[PATCH] PCI: Make pci_bus_type constant

[PATCH] PCI: Make pci_bus_type constant

[Kunwu Chan]

From: Kunwu Chan <chentao@kylinos.cn>

Since commit d492cc2573a0 ("driver core: device.h: make struct
bus_type a const *"), the driver core can properly handle constant
struct bus_type, move the pci_bus_type variable to be a constant
structure as well, placing it into read-only memory which can not be
modified at runtime.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
---
 drivers/pci/pci-driver.c | 2 +-
 include/linux/pci.h      | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index f412ef73a6e4..35270172c833 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -1670,7 +1670,7 @@ static void pci_dma_cleanup(struct device *dev)
 		iommu_device_unuse_default_domain(dev);
 }
 
-struct bus_type pci_bus_type = {
+const struct bus_type pci_bus_type = {
 	.name		= "pci",
 	.match		= pci_bus_match,
 	.uevent		= pci_uevent,
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 4246cb790c7b..0d6c1c089aca 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1098,7 +1098,7 @@ enum pcie_bus_config_types {
 
 extern enum pcie_bus_config_types pcie_bus_config;
 
-extern struct bus_type pci_bus_type;
+extern const struct bus_type pci_bus_type;
 
 /* Do NOT directly access these two variables, unless you are arch-specific PCI
  * code, or PCI core code. */
-- 
2.41.0

Re: [PATCH] PCI: Make pci_bus_type constant

[Bjorn Helgaas]

On Fri, Aug 23, 2024 at 03:42:01PM +0800, Kunwu Chan wrote:
> From: Kunwu Chan <chentao@kylinos.cn>
> 
> Since commit d492cc2573a0 ("driver core: device.h: make struct
> bus_type a const *"), the driver core can properly handle constant
> struct bus_type, move the pci_bus_type variable to be a constant
> structure as well, placing it into read-only memory which can not be
> modified at runtime.
> 
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> 
> Signed-off-by: Kunwu Chan <chentao@kylinos.cn>

Applied to pci/misc for v6.12, thanks!

> ---
>  drivers/pci/pci-driver.c | 2 +-
>  include/linux/pci.h      | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
> index f412ef73a6e4..35270172c833 100644
> --- a/drivers/pci/pci-driver.c
> +++ b/drivers/pci/pci-driver.c
> @@ -1670,7 +1670,7 @@ static void pci_dma_cleanup(struct device *dev)
>  		iommu_device_unuse_default_domain(dev);
>  }
>  
> -struct bus_type pci_bus_type = {
> +const struct bus_type pci_bus_type = {
>  	.name		= "pci",
>  	.match		= pci_bus_match,
>  	.uevent		= pci_uevent,
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 4246cb790c7b..0d6c1c089aca 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -1098,7 +1098,7 @@ enum pcie_bus_config_types {
>  
>  extern enum pcie_bus_config_types pcie_bus_config;
>  
> -extern struct bus_type pci_bus_type;
> +extern const struct bus_type pci_bus_type;
>  
>  /* Do NOT directly access these two variables, unless you are arch-specific PCI
>   * code, or PCI core code. */
> -- 
> 2.41.0
>