diff options
| author | Matthew Wilcox <matthew@wil.cx> | 2010-01-17 14:01:41 -0700 |
|---|---|---|
| committer | Jesse Barnes <jbarnes@virtuousgeek.org> | 2010-02-22 16:17:17 -0800 |
| commit | 4fb88c1a28a8dc302bdc09858e7cdafc97bef794 (patch) | |
| tree | cd2d6ff98626d6d8782edd848c357bc4607ece17 | |
| parent | 0bf01c3c86d4b9ea279d6215420484db887f5db5 (diff) | |
PCI: Make pci_scan_slot more robust
Yinghai pointed out that the new pci_scan_slot() crashes when called
on an ARI-capable slot that is empty. Fix this by exiting early from
pci_scan_slot if there is no device in the slot.
Also make next_ari_func() robust against devices not existing in case
the ARI capability is corrupt. ARI also requires that the devices be
listed in order, so if we find a function listed that is out of order,
stop scanning to prevent loops.
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
| -rw-r--r-- | drivers/pci/probe.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 9672760c7ade..233d1c275d96 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1222,11 +1222,19 @@ EXPORT_SYMBOL(pci_scan_single_device); static unsigned next_ari_fn(struct pci_dev *dev, unsigned fn) { u16 cap; - unsigned pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI); + unsigned pos, next_fn; + + if (!dev) + return 0; + + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI); if (!pos) return 0; pci_read_config_word(dev, pos + 4, &cap); - return cap >> 8; + next_fn = cap >> 8; + if (next_fn <= fn) + return 0; + return next_fn; } static unsigned next_trad_fn(struct pci_dev *dev, unsigned fn) @@ -1271,12 +1279,14 @@ int pci_scan_slot(struct pci_bus *bus, int devfn) return 0; /* Already scanned the entire slot */ dev = pci_scan_single_device(bus, devfn); - if (dev && !dev->is_added) /* new device? */ + if (!dev) + return 0; + if (!dev->is_added) nr++; if (pci_ari_enabled(bus)) next_fn = next_ari_fn; - else if (dev && dev->multifunction) + else if (dev->multifunction) next_fn = next_trad_fn; for (fn = next_fn(dev, 0); fn > 0; fn = next_fn(dev, fn)) { |