uml: network interface hotplug error handling
This fixes a number of problems associated with network interface hotplug.
The userspace initialization function can fail in some cases, but the
failure was never passed back to eth_configure, which proceeded with the
configuration. This results in a zombie device that is present, but can't
work. This is fixed by allowing the initialization routines to return an
error, which is checked, and the configuration aborted on failure.
eth_configure failed to check for many failures. Even when it did check,
it didn't undo whatever initializations has already happened, so a present,
but partially initialized and non-working device could result. It now
checks everything that can fail, and bails out, undoing whatever had been
done.
The return value of eth_configure was always ignored, so it is now just
void.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/um/drivers/pcap_user.c b/arch/um/drivers/pcap_user.c
index a1747dc..dc0a903 100644
--- a/arch/um/drivers/pcap_user.c
+++ b/arch/um/drivers/pcap_user.c
@@ -18,7 +18,7 @@
#define PCAP_FD(p) (*(int *)(p))
-static void pcap_user_init(void *data, void *dev)
+static int pcap_user_init(void *data, void *dev)
{
struct pcap_data *pri = data;
pcap_t *p;
@@ -28,11 +28,12 @@
if(p == NULL){
printk("pcap_user_init : pcap_open_live failed - '%s'\n",
errors);
- return;
+ return -EINVAL;
}
pri->dev = dev;
pri->pcap = p;
+ return 0;
}
static int pcap_open(void *data)