[PATCH] net: thunderx: Fix broken of_node_put() code.

David Daney
2016-04-08T16:29:04Z

From: David Daney <david.daney@cavium.com>

commit b7d3e3d3d21a ("net: thunderx: Don't leak phy device references
on -EPROBE_DEFER condition.") incorrectly moved the call to
of_node_put() outside of the loop. Under normal loop exit, the node
has already had of_node_put() called, so the extra call results in:

[ 8.228020] ERROR: Bad of_node_put() on /soc@0/pci@848000000000/mrml-bridge0@1,0/bgx0/xlaui00
[ 8.239433] CPU: 16 PID: 608 Comm: systemd-udevd Not tainted 4.6.0-rc1-numa+ #157
[ 8.247380] Hardware name: www.cavium.com EBB8800/EBB8800, BIOS 0.3 Mar 2 2016
[ 8.273541] Call trace:
[ 8.273550] [<fffffc0008097364>] dump_backtrace+0x0/0x210
[ 8.273557] [<fffffc0008097598>] show_stack+0x24/0x2c
[ 8.273560] [<fffffc0008399ed0>] dump_stack+0x8c/0xb4
[ 8.273566] [<fffffc00085aa828>] of_node_release+0xa8/0xac
[ 8.273570] [<fffffc000839cad8>] kobject_cleanup+0x8c/0x194
[ 8.273573] [<fffffc000839c97c>] kobject_put+0x44/0x6c
[ 8.273576] [<fffffc00085a9ab0>] of_node_put+0x24/0x30
[ 8.273587] [<fffffc0000bd0f74>] bgx_probe+0x17c/0xcd8 [thunder_bgx]
[ 8.273591] [<fffffc00083ed220>] pci_device_probe+0xa0/0x114
[ 8.273596] [<fffffc0008473fbc>] driver_probe_device+0x178/0x418
[ 8.273599] [<fffffc000847435c>] __driver_attach+0x100/0x118
[ 8.273602] [<fffffc0008471b58>] bus_for_each_dev+0x6c/0xac
[ 8.273605] [<fffffc0008473884>] driver_attach+0x30/0x38
[ 8.273608] [<fffffc00084732f4>] bus_add_driver+0x1f8/0x29c
[ 8.273611] [<fffffc0008475028>] driver_register+0x70/0x110
[ 8.273617] [<fffffc00083ebf08>] __pci_register_driver+0x60/0x6c
[ 8.273623] [<fffffc0000bf0040>] bgx_init_module+0x40/0x48 [thunder_bgx]
[ 8.273626] [<fffffc0008090d04>] do_one_initcall+0xcc/0x1c0
[ 8.273631] [<fffffc0008198abc>] do_init_module+0x68/0x1c8
[ 8.273635] [<fffffc0008125668>] load_module+0xf44/0x11f4
[ 8.273638] [<fffffc0008125b64>] SyS_finit_module+0xb8/0xe0
[ 8.273641] [<fffffc0008093b30>] el0_svc_naked+0x24/0x28

Go back to the previous (correct) code that only did the extra
of_node_put() call on early exit from the loop.

Signed-off-by: David Daney <david.daney@cavium.com>
---
drivers/net/ethernet/cavium/thunder/thunder_bgx.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/cavium/thunder/thunder_bgx.c b/drivers/net/ethernet/cavium/thunder/thunder_bgx.c
index 9679515..d20539a 100644
--- a/drivers/net/ethernet/cavium/thunder/thunder_bgx.c
+++ b/drivers/net/ethernet/cavium/thunder/thunder_bgx.c
@@ -1011,10 +1011,11 @@ static int bgx_init_of_phy(struct bgx *bgx)
}

lmac++;
- if (lmac == MAX_LMAC_PER_BGX)
+ if (lmac == MAX_LMAC_PER_BGX) {
+ of_node_put(node);
break;
+ }
}
- of_node_put(node);
return 0;

defer:
--
1.8.3.1