Re: mmotm 2008-11-26-17-00 uploaded (hwmon / dev_attr_name)

[Rodolfo Giometti]

On Sun, Nov 30, 2008 at 09:53:50PM -0800, Andrew Morton wrote:
> On Sat, 29 Nov 2008 09:25:13 -0800 Randy Dunlap <randy.dunlap@xxxxxxxxxx> wrote:
> 
> > Andrew Morton wrote:
> > > On Fri, 28 Nov 2008 21:01:29 -0800 Randy Dunlap <randy.dunlap@xxxxxxxxxx> wrote:
> > > 
> > >> akpm@xxxxxxxxxxxxxxxxxxxx wrote:
> > >>> The mm-of-the-moment snapshot 2008-11-26-17-00 has been uploaded to
> > >>>
> > >>>    http://userweb.kernel.org/~akpm/mmotm/
> > >>
> > >> I'm getting lots of these build errors:
> > >>
> > >> drivers/hwmon/built-in.o:(.data+0x7c70): multiple definition of `dev_attr_name'
> > > 
> > > -ENOREPRODUCE.  What config?
> > 
> > Could be some kind of tools issue, I suppose.
> > 
> > config attached.
> 
> OK, it was a couple of instances of
> 
> DEVICE_ATTR(name, ...)
> 
> (in hwmon and pps) which both emitted a global symbol dev_attr_name, so
> the linker got upset.
> 
> This happens a lot.  Because it's a pukey macro, people don't realise
> that it's declaring storage and they don't think to make it static.  It
> would be good to do a tree-wide grep for non-static DEVICE_ATTRs and
> fix them up where possible.
> 
> 
> Rodolfo, I fixed pps this way:

This is not correct, the right patch is:

diff --git a/drivers/pps/sysfs.c b/drivers/pps/sysfs.c
index 99528a8..7c2b0c4 100644
--- a/drivers/pps/sysfs.c
+++ b/drivers/pps/sysfs.c
@@ -41,7 +41,6 @@ static ssize_t pps_show_assert(struct device *dev,
                        (long long) pps->assert_tu.sec,
			pps->assert_tu.nsec,
                        pps->assert_sequence);
 }
-DEVICE_ATTR(assert, S_IRUGO, pps_show_assert, NULL);
 
 static ssize_t pps_show_clear(struct device *dev,
                                struct device_attribute *attr, char
				*buf)
@@ -55,7 +54,6 @@ static ssize_t pps_show_clear(struct device *dev,
                        (long long) pps->clear_tu.sec,
			pps->clear_tu.nsec,
                        pps->clear_sequence);
 }
-DEVICE_ATTR(clear, S_IRUGO, pps_show_clear, NULL);
 
 static ssize_t pps_show_mode(struct device *dev,
                                struct device_attribute *attr, char
				*buf)
@@ -64,7 +62,6 @@ static ssize_t pps_show_mode(struct device *dev,
 
        return sprintf(buf, "%4x\n", pps->info.mode);
 }
-DEVICE_ATTR(mode, S_IRUGO, pps_show_mode, NULL);
 
 static ssize_t pps_show_echo(struct device *dev,
                                struct device_attribute *attr, char
				*buf)
@@ -73,7 +70,6 @@ static ssize_t pps_show_echo(struct device *dev,
 
        return sprintf(buf, "%d\n", !!pps->info.echo);
 }
-DEVICE_ATTR(echo, S_IRUGO, pps_show_echo, NULL);
 
 static ssize_t pps_show_name(struct device *dev,
                                struct device_attribute *attr, char
				*buf)
@@ -82,7 +78,6 @@ static ssize_t pps_show_name(struct device *dev,
 
        return sprintf(buf, "%s\n", pps->info.name);
 }
-DEVICE_ATTR(name, S_IRUGO, pps_show_name, NULL);
 
 static ssize_t pps_show_path(struct device *dev,
                                struct device_attribute *attr, char
				*buf)
@@ -91,7 +86,6 @@ static ssize_t pps_show_path(struct device *dev,
 
        return sprintf(buf, "%s\n", pps->info.path);
 }
-DEVICE_ATTR(path, S_IRUGO, pps_show_path, NULL);
 
 struct device_attribute pps_attrs[] = {
        __ATTR(assert, S_IRUGO, pps_show_assert, NULL),

We can just remove the DEVICE_ATTR(name, ...) since all the variables
are into pps_attrs[].

Please, let me know if you wish a proper patch for this or you can do
it by yourself.

> and the x86_64 build got noisier:
> 
> drivers/pps/sysfs.c:44: warning: 'dev_attr_assert' defined but not used
> drivers/pps/sysfs.c:58: warning: 'dev_attr_clear' defined but not used
> drivers/pps/sysfs.c:67: warning: 'dev_attr_mode' defined but not used
> drivers/pps/sysfs.c:76: warning: 'dev_attr_echo' defined but not used
> drivers/pps/sysfs.c:85: warning: 'dev_attr_name' defined but not used
> drivers/pps/sysfs.c:94: warning: 'dev_attr_path' defined but not used

This will be fixed by the above patch.

> drivers/pps/clients/pps-ldisc.c: In function 'pps_tty_dcd_change':
> drivers/pps/clients/pps-ldisc.c:32: warning: cast from pointer to integer of different size
> drivers/pps/clients/pps-ldisc.c: In function 'pps_tty_open':
> drivers/pps/clients/pps-ldisc.c:77: warning: cast to pointer from integer of different size
> drivers/pps/clients/pps-ldisc.c:82: warning: cast from pointer to integer of different size
> drivers/pps/clients/pps-ldisc.c: In function 'pps_tty_close':
> drivers/pps/clients/pps-ldisc.c:91: warning: cast from pointer to integer of different size
> 
> 
> For the ->disc_data warnings you could perhaps just make all the
> relevant scalar types `long', not `int'.

But doing like this will breaks 32bit archs... =:-o

Ciao,

Rodolfo

-- 

GNU/Linux Solutions                  e-mail: giometti@xxxxxxxxxxxx
Linux Device Driver                          giometti@xxxxxxxx
Embedded Systems                     phone:  +39 349 2432127
UNIX programming                     skype:  rodolfo.giometti
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