Messages in this thread | | | From | Denis Vlasenko <> | Subject | Re: [PATCH] cli()/sti() fix for drivers/net/depca.c | Date | Thu, 3 Oct 2002 00:26:53 -0200 |
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On 2 October 2002 18:40, Francois Romieu wrote: > Denis Vlasenko <vda@port.imtp.ilyichevsk.odessa.ua> : > > diff -u --recursive linux-2.5.38orig/drivers/net/depca.c > > linux-2.5.38/drivers/net/depca.c --- > > linux-2.5.38orig/drivers/net/depca.c Sun Sep 22 04:25:10 2002 +++ > > linux-2.5.38/drivers/net/depca.c Wed Oct 2 01:16:57 2002 > > [...] > > > @@ -1999,18 +2000,19 @@ > > break; > > > > case DEPCA_GET_STATS: /* Get the driver statistics */ > > - cli(); > > + > > + spin_lock_irqsave(&lp->lock, flags); > > ioc->len = sizeof(lp->pktStats); > > if (copy_to_user(ioc->data, &lp->pktStats, ioc->len)) > > status = -EFAULT; > > - sti(); > > + spin_unlock_irqrestore(&lp->lock, flags);
Did I say it's my first network patch? :-)
> - copy_to_user() may sleep. Sleeping with spinlock held hurts badly.
Ho to do it properly? Make a copy on stack under lock, release lock, proceed with copy_to_user? That's 88 bytes at least...
> - on SMP, pktStat can be updated while the copy progresses, see depca_rx().
Should I place these pktStat updates under lp->lock? -- vda - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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