[PATCH] lockdep: irqtrace subsystem, core
Accurate hard-IRQ-flags and softirq-flags state tracing.
This allows us to attach extra functionality to IRQ flags on/off
events (such as trace-on/off).
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index 114ae58..b1d4332 100644
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -86,9 +86,6 @@
# define synchronize_irq(irq) barrier()
#endif
-#define nmi_enter() irq_enter()
-#define nmi_exit() sub_preempt_count(HARDIRQ_OFFSET)
-
struct task_struct;
#ifndef CONFIG_VIRT_CPU_ACCOUNTING
@@ -97,12 +94,35 @@
}
#endif
+/*
+ * It is safe to do non-atomic ops on ->hardirq_context,
+ * because NMI handlers may not preempt and the ops are
+ * always balanced, so the interrupted value of ->hardirq_context
+ * will always be restored.
+ */
#define irq_enter() \
do { \
account_system_vtime(current); \
add_preempt_count(HARDIRQ_OFFSET); \
+ trace_hardirq_enter(); \
} while (0)
+/*
+ * Exit irq context without processing softirqs:
+ */
+#define __irq_exit() \
+ do { \
+ trace_hardirq_exit(); \
+ account_system_vtime(current); \
+ sub_preempt_count(HARDIRQ_OFFSET); \
+ } while (0)
+
+/*
+ * Exit irq context and process softirqs if needed:
+ */
extern void irq_exit(void);
+#define nmi_enter() irq_enter()
+#define nmi_exit() __irq_exit()
+
#endif /* LINUX_HARDIRQ_H */
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 1b7bb37..444a3ae 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -3,6 +3,7 @@
#include <linux/file.h>
#include <linux/rcupdate.h>
+#include <linux/irqflags.h>
#define INIT_FDTABLE \
{ \
@@ -124,6 +125,7 @@
.cpu_timers = INIT_CPU_TIMERS(tsk.cpu_timers), \
.fs_excl = ATOMIC_INIT(0), \
.pi_lock = SPIN_LOCK_UNLOCKED, \
+ INIT_TRACE_IRQFLAGS \
}
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 73463fb..d5afee9 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -10,6 +10,7 @@
#include <linux/irqreturn.h>
#include <linux/hardirq.h>
#include <linux/sched.h>
+#include <linux/irqflags.h>
#include <asm/atomic.h>
#include <asm/ptrace.h>
#include <asm/system.h>
@@ -199,13 +200,11 @@
#define save_and_cli(x) save_and_cli(&x)
#endif /* CONFIG_SMP */
-/* SoftIRQ primitives. */
-#define local_bh_disable() \
- do { add_preempt_count(SOFTIRQ_OFFSET); barrier(); } while (0)
-#define __local_bh_enable() \
- do { barrier(); sub_preempt_count(SOFTIRQ_OFFSET); } while (0)
-
+extern void local_bh_disable(void);
+extern void __local_bh_enable(void);
+extern void _local_bh_enable(void);
extern void local_bh_enable(void);
+extern void local_bh_enable_ip(unsigned long ip);
/* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
frequency threaded job scheduling. For almost all the purposes
diff --git a/include/linux/irqflags.h b/include/linux/irqflags.h
new file mode 100644
index 0000000..412e025
--- /dev/null
+++ b/include/linux/irqflags.h
@@ -0,0 +1,96 @@
+/*
+ * include/linux/irqflags.h
+ *
+ * IRQ flags tracing: follow the state of the hardirq and softirq flags and
+ * provide callbacks for transitions between ON and OFF states.
+ *
+ * This file gets included from lowlevel asm headers too, to provide
+ * wrapped versions of the local_irq_*() APIs, based on the
+ * raw_local_irq_*() macros from the lowlevel headers.
