From: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx> Date: Mon, 3 Oct 2016 00:31:12 -0700 > From: Guilherme G Piccoli <gpiccoli@xxxxxxxxxxxxxxxxxx> > > Although rare, it's possible to hit PCI error early on device > probe, meaning possibly some structs are not entirely initialized, > and some might even be completely uninitialized, leading to NULL > pointer dereference. > > The i40e driver currently presents a "bad" behavior if device hits > such early PCI error: firstly, the struct i40e_pf might not be > attached to pci_dev yet, leading to a NULL pointer dereference on > access to pf->state. > > Even checking if the struct is NULL and avoiding the access in that > case isn't enough, since the driver cannot recover from PCI error > that early; in our experiments we saw multiple failures on kernel > log, like: > > [549.664] i40e 0007:01:00.1: Initial pf_reset failed: -15 > [549.664] i40e: probe of 0007:01:00.1 failed with error -15 > [...] > [871.644] i40e 0007:01:00.1: The driver for the device stopped because the > device firmware failed to init. Try updating your NVM image. > [871.644] i40e: probe of 0007:01:00.1 failed with error -32 > [...] > [872.516] i40e 0007:01:00.0: ARQ: Unknown event 0x0000 ignored > > Between the first probe failure (error -15) and the second (error -32) > another PCI error happened due to the first bad probe. Also, driver > started to flood console with those ARQ event messages. > > This patch will prevent these issues by allowing error recovery > mechanism to remove the failed device from the system instead of > trying to recover from early PCI errors during device probe. > > CC: <stable@xxxxxxxxxxxxxxx> > Signed-off-by: Guilherme G Piccoli <gpiccoli@xxxxxxxxxxxxxxxxxx> > Acked-by: Jacob Keller <jacob.e.keller@xxxxxxxxx> > Tested-by: Andrew Bowers <andrewx.bowers@xxxxxxxxx> > Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx> Applied. -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html