Re: [PATCH 16/22] Implement mincore(2)

[Richard Henderson <richard.henderson@linaro.org>]

On 8/19/23 02:48, Karim Taha wrote:
> +/* mincore(2) */
> +static inline abi_long do_bsd_mincore(abi_ulong target_addr, abi_ulong len,
> +        abi_ulong target_vec)
> +{
> +    abi_long ret;
> +    void *p, *a;
> +
> +    a = lock_user(VERIFY_WRITE, target_addr, len, 0);
> +    if (a == NULL) {
> +        return -TARGET_EFAULT;
> +    }
> +    p = lock_user_string(target_vec);
> +    if (p == NULL) {
> +        unlock_user(a, target_addr, 0);
> +        return -TARGET_EFAULT;
> +    }
> +    ret = get_errno(mincore(a, len, p));
> +    unlock_user(p, target_vec, ret);
> +    unlock_user(a, target_addr, 0);
> +
> +    return ret;

This is wrong.

(1) VERIFY_WRITE is incorrect.  Here you need a combination of guest_range_valid_untagged 
and page_check_range(addr, len, PAGE_VALID).

(2) vec is not a string, it is an array of size DIV_ROUND_UP(len, TARGET_PAGE_SIZE).  For 
that, you do want lock_user(VERIFY_WRITE).


r~