Re: -git tree build failure #2: drivers/net/cnic.c:2520: error: implicit declaration of function ‘__symbol_get’

James Bottomley
2009-06-13T20:42:40Z

On Sat, 2009-06-13 at 13:11 -0700, Linus Torvalds wrote:
>
> On Sat, 13 Jun 2009, Ingo Molnar wrote:
> >
> > > I just posted a patch for this to netdev and it was acked by its maintainer.
> > > Patch is below.
> >
> > This solves the first build failure but there's still a second build
> > failure:
> >
> > drivers/net/cnic.c: In function ‘init_bnx2_cnic’:
> > drivers/net/cnic.c:2520: error: implicit declaration of function ‘__symbol_get’
> > drivers/net/cnic.c:2520: warning: assignment makes pointer from integer without a cast
> > make[1]: *** [drivers/net/cnic.o] Error 1
> > make: *** [drivers/net/cnic.o] Error 2
> >
> > This too triggers with the config i sent. The patch below solves it
> > - but i havent done more testing.
> >
> > Ingo
> >
> > Signed-off-by: Ingo Molnar <mingo@elte.hu>
> >
> > diff --git a/drivers/net/cnic.c b/drivers/net/cnic.c
> > index 8d74037..49135cc 100644
> > --- a/drivers/net/cnic.c
> > +++ b/drivers/net/cnic.c
> > @@ -25,6 +25,8 @@
> > #include <linux/delay.h>
> > #include <linux/ethtool.h>
> > #include <linux/if_vlan.h>
> > +#include <linux/module.h>
> > +
>
> That makes no sense.
>
> Look at the first #include in the file - it already includes
> <linux/module.h>.
>
> Why do we need to do it twice?

We don't ... it's the wrong fix. The actual problem is that
__symbol_get() is only defined for the modular case. What it looks to
be doing is a reflection call on bnx2_cnic_probe(). I'm not sure why
it's doing this ... other than perhaps cnic wants to avoid an explicit
bnx2 dependency? I actually think it's incorrect, since the netdev code
before it just checked bnx2 is present, so I see no harm in an explicit
call, so this should fix it.

If it had a good reason for the reflective call, then symbol_get()
without the __ should be used.

Michael Chan, could you confirm?

James

---

diff --git a/drivers/net/bnx2.h b/drivers/net/bnx2.h
index a1ff739..d49b6da 100644
--- a/drivers/net/bnx2.h
+++ b/drivers/net/bnx2.h
@@ -7345,4 +7345,6 @@ struct bnx2_rv2p_fw_file {

#define HOST_VIEW_SHMEM_BASE 0x167c00

+struct cnic_eth_dev *bnx2_cnic_probe(struct net_device *dev);
+
#endif
diff --git a/drivers/net/cnic.c b/drivers/net/cnic.c
index 44f77eb..3db64ad 100644
--- a/drivers/net/cnic.c
+++ b/drivers/net/cnic.c
@@ -2520,14 +2520,9 @@ static struct cnic_dev *init_bnx2_cnic(struct net_device *dev)
struct pci_dev *pdev;
struct cnic_dev *cdev;
struct cnic_local *cp;
- struct cnic_eth_dev *ethdev = NULL;
- struct cnic_eth_dev *(*probe)(void *) = NULL;
+ struct cnic_eth_dev *ethdev;

- probe = __symbol_get("bnx2_cnic_probe");
- if (probe) {
- ethdev = (*probe)(dev);
- symbol_put_addr(probe);
- }
+ ethdev = bnx2_cnic_probe(dev);
if (!ethdev)
return NULL;