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authorTejun Heo <tj@kernel.org>2011-01-20 06:06:35 -0500
committerIngo Molnar <mingo@elte.hu>2011-01-20 07:32:33 -0500
commit2ce802f62ba32a7d95748ac92bf351f76affb6ff (patch)
tree54dd0d6063ca61619e6b8ca84dd95b8e5a3c1402
parent12fcdba1b7ae8b25696433f420b775aeb556d89b (diff)
lockdep: Move early boot local IRQ enable/disable status to init/main.c
During early boot, local IRQ is disabled until IRQ subsystem is properly initialized. During this time, no one should enable local IRQ and some operations which usually are not allowed with IRQ disabled, e.g. operations which might sleep or require communications with other processors, are allowed. lockdep tracked this with early_boot_irqs_off/on() callbacks. As other subsystems need this information too, move it to init/main.c and make it generally available. While at it, toggle the boolean to early_boot_irqs_disabled instead of enabled so that it can be initialized with %false and %true indicates the exceptional condition. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <20110120110635.GB6036@htj.dyndns.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--arch/x86/xen/enlighten.c2
-rw-r--r--include/linux/kernel.h2
-rw-r--r--include/linux/lockdep.h8
-rw-r--r--init/main.c13
-rw-r--r--kernel/lockdep.c18
-rw-r--r--kernel/trace/trace_irqsoff.c8
6 files changed, 15 insertions, 36 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 7e8d3bc80af6..50542efe45fb 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1194,7 +1194,7 @@ asmlinkage void __init xen_start_kernel(void)
1194 per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0]; 1194 per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
1195 1195
1196 local_irq_disable(); 1196 local_irq_disable();
1197 early_boot_irqs_off(); 1197 early_boot_irqs_disabled = true;
1198 1198
1199 memblock_init(); 1199 memblock_init();
1200 1200
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 5a9d9059520b..d07d8057e440 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -243,6 +243,8 @@ extern int test_taint(unsigned flag);
243extern unsigned long get_taint(void); 243extern unsigned long get_taint(void);
244extern int root_mountflags; 244extern int root_mountflags;
245 245
246extern bool early_boot_irqs_disabled;
247
246/* Values used for system_state */ 248/* Values used for system_state */
247extern enum system_states { 249extern enum system_states {
248 SYSTEM_BOOTING, 250 SYSTEM_BOOTING,
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 71c09b26c759..f638fd78d106 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -436,16 +436,8 @@ do { \
436#endif /* CONFIG_LOCKDEP */ 436#endif /* CONFIG_LOCKDEP */
437 437
438#ifdef CONFIG_TRACE_IRQFLAGS 438#ifdef CONFIG_TRACE_IRQFLAGS
439extern void early_boot_irqs_off(void);
440extern void early_boot_irqs_on(void);
441extern void print_irqtrace_events(struct task_struct *curr); 439extern void print_irqtrace_events(struct task_struct *curr);
442#else 440#else
443static inline void early_boot_irqs_off(void)
444{
445}
446static inline void early_boot_irqs_on(void)
447{
448}
449static inline void print_irqtrace_events(struct task_struct *curr) 441static inline void print_irqtrace_events(struct task_struct *curr)
450{ 442{
451} 443}
diff --git a/init/main.c b/init/main.c
index 00799c1d4628..33c37c379e96 100644
--- a/init/main.c
+++ b/init/main.c
@@ -96,6 +96,15 @@ static inline void mark_rodata_ro(void) { }
96extern void tc_init(void); 96extern void tc_init(void);
97#endif 97#endif
98 98
99/*
100 * Debug helper: via this flag we know that we are in 'early bootup code'
101 * where only the boot processor is running with IRQ disabled. This means
102 * two things - IRQ must not be enabled before the flag is cleared and some
103 * operations which are not allowed with IRQ disabled are allowed while the
104 * flag is set.
105 */
106bool early_boot_irqs_disabled __read_mostly;
107
99enum system_states system_state __read_mostly; 108enum system_states system_state __read_mostly;
100EXPORT_SYMBOL(system_state); 109EXPORT_SYMBOL(system_state);
101 110
@@ -554,7 +563,7 @@ asmlinkage void __init start_kernel(void)
554 cgroup_init_early(); 563 cgroup_init_early();
555 564
556 local_irq_disable(); 565 local_irq_disable();
557 early_boot_irqs_off(); 566 early_boot_irqs_disabled = true;
558 567
559/* 568/*
560 * Interrupts are still disabled. Do necessary setups, then 569 * Interrupts are still disabled. Do necessary setups, then
@@ -621,7 +630,7 @@ asmlinkage void __init start_kernel(void)
621 if (!irqs_disabled()) 630 if (!irqs_disabled())
622 printk(KERN_CRIT "start_kernel(): bug: interrupts were " 631 printk(KERN_CRIT "start_kernel(): bug: interrupts were "
623 "enabled early\n"); 632 "enabled early\n");
624 early_boot_irqs_on(); 633 early_boot_irqs_disabled = false;
625 local_irq_enable(); 634 local_irq_enable();
626 635
627 /* Interrupts are enabled now so all GFP allocations are safe. */ 636 /* Interrupts are enabled now so all GFP allocations are safe. */
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 42ba65dff7d9..0d2058da80f5 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -2292,22 +2292,6 @@ mark_held_locks(struct task_struct *curr, enum mark_type mark)
2292} 2292}
2293 2293
2294/* 2294/*
2295 * Debugging helper: via this flag we know that we are in
2296 * 'early bootup code', and will warn about any invalid irqs-on event:
2297 */
2298static int early_boot_irqs_enabled;
2299
2300void early_boot_irqs_off(void)
2301{
2302 early_boot_irqs_enabled = 0;
2303}
2304
2305void early_boot_irqs_on(void)
2306{
2307 early_boot_irqs_enabled = 1;
2308}
2309
2310/*
2311 * Hardirqs will be enabled: 2295 * Hardirqs will be enabled:
2312 */ 2296 */
2313void trace_hardirqs_on_caller(unsigned long ip) 2297void trace_hardirqs_on_caller(unsigned long ip)
@@ -2319,7 +2303,7 @@ void trace_hardirqs_on_caller(unsigned long ip)
2319 if (unlikely(!debug_locks || current->lockdep_recursion)) 2303 if (unlikely(!debug_locks || current->lockdep_recursion))
2320 return; 2304 return;
2321 2305
2322 if (DEBUG_LOCKS_WARN_ON(unlikely(!early_boot_irqs_enabled))) 2306 if (DEBUG_LOCKS_WARN_ON(unlikely(early_boot_irqs_disabled)))
2323 return; 2307 return;
2324 2308
2325 if (unlikely(curr->hardirqs_enabled)) { 2309 if (unlikely(curr->hardirqs_enabled)) {
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index 5cf8c602b880..92b6e1e12d98 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -453,14 +453,6 @@ void time_hardirqs_off(unsigned long a0, unsigned long a1)
453 * Stubs: 453 * Stubs:
454 */ 454 */
455 455
456void early_boot_irqs_off(void)
457{
458}
459
460void early_boot_irqs_on(void)
461{
462}
463
464void trace_softirqs_on(unsigned long ip) 456void trace_softirqs_on(unsigned long ip)
465{ 457{
466} 458}