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Re: [PATCH v3 1/9] bsd-user/mmap.c: Always zero MAP_ANONYMOUS memory in
From: |
Kyle Evans |
Subject: |
Re: [PATCH v3 1/9] bsd-user/mmap.c: Always zero MAP_ANONYMOUS memory in mmap_frag() |
Date: |
Thu, 14 Oct 2021 10:05:13 -0500 |
On Fri, Oct 8, 2021 at 4:24 PM Warner Losh <imp@bsdimp.com> wrote:
>
> From: Mikaël Urankar <mikael.urankar@gmail.com>
>
> Similar to the equivalent linux-user commit e6deac9cf99
>
> When mapping MAP_ANONYMOUS memory fragments, still need notice about to
> set it zero, or it will cause issues.
>
> Signed-off-by: Mikaël Urankar <mikael.urankar@gmail.com>
> Signed-off-by: Warner Losh <imp@bsdimp.com>
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
> ---
> bsd-user/mmap.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/bsd-user/mmap.c b/bsd-user/mmap.c
> index b40ab9045f..fc3c1480f5 100644
> --- a/bsd-user/mmap.c
> +++ b/bsd-user/mmap.c
> @@ -180,10 +180,12 @@ 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) {
> + memset(g2h_untagged(start), 0, end - start);
> + }
> }
> return 0;
> }
> --
> 2.32.0
>
Reviewed-by: Kyle Evans <kevans@FreeBSD.org>
- [PATCH v3 0/9] bsd-user mmap fixes, Warner Losh, 2021/10/08
- [PATCH v3 1/9] bsd-user/mmap.c: Always zero MAP_ANONYMOUS memory in mmap_frag(), Warner Losh, 2021/10/08
- Re: [PATCH v3 1/9] bsd-user/mmap.c: Always zero MAP_ANONYMOUS memory in mmap_frag(),
Kyle Evans <=
- [PATCH v3 2/9] bsd-user/mmap.c: check pread's return value to fix warnings with _FORTIFY_SOURCE, Warner Losh, 2021/10/08
- [PATCH v3 6/9] bsd-user/mmap.c: Convert to qemu_log logging for mmap debugging, Warner Losh, 2021/10/08
- [PATCH v3 4/9] bsd-user/mmap.c: mmap return ENOMEM on overflow, Warner Losh, 2021/10/08
- [PATCH v3 3/9] bsd-user/mmap.c: MAP_ symbols are defined, so no need for ifdefs, Warner Losh, 2021/10/08