Re: [PATCH v3 21/33] linux-user: Split out mmap_h_eq_g

[Ilya Leoshkevich]

On Tue, Jan 02, 2024 at 12:57:56PM +1100, Richard Henderson wrote:
> Move the MAX_FIXED_NOREPLACE check for reserved_va earlier.
> Move the computation of host_prot earlier.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  linux-user/mmap.c | 66 +++++++++++++++++++++++++++++++++++++----------
>  1 file changed, 53 insertions(+), 13 deletions(-)
> 
> diff --git a/linux-user/mmap.c b/linux-user/mmap.c
> index 42eb3eb2b4..00003b8329 100644
> --- a/linux-user/mmap.c
> +++ b/linux-user/mmap.c
> @@ -527,6 +527,31 @@ static abi_long mmap_end(abi_ulong start, abi_ulong last,
>      return start;
>  }
>  
> +/*
> + * Special case host page size == target page size,
> + * where there are no edge conditions.
> + */
> +static abi_long mmap_h_eq_g(abi_ulong start, abi_ulong len,
> +                            int host_prot, int flags, int page_flags,
> +                            int fd, off_t offset)
> +{
> +    void *p, *want_p = g2h_untagged(start);
> +    abi_ulong last;
> +
> +    p = mmap(want_p, len, host_prot, flags, fd, offset);
> +    if (p == MAP_FAILED) {
> +        return -1;
> +    }
> +    if ((flags & MAP_FIXED_NOREPLACE) && p != want_p) {

Should we munmap() here?
I've seen this situation in some of the previous patches as well, but
there we were about to exit, and here the program may continue
running.

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