Re: [PATCH 2/9] libxl: turn two malloc's to libxl__malloc

[Wei Liu <wei.liu2@citrix.com>]

On Mon, Jul 13, 2015 at 11:00:15AM +0100, Ian Campbell wrote:
> On Fri, 2015-07-10 at 19:00 +0100, Wei Liu wrote:
> > One is to combine malloc + libxl__alloc_failed. The other is to avoid
> > dereferencing NULL pointer in case of malloc failure.
> 
> The non-use of a gc for the latter in particular looks a bit suspicious
> to me, but nonetheless this is an improvement:
> 

There is a free() later in this function. I wanted to make this patch
minimum so I didn't switch to using gc and  delete that free.

> > Signed-off-by: Wei Liu <wei.liu2@citrix.com>
> 
> Acked-by: Ian Campbell <ian.campbell@citrix.com>

Thanks.

Wei.

> 
> > ---
> >  tools/libxl/libxl_aoutils.c | 3 +--
> >  tools/libxl/libxl_dm.c      | 2 +-
> >  2 files changed, 2 insertions(+), 3 deletions(-)
> > 
> > diff --git a/tools/libxl/libxl_aoutils.c b/tools/libxl/libxl_aoutils.c
> > index 0931eee..0300396 100644
> > --- a/tools/libxl/libxl_aoutils.c
> > +++ b/tools/libxl/libxl_aoutils.c
> > @@ -245,8 +245,7 @@ static void datacopier_readable(libxl__egc *egc, libxl__ev_fd *ev,
> >  
> >              buf = LIBXL_TAILQ_LAST(&dc->bufs, libxl__datacopier_bufs);
> >              if (!buf || buf->used >= sizeof(buf->buf)) {
> > -                buf = malloc(sizeof(*buf));
> > -                if (!buf) libxl__alloc_failed(CTX, __func__, 1, sizeof(*buf));
> > +                buf = libxl__malloc(NOGC, sizeof(*buf));
> >                  buf->used = 0;
> >                  LIBXL_TAILQ_INSERT_TAIL(&dc->bufs, buf, entry);
> >              }
> > diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c
> > index ad434f0..0cc73be 100644
> > --- a/tools/libxl/libxl_dm.c
> > +++ b/tools/libxl/libxl_dm.c
> > @@ -1010,7 +1010,7 @@ static int libxl__write_stub_dmargs(libxl__gc *gc,
> >          i++;
> >      }
> >      dmargs_size++;
> > -    dmargs = (char *) malloc(dmargs_size);
> > +    dmargs = (char *) libxl__malloc(NOGC, dmargs_size);
> >      i = 1;
> >      dmargs[0] = '\0';
> >      while (args[i] != NULL) {
>