Commits
Neil Horman committed 424eb391596
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>