On Thu, 2014-10-02 at 18:37 +0000, Elliott, Robert (Server Storage)
wrote:
> > -----Original Message-----
> > From: Hannes Reinecke [mailto:[email protected]]
> ...
> > diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
> > index 4c3ab83..c01dc89 100644
> > --- a/drivers/scsi/sd.h
> > +++ b/drivers/scsi/sd.h
> > @@ -103,9 +103,10 @@ static inline struct scsi_disk *scsi_disk(struct
> > gendisk
> > *disk)
> >
> > #define sd_printk(prefix, sdsk, fmt, a...) \
> > (sdsk)->disk ?
> > \
> > - sdev_printk(prefix, (sdsk)->device, "[%s] " fmt, \
> > - (sdsk)->disk->disk_name, ##a) : \
> > - sdev_printk(prefix, (sdsk)->device, fmt, ##a)
> > + sdev_prefix_printk(prefix, (sdsk)->device, \
> > + (sdsk)->disk->disk_name, fmt, ##a) : \
> > + sdev_prefix_printk(prefix, (sdsk)->device, \
> > + NULL, fmt, ##a)
> >
> > #define sd_first_printk(prefix, sdsk, fmt, a...) \
> > do { \
> ...
> > diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
> > index 27ecee7..0b18a09 100644
> > --- a/include/scsi/scsi_device.h
> > +++ b/include/scsi/scsi_device.h
> > @@ -244,6 +244,15 @@ struct scsi_dh_data {
> > #define sdev_dbg(sdev, fmt, a...) \
> > dev_dbg(&(sdev)->sdev_gendev, fmt, ##a)
> >
> > +/*
> > + * like scmd_printk, but the device name is passed in
> > + * as a string pointer
> > + */
> > +#define sdev_prefix_printk(l, sdev, p, fmt, a...) \
> > + (p) ? \
> > + sdev_printk(l, sdev, "[%s] " fmt, p, ##a) : \
> > + sdev_printk(l, sdev, fmt, ##a)
> > +
> > #define scmd_printk(prefix, scmd, fmt, a...)
> > \
> > (scmd)->request->rq_disk ? \
> > sdev_printk(prefix, (scmd)->device, "[%s] " fmt, \
> > --
> > 1.8.5.2
>
> This triggers lots of compiler warnings with gcc 4.4.7 like:
>
> drivers/scsi/sd.c: In function 'sd_open':
> drivers/scsi/sd.c:1179: warning: reading through null pointer (argument 4)
> drivers/scsi/sd.c:1179: warning: format '%s' expects type 'char *', but
> argument 4 has type 'void *'
>
>
> That is from:
> SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_open\n"));
>
> Since:
> #define NULL ((void *)0)
>
> gcc probably doesn't realize the (p)? prevents the NULL (a void *)
> from being passed to sdev_printk.
>
> Passing "" rather than NULL eliminates the compiler warnings.
It eliminates the warnings, but unfortunately we then get log messages
that look like:
Oct 3 11:30:08 rhel-storage-01 kernel: sd 10:0:0:0: [sde] (null)FAILED Result:
hostbyte=DID_OK driverbyte=DRIVER_SENSE
^^^^^^
Changing it to (char *)NULL, like this:
#define sd_printk(prefix, sdsk, fmt, a...) \
(sdsk)->disk ? \
sdev_prefix_printk(prefix, (sdsk)->device, \
(sdsk)->disk->disk_name, fmt, ##a) : \
sdev_prefix_printk(prefix, (sdsk)->device, \
(char *)NULL, fmt, ##a)
doesn't work either. The compiler gives an error:
drivers/scsi/sd.c: In function 'sd_open':
drivers/scsi/sd.c:1158:2: error: reading through null pointer (argument 4)
[-Werror=format=]
SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_open\n"));
^
-Ewan
>
> There should probably be a () around p in the sdev_printk call, too.
>
>
> ---
> Rob Elliott HP Server Storage
>
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
