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authorLinus Torvalds <torvalds@linux-foundation.org>2011-01-20 18:30:37 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2011-01-20 18:30:37 -0800
commit2b1caf6ed7b888c95a1909d343799672731651a5 (patch)
tree7ab9a7ae13bc02376bce6267df67f6f2aa9091f1
parentd551d81d6a720542873f478def60baab6b5df403 (diff)
parentbd924e8cbd4b73ffb7d707a774c04f7e2cae88ed (diff)
Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: smp: Allow on_each_cpu() to be called while early_boot_irqs_disabled status to init/main.c lockdep: Move early boot local IRQ enable/disable status to init/main.c
-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/smp.c11
-rw-r--r--kernel/trace/trace_irqsoff.c8
7 files changed, 22 insertions, 40 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)
per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
local_irq_disable();
- early_boot_irqs_off();
+ early_boot_irqs_disabled = true;
memblock_init();
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);
extern unsigned long get_taint(void);
extern int root_mountflags;
+extern bool early_boot_irqs_disabled;
+
/* Values used for system_state */
extern enum system_states {
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 { \
#endif /* CONFIG_LOCKDEP */
#ifdef CONFIG_TRACE_IRQFLAGS
-extern void early_boot_irqs_off(void);
-extern void early_boot_irqs_on(void);
extern void print_irqtrace_events(struct task_struct *curr);
#else
-static inline void early_boot_irqs_off(void)
-{
-}
-static inline void early_boot_irqs_on(void)
-{
-}
static inline void print_irqtrace_events(struct task_struct *curr)
{
}
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) { }
extern void tc_init(void);
#endif
+/*
+ * Debug helper: via this flag we know that we are in 'early bootup code'
+ * where only the boot processor is running with IRQ disabled. This means
+ * two things - IRQ must not be enabled before the flag is cleared and some
+ * operations which are not allowed with IRQ disabled are allowed while the
+ * flag is set.
+ */
+bool early_boot_irqs_disabled __read_mostly;
+
enum system_states system_state __read_mostly;
EXPORT_SYMBOL(system_state);
@@ -554,7 +563,7 @@ asmlinkage void __init start_kernel(void)
cgroup_init_early();
local_irq_disable();
- early_boot_irqs_off();
+ early_boot_irqs_disabled = true;
/*
* Interrupts are still disabled. Do necessary setups, then
@@ -621,7 +630,7 @@ asmlinkage void __init start_kernel(void)
if (!irqs_disabled())
printk(KERN_CRIT "start_kernel(): bug: interrupts were "
"enabled early\n");
- early_boot_irqs_on();
+ early_boot_irqs_disabled = false;
local_irq_enable();
/* 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)
}
/*
- * Debugging helper: via this flag we know that we are in
- * 'early bootup code', and will warn about any invalid irqs-on event:
- */
-static int early_boot_irqs_enabled;
-
-void early_boot_irqs_off(void)
-{
- early_boot_irqs_enabled = 0;
-}
-
-void early_boot_irqs_on(void)
-{
- early_boot_irqs_enabled = 1;
-}
-
-/*
* Hardirqs will be enabled:
*/
void trace_hardirqs_on_caller(unsigned long ip)
@@ -2319,7 +2303,7 @@ void trace_hardirqs_on_caller(unsigned long ip)
if (unlikely(!debug_locks || current->lockdep_recursion))
return;
- if (DEBUG_LOCKS_WARN_ON(unlikely(!early_boot_irqs_enabled)))
+ if (DEBUG_LOCKS_WARN_ON(unlikely(early_boot_irqs_disabled)))
return;
if (unlikely(curr->hardirqs_enabled)) {
diff --git a/kernel/smp.c b/kernel/smp.c
index 2fe66f7c617a..9910744f0856 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -459,7 +459,7 @@ void smp_call_function_many(const struct cpumask *mask,
* can't happen.
*/
WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled()
- && !oops_in_progress);
+ && !oops_in_progress && !early_boot_irqs_disabled);
/* So, what's a CPU they want? Ignoring this one. */
cpu = cpumask_first_and(mask, cpu_online_mask);
@@ -572,17 +572,20 @@ void ipi_call_unlock_irq(void)
#endif /* USE_GENERIC_SMP_HELPERS */
/*
- * Call a function on all processors
+ * Call a function on all processors. May be used during early boot while
+ * early_boot_irqs_disabled is set. Use local_irq_save/restore() instead
+ * of local_irq_disable/enable().
*/
int on_each_cpu(void (*func) (void *info), void *info, int wait)
{
+ unsigned long flags;
int ret = 0;
preempt_disable();
ret = smp_call_function(func, info, wait);
- local_irq_disable();
+ local_irq_save(flags);
func(info);
- local_irq_enable();
+ local_irq_restore(flags);
preempt_enable();
return ret;
}
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)
* Stubs:
*/
-void early_boot_irqs_off(void)
-{
-}
-
-void early_boot_irqs_on(void)
-{
-}
-
void trace_softirqs_on(unsigned long ip)
{
}