Re: [Qemu-devel] [PATCH for-4.0 v4 2/4] refactor load_image_size

[Li Zhijian]

On 12/22/18 00:12, Michael S. Tsirkin wrote:
> On Thu, Dec 06, 2018 at 10:32:11AM +0800, Li Zhijian wrote:
> > Don't expect read(2) can always read as many as it's told.
> >
> > Signed-off-by: Li Zhijian <address@hidden>
> > Reviewed-by: Richard Henderson <address@hidden>
> This is more a theoretical bugfix than a refactoring right?

Yes， it does.

how about change the title to : "enhance reading on load_image_size()" or such

Thanks
Zhijian


> > ---
> > V4: add reviewed-by tag
> > ---
> >   hw/core/loader.c | 11 +++++------
> >   1 file changed, 5 insertions(+), 6 deletions(-)
> >
> > diff --git a/hw/core/loader.c b/hw/core/loader.c
> > index fa41842..9cbceab 100644
> > --- a/hw/core/loader.c
> > +++ b/hw/core/loader.c
> > @@ -77,21 +77,20 @@ int64_t get_image_size(const char *filename)
> >   ssize_t load_image_size(const char *filename, void *addr, size_t size)
> >   {
> >       int fd;
> > -    ssize_t actsize;
> > +    ssize_t actsize, l = 0;
> >   
> >       fd = open(filename, O_RDONLY | O_BINARY);
> >       if (fd < 0) {
> >           return -1;
> >       }
> >   
> > -    actsize = read(fd, addr, size);
> > -    if (actsize < 0) {
> > -        close(fd);
> > -        return -1;
> > +    while ((actsize = read(fd, addr + l, size - l)) > 0) {
> > +        l += actsize;
> >       }
> > +
> >       close(fd);
> >   
> > -    return actsize;
> > +    return actsize < 0 ? -1 : l;
> >   }
> >   
> >   /* read()-like version */
> > --
> > 2.7.4
--
Best regards.
Li Zhijian (8528)