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authorAlan Stern <stern@rowland.harvard.edu>2006-03-27 01:16:30 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-03-27 08:44:50 -0800
commite041c683412d5bf44dc2b109053e3b837b71742d (patch)
tree9d271066ef379da0c0fb3b8cb4137abd5d2ebba0 /arch
parent76b81e2b0e2241accebcc68e126bc5ab958661b9 (diff)
downloadlinux-e041c683412d5bf44dc2b109053e3b837b71742d.tar.bz2
[PATCH] Notifier chain update: API changes
The kernel's implementation of notifier chains is unsafe. There is no protection against entries being added to or removed from a chain while the chain is in use. The issues were discussed in this thread: http://marc.theaimsgroup.com/?l=linux-kernel&m=113018709002036&w=2 We noticed that notifier chains in the kernel fall into two basic usage classes: "Blocking" chains are always called from a process context and the callout routines are allowed to sleep; "Atomic" chains can be called from an atomic context and the callout routines are not allowed to sleep. We decided to codify this distinction and make it part of the API. Therefore this set of patches introduces three new, parallel APIs: one for blocking notifiers, one for atomic notifiers, and one for "raw" notifiers (which is really just the old API under a new name). New kinds of data structures are used for the heads of the chains, and new routines are defined for registration, unregistration, and calling a chain. The three APIs are explained in include/linux/notifier.h and their implementation is in kernel/sys.c. With atomic and blocking chains, the implementation guarantees that the chain links will not be corrupted and that chain callers will not get messed up by entries being added or removed. For raw chains the implementation provides no guarantees at all; users of this API must provide their own protections. (The idea was that situations may come up where the assumptions of the atomic and blocking APIs are not appropriate, so it should be possible for users to handle these things in their own way.) There are some limitations, which should not be too hard to live with. For atomic/blocking chains, registration and unregistration must always be done in a process context since the chain is protected by a mutex/rwsem. Also, a callout routine for a non-raw chain must not try to register or unregister entries on its own chain. (This did happen in a couple of places and the code had to be changed to avoid it.) Since atomic chains may be called from within an NMI handler, they cannot use spinlocks for synchronization. Instead we use RCU. The overhead falls almost entirely in the unregister routine, which is okay since unregistration is much less frequent that calling a chain. Here is the list of chains that we adjusted and their classifications. None of them use the raw API, so for the moment it is only a placeholder. ATOMIC CHAINS ------------- arch/i386/kernel/traps.c: i386die_chain arch/ia64/kernel/traps.c: ia64die_chain arch/powerpc/kernel/traps.c: powerpc_die_chain arch/sparc64/kernel/traps.c: sparc64die_chain arch/x86_64/kernel/traps.c: die_chain drivers/char/ipmi/ipmi_si_intf.c: xaction_notifier_list kernel/panic.c: panic_notifier_list kernel/profile.c: task_free_notifier net/bluetooth/hci_core.c: hci_notifier net/ipv4/netfilter/ip_conntrack_core.c: ip_conntrack_chain net/ipv4/netfilter/ip_conntrack_core.c: ip_conntrack_expect_chain net/ipv6/addrconf.c: inet6addr_chain