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| author | Zhang Yanmin <yanmin.zhang@intel.com> | 2006-06-02 08:35:43 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2006-06-21 23:00:01 +0400 |
| commit | d71374dafbba7ec3f67371d3b7e9f6310a588808 (patch) | |
| tree | 116dcd65fde3701d10fea954cdbd5bb063182b2c /drivers/pci/probe.c | |
| parent | 733a7fe12248072e1bca729c88a26298666f1956 (diff) | |
| download | linux-d71374dafbba7ec3f67371d3b7e9f6310a588808.tar.xz | |
[PATCH] PCI: fix race with pci_walk_bus and pci_destroy_dev
pci_walk_bus has a race with pci_destroy_dev. When cb is called
in pci_walk_bus, pci_destroy_dev might unlink the dev pointed by next.
Later on in the next loop, pointer next becomes NULL and cause
kernel panic.
Below patch against 2.6.17-rc4 fixes it by changing pci_bus_lock (spin_lock)
to pci_bus_sem (rw_semaphore).
Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/pci/probe.c')
| -rw-r--r-- | drivers/pci/probe.c | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 27148db06ba0..f89dbc3738b7 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -383,9 +383,9 @@ struct pci_bus * __devinit pci_add_new_bus(struct pci_bus *parent, struct pci_de child = pci_alloc_child_bus(parent, dev, busnr); if (child) { - spin_lock(&pci_bus_lock); + down_write(&pci_bus_sem); list_add_tail(&child->node, &parent->children); - spin_unlock(&pci_bus_lock); + up_write(&pci_bus_sem); } return child; } @@ -844,9 +844,9 @@ void __devinit pci_device_add(struct pci_dev *dev, struct pci_bus *bus) * and the bus list for fixup functions, etc. */ INIT_LIST_HEAD(&dev->global_list); - spin_lock(&pci_bus_lock); + down_write(&pci_bus_sem); list_add_tail(&dev->bus_list, &bus->devices); - spin_unlock(&pci_bus_lock); + up_write(&pci_bus_sem); } struct pci_dev * __devinit @@ -981,9 +981,10 @@ struct pci_bus * __devinit pci_create_bus(struct device *parent, pr_debug("PCI: Bus %04x:%02x already known\n", pci_domain_nr(b), bus); goto err_out; } - spin_lock(&pci_bus_lock); + + down_write(&pci_bus_sem); list_add_tail(&b->node, &pci_root_buses); - spin_unlock(&pci_bus_lock); + up_write(&pci_bus_sem); memset(dev, 0, sizeof(*dev)); dev->parent = parent; @@ -1023,9 +1024,9 @@ class_dev_create_file_err: class_dev_reg_err: device_unregister(dev); dev_reg_err: - spin_lock(&pci_bus_lock); + down_write(&pci_bus_sem); list_del(&b->node); - spin_unlock(&pci_bus_lock); + up_write(&pci_bus_sem); err_out: kfree(dev); kfree(b); |