[PATCH 0/1] Constify struct usb_mon_operations for 2.6.32-git-053fe57ac v2

[PATCH 0/1] Constify struct usb_mon_operations for 2.6.32-git-053fe57ac v2

[re.emese]

From: Emese Revfy <re.emese@gmail.com>

Hello everyone!

The following patch series attempts to constify several structures
that hold function pointers. This is only the initial batch, there
are about over 150 candidate structures, some of which can be
constified as well, I plan to submit them in the future.

The list of constified structures in this series (* marks this thread):
acpi_dock_ops
address_space_operations
backlight_ops
block_device_operations
dma_map_ops
extent_io_ops
file_lock_operations
file_operations
hv_ops
intel_dvo_dev_ops
item_operations
iwl_ops
kgdb_arch
kgdb_io
kset_uevent_ops
lock_manager_operations
microcode_ops
mtrr_ops
neigh_ops
nlmsvc_binding
pci_raw_ops
platform_hibernation_ops
platform_suspend_ops
snd_ac97_build_ops
sysfs_ops
* usb_mon_operations
wd_ops

There are certain exceptions where a given instance of the structure
cannot be const, they are marked with a comment in the patch.

The patches compile fine with an allyesconfig kernel on i386 and x86_64.

Please let me know if any of these structures should not be constified
and any other issues you see with them.


Changelog:
----------
v1 -> v2
	- updated to linus-git-053fe57
	- extended comments with a reference to code that prevents constification
	- split up patches by subsystem as suggested by Greg KH, Jiri Slaby
	- added all Acked-by's received so far
	- removed patch for super_operations for now
	- removed patch for ptmx_fops

Thanks,
   Emese

 drivers/usb/core/hcd.c     |    4 ++--
 drivers/usb/core/hcd.h     |   10 +++++-----
 drivers/usb/mon/mon_main.c |    2 +-
 3 files changed, 8 insertions(+), 8 deletions(-)

[PATCH 1/1] Constify struct usb_mon_operations for 2.6.32-git-053fe57ac v2

[re.emese]

From: Emese Revfy <re.emese@gmail.com>


Signed-off-by: Emese Revfy <re.emese@gmail.com>
---
 drivers/usb/core/hcd.c     |    4 ++--
 drivers/usb/core/hcd.h     |   10 +++++-----
 drivers/usb/mon/mon_main.c |    2 +-
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 6dac3b8..e160b54 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -2246,7 +2246,7 @@ EXPORT_SYMBOL_GPL(usb_hcd_platform_shutdown);
 
 #if defined(CONFIG_USB_MON) || defined(CONFIG_USB_MON_MODULE)
 
-struct usb_mon_operations *mon_ops;
+const struct usb_mon_operations *mon_ops;
 
 /*
  * The registration is unlocked.
@@ -2256,7 +2256,7 @@ struct usb_mon_operations *mon_ops;
  * symbols from usbcore, usbcore gets referenced and cannot be unloaded first.
  */
  
-int usb_mon_register (struct usb_mon_operations *ops)
+int usb_mon_register (const struct usb_mon_operations *ops)
 {
 
 	if (mon_ops)
diff --git a/drivers/usb/core/hcd.h b/drivers/usb/core/hcd.h
index d8b43ae..17521a6 100644
--- a/drivers/usb/core/hcd.h
+++ b/drivers/usb/core/hcd.h
@@ -501,13 +501,13 @@ static inline void usbfs_cleanup(void) { }
 #if defined(CONFIG_USB_MON) || defined(CONFIG_USB_MON_MODULE)
 
 struct usb_mon_operations {
-	void (*urb_submit)(struct usb_bus *bus, struct urb *urb);
-	void (*urb_submit_error)(struct usb_bus *bus, struct urb *urb, int err);
-	void (*urb_complete)(struct usb_bus *bus, struct urb *urb, int status);
+	void (* const urb_submit)(struct usb_bus *bus, struct urb *urb);
+	void (* const urb_submit_error)(struct usb_bus *bus, struct urb *urb, int err);
+	void (* const urb_complete)(struct usb_bus *bus, struct urb *urb, int status);
 	/* void (*urb_unlink)(struct usb_bus *bus, struct urb *urb); */
 };
 
-extern struct usb_mon_operations *mon_ops;
+extern const struct usb_mon_operations *mon_ops;
 
 static inline void usbmon_urb_submit(struct usb_bus *bus, struct urb *urb)
 {
@@ -529,7 +529,7 @@ static inline void usbmon_urb_complete(struct usb_bus *bus, struct urb *urb,
 		(*mon_ops->urb_complete)(bus, urb, status);
 }
 
-int usb_mon_register(struct usb_mon_operations *ops);
+int usb_mon_register(const struct usb_mon_operations *ops);
 void usb_mon_deregister(void);
 
 #else
diff --git a/drivers/usb/mon/mon_main.c b/drivers/usb/mon/mon_main.c
index e0c2db3..bd8cb66 100644
--- a/drivers/usb/mon/mon_main.c
+++ b/drivers/usb/mon/mon_main.c
@@ -238,7 +238,7 @@ static struct notifier_block mon_nb = {
 /*
  * Ops
  */
-static struct usb_mon_operations mon_ops_0 = {
+static const struct usb_mon_operations mon_ops_0 = {
 	.urb_submit =	mon_submit,
 	.urb_submit_error = mon_submit_error,
 	.urb_complete =	mon_complete,
-- 
1.6.5.3

[PATCH 1/1] Constify struct wd_ops for 2.6.32-git-053fe57ac v2

[re.emese]

From: Emese Revfy <re.emese@gmail.com>


Signed-off-by: Emese Revfy <re.emese@gmail.com>
---
 arch/x86/kernel/cpu/perfctr-watchdog.c |   12 +++++++-----
 1 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/cpu/perfctr-watchdog.c b/arch/x86/kernel/cpu/perfctr-watchdog.c
index 898df97..89dad0b 100644
--- a/arch/x86/kernel/cpu/perfctr-watchdog.c
+++ b/arch/x86/kernel/cpu/perfctr-watchdog.c
@@ -30,11 +30,11 @@ struct nmi_watchdog_ctlblk {
 
 /* Interface defining a CPU specific perfctr watchdog */
 struct wd_ops {
-	int (*reserve)(void);
-	void (*unreserve)(void);
-	int (*setup)(unsigned nmi_hz);
-	void (*rearm)(struct nmi_watchdog_ctlblk *wd, unsigned nmi_hz);
-	void (*stop)(void);
+	int (* const reserve)(void);
+	void (* const unreserve)(void);
+	int (* const setup)(unsigned nmi_hz);
+	void (* const rearm)(struct nmi_watchdog_ctlblk *wd, unsigned nmi_hz);
+	void (* const stop)(void);
 	unsigned perfctr;
 	unsigned evntsel;
 	u64 checkbit;
@@ -645,6 +645,7 @@ static const struct wd_ops p4_wd_ops = {
 #define ARCH_PERFMON_NMI_EVENT_SEL	ARCH_PERFMON_UNHALTED_CORE_CYCLES_SEL
 #define ARCH_PERFMON_NMI_EVENT_UMASK	ARCH_PERFMON_UNHALTED_CORE_CYCLES_UMASK
 
+/* cannot be const, see probe_nmi_watchdog */
 static struct wd_ops intel_arch_wd_ops;
 
 static int setup_intel_arch_watchdog(unsigned nmi_hz)
@@ -697,6 +698,7 @@ static int setup_intel_arch_watchdog(unsigned nmi_hz)
 	return 1;
 }
 
+/* cannot be const, see probe_nmi_watchdog */
 static struct wd_ops intel_arch_wd_ops __read_mostly = {
 	.reserve	= single_msr_reserve,
 	.unreserve	= single_msr_unreserve,
-- 
1.6.5.3