net/netfilter/nf_conntrack_core.c: nf_conntrack_chain net/netfilter/nf_conntrack_core.c: nf_conntrack_expect_chain net/netlink/af_netlink.c: netlink_chain BLOCKING CHAINS --------------- arch/powerpc/platforms/pseries/reconfig.c: pSeries_reconfig_chain arch/s390/kernel/process.c: idle_chain arch/x86_64/kernel/process.c idle_notifier drivers/base/memory.c: memory_chain drivers/cpufreq/cpufreq.c cpufreq_policy_notifier_list drivers/cpufreq/cpufreq.c cpufreq_transition_notifier_list drivers/macintosh/adb.c: adb_client_list drivers/macintosh/via-pmu.c sleep_notifier_list drivers/macintosh/via-pmu68k.c sleep_notifier_list drivers/macintosh/windfarm_core.c wf_client_list drivers/usb/core/notify.c usb_notifier_list drivers/video/fbmem.c fb_notifier_list kernel/cpu.c cpu_chain kernel/module.c module_notify_list kernel/profile.c munmap_notifier kernel/profile.c task_exit_notifier kernel/sys.c reboot_notifier_list net/core/dev.c netdev_chain net/decnet/dn_dev.c: dnaddr_chain net/ipv4/devinet.c: inetaddr_chain It's possible that some of these classifications are wrong. If they are, please let us know or submit a patch to fix them. Note that any chain that gets called very frequently should be atomic, because the rwsem read-locking used for blocking chains is very likely to incur cache misses on SMP systems. (However, if the chain's callout routines may sleep then the chain cannot be atomic.) The patch set was written by Alan Stern and Chandra Seetharaman, incorporating material written by Keith Owens and suggestions from Paul McKenney and Andrew Morton. [jes@sgi.com: restructure the notifier chain initialization macros] Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Jes Sorensen <jes@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/alpha/kernel/setup.c5
-rw-r--r--arch/arm/mach-omap1/board-netstar.c2
-rw-r--r--arch/arm/mach-omap1/board-voiceblue.c2
-rw-r--r--arch/i386/kernel/traps.c17
-rw-r--r--arch/ia64/kernel/traps.c6
-rw-r--r--arch/mips/lasat/setup.c3
-rw-r--r--arch/mips/sgi-ip22/ip22-reset.c2
-rw-r--r--arch/mips/sgi-ip32/ip32-reset.c2
-rw-r--r--arch/parisc/kernel/pdc_chassis.c3
-rw-r--r--arch/powerpc/kernel/setup_64.c3
-rw-r--r--arch/powerpc/kernel/traps.c16
-rw-r--r--arch/powerpc/platforms/pseries/reconfig.c10
-rw-r--r--arch/ppc/platforms/prep_setup.c2
-rw-r--r--arch/s390/kernel/process.c11
-rw-r--r--arch/sparc64/kernel/traps.c17
-rw-r--r--arch/um/drivers/mconsole_kern.c3
-rw-r--r--arch/um/kernel/um_arch.c3
-rw-r--r--arch/x86_64/kernel/process.c17
-rw-r--r--arch/x86_64/kernel/traps.c18
-rw-r--r--arch/xtensa/platform-iss/setup.c2
20 files changed, 72 insertions, 72 deletions
diff --git a/arch/alpha/kernel/setup.c b/arch/alpha/kernel/setup.c
index 9402624453c2..dd8769670596 100644
--- a/arch/alpha/kernel/setup.c
+++ b/arch/alpha/kernel/setup.c
@@ -43,7 +43,7 @@
#include <asm/setup.h>
#include <asm/io.h>
-extern struct notifier_block *panic_notifier_list;
+extern struct atomic_notifier_head panic_notifier_list;
static int alpha_panic_event(struct notifier_block *, unsigned long, void *);
static struct notifier_block alpha_panic_block = {
alpha_panic_event,
@@ -500,7 +500,8 @@ setup_arch(char **cmdline_p)
}
/* Register a call for panic conditions. */
- notifier_chain_register(&panic_notifier_list, &alpha_panic_block);
+ atomic_notifier_chain_register(&panic_notifier_list,
+ &alpha_panic_block);
#ifdef CONFIG_ALPHA_GENERIC
/* Assume that we've booted from SRM if we haven't booted from MILO.
diff --git a/arch/arm/mach-omap1/board-netstar.c b/arch/arm/mach-omap1/board-netstar.c
index 60d5f8a3339c..7520e602d7a2 100644
--- a/arch/arm/mach-omap1/board-netstar.c
+++ b/arch/arm/mach-omap1/board-netstar.c
@@ -141,7 +141,7 @@ static int __init netstar_late_init(void)
/* TODO: Setup front panel switch here */
/* Setup panic notifier */
- notifier_chain_register(&panic_notifier_list, &panic_block);
+ atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
return 0;
}
diff --git a/arch/arm/mach-omap1/board-voiceblue.c b/arch/arm/mach-omap1/board-voiceblue.c
index bfd5fdd1a875..52e4a9d69642 100644
--- a/arch/arm/mach-omap1/board-voiceblue.c
+++ b/arch/arm/mach-omap1/board-voiceblue.c
@@ -235,7 +235,7 @@ static struct notifier_block panic_block = {
static int __init voiceblue_setup(void)
{
/* Setup panic notifier */
- notifier_chain_register(&panic_notifier_list, &panic_block);
+ atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
return 0;
}
diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index 4624f8ca2459..6b63a5aa1e46 100644
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -92,22 +92,21 @@ asmlinkage void spurious_interrupt_bug(void);
asmlinkage void machine_check(void);
static int kstack_depth_to_print = 24;
-struct notifier_block *i386die_chain;
-static DEFINE_SPINLOCK(die_notifier_lock);
+ATOMIC_NOTIFIER_HEAD(i386die_chain);
int register_die_notifier(struct notifier_block *nb)
{
- int err = 0;
- unsigned long flags;
-
vmalloc_sync_all();
- spin_lock_irqsave(&die_notifier_lock, flags);
- err = notifier_chain_register(&i386die_chain, nb);
- spin_unlock_irqrestore(&die_notifier_lock, flags);
- return err;
+ return atomic_notifier_chain_register(&i386die_chain, nb);
}
EXPORT_SYMBOL(register_die_notifier);
+int unregister_die_notifier(struct notifier_block *nb)
+{
+ return atomic_notifier_chain_unregister(&i386die_chain, nb);
+}
+EXPORT_SYMBOL(unregister_die_notifier);
+
static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
{
return p > (void *)tinfo &&
diff --git a/arch/ia64/kernel/traps.c b/arch/ia64/kernel/traps.c
index dabd6c32641e..7c1ddc8ac443 100644
--- a/arch/ia64/kernel/traps.c
+++ b/arch/ia64/kernel/traps.c
@@ -30,19 +30,19 @@ extern spinlock_t timerlist_lock;
fpswa_interface_t *fpswa_interface;
EXPORT_SYMBOL(fpswa_interface);
-struct notifier_block *ia64die_chain;
+ATOMIC_NOTIFIER_HEAD(ia64die_chain);
int
register_die_notifier(struct notifier_block *nb)
{
- return notifier_chain_register(&ia64die_chain, nb);
+ return atomic_notifier_chain_register(&ia64die_chain, nb);
}
EXPORT_SYMBOL_GPL(register_die_notifier);
int
unregister_die_notifier(struct notifier_block *nb)
{
- return notifier_chain_unregister(&ia64die_chain, nb);
+ return atomic_notifier_chain_unregister(&ia64die_chain, nb);
}
EXPORT_SYMBOL_GPL(unregister_die_notifier);
diff --git a/arch/mips/lasat/setup.c b/arch/mips/lasat/setup.c
index 83eb08b7a072..e9e9a89c6741 100644
--- a/arch/mips/lasat/setup.c
+++ b/arch/mips/lasat/setup.c
@@ -165,7 +165,8 @@ void __init plat_setup(void)
/* Set up panic notifier */
for (i = 0; i < sizeof(lasat_panic_block) / sizeof(struct notifier_block); i++)
- notifier_chain_register(&panic_notifier_list, &lasat_panic_block[i]);
+ atomic_notifier_chain_register(&panic_notifier_list,
+ &lasat_panic_block[i]);
lasat_reboot_setup();
diff --git a/arch/mips/sgi-ip22/ip22-reset.c b/arch/mips/sgi-ip22/ip22-reset.c
index 92a3b3c15ed3..a9c58e067b53 100644
--- a/arch/mips/sgi-ip22/ip22-reset.c
+++ b/arch/mips/sgi-ip22/ip22-reset.c
@@ -238,7 +238,7 @@ static int __init reboot_setup(void)
request_irq(SGI_PANEL_IRQ, panel_int, 0, "Front Panel", NULL);
init_timer(&blink_timer);
blink_timer.function = blink_timeout;
- notifier_chain_register(&panic_notifier_list, &panic_block);
+ atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
return 0;
}
diff --git a/arch/mips/sgi-ip32/ip32-reset.c b/arch/mips/sgi-ip32/ip32-reset.c
index 0c948008b023..ab9d9cef089e 100644
--- a/arch/mips/sgi-ip32/ip32-reset.c
+++ b/arch/mips/sgi-ip32/ip32-reset.c
@@ -193,7 +193,7 @@ static __init int ip32_reboot_setup(void)
init_timer(&blink_timer);
blink_timer.function = blink_timeout;
- notifier_chain_register(&panic_notifier_list, &panic_block);
+ atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
