Hi Boris, On Mon, Oct 17, 2016 at 1:02 PM, Boris Brezillon <boris.brezil...@free-electrons.com> wrote: > On Mon, 17 Oct 2016 10:00:25 +0200 > Geert Uytterhoeven <ge...@linux-m68k.org> wrote: >> On Thu, Oct 13, 2016 at 4:24 PM, Boris Brezillon >> <boris.brezil...@free-electrons.com> wrote: >> > On Thu, 13 Oct 2016 16:05:36 +0200 >> > Geert Uytterhoeven <ge...@linux-m68k.org> wrote: >> > >> >> drivers/mtd/ubi/eba.c: In function ‘try_recover_peb’: >> >> drivers/mtd/ubi/eba.c:744: warning: ‘vid_hdr’ is used uninitialized >> >> in this function >> >> >> >> The pointer vid_hdr is indeed not initialized, leading to a crash when >> >> it is dereferenced. >> >> >> >> Fix this by obtaining the pointer from the VID buffer, like is done >> >> everywhere else. >> > >> > Indeed, I don't know how I missed that one :-/. >> > >> >> >> >> Fixes: 3291b52f9ff0acc8 ("UBI: introduce the VID buffer concept") >> >> Signed-off-by: Geert Uytterhoeven <ge...@linux-m68k.org> >> > >> > One minor comment below, otherwise >> > >> > Reviewed-by: Boris Brezillon <boris.brezil...@free-electrons.com> >> >> Thanks! >> >> >> --- >> >> Completely untested. And I know nothing about UBI ;-) >> >> --- >> >> drivers/mtd/ubi/eba.c | 1 + >> >> 1 file changed, 1 insertion(+) >> >> >> >> diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c >> >> index 95c4048a371e87b6..388e46be6ad92805 100644 >> >> --- a/drivers/mtd/ubi/eba.c >> >> +++ b/drivers/mtd/ubi/eba.c >> >> @@ -741,6 +741,7 @@ static int try_recover_peb(struct ubi_volume *vol, >> >> int pnum, int lnum, >> >> goto out_put; >> >> } >> >> >> >> + vid_hdr = ubi_get_vid_hdr(vidb); >> > >> > Can you move this assignment at variable declaration time? >> >> I can do that. However, that moves the call to ubi_get_vid_hdr() _before_ >> the call to ubi_io_read_vid_hdr(). >> >> While that would still work (ubi_get_vid_hdr() would just return a pointer to >> the not-yet-read data), I think it's better to not move it, to prevent people >> from accidentally trying to use it before the data has been read. > > Well, maybe. I just thought it would be safer to assign it as early as > possible to avoid another 'uninitialized var' bug if move code around > again (which will happen soon ;-)).
I prefer seeing the warning again (I _will_ notice if it pops up again!) over failing at runtime because the data structure it points to hasn't been initialized yet, which the compiler can't warn me about... Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds