tracing: cleanups, updates, and fixes

GIT PULL New Steven Rostedt 1 participant 10 messages Feb 14, 2012

Subsystems (6)

Documentation x86 Tracing ftrace +2 more subsystems

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Steven Rostedt

author maintainer

2012-02-14 03:40 UTC #0 lore raw

Ingo,

Please pull the latest tip/perf/core tree, which can be found at:

git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
tip/perf/core

Head SHA1: 47b0edcb599ea6eb9ef16d3a08932a0e01485293

Geunsik Lim (2):
ftrace: sched_switch plugin is deprecated
ftrace: Append wakeup_rt description of ftrace doc

Jiri Olsa (1):
ftrace: Change filter/notrace set functions to return exit code

Johannes Berg (1):
printk/tracing: Add console output tracing

Steven Rostedt (4):
tracing/softirq: Move __raise_softirq_irqoff() out of header
tracing/rcu: Add trace_##name##__rcuidle() static tracepoint for inside rcu_idle_exit() sections x86/tracing: Denote the power and cpuidle tracepoints as _rcuidle() cpuidle/tracing: Denote the tracepoints as being in rcu_idle_exit() section

Thomas Meyer (1):
tracing/trivial: Use kcalloc instead of kzalloc to allocate array

----

 Documentation/trace/ftrace.txt     |    7 ++++++
 arch/x86/kernel/process.c          |   24 ++++++++++----------
 drivers/cpuidle/cpuidle.c          |    8 +++---
 include/linux/ftrace.h             |    4 +-
 include/linux/interrupt.h          |    7 +-----
 include/linux/tracepoint.h         |   22 +++++++++++++++---
 include/trace/events/power.h       |    2 +
 include/trace/events/printk.h      |   41 ++++++++++++++++++++++++++++++++++++
 kernel/irq/chip.c                  |    2 +
 kernel/printk.c                    |    5 ++++
 kernel/softirq.c                   |    6 +++++
 kernel/trace/ftrace.c              |   17 ++++++++------
 kernel/trace/trace.c               |    6 ++--
 kernel/trace/trace_events_filter.c |    7 ++---
 kernel/trace/trace_syscalls.c      |    4 +-
 15 files changed, 118 insertions(+), 44 deletions(-)

Steven Rostedt

author maintainer

2012-02-14 03:40 UTC #1 lore raw

PATCH 1/9 ftrace: Change filter/notrace set functions to return exit code

From: Jiri Olsa <[email protected]>

Currently the ftrace_set_filter and ftrace_set_notrace functions do not return any return code. So there's no way for ftrace_ops user to tell wether the filter was correctly applied.

The set_ftrace_filter interface returns error in case the filter did not match:

  # echo krava > set_ftrace_filter
  bash: echo: write error: Invalid argument

Changing both ftrace_set_filter and ftrace_set_notrace functions to return zero if the filter was applied correctly or -E* values in case of error.

Link http://lkml.kernel.org/r/[email protected] open here

Acked-by Frederic Weisbecker <[email protected]>

Signed-off-by Jiri Olsa <[email protected]>

Signed-off-by Steven Rostedt <[email protected]>

---
 include/linux/ftrace.h |    4 ++--
 kernel/trace/ftrace.c  |   15 +++++++++------
 2 files changed, 11 insertions(+), 8 deletions(-)

include/linux/ftrace.h +2 -2

index 028e26f..f33fb3b 100644
@@ -178,9 +178,9 @@ struct dyn_ftrace {
 };
 
 int ftrace_force_update(void);
-void ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
+int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
 		       int len, int reset);
-void ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
+int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
 			int len, int reset);
 void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);

kernel/trace/ftrace.c +9 -6

index 683d559..e2e0597 100644
@@ -3146,8 +3146,10 @@ ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
 	mutex_lock(&ftrace_regex_lock);
 	if (reset)
 		ftrace_filter_reset(hash);
-	if (buf)
-		ftrace_match_records(hash, buf, len);
+	if (buf && !ftrace_match_records(hash, buf, len)) {
+		ret = -EINVAL;
+		goto out_regex_unlock;
+	}
 
 	mutex_lock(&ftrace_lock);
 	ret = ftrace_hash_move(ops, enable, orig_hash, hash);

@@ -3157,6 +3159,7 @@ ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
 
 	mutex_unlock(&ftrace_lock);
 
+ out_regex_unlock:
 	mutex_unlock(&ftrace_regex_lock);
 
 	free_ftrace_hash(hash);

@@ -3173,10 +3176,10 @@ ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
  * Filters denote which functions should be enabled when tracing is enabled.
  * If @buf is NULL and reset is set, all functions will be enabled for tracing.
  */
-void ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
+int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
 		       int len, int reset)
 {
-	ftrace_set_regex(ops, buf, len, reset, 1);
+	return ftrace_set_regex(ops, buf, len, reset, 1);
 }
 EXPORT_SYMBOL_GPL(ftrace_set_filter);

@@ -3191,10 +3194,10 @@ EXPORT_SYMBOL_GPL(ftrace_set_filter);
  * is enabled. If @buf is NULL and reset is set, all functions will be enabled
  * for tracing.
  */
-void ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
+int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
 			int len, int reset)
 {
-	ftrace_set_regex(ops, buf, len, reset, 0);
+	return ftrace_set_regex(ops, buf, len, reset, 0);
 }
 EXPORT_SYMBOL_GPL(ftrace_set_notrace);
 /**

Signature · 1 line

1.7.8.3

Steven Rostedt

author maintainer

2012-02-14 03:40 UTC #2 lore raw

PATCH 2/9 tracing/softirq: Move __raise_softirq_irqoff() out of header

In reply to Steven Rostedt

From: Steven Rostedt <[email protected]>

The __raise_softirq_irqoff() contains a tracepoint. As tracepoints in headers can cause issues, and not to mention, bloats the kernel when they are in a static inline, it is best to move the function that contains the tracepoint out of the header and into softirq.c.

Link http://lkml.kernel.org/r/[email protected] open here

Signed-off-by Steven Rostedt <[email protected]>

---
 include/linux/interrupt.h |    7 +------
 kernel/irq/chip.c         |    2 ++
 kernel/softirq.c          |    6 ++++++
 3 files changed, 9 insertions(+), 6 deletions(-)

include/linux/interrupt.h +1 -6

index a64b00e..3f830e0 100644
@@ -20,7 +20,6 @@
 #include <linux/atomic.h>
 #include <asm/ptrace.h>
 #include <asm/system.h>
-#include <trace/events/irq.h>
 
 /*
  * These correspond to the IORESOURCE_IRQ_* defines in

@@ -456,11 +455,7 @@ asmlinkage void do_softirq(void);
 asmlinkage void __do_softirq(void);
 extern void open_softirq(int nr, void (*action)(struct softirq_action *));
 extern void softirq_init(void);
-static inline void __raise_softirq_irqoff(unsigned int nr)
-{
-	trace_softirq_raise(nr);
-	or_softirq_pending(1UL << nr);
-}
+extern void __raise_softirq_irqoff(unsigned int nr);
 
 extern void raise_softirq_irqoff(unsigned int nr);
 extern void raise_softirq(unsigned int nr);

kernel/irq/chip.c +2 -0

index f7c543a..fc41824 100644
@@ -16,6 +16,8 @@
 #include <linux/interrupt.h>
 #include <linux/kernel_stat.h>
 
+#include <trace/events/irq.h>
+
 #include "internals.h"
 
 /**

kernel/softirq.c +6 -0

index 4eb3a0f..06d4099 100644
@@ -385,6 +385,12 @@ void raise_softirq(unsigned int nr)
 	local_irq_restore(flags);
 }
 
+void __raise_softirq_irqoff(unsigned int nr)
+{
+	trace_softirq_raise(nr);
+	or_softirq_pending(1UL << nr);
+}
+
 void open_softirq(int nr, void (*action)(struct softirq_action *))
 {
 	softirq_vec[nr].action = action;

Signature · 1 line

1.7.8.3

Steven Rostedt

author maintainer

2012-02-14 03:42 UTC #3 lore raw

PATCH 3/9 tracing/rcu: Add trace_##name##__rcuidle() static tracepoint for inside rcu_idle_exit() sections

In reply to Steven Rostedt

From: Steven Rostedt <[email protected]>

Added is a new static inline function that lets *any* tracepoint be used inside a rcu_idle_exit() section. And this also solves the problem where the same tracepoint may be used inside a rcu_idle_exit() section as well as outside of one.

I added a new tracepoint function with a "_rcuidle" extension. All tracepoints can be used with either the normal "trace_foobar()" function, or the "trace_foobar_rcuidle()" function when inside a rcu_idle_exit() section.

All tracepoints defined by TRACE_EVENT() or any of the derivatives will have a "_rcuidle()" function also defined. When a tracepoint is used within an rcu_idle_exit() section, the "_rcuidle()" version must be used. This denotes that the tracepoint is within rcu_idle_exit() and it allows the rcu read locks within the tracepoint to still be valid, as this version takes us out of rcu_idle_exit().

Another nice aspect about this patch is that "static inline"s are not compiled into text when not used. So only the tracepoints that actually use the _rcuidle() version will have them defined in the actual text that is booted.

Link http://lkml.kernel.org/r/[email protected]> open here

Acked-by Paul E. McKenney <[email protected]>

Reviewed-by Josh Triplett <[email protected]>

Signed-off-by Steven Rostedt <[email protected]>

---
 include/linux/tracepoint.h |   22 ++++++++++++++++++----
 1 files changed, 18 insertions(+), 4 deletions(-)

include/linux/tracepoint.h +18 -4

index df0a779..fc36da9 100644
@@ -114,7 +114,7 @@ static inline void tracepoint_synchronize_unregister(void)
  * as "(void *, void)". The DECLARE_TRACE_NOARGS() will pass in just
  * "void *data", where as the DECLARE_TRACE() will pass in "void *data, proto".
  */
-#define __DO_TRACE(tp, proto, args, cond)				\
+#define __DO_TRACE(tp, proto, args, cond, prercu, postrcu)		\
 	do {								\
 		struct tracepoint_func *it_func_ptr;			\
 		void *it_func;						\

@@ -122,6 +122,7 @@ static inline void tracepoint_synchronize_unregister(void)
 									\
 		if (!(cond))						\
 			return;						\
+		prercu;							\
 		rcu_read_lock_sched_notrace();				\
 		it_func_ptr = rcu_dereference_sched((tp)->funcs);	\
 		if (it_func_ptr) {					\

@@ -132,6 +133,7 @@ static inline void tracepoint_synchronize_unregister(void)
 			} while ((++it_func_ptr)->func);		\
 		}							\
 		rcu_read_unlock_sched_notrace();			\
+		postrcu;						\
 	} while (0)
 
 /*

@@ -139,7 +141,7 @@ static inline void tracepoint_synchronize_unregister(void)
  * not add unwanted padding between the beginning of the section and the
  * structure. Force alignment to the same alignment as the section start.
  */
-#define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args)	\
+#define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \
 	extern struct tracepoint __tracepoint_##name;			\
 	static inline void trace_##name(proto)				\
 	{								\

@@ -147,7 +149,17 @@ static inline void tracepoint_synchronize_unregister(void)
 			__DO_TRACE(&__tracepoint_##name,		\
 				TP_PROTO(data_proto),			\
 				TP_ARGS(data_args),			\
-				TP_CONDITION(cond));			\
+				TP_CONDITION(cond),,);			\
+	}								\
+	static inline void trace_##name##_rcuidle(proto)		\
+	{								\
+		if (static_branch(&__tracepoint_##name.key))		\
+			__DO_TRACE(&__tracepoint_##name,		\
+				TP_PROTO(data_proto),			\
+				TP_ARGS(data_args),			\
+				TP_CONDITION(cond),			\
+				rcu_idle_exit(),			\
+				rcu_idle_enter());			\
 	}								\
 	static inline int						\
 	register_trace_##name(void (*probe)(data_proto), void *data)	\

@@ -190,9 +202,11 @@ static inline void tracepoint_synchronize_unregister(void)
 	EXPORT_SYMBOL(__tracepoint_##name)
 
 #else /* !CONFIG_TRACEPOINTS */
-#define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args)	\
+#define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \
 	static inline void trace_##name(proto)				\
 	{ }								\
+	static inline void trace_##name##_rcuidle(proto)		\
+	{ }								\
 	static inline int						\
 	register_trace_##name(void (*probe)(data_proto),		\
 			      void *data)				\

Signature · 1 line

1.7.8.3

Steven Rostedt

author maintainer

2012-02-14 03:40 UTC #4 lore raw

PATCH 4/9 x86/tracing: Denote the power and cpuidle tracepoints as _rcuidle()

In reply to Steven Rostedt

From: Steven Rostedt <[email protected]>

The power and cpuidle tracepoints are called within a rcu_idle_exit() section, and must be denoted with the _rcuidle() version of the tracepoint.

Acked-by Paul E. McKenney <[email protected]>

Reviewed-by Josh Triplett <[email protected]>

Signed-off-by Steven Rostedt <[email protected]>

---
 arch/x86/kernel/process.c    |   24 ++++++++++++------------
 include/trace/events/power.h |    2 ++
 2 files changed, 14 insertions(+), 12 deletions(-)

arch/x86/kernel/process.c +12 ~~-12~~

index 15763af..44eefde 100644
@@ -377,8 +377,8 @@ static inline int hlt_use_halt(void)
 void default_idle(void)
 {
 	if (hlt_use_halt()) {
-		trace_power_start(POWER_CSTATE, 1, smp_processor_id());
-		trace_cpu_idle(1, smp_processor_id());
+		trace_power_start_rcuidle(POWER_CSTATE, 1, smp_processor_id());
+		trace_cpu_idle_rcuidle(1, smp_processor_id());
 		current_thread_info()->status &= ~TS_POLLING;
 		/*
 		 * TS_POLLING-cleared state must be visible before we

@@ -391,8 +391,8 @@ void default_idle(void)
 		else
 			local_irq_enable();
 		current_thread_info()->status |= TS_POLLING;
-		trace_power_end(smp_processor_id());
-		trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());
+		trace_power_end_rcuidle(smp_processor_id());
+		trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
 	} else {
 		local_irq_enable();
 		/* loop is done by the caller */

@@ -450,8 +450,8 @@ EXPORT_SYMBOL_GPL(cpu_idle_wait);
 static void mwait_idle(void)
 {
 	if (!need_resched()) {
-		trace_power_start(POWER_CSTATE, 1, smp_processor_id());
-		trace_cpu_idle(1, smp_processor_id());
+		trace_power_start_rcuidle(POWER_CSTATE, 1, smp_processor_id());
+		trace_cpu_idle_rcuidle(1, smp_processor_id());
 		if (this_cpu_has(X86_FEATURE_CLFLUSH_MONITOR))
 			clflush((void *)&current_thread_info()->flags);

@@ -461,8 +461,8 @@ static void mwait_idle(void)
 			__sti_mwait(0, 0);
 		else
 			local_irq_enable();
-		trace_power_end(smp_processor_id());
-		trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());
+		trace_power_end_rcuidle(smp_processor_id());
+		trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
 	} else
 		local_irq_enable();
 }

@@ -474,13 +474,13 @@ static void mwait_idle(void)
  */
 static void poll_idle(void)
 {
-	trace_power_start(POWER_CSTATE, 0, smp_processor_id());
-	trace_cpu_idle(0, smp_processor_id());
+	trace_power_start_rcuidle(POWER_CSTATE, 0, smp_processor_id());
+	trace_cpu_idle_rcuidle(0, smp_processor_id());
 	local_irq_enable();
 	while (!need_resched())
 		cpu_relax();
-	trace_power_end(smp_processor_id());
-	trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());
+	trace_power_end_rcuidle(smp_processor_id());
+	trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
 }
 
 /*

include/trace/events/power.h +2 -0

index 1bcc2a8..14b3894 100644
@@ -151,6 +151,8 @@ enum {
    events get removed */
 static inline void trace_power_start(u64 type, u64 state, u64 cpuid) {};
 static inline void trace_power_end(u64 cpuid) {};
+static inline void trace_power_start_rcuidle(u64 type, u64 state, u64 cpuid) {};
+static inline void trace_power_end_rcuidle(u64 cpuid) {};
 static inline void trace_power_frequency(u64 type, u64 state, u64 cpuid) {};
 #endif /* _PWR_EVENT_AVOID_DOUBLE_DEFINING_DEPRECATED */

Signature · 1 line

1.7.8.3

Steven Rostedt

author maintainer

2012-02-14 03:40 UTC #5 lore raw

PATCH 5/9 cpuidle/tracing: Denote the tracepoints as being in rcu_idle_exit() section

In reply to Steven Rostedt

From: Steven Rostedt <[email protected]>

As the tracepoints in the cpuidle code are called when rcu_idle_exit() is in effect, the _rcuidle() version must be used, otherwise the rcu_read_lock()s that protect the tracepoint will not be honored.

Cc Len Brown <[email protected]>

Reviewed-by Josh Triplett <[email protected]>

Reviewed-by Paul E. McKenney <[email protected]>

Signed-off-by Steven Rostedt <[email protected]>

---
 drivers/cpuidle/cpuidle.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

drivers/cpuidle/cpuidle.c +4 -4

index 59f4261..6588f43 100644
@@ -94,13 +94,13 @@ int cpuidle_idle_call(void)
 
 	target_state = &drv->states[next_state];
 
-	trace_power_start(POWER_CSTATE, next_state, dev->cpu);
-	trace_cpu_idle(next_state, dev->cpu);
+	trace_power_start_rcuidle(POWER_CSTATE, next_state, dev->cpu);
+	trace_cpu_idle_rcuidle(next_state, dev->cpu);
 
 	entered_state = target_state->enter(dev, drv, next_state);
 
-	trace_power_end(dev->cpu);
-	trace_cpu_idle(PWR_EVENT_EXIT, dev->cpu);
+	trace_power_end_rcuidle(dev->cpu);
+	trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu);
 
 	if (entered_state >= 0) {
 		/* Update cpuidle counters */

Signature · 1 line

1.7.8.3

Steven Rostedt

author maintainer

2012-02-14 03:41 UTC #6 lore raw

PATCH 6/9 ftrace: sched_switch plugin is deprecated

In reply to Steven Rostedt

From: Geunsik Lim <[email protected]>

Actually, sched_switch function tracer is merged into wakeup/wakeup_rt Update 'mini-HOWTO' for ftrace(Kernel function tracer).
If we want to trace "sched:sched_switch" to trace sched_switch func, We may utilize event option.(e.g: trace-cmd list -e | grep sched) This patch is based on Linux-3.3.rc2-SMP-PREEMPT

Link http://lkml.kernel.org/r/[email protected] open here

Cc Randy Dunlap <[email protected]>

Signed-off-by Geunsik Lim <[email protected]>

Signed-off-by Steven Rostedt <[email protected]>

---
 kernel/trace/trace.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

kernel/trace/trace.c +3 -3

index a3f1bc5..10d5503 100644
@@ -2764,12 +2764,12 @@ static const char readme_msg[] =
 	"tracing mini-HOWTO:\n\n"
 	"# mount -t debugfs nodev /sys/kernel/debug\n\n"
 	"# cat /sys/kernel/debug/tracing/available_tracers\n"
-	"wakeup preemptirqsoff preemptoff irqsoff function sched_switch nop\n\n"
+	"wakeup wakeup_rt preemptirqsoff preemptoff irqsoff function nop\n\n"
 	"# cat /sys/kernel/debug/tracing/current_tracer\n"
 	"nop\n"
-	"# echo sched_switch > /sys/kernel/debug/tracing/current_tracer\n"
+	"# echo wakeup > /sys/kernel/debug/tracing/current_tracer\n"
 	"# cat /sys/kernel/debug/tracing/current_tracer\n"
-	"sched_switch\n"
+	"wakeup\n"
 	"# cat /sys/kernel/debug/tracing/trace_options\n"
 	"noprint-parent nosym-offset nosym-addr noverbose\n"
 	"# echo print-parent > /sys/kernel/debug/tracing/trace_options\n"

Signature · 1 line

1.7.8.3

Steven Rostedt

author maintainer

2012-02-14 03:40 UTC #7 lore raw

PATCH 7/9 ftrace: Append wakeup_rt description of ftrace doc

In reply to Steven Rostedt

From: Geunsik Lim <[email protected]>

Append and update the description about wakeup/wakeup_rt usage.

Link http://lkml.kernel.org/r/[email protected] open here

Cc Randy Dunlap <[email protected]>

Signed-off-by Geunsik Lim <[email protected]>

Signed-off-by Steven Rostedt <[email protected]>

---
 Documentation/trace/ftrace.txt |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

Documentation/trace/ftrace.txt +7 -0

index 1ebc24c..6f51fed 100644
@@ -226,6 +226,13 @@ Here is the list of current tracers that may be configured.
 	Traces and records the max latency that it takes for
 	the highest priority task to get scheduled after
 	it has been woken up.
+        Traces all tasks as an average developer would expect.
+
+  "wakeup_rt"
+
+        Traces and records the max latency that it takes for just
+        RT tasks (as the current "wakeup" does). This is useful
+        for those interested in wake up timings of RT tasks.
 
   "hw-branch-tracer"

Signature · 1 line

1.7.8.3

Steven Rostedt

author maintainer

2012-02-14 03:40 UTC #8 lore raw

PATCH 8/9 printk/tracing: Add console output tracing

In reply to Steven Rostedt

From: Johannes Berg <[email protected]>

Add a printk.console trace point to record any printk messages into the trace, regardless of the current console loglevel. This can help correