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| author | Hans Zhang <18255117159@163.com> | 2026-03-14 00:55:18 +0800 |
|---|---|---|
| committer | Manivannan Sadhasivam <mani@kernel.org> | 2026-03-27 00:00:08 +0530 |
| commit | 28d20b0d895849ce3fe8c6f77baffc08886c2157 (patch) | |
| tree | 58f8480cf19b236ea70fc459d9bf0bd6b7cfcec6 | |
| parent | 6de23f81a5e08be8fbf5e8d7e9febc72a5b5f27f (diff) | |
| download | linux-28d20b0d895849ce3fe8c6f77baffc08886c2157.tar.gz linux-28d20b0d895849ce3fe8c6f77baffc08886c2157.zip | |
PCI: Add pcie_get_link_speed() helper for safe array access
The pcie_link_speed[] array is indexed by PCIe generation numbers
(1 = 2.5 GT/s, 2 = 5 GT/s, ...). Several drivers use it directly,
which can lead to out-of-bounds accesses if an invalid generation
number is used.
Introduce a helper function pcie_get_link_speed() that returns the
pci_bus_speed value for a given generation number, or PCI_SPEED_UNKNOWN if
the generation is out of range. This will allow us to safely handle
invalid values after the range check is removed from
of_pci_get_max_link_speed().
Signed-off-by: Hans Zhang <18255117159@163.com>
[mani: Fixed kernel-doc]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20260313165522.123518-2-18255117159@163.com
| -rw-r--r-- | drivers/pci/pci.h | 2 | ||||
| -rw-r--r-- | drivers/pci/probe.c | 16 |
2 files changed, 18 insertions, 0 deletions
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 13d998fbacce..409aca7d737a 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -108,6 +108,8 @@ struct pcie_tlp_log; PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE) extern const unsigned char pcie_link_speed[]; +unsigned char pcie_get_link_speed(unsigned int speed); + extern bool pci_early_dump; extern struct mutex pci_rescan_remove_lock; diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index bccc7a4bdd79..f85da50a3d83 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -783,6 +783,22 @@ const unsigned char pcie_link_speed[] = { }; EXPORT_SYMBOL_GPL(pcie_link_speed); +/** + * pcie_get_link_speed - Get speed value from PCIe generation number + * @speed: PCIe speed (1-based: 1 = 2.5GT, 2 = 5GT, ...) + * + * Returns the speed value (e.g., PCIE_SPEED_2_5GT) if @speed is valid, + * otherwise returns PCI_SPEED_UNKNOWN. + */ +unsigned char pcie_get_link_speed(unsigned int speed) +{ + if (speed >= ARRAY_SIZE(pcie_link_speed)) + return PCI_SPEED_UNKNOWN; + + return pcie_link_speed[speed]; +} +EXPORT_SYMBOL_GPL(pcie_get_link_speed); + const char *pci_speed_string(enum pci_bus_speed speed) { /* Indexed by the pci_bus_speed enum */ |