Re: [PATCH 5/6] in_initrd: fix gcc compiler error

[NeilBrown <neilb@suse.de>]

[-- Attachment #1: Type: text/plain, Size: 1059 bytes --]

On Fri, 16 Aug 2013 20:21:59 +0200 mwilck@arcor.de wrote:

> On some systems, this code caused a "comparison between signed
> and unsigned" error.
> 
> Signed-off-by: Martin Wilck <mwilck@arcor.de>
> ---
>  util.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/util.c b/util.c
> index 8096e29..491a107 100644
> --- a/util.c
> +++ b/util.c
> @@ -1949,6 +1949,6 @@ int in_initrd(void)
>  	/* This is based on similar function in systemd. */
>  	struct statfs s;
>  	return  statfs("/", &s) >= 0 &&
> -		(s.f_type == TMPFS_MAGIC ||
> -		 s.f_type == RAMFS_MAGIC);
> +		((unsigned long)s.f_type == TMPFS_MAGIC ||
> +		 (unsigned long)s.f_type == RAMFS_MAGIC);
>  }

That is rather horrible.  It seems that some architectures like this field to
be signed and other unsigned.
But aren't TMPFS_MAGIC and  RAMFS_MAGIC simple constants and so signed by
default?
What are that defined to on the system that produces the error?

Maybe we need to cast both LHS and RHS to "unsigned long"....

NeilBrown

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 828 bytes --]