>-----Original Message----- >From: David Miller [mailto:davem@xxxxxxxxxxxxx] >Sent: Friday, September 10, 2010 1:22 PM >To: error27@xxxxxxxxx >Cc: Rose, Gregory V; Kirsher, Jeffrey T; netdev@xxxxxxxxxxxxxxx; kernel- >janitors@xxxxxxxxxxxxxxx >Subject: Re: [patch] ixgbevf: potential NULL dereference on allocation >failure > >It's trying to optimize out the "down/up" of the device, which needs >to be done if we allocated a new TX ring. > >It also adjusts the semantics of the error return, in that if the >TX ring re-sizing went OK but the RX resizing failed, it returns >success. > >That's kind of crummy semantics, if any part fails we should unwind >and return an error. So just do the necessary memory allocations >first, and don't make any changes unless they all succeed. > >This code also seems to be incredibly racy. It allocates the new RING >structure, and copies the existing entries over. Meanwhile the chip >is still running and we're potentially processing these same ring >entries, so by the time we actually assign adapter->{rx,tx}_ring >pointers the contents could have changed. > >Probably the simplest thing to do is to structure this such that the >chip is quiesced around the entire ring set operation, so something >like: [snip] I'll take this up and see what I can do to fix it up a bit and address your concerns. Thanks for the suggestions. - Greg -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