request_irq(MACEISA_RTC_IRQ, ip32_rtc_int, 0, "rtc", NULL);
diff --git a/arch/parisc/kernel/pdc_chassis.c b/arch/parisc/kernel/pdc_chassis.c
index 2a01fe1bdc98..0cea6958f427 100644
--- a/arch/parisc/kernel/pdc_chassis.c
+++ b/arch/parisc/kernel/pdc_chassis.c
@@ -150,7 +150,8 @@ void __init parisc_pdc_chassis_init(void)
if (handle) {
/* initialize panic notifier chain */
- notifier_chain_register(&panic_notifier_list, &pdc_chassis_panic_block);
+ atomic_notifier_chain_register(&panic_notifier_list,
+ &pdc_chassis_panic_block);
/* initialize reboot notifier chain */
register_reboot_notifier(&pdc_chassis_reboot_block);
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 2f3fdad35594..e20c1fae3423 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -579,7 +579,8 @@ void __init setup_arch(char **cmdline_p)
panic_timeout = 180;
if (ppc_md.panic)
- notifier_chain_register(&panic_notifier_list, &ppc64_panic_block);
+ atomic_notifier_chain_register(&panic_notifier_list,
+ &ppc64_panic_block);
init_mm.start_code = PAGE_OFFSET;
init_mm.end_code = (unsigned long) _etext;
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 98660aedeeb7..9763faab6739 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -74,19 +74,19 @@ EXPORT_SYMBOL(__debugger_dabr_match);
EXPORT_SYMBOL(__debugger_fault_handler);
#endif
-struct notifier_block *powerpc_die_chain;
-static DEFINE_SPINLOCK(die_notifier_lock);
+ATOMIC_NOTIFIER_HEAD(powerpc_die_chain);
int register_die_notifier(struct notifier_block *nb)
{
- int err = 0;
- unsigned long flags;
+ return atomic_notifier_chain_register(&powerpc_die_chain, nb);
+}
+EXPORT_SYMBOL(register_die_notifier);
- spin_lock_irqsave(&die_notifier_lock, flags);
- err = notifier_chain_register(&powerpc_die_chain, nb);
- spin_unlock_irqrestore(&die_notifier_lock, flags);
- return err;
+int unregister_die_notifier(struct notifier_block *nb)
+{
+ return atomic_notifier_chain_unregister(&powerpc_die_chain, nb);
}
+EXPORT_SYMBOL(unregister_die_notifier);
/*
* Trap & Exception support
diff --git a/arch/powerpc/platforms/pseries/reconfig.c b/arch/powerpc/platforms/pseries/reconfig.c
index 86cfa6ecdcf3..5ad90676567a 100644
--- a/arch/powerpc/platforms/pseries/reconfig.c
+++ b/arch/powerpc/platforms/pseries/reconfig.c
@@ -94,16 +94,16 @@ static struct device_node *derive_parent(const char *path)
return parent;
}
-static struct notifier_block *pSeries_reconfig_chain;
+static BLOCKING_NOTIFIER_HEAD(pSeries_reconfig_chain);
int pSeries_reconfig_notifier_register(struct notifier_block *nb)
{
- return notifier_chain_register(&pSeries_reconfig_chain, nb);
+ return blocking_notifier_chain_register(&pSeries_reconfig_chain, nb);
}
void pSeries_reconfig_notifier_unregister(struct notifier_block *nb)
{
- notifier_chain_unregister(&pSeries_reconfig_chain, nb);
+ blocking_notifier_chain_unregister(&pSeries_reconfig_chain, nb);
}
static int pSeries_reconfig_add_node(const char *path, struct property *proplist)
@@ -131,7 +131,7 @@ static int pSeries_reconfig_add_node(const char *path, struct property *proplist
goto out_err;
}
- err = notifier_call_chain(&pSeries_reconfig_chain,
+ err = blocking_notifier_call_chain(&pSeries_reconfig_chain,
PSERIES_RECONFIG_ADD, np);
if (err == NOTIFY_BAD) {
printk(KERN_ERR "Failed to add device node %s\n", path);
@@ -171,7 +171,7 @@ static int pSeries_reconfig_remove_node(struct device_node *np)
remove_node_proc_entries(np);
- notifier_call_chain(&pSeries_reconfig_chain,
+ blocking_notifier_call_chain(&pSeries_reconfig_chain,
PSERIES_RECONFIG_REMOVE, np);
of_detach_node(np);
diff --git a/arch/ppc/platforms/prep_setup.c b/arch/ppc/platforms/prep_setup.c
index a0fc628ffb1e..d95c05d9824d 100644
--- a/arch/ppc/platforms/prep_setup.c
+++ b/arch/ppc/platforms/prep_setup.c
@@ -736,7 +736,7 @@ ibm_statusled_progress(char *s, unsigned short hex)
hex = 0xfff;
if (!notifier_installed) {
++notifier_installed;
- notifier_chain_register(&panic_notifier_list,
+ atomic_notifier_chain_register(&panic_notifier_list,
&ibm_statusled_block);
}
}
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index 99182a415fe7..4a0f5a1551ea 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -76,17 +76,17 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
/*
* Need to know about CPUs going idle?
