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authorNeil Horman <nhorman@tuxdriver.com>2012-01-03 10:29:54 -0500
committerJesse Barnes <jbarnes@virtuousgeek.org>2012-01-06 12:11:17 -0800
commit424eb391596a38ddf422bee1617e4b9dea60126f (patch)
tree9fd3f9e7485d83e5138635f0c19d61c6a31ab738 /drivers/pci
parentd56641c7723c92487fb4bbcd995ad74169e2329b (diff)
PCI: msi: fix imbalanced refcount of msi irq sysfs objects
This warning was recently reported to me: ------------[ cut here ]------------ WARNING: at lib/kobject.c:595 kobject_put+0x50/0x60() Hardware name: VMware Virtual Platform kobject: '(null)' (ffff880027b0df40): is not initialized, yet kobject_put() is being called. Modules linked in: vmxnet3(+) vmw_balloon i2c_piix4 i2c_core shpchp raid10 vmw_pvscsi Pid: 630, comm: modprobe Tainted: G W 3.1.6-1.fc16.x86_64 #1 Call Trace: [<ffffffff8106b73f>] warn_slowpath_common+0x7f/0xc0 [<ffffffff8106b836>] warn_slowpath_fmt+0x46/0x50 [<ffffffff810da293>] ? free_desc+0x63/0x70 [<ffffffff812a9aa0>] kobject_put+0x50/0x60 [<ffffffff812e4c25>] free_msi_irqs+0xd5/0x120 [<ffffffff812e524c>] pci_enable_msi_block+0x24c/0x2c0 [<ffffffffa017c273>] vmxnet3_alloc_intr_resources+0x173/0x240 [vmxnet3] [<ffffffffa0182e94>] vmxnet3_probe_device+0x615/0x834 [vmxnet3] [<ffffffff812d141c>] local_pci_probe+0x5c/0xd0 [<ffffffff812d2cb9>] pci_device_probe+0x109/0x130 [<ffffffff8138ba2c>] driver_probe_device+0x9c/0x2b0 [<ffffffff8138bceb>] __driver_attach+0xab/0xb0 [<ffffffff8138bc40>] ? driver_probe_device+0x2b0/0x2b0 [<ffffffff8138bc40>] ? driver_probe_device+0x2b0/0x2b0 [<ffffffff8138a8ac>] bus_for_each_dev+0x5c/0x90 [<ffffffff8138b63e>] driver_attach+0x1e/0x20 [<ffffffff8138b240>] bus_add_driver+0x1b0/0x2a0 [<ffffffffa0188000>] ? 0xffffffffa0187fff [<ffffffff8138c246>] driver_register+0x76/0x140 [<ffffffff815ca414>] ? printk+0x51/0x53 [<ffffffffa0188000>] ? 0xffffffffa0187fff [<ffffffff812d2996>] __pci_register_driver+0x56/0xd0 [<ffffffffa018803a>] vmxnet3_init_module+0x3a/0x3c [vmxnet3] [<ffffffff81002042>] do_one_initcall+0x42/0x180 [<ffffffff810aad71>] sys_init_module+0x91/0x200 [<ffffffff815dccc2>] system_call_fastpath+0x16/0x1b ---[ end trace 44593438a59a9558 ]--- Using INTx interrupt, #Rx queues: 1. It occurs when populate_msi_sysfs fails, which in turn causes free_msi_irqs to be called. Because populate_msi_sysfs fails, we never registered any of the msi irq sysfs objects, but free_msi_irqs still calls kobject_del and kobject_put on each of them, which gets flagged in the above stack trace. The fix is pretty straightforward. We can key of the parent pointer in the kobject. It is only set if the kobject_init_and_add succededs in populate_msi_sysfs. If anything fails there, each kobject has its parent reset to NULL Signed-off-by: Neil Horman <nhorman@tuxdriver.com> CC: Bjorn Helgaas <bhelgaas@google.com> CC: Greg Kroah-Hartman <gregkh@suse.de> CC: linux-pci@vger.kernel.org Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/msi.c14
1 files changed, 12 insertions, 2 deletions
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 337e16ab4a9..82de95ec2ea 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -323,8 +323,18 @@ static void free_msi_irqs(struct pci_dev *dev)
if (list_is_last(&entry->list, &dev->msi_list))
iounmap(entry->mask_base);
}
- kobject_del(&entry->kobj);
- kobject_put(&entry->kobj);
+
+ /*
+ * Its possible that we get into this path
+ * When populate_msi_sysfs fails, which means the entries
+ * were not registered with sysfs. In that case don't
+ * unregister them.
+ */
+ if (entry->kobj.parent) {
+ kobject_del(&entry->kobj);
+ kobject_put(&entry->kobj);
+ }
+
list_del(&entry->list);
kfree(entry);
}