---
> linux-user/elfload.c | 34 +++++++++++++++++++---------------
> 1 file changed, 19 insertions(+), 15 deletions(-)
>
> diff --git a/linux-user/elfload.c b/linux-user/elfload.c
> index b560f5d6fe..5c0ad65611 100644
> --- a/linux-user/elfload.c
> +++ b/linux-user/elfload.c
> @@ -1906,24 +1906,28 @@ unsigned long init_guest_space(unsigned long
> host_start,
> }
>
> /* Check to see if the address is valid. */
> - if (!host_start || aligned_start == current_start) {
> + 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,
> - aligned_size + guest_start);
> - if (valid == 1) {
> - break;
> - } else if (valid == -1) {
> - munmap((void *)real_start, real_size);
> - return (unsigned long)-1;
> - }
> - /* valid == 0, so try again. */
> -#else
> - /* On other architectures, whatever we have here is fine. */
> - break;
> -#endif
> + /* On 32-bit ARM, we need to also be able to map the commpage. */
> + int valid = init_guest_commpage(aligned_start - guest_start,
> + aligned_size + guest_start);
> + if (valid == -1) {
> + munmap((void *)real_start, real_size);
> + return (unsigned long)-1;
> + } else if (valid == -1) {
I think it should be "if (valid == 0)" here.
> + goto try_again;
> }
> +#endif
> +
> + /* If nothing has said `return -1` or `goto try_again` yet,
> + * then the address we have is good.
> + */
> + break;
>
> + try_again:
> /* That address didn't work. Unmap and try a different one.
> * The address the host picked because is typically right at
> * the top of the host address space and leaves the guest with
>
Thanks,
Laurent