*/
-static struct notifier_block *idle_chain;
+static ATOMIC_NOTIFIER_HEAD(idle_chain);
int register_idle_notifier(struct notifier_block *nb)
{
- return notifier_chain_register(&idle_chain, nb);
+ return atomic_notifier_chain_register(&idle_chain, nb);
}
EXPORT_SYMBOL(register_idle_notifier);
int unregister_idle_notifier(struct notifier_block *nb)
{
- return notifier_chain_unregister(&idle_chain, nb);
+ return atomic_notifier_chain_unregister(&idle_chain, nb);
}
EXPORT_SYMBOL(unregister_idle_notifier);
@@ -95,7 +95,7 @@ void do_monitor_call(struct pt_regs *regs, long interruption_code)
/* disable monitor call class 0 */
__ctl_clear_bit(8, 15);
- notifier_call_chain(&idle_chain, CPU_NOT_IDLE,
+ atomic_notifier_call_chain(&idle_chain, CPU_NOT_IDLE,
(void *)(long) smp_processor_id());
}
@@ -116,7 +116,8 @@ static void default_idle(void)
return;
}
- rc = notifier_call_chain(&idle_chain, CPU_IDLE, (void *)(long) cpu);
+ rc = atomic_notifier_call_chain(&idle_chain,
+ CPU_IDLE, (void *)(long) cpu);
if (rc != NOTIFY_OK && rc != NOTIFY_DONE)
BUG();
if (rc != NOTIFY_OK) {
diff --git a/arch/sparc64/kernel/traps.c b/arch/sparc64/kernel/traps.c
index df612e4f75f9..ff090bb9734b 100644
--- a/arch/sparc64/kernel/traps.c
+++ b/arch/sparc64/kernel/traps.c
@@ -43,18 +43,19 @@
#include <linux/kmod.h>
#endif
-struct notifier_block *sparc64die_chain;
-static DEFINE_SPINLOCK(die_notifier_lock);
+ATOMIC_NOTIFIER_HEAD(sparc64die_chain);
int register_die_notifier(struct notifier_block *nb)
{
- int err = 0;
- unsigned long flags;
- spin_lock_irqsave(&die_notifier_lock, flags);
- err = notifier_chain_register(&sparc64die_chain, nb);
- spin_unlock_irqrestore(&die_notifier_lock, flags);
- return err;
+ return atomic_notifier_chain_register(&sparc64die_chain, nb);
}
+EXPORT_SYMBOL(register_die_notifier);
+
+int unregister_die_notifier(struct notifier_block *nb)
+{
+ return atomic_notifier_chain_unregister(&sparc64die_chain, nb);
+}
+EXPORT_SYMBOL(unregister_die_notifier);
/* When an irrecoverable trap occurs at tl > 0, the trap entry
* code logs the trap state registers at every level in the trap
diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index 54388d10bcf9..1488816588ea 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -762,7 +762,8 @@ static struct notifier_block panic_exit_notifier = {
static int add_notifier(void)
{
- notifier_chain_register(&panic_notifier_list, &panic_exit_notifier);
+ atomic_notifier_chain_register(&panic_notifier_list,
+ &panic_exit_notifier);
return(0);
}
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index bb1c87211ac1..7d51dd7201c3 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -477,7 +477,8 @@ static struct notifier_block panic_exit_notifier = {
void __init setup_arch(char **cmdline_p)
{
- notifier_chain_register(&panic_notifier_list, &panic_exit_notifier);
+ atomic_notifier_chain_register(&panic_notifier_list,
+ &panic_exit_notifier);
paging_init();
strlcpy(saved_command_line, command_line, COMMAND_LINE_SIZE);
*cmdline_p = command_line;
diff --git a/arch/x86_64/kernel/process.c b/arch/x86_64/kernel/process.c
index 0370720515f1..70dd8e5c6889 100644
--- a/arch/x86_64/kernel/process.c
+++ b/arch/x86_64/kernel/process.c
@@ -66,24 +66,17 @@ EXPORT_SYMBOL(boot_option_idle_override);
void (*pm_idle)(void);
static DEFINE_PER_CPU(unsigned int, cpu_idle_state);
-static struct notifier_block *idle_notifier;
-static DEFINE_SPINLOCK(idle_notifier_lock);
+static ATOMIC_NOTIFIER_HEAD(idle_notifier);
void idle_notifier_register(struct notifier_block *n)
{
- unsigned long flags;
- spin_lock_irqsave(&idle_notifier_lock, flags);
- notifier_chain_register(&idle_notifier, n);
- spin_unlock_irqrestore(&idle_notifier_lock, flags);
+ atomic_notifier_chain_register(&idle_notifier, n);
}
EXPORT_SYMBOL_GPL(idle_notifier_register);
void idle_notifier_unregister(struct notifier_block *n)
{
- unsigned long flags;
- spin_lock_irqsave(&idle_notifier_lock, flags);
- notifier_chain_unregister(&idle_notifier, n);
- spin_unlock_irqrestore(&idle_notifier_lock, flags);
+ atomic_notifier_chain_unregister(&idle_notifier, n);
}
EXPORT_SYMBOL(idle_notifier_unregister);
@@ -93,13 +86,13 @@ static DEFINE_PER_CPU(enum idle_state, idle_state) = CPU_NOT_IDLE;
void enter_idle(void)
{
__get_cpu_var(idle_state) = CPU_IDLE;
- notifier_call_chain(&idle_notifier, IDLE_START, NULL);
+ atomic_notifier_call_chain(&idle_notifier, IDLE_START, NULL);
}
static void __exit_idle(void)
{
__get_cpu_var(idle_state) = CPU_NOT_IDLE;
- notifier_call_chain(&idle_notifier, IDLE_END, NULL);
+ atomic_notifier_call_chain(&idle_notifier, IDLE_END, NULL);
}
/* Called from interrupts to signify idle end */
diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c
index 7b148309c529..edaa9fe654dc 100644
--- a/arch/x86_64/kernel/traps.c
+++ b/arch/x86_64/kernel/traps.c
@@ -69,20 +69,20 @@ asmlinkage void alignment_check(void);
asmlinkage void machine_check(void);
asmlinkage void spurious_interrupt_bug(void);
-struct notifier_block *die_chain;
-static DEFINE_SPINLOCK(die_notifier_lock);
+ATOMIC_NOTIFIER_HEAD(die_chain);
int register_die_notifier(struct notifier_block *nb)
{
- int err = 0;
- unsigned long flags;
-
vmalloc_sync_all();
- spin_lock_irqsave(&die_notifier_lock, flags);
- err = notifier_chain_register(&die_chain, nb);
- spin_unlock_irqrestore(&die_notifier_lock, flags);
- return err;
+ return atomic_notifier_chain_register(&die_chain, nb);
+}
+EXPORT_SYMBOL(register_die_notifier);
+
+int unregister_die_notifier(struct notifier_block *nb)
+{
+ return atomic_notifier_chain_unregister(&die_chain, nb);
}
+EXPORT_SYMBOL(unregister_die_notifier);
static inline void conditional_sti(struct pt_regs *regs)
{
diff --git a/arch/xtensa/platform-iss/setup.c b/arch/xtensa/platform-iss/setup.c
index 2e6dcbf0cc04..23790a5610e2 100644
--- a/arch/xtensa/platform-iss/setup.c
+++ b/arch/xtensa/platform-iss/setup.c
@@ -108,5 +108,5 @@ static struct notifier_block iss_panic_block = {
void __init platform_setup(char **p_cmdline)
{
- notifier_chain_register(&panic_notifier_list, &iss_panic_block);
+ atomic_notifier_chain_register(&panic_notifier_list, &iss_panic_block);
}