Re: slab corruption in skb allocs

Scott Feldman
2005-03-07T05:08:38Z

On Mar 6, 2005, at 10:40 AM, Richard Fuchs wrote:

> Scott Feldman wrote:
>> A bug in the driver. I have a hunch: please try this patch with
>> 2.6.9 or higher:
>> http://marc.theaimsgroup.com/?l=linux-netdev&m=110726809431611&w=2
>
> bingo, that fixes it. too bad neither this patch nor the removal of
> the NAPI config option made it into 2.6.11...

Jesse Brandeburg @ Intel found the fix for the bug but I don't think
it's been pushed out to Jeff's tree yet, AFAIK. Soon, I would guess.

Would you mind giving this patch a try against 2.6.11? I think it's
equivalent to Jesse's patch, but less intrusive to the driver.

--- linux-2.6.11/drivers/net/e100.c.orig Sun Mar 6 20:58:15 2005
+++ linux-2.6.11/drivers/net/e100.c Sun Mar 6 21:01:34 2005
@@ -1471,8 +1471,12 @@ static inline int e100_rx_indicate(struc

/* If data isn't ready, nothing to indicate */
if(unlikely(!(rfd_status & cb_complete)))
- return -EAGAIN;
+ return -ENODATA;

+ /* This allows for a fast restart without re-enabling
interrupts */
+ if(le16_to_cpu(rfd->command) & cb_el)
+ nic->ru_running = 0;
+
/* Get actual data size */
actual_size = le16_to_cpu(rfd->actual_size) & 0x3FFF;
if(unlikely(actual_size > RFD_BUF_LEN - sizeof(struct rfd)))
@@ -1527,7 +1531,11 @@ static inline void e100_rx_clean(struct
break; /* Better luck next time (see watchdog)
*/
}

- e100_start_receiver(nic);
+ /* NAPI: attempt to restart the receiver iff the list is
+ * totally clean otherwise we'll race between hardware and
+ * nic->rx_to_clean. */
+ if(!work_done || *work_done == 0)
+ e100_start_receiver(nic);
}

static void e100_rx_clean_list(struct nic *nic)

>> No. e1000 is a totally different driver/device with very similar
>> name.
>
> too bad, i was hoping for an explanation for some unexplainable
> crashes i've been experiencing... ;)

Take the e1000 issue to linux-netdev.

-scott