Re: [RFC] 3.16-rc6 -- fs/direct-io.c:1011 from and to uninitialized.

From: Ian Kumlien
Date: Tue Jul 22 2014 - 15:18:57 EST


On tis, 2014-07-22 at 21:12 +0200, Richard Weinberger wrote:
> On Tue, Jul 22, 2014 at 9:03 PM, Ian Kumlien <ian.kumlien@xxxxxxxxx> wrote:
> > This is a resend, try two...
>
> Please see "[PATCH v3] direct-io: fix uninitialized warning in do_direct_IO()".

That looks like a better approach, couldn't find it before i started
sending this and my emails are autofiltered if you send via the web
ui.. ;)

> > ---
> > Hi,
> >
> > While playing around compiling the kernel i noticed the following:
> > fs/direct-io.c: In function âdo_blockdev_direct_IOâ:
> > fs/direct-io.c:1022:29: warning: âfromâ may be used uninitialized in
> > this function [-Wmaybe-uninitialized]
> > ret = submit_page_section(dio, sdio, page,
> > ^
> > fs/direct-io.c:913:10: note: âfromâ was declared here
> > size_t from, to;
> > ^
> > fs/direct-io.c:1011:12: warning: âtoâ may be used uninitialized in this
> > function [-Wmaybe-uninitialized]
> > u = (to - from) >> blkbits;
> > ^
> > fs/direct-io.c:913:16: note: âtoâ was declared here
> > size_t from, to;
> > ^
> > ---
> >
> >
> > And while the fix is simple, something along the lines of:
> > diff --git a/fs/direct-io.c b/fs/direct-io.c
> > index 98040ba..64a8286 100644
> > --- a/fs/direct-io.c
> > +++ b/fs/direct-io.c
> > @@ -910,7 +910,7 @@ static int do_direct_IO(struct dio *dio, struct
> > dio_submit *sdi
> >
> > while (sdio->block_in_file < sdio->final_block_in_request) {
> > struct page *page;
> > - size_t from, to;
> > + size_t from, to = {0};
> > page = dio_get_page(dio, sdio, &from, &to);
> > if (IS_ERR(page)) {
> > ret = PTR_ERR(page);
> > ---
> >
> > I however don't know if it's in the correct C standard, it compiles fine
> > though... (or if this is more gcc speific)
> >
> >
> >
>
>
>


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/