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From: Dennis Dalessandro <dennis.dalessandro@intel.com>
To: jgg@ziepe.ca, dledford@redhat.com
Cc: linux-rdma@vger.kernel.org,
	Mike Marciniszyn <mike.marciniszyn@intel.com>,
	Kaike Wan <kaike.wan@intel.com>
Subject: [PATCH for-rc 1/2] IB/hfi1: Restore kfree in dummy_netdev cleanup
Date: Tue, 23 Jun 2020 16:32:24 -0400	[thread overview]
Message-ID: <20200623203224.106975.16926.stgit@awfm-01.aw.intel.com> (raw)
In-Reply-To: <20200623202519.106975.94246.stgit@awfm-01.aw.intel.com>

We need to do some rework on the dummy netdev. Calling the free_netdev() would
normally make sense, and that will be addressed in an upcoming patch. For now
just revert the behavior to what it was before keeping the unused variable
removal part of the patch.

The dd->dumm_netdev is mainly used for packet receiving through
NAPI. Consequently, it is allocated with kcalloc_node instead of
alloc_netdev_mqs for typical net devices. A a result, it should be
freed with kfree instead of free_netdev that leads to a crash when
unloading the hfi1 module:

[32200.283994] ########### Unload/Load : Unloading HFI driver on
phwtpriv58.ph.intel.com #########
[32200.455609] infiniband hfi1_0: removing VNIC client
[32200.565845] hfi1 0000:05:00.0: hfi1_0: hfi1 netdev freed
[32200.572643] BUG: kernel NULL pointer dereference, address: 0000000000000000
[32200.581028] #PF: supervisor read access in kernel mode
[32200.587330] #PF: error_code(0x0000) - not-present page
[32200.593614] PGD 8000000855b54067 P4D 8000000855b54067 PUD 84a4f5067 PMD 0
[32200.601899] Oops: 0000 [#1] SMP PTI
[32200.606346] CPU: 73 PID: 10299 Comm: modprobe Not tainted 5.6.0-rc5+ #1
[32200.614292] Hardware name: Intel Corporation S2600WT2R/S2600WT2R, BIOS
SE5C610.86B.01.01.0016.033120161139 03/31/2016
[32200.626704] RIP: 0010:__hw_addr_flush+0x12/0x80
[32200.632310] Code: 40 00 48 83 c4 08 4c 89 e7 5b 5d 41 5c e9 76 77 18 00 66 0f
1f 44 00 00 0f 1f 44 00 00 41 54 49 89 fc 55 53 48 8b 1f 48 39 df <48> 8b 2b 75
08 eb 4a 48 89 eb 48 89 c5 48 89 df e8 99 bf d0 ff 84
[32200.654441] RSP: 0018:ffffb40e08783db8 EFLAGS: 00010282
[32200.660901] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002
[32200.669422] RDX: ffffb40e00000000 RSI: 0000000000000246 RDI: ffff88ab13662298
[32200.677997] RBP: ffff88ab13662000 R08: 0000000000001549 R09: 0000000000001549
[32200.686508] R10: 0000000000000001 R11: 0000000000aaaaaa R12: ffff88ab13662298
[32200.695085] R13: ffff88ab1b259e20 R14: ffff88ab1b259e42 R15: 0000000000000000
[32200.703627] FS:  00007fb39b534740(0000) GS:ffff88b31f940000(0000)
knlGS:0000000000000000
[32200.713263] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[32200.720278] CR2: 0000000000000000 CR3: 000000084d3ea004 CR4: 00000000003606e0
[32200.728865] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[32200.737386] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[32200.745976] Call Trace:
[32200.749298]  dev_addr_flush+0x15/0x30
[32200.753989]  free_netdev+0x7e/0x130
[32200.758450]  hfi1_netdev_free+0x59/0x70 [hfi1]
[32200.764043]  remove_one+0x65/0x110 [hfi1]
[32200.769130]  pci_device_remove+0x3b/0xc0
[32200.774121]  device_release_driver_internal+0xec/0x1b0
[32200.780404]  driver_detach+0x46/0x90
[32200.784982]  bus_remove_driver+0x58/0xd0
[32200.789970]  pci_unregister_driver+0x26/0xa0
[32200.795309]  hfi1_mod_cleanup+0xc/0xd54 [hfi1]
[32200.800844]  __x64_sys_delete_module+0x16c/0x260
[32200.806513]  ? exit_to_usermode_loop+0xa4/0xc0
[32200.812054]  do_syscall_64+0x5b/0x200
[32200.816655]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 3584adcd8898 ("IB/hfi1: Use free_netdev() in hfi1_netdev_free()")
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
---
 drivers/infiniband/hw/hfi1/netdev_rx.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/hfi1/netdev_rx.c b/drivers/infiniband/hw/hfi1/netdev_rx.c
index 63688e8..6d263c9 100644
--- a/drivers/infiniband/hw/hfi1/netdev_rx.c
+++ b/drivers/infiniband/hw/hfi1/netdev_rx.c
@@ -373,7 +373,7 @@ void hfi1_netdev_free(struct hfi1_devdata *dd)
 {
 	if (dd->dummy_netdev) {
 		dd_dev_info(dd, "hfi1 netdev freed\n");
-		free_netdev(dd->dummy_netdev);
+		kfree(dd->dummy_netdev);
 		dd->dummy_netdev = NULL;
 	}
 }


  reply	other threads:[~2020-06-23 20:32 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-23 20:32 [PATCH for-rc 0/2] Fixes for module unload Dennis Dalessandro
2020-06-23 20:32 ` Dennis Dalessandro [this message]
2020-06-24 18:53   ` [PATCH for-rc 1/2] IB/hfi1: Restore kfree in dummy_netdev cleanup Jason Gunthorpe
2020-06-25 18:11     ` Marciniszyn, Mike
2020-06-23 20:32 ` [PATCH for-rc 2/2] IB/hfi1: Fix module use count flaw due to leftover module put calls Dennis Dalessandro
2020-06-24 19:01 ` [PATCH for-rc 0/2] Fixes for module unload Jason Gunthorpe
2020-06-25 11:46   ` Dennis Dalessandro

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