+ */
+#ifndef _LINUX_TRACE_IRQFLAGS_H
+#define _LINUX_TRACE_IRQFLAGS_H
+
+#ifdef CONFIG_TRACE_IRQFLAGS
+ extern void trace_hardirqs_on(void);
+ extern void trace_hardirqs_off(void);
+ extern void trace_softirqs_on(unsigned long ip);
+ extern void trace_softirqs_off(unsigned long ip);
+# define trace_hardirq_context(p) ((p)->hardirq_context)
+# define trace_softirq_context(p) ((p)->softirq_context)
+# define trace_hardirqs_enabled(p) ((p)->hardirqs_enabled)
+# define trace_softirqs_enabled(p) ((p)->softirqs_enabled)
+# define trace_hardirq_enter() do { current->hardirq_context++; } while (0)
+# define trace_hardirq_exit() do { current->hardirq_context--; } while (0)
+# define trace_softirq_enter() do { current->softirq_context++; } while (0)
+# define trace_softirq_exit() do { current->softirq_context--; } while (0)
+# define INIT_TRACE_IRQFLAGS .softirqs_enabled = 1,
+#else
+# define trace_hardirqs_on() do { } while (0)
+# define trace_hardirqs_off() do { } while (0)
+# define trace_softirqs_on(ip) do { } while (0)
+# define trace_softirqs_off(ip) do { } while (0)
+# define trace_hardirq_context(p) 0
+# define trace_softirq_context(p) 0
+# define trace_hardirqs_enabled(p) 0
+# define trace_softirqs_enabled(p) 0
+# define trace_hardirq_enter() do { } while (0)
+# define trace_hardirq_exit() do { } while (0)
+# define trace_softirq_enter() do { } while (0)
+# define trace_softirq_exit() do { } while (0)
+# define INIT_TRACE_IRQFLAGS
+#endif
+
+#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
+
+#include <asm/irqflags.h>
+
+#define local_irq_enable() \
+ do { trace_hardirqs_on(); raw_local_irq_enable(); } while (0)
+#define local_irq_disable() \
+ do { raw_local_irq_disable(); trace_hardirqs_off(); } while (0)
+#define local_irq_save(flags) \
+ do { raw_local_irq_save(flags); trace_hardirqs_off(); } while (0)
+
+#define local_irq_restore(flags) \
+ do { \
+ if (raw_irqs_disabled_flags(flags)) { \
+ raw_local_irq_restore(flags); \
+ trace_hardirqs_off(); \
+ } else { \
+ trace_hardirqs_on(); \
+ raw_local_irq_restore(flags); \
+ } \
+ } while (0)
+#else /* !CONFIG_TRACE_IRQFLAGS_SUPPORT */
+/*
+ * The local_irq_*() APIs are equal to the raw_local_irq*()
+ * if !TRACE_IRQFLAGS.
+ */
+# define raw_local_irq_disable() local_irq_disable()
+# define raw_local_irq_enable() local_irq_enable()
+# define raw_local_irq_save(flags) local_irq_save(flags)
+# define raw_local_irq_restore(flags) local_irq_restore(flags)
+#endif /* CONFIG_TRACE_IRQFLAGS_SUPPORT */
+
+#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
+#define safe_halt() \
+ do { \
+ trace_hardirqs_on(); \
+ raw_safe_halt(); \
+ } while (0)
+
+#define local_save_flags(flags) raw_local_save_flags(flags)
+
+#define irqs_disabled() \
+({ \
+ unsigned long flags; \
+ \
+ raw_local_save_flags(flags); \
+ raw_irqs_disabled_flags(flags); \
+})
+
+#define irqs_disabled_flags(flags) raw_irqs_disabled_flags(flags)
+#endif /* CONFIG_X86 */
+
+#endif
diff --git a/include/linux/sched.h b/include/linux/sched.h
index bdabeee..ad7a890 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -871,6 +871,21 @@
/* mutex deadlock detection */
struct mutex_waiter *blocked_on;
#endif
+#ifdef CONFIG_TRACE_IRQFLAGS
+ unsigned int irq_events;
+ int hardirqs_enabled;
+ unsigned long hardirq_enable_ip;
+ unsigned int hardirq_enable_event;
+ unsigned long hardirq_disable_ip;
+ unsigned int hardirq_disable_event;
+ int softirqs_enabled;
+ unsigned long softirq_disable_ip;
+ unsigned int softirq_disable_event;
+ unsigned long softirq_enable_ip;
+ unsigned int softirq_enable_event;
+ int hardirq_context;
+ int softirq_context;
+#endif
/* journalling filesystem info */
void *journal_info;