Re: [Qemu-trivial] [Qemu-devel] [PATCH] replace functions which are only available in glib-2.24

[Markus Armbruster]

Olaf Hering <address@hidden> writes:

> Currently the minimal supported version of glib is 2.22.
> Since testing is done with a glib that claims to be 2.22, but in fact
> has APIs from newer version of glib, this bug was not caught during
> submit of the patch referenced below.
>
> Replace g_realloc_n, which is available only since 2.24, with g_renew.

We're about to bump our required GLib version to 2.34.  See
https://lists.gnu.org/archive/html/qemu-devel/2018-05/msg02562.html
Message-ID: <address@hidden>

However, the patch may make sense for stable anyway.

> Fixes commit 418026ca43 ("util: Introduce vfio helpers")
>
> Signed-off-by: Olaf Hering <address@hidden>
> ---
>
> This must go into stable-2.12.

Please see docs/devel/stable-process.rst for how to get a patch into a
stable release.

>  util/vfio-helpers.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/util/vfio-helpers.c b/util/vfio-helpers.c
> index 006674c916..5fd4f5f212 100644
> --- a/util/vfio-helpers.c
> +++ b/util/vfio-helpers.c
> @@ -522,8 +522,7 @@ static IOVAMapping *qemu_vfio_add_mapping(QEMUVFIOState 
> *s,
>  
>      assert(index >= 0);
>      s->nr_mappings++;
> -    s->mappings = g_realloc_n(s->mappings, sizeof(s->mappings[0]),
> -                              s->nr_mappings);
> +    s->mappings = g_renew(IOVAMapping *, s->mappings, s->nr_mappings);

I'm afraid this switches from allocating a bunch of IOVAMapping to a
bunch of IOVAMapping *.  My gcc duly warns.

>      insert = &s->mappings[index];
>      shift = s->nr_mappings - index - 1;
>      if (shift) {
> @@ -577,8 +576,7 @@ static void qemu_vfio_undo_mapping(QEMUVFIOState *s, 
> IOVAMapping *mapping,
>      memmove(mapping, &s->mappings[index + 1],
>              sizeof(s->mappings[0]) * (s->nr_mappings - index - 1));
>      s->nr_mappings--;
> -    s->mappings = g_realloc_n(s->mappings, sizeof(s->mappings[0]),
> -                              s->nr_mappings);
> +    s->mappings = g_renew(IOVAMapping *, s->mappings, s->nr_mappings);

Likewise.

>  }
>  
>  /* Check if the mapping list is (ascending) ordered. */