Re: [PATCH 16/17] bsd-user: Define validate_prot_to_pageflags and use in mprotect

[Richard Henderson]

On 8/3/24 09:56, Warner Losh wrote:
> Define validate_prot_to_pageflags. Use it in target_mprotect to validate
> the flags. Our taraget_mmap needs more work before it can be used there,
> do don't copy linux-user's use of it there. This should hvae no net
> functional change, but does make target_mprotect more similar to
> linux-user's.
>
> Signed-off-by: Warner Losh <imp@bsdimp.com>
> ---
>   bsd-user/mmap.c | 28 +++++++++++++++++++++++-----
>   1 file changed, 23 insertions(+), 5 deletions(-)

> +/*
> + * Validate target prot bitmask.
> + * Return the prot bitmask for the host in *HOST_PROT.
> + * Return 0 if the target prot bitmask is invalid, otherwise
> + * the internal qemu page_flags (which will include PAGE_VALID).
> + */
> +static int validate_prot_to_pageflags(int prot)
> +{
> +    int valid = PROT_READ | PROT_WRITE | PROT_EXEC;
> +    int page_flags = (prot & PAGE_RWX) | PAGE_VALID;
> +
> +    return prot & ~valid ? 0 : page_flags;
> +}

Comment still refers to @host_prot, which you removed.

Otherwise,
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~