Messages in this thread | | | From | Alexander Duyck <> | Date | Mon, 7 Oct 2019 10:23:58 -0700 | Subject | Re: [RFC PATCH] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm |
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On Mon, Oct 7, 2019 at 10:12 AM David Z. Dai <zdai@linux.vnet.ibm.com> wrote: > > On Mon, 2019-10-07 at 10:02 -0700, Alexander Duyck wrote: > > On Mon, Oct 7, 2019 at 8:51 AM David Z. Dai <zdai@linux.vnet.ibm.com> wrote: > > > > > > > <snip> > > > > > We have tested on one of the test box. > > > With this patch, it doesn't crash kernel anymore, which is good! > > > > > > However we see this warning message from the log file for irq number 0: > > > [10206.317270] Trying to free already-free IRQ 0 > > > > > > With this stack: > > > [10206.317344] NIP [c00000000018cbf8] __free_irq+0x308/0x370 > > > [10206.317346] LR [c00000000018cbf4] __free_irq+0x304/0x370 > > > [10206.317347] Call Trace: > > > [10206.317348] [c00000008b92b970] [c00000000018cbf4] __free_irq > > > +0x304/0x370 (unreliable) > > > [10206.317351] [c00000008b92ba00] [c00000000018cd84] free_irq+0x84/0xf0 > > > [10206.317358] [c00000008b92ba30] [d000000007449e60] e1000_free_irq > > > +0x98/0xc0 [e1000e] > > > [10206.317365] [c00000008b92ba60] [d000000007458a70] e1000e_pm_freeze > > > +0xb8/0x100 [e1000e] > > > [10206.317372] [c00000008b92baa0] [d000000007458b6c] > > > e1000_io_error_detected+0x34/0x70 [e1000e] > > > [10206.317375] [c00000008b92bad0] [c000000000040358] eeh_report_failure > > > +0xc8/0x190 > > > [10206.317377] [c00000008b92bb20] [c00000000003eb2c] eeh_pe_dev_traverse > > > +0x9c/0x170 > > > [10206.317379] [c00000008b92bbb0] [c000000000040d84] > > > eeh_handle_normal_event+0xe4/0x580 > > > [10206.317382] [c00000008b92bc60] [c000000000041330] eeh_handle_event > > > +0x30/0x340 > > > [10206.317384] [c00000008b92bd10] [c000000000041780] eeh_event_handler > > > +0x140/0x200 > > > [10206.317386] [c00000008b92bdc0] [c0000000001397c8] kthread+0x1a8/0x1b0 > > > [10206.317389] [c00000008b92be30] [c00000000000b560] > > > ret_from_kernel_thread+0x5c/0x7c > > > > > > Thanks! - David > > > > Hmm. I wonder if it is possibly calling the report > > e1000_io_error_detected multiple times. If so then the secondary calls > > to e1000_pm_freeze would cause issues. > > > > I will add a check so that we only down the interface and free the > > IRQs if the interface is in the present and running state. > > > > I'll submit an update patch shortly. > > > > Thanks. > > > > - Alex > It only complains about IRQ number 0 in the log.
I suspect that is because the IRQ is already freed. So there are no other interrupts enabled and it thinks it is running in legacy IRQ mode.
> Could you please let me know the actual place where you will add the > check? > I can retest it again. > > Thanks! - David
So I will need to add another variable called "present" to e1000_pm_freeze, I will assign netif_device_present() to it after taking the rtnl_lock and before I detach the interface, and will test for it and netif_running() before calling the logic that calls e1000_down and e1000_free_irq.
- Alex
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