Le 21/12/2015 03:33, cheng...@emindsoft.com.cn a écrit :
> From: Chen Gang
>
> When mapping MAP_ANONYMOUS memory fragments, still need notice about to
> set it zero, or it will cause issues.
Perhaps you can explain in the commit message why this page is not
already filled by zeros ?
> Signed-off-by: Chen Gang
> ---
> linux-user/mmap.c |4 +++-
> 1 files changed, 3 insertions(+), 1 deletions(-)
>
> diff --git a/linux-user/mmap.c b/linux-user/mmap.c
> index 7b459d5..29fe646 100644
> --- a/linux-user/mmap.c
> +++ b/linux-user/mmap.c
> @@ -186,10 +186,12 @@ static int mmap_frag(abi_ulong real_start,
> if (prot_new != (prot1 | PROT_WRITE))
> mprotect(host_start, qemu_host_page_size, prot_new);
> } else {
> -/* just update the protection */
> if (prot_new != prot1) {
> mprotect(host_start, qemu_host_page_size, prot_new);
> }
> +if ((prot_new & PROT_WRITE) && ((flags & MAP_PRIVATE) || (fd ==
> -1))) {
According to manpage, for MAP_ANONYMOUS, fd can be ignored.
Why do you check if the page is MAP_PRIVATE or not ?
> +memset(g2h(start), 0, end - start);
> +}
> }
> return 0;
> }
>