Re: [Qemu-trivial] [Qemu-devel] [PATCH v2] linux-user/syscall.c: Free the vec[i] in failure processing code block

[Peter Maydell]

On 23 January 2015 at 10:01, Chen Gang S <address@hidden> wrote:
> When failure occurs during allocating vec[i], also need free all
> allocated vec[i] in failure processing code block before return.
>
> In unlock_user(), it will check vec[i].iov_base whether is NULL, so need
> not check it again outside.
>
> If error is EFAULT when "i == 0", vec[i].iov_base is NULL, then can just
> skip it, so can still use "while (--i >= 0)" for the free looping.
>
> Signed-off-by: Chen Gang <address@hidden>
> ---
>  linux-user/syscall.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 290fdea..a66c2ae 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -1873,6 +1873,11 @@ static struct iovec *lock_iovec(int type, abi_ulong 
> target_addr,
>      return vec;
>
>   fail:
> +    while (--i >= 0) {
> +        if (tswapal(target_vec[i].iov_len) > 0) {
> +            unlock_user(vec[i].iov_base, tswapal(target_vec[i].iov_base), 0);
> +        }
> +    }
>      unlock_user(target_vec, target_addr, 0);
>   fail2:
>      free(vec);
> --
> 1.9.3 (Apple Git-50)

Reviewed-by: Peter Maydell <address@hidden>

thanks
-- PMM




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