Re: [Qemu-devel] [PATCH v4 1/2] tests: Use real size for iov tests

["Daniel P. Berrange" <berrange@redhat.com>]

On Fri, Sep 01, 2017 at 01:54:59PM +0200, Juan Quintela wrote:
> We were using -1 instead of the real size because the functions check
> what is bigger, size in bytes or the size of the iov.  Recent gcc's
> barf at this.
> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> Reviewed-by: Peter Xu <peterx@redhat.com>
> Tested-by: Cleber Rosa <crosa@redhat.com>
> --
> 
> Remove comments about this feature.
> Fix missing -1.
> ---
>  include/qemu/iov.h |  6 ------
>  tests/test-iov.c   | 10 +++++-----
>  2 files changed, 5 insertions(+), 11 deletions(-)
> 
> diff --git a/include/qemu/iov.h b/include/qemu/iov.h
> index bd9fd55b0a..72d4c559b4 100644
> --- a/include/qemu/iov.h
> +++ b/include/qemu/iov.h
> @@ -31,11 +31,6 @@ size_t iov_size(const struct iovec *iov, const unsigned int iov_cnt);
>   * Number of bytes actually copied will be returned, which is
>   *  min(bytes, iov_size(iov)-offset)
>   * `Offset' must point to the inside of iovec.
> - * It is okay to use very large value for `bytes' since we're
> - * limited by the size of the iovec anyway, provided that the
> - * buffer pointed to by buf has enough space.  One possible
> - * such "large" value is -1 (sinice size_t is unsigned),
> - * so specifying `-1' as `bytes' means 'up to the end of iovec'.
>   */
>  size_t iov_from_buf_full(const struct iovec *iov, unsigned int iov_cnt,
>                           size_t offset, const void *buf, size_t bytes);
> @@ -76,7 +71,6 @@ iov_to_buf(const struct iovec *iov, const unsigned int iov_cnt,
>   * up to the end of it, will be filled with the specified value.
>   * Function return actual number of bytes processed, which is
>   * min(size, iov_size(iov) - offset).
> - * Again, it is okay to use large value for `bytes' to mean "up to the end".
>   */
>  size_t iov_memset(const struct iovec *iov, const unsigned int iov_cnt,
>                    size_t offset, int fillc, size_t bytes);

I'm not sure its right to be removing these comments, unless you've
audited the code to ensure no caller outside the test suite is
relying on this documented behaviour.

> diff --git a/tests/test-iov.c b/tests/test-iov.c
> index fa3d75aee1..458ca25099 100644
> --- a/tests/test-iov.c
> +++ b/tests/test-iov.c
> @@ -81,17 +81,17 @@ static void test_to_from_buf_1(void)
>            * skip whole vector and process exactly 0 bytes */
>  
>           /* first set bytes [i..sz) to some "random" value */
> -         n = iov_memset(iov, niov, 0, 0xff, -1);
> +         n = iov_memset(iov, niov, 0, 0xff, sz);
>           g_assert(n == sz);
>  
>           /* next copy bytes [i..sz) from ibuf to iovec */
> -         n = iov_from_buf(iov, niov, i, ibuf + i, -1);
> +         n = iov_from_buf(iov, niov, i, ibuf + i, sz - i);
>           g_assert(n == sz - i);
>  
>           /* clear part of obuf */
>           memset(obuf + i, 0, sz - i);
>           /* and set this part of obuf to values from iovec */
> -         n = iov_to_buf(iov, niov, i, obuf + i, -1);
> +         n = iov_to_buf(iov, niov, i, obuf + i, sz - i);
>           g_assert(n == sz - i);
>  
>           /* now compare resulting buffers */
> @@ -109,7 +109,7 @@ static void test_to_from_buf_1(void)
>                * with j in [i..sz]. */
>  
>               /* clear iovec */
> -             n = iov_memset(iov, niov, 0, 0xff, -1);
> +             n = iov_memset(iov, niov, 0, 0xff, sz);
>               g_assert(n == sz);
>  
>               /* copy bytes [i..j) from ibuf to iovec */
> @@ -225,7 +225,7 @@ static void test_io(void)
>         for (i = 0; i <= sz; ++i) {
>             for (j = i; j <= sz; ++j) {
>                 k = i;
> -               iov_memset(iov, niov, 0, 0xff, -1);
> +               iov_memset(iov, niov, 0, 0xff, sz);
>                 do {
>                     s = g_test_rand_int_range(0, j - k + 1);
>                     r = iov_recv(sv[0], iov, niov, k, s);

For the test-iov.c changes though you can have

Reviewed-by: Daniel P. Berrange <berrange@redhat.com>


Regards,
Daniel
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