Corinna Vinschen bc6ed2fa24 igb: clean up in all error paths when enabling SR-IOV
After commit 50f303496d ("igb: Enable SR-IOV after reinit"), removing
the igb module could hang or crash (depending on the machine) when the
module has been loaded with the max_vfs parameter set to some value != 0.

In case of one test machine with a dual port 82580, this hang occurred:

[  232.480687] igb 0000:41:00.1: removed PHC on enp65s0f1
[  233.093257] igb 0000:41:00.1: IOV Disabled
[  233.329969] pcieport 0000:40:01.0: AER: Multiple Uncorrected (Non-Fatal) err0
[  233.340302] igb 0000:41:00.0: PCIe Bus Error: severity=Uncorrected (Non-Fata)
[  233.352248] igb 0000:41:00.0:   device [8086:1516] error status/mask=00100000
[  233.361088] igb 0000:41:00.0:    [20] UnsupReq               (First)
[  233.368183] igb 0000:41:00.0: AER:   TLP Header: 40000001 0000040f cdbfc00c c
[  233.376846] igb 0000:41:00.1: PCIe Bus Error: severity=Uncorrected (Non-Fata)
[  233.388779] igb 0000:41:00.1:   device [8086:1516] error status/mask=00100000
[  233.397629] igb 0000:41:00.1:    [20] UnsupReq               (First)
[  233.404736] igb 0000:41:00.1: AER:   TLP Header: 40000001 0000040f cdbfc00c c
[  233.538214] pci 0000:41:00.1: AER: can't recover (no error_detected callback)
[  233.538401] igb 0000:41:00.0: removed PHC on enp65s0f0
[  233.546197] pcieport 0000:40:01.0: AER: device recovery failed
[  234.157244] igb 0000:41:00.0: IOV Disabled
[  371.619705] INFO: task irq/35-aerdrv:257 blocked for more than 122 seconds.
[  371.627489]       Not tainted 6.4.0-dirty #2
[  371.632257] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this.
[  371.641000] task:irq/35-aerdrv   state:D stack:0     pid:257   ppid:2      f0
[  371.650330] Call Trace:
[  371.653061]  <TASK>
[  371.655407]  __schedule+0x20e/0x660
[  371.659313]  schedule+0x5a/0xd0
[  371.662824]  schedule_preempt_disabled+0x11/0x20
[  371.667983]  __mutex_lock.constprop.0+0x372/0x6c0
[  371.673237]  ? __pfx_aer_root_reset+0x10/0x10
[  371.678105]  report_error_detected+0x25/0x1c0
[  371.682974]  ? __pfx_report_normal_detected+0x10/0x10
[  371.688618]  pci_walk_bus+0x72/0x90
[  371.692519]  pcie_do_recovery+0xb2/0x330
[  371.696899]  aer_process_err_devices+0x117/0x170
[  371.702055]  aer_isr+0x1c0/0x1e0
[  371.705661]  ? __set_cpus_allowed_ptr+0x54/0xa0
[  371.710723]  ? __pfx_irq_thread_fn+0x10/0x10
[  371.715496]  irq_thread_fn+0x20/0x60
[  371.719491]  irq_thread+0xe6/0x1b0
[  371.723291]  ? __pfx_irq_thread_dtor+0x10/0x10
[  371.728255]  ? __pfx_irq_thread+0x10/0x10
[  371.732731]  kthread+0xe2/0x110
[  371.736243]  ? __pfx_kthread+0x10/0x10
[  371.740430]  ret_from_fork+0x2c/0x50
[  371.744428]  </TASK>

The reproducer was a simple script:

  #!/bin/sh
  for i in `seq 1 5`; do
    modprobe -rv igb
    modprobe -v igb max_vfs=1
    sleep 1
    modprobe -rv igb
  done

It turned out that this could only be reproduce on 82580 (quad and
dual-port), but not on 82576, i350 and i210.  Further debugging showed
that igb_enable_sriov()'s call to pci_enable_sriov() is failing, because
dev->is_physfn is 0 on 82580.

Prior to commit 50f303496d ("igb: Enable SR-IOV after reinit"),
igb_enable_sriov() jumped into the "err_out" cleanup branch.  After this
commit it only returned the error code.

So the cleanup didn't take place, and the incorrect VF setup in the
igb_adapter structure fooled the igb driver into assuming that VFs have
been set up where no VF actually existed.

Fix this problem by cleaning up again if pci_enable_sriov() fails.

Fixes: 50f303496d ("igb: Enable SR-IOV after reinit")
Signed-off-by: Corinna Vinschen <vinschen@redhat.com>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-09-13 12:24:29 +01:00
2022-09-28 09:02:20 +02:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Description
Linux kernel source tree
Readme 8.3 GiB
Languages
C 97.1%
Assembly 1%
Shell 0.6%
Rust 0.4%
Python 0.4%
Other 0.3%