Re: [PATCH] staging: erofs: initialize `pblk' with 0 first in `z_erofs_map_blocks_iter'

From: Greg Kroah-Hartman
Date: Tue Sep 18 2018 - 09:57:51 EST


On Tue, Sep 18, 2018 at 09:44:36PM +0800, Gao Xiang wrote:
> This commit message helps to understand why `pblk' is assigned with 0 here.
>
> [ Greg reported a warning raised by gcc. ]
> In file included from drivers/staging/erofs/unzip_vle.h:16:0,
> from drivers/staging/erofs/unzip_vle.c:13:
> drivers/staging/erofs/unzip_vle.c: In function âz_erofs_map_blocks_iterâ:
> drivers/staging/erofs/internal.h:303:34: warning: âpblkâ may be used uninitialized in this function [-Wmaybe-uninitialized]
> #define blknr_to_addr(nr) ((erofs_off_t)(nr) * EROFS_BLKSIZ)
> ^
> drivers/staging/erofs/unzip_vle.c:1574:20: note: âpblkâ was declared here
> erofs_blk_t mblk, pblk;
> ^~~~
>
> Actually, it is a false-positive warning when looking into that. [1]
> Just initialize the variable to keep gcc from printing foolish warnings.
>
> [1] https://lists.ozlabs.org/pipermail/linux-erofs/2018-September/000637.html
>
> Reported-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Thanks-to: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Signed-off-by: Gao Xiang <gaoxiang25@xxxxxxxxxx>
> ---
> drivers/staging/erofs/unzip_vle.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

Please roll this into the original patch. I have dropped that whole
series from my tree, it is no longer present and needs to be resent in
order for me to be able to accept any of these.

thanks,

greg k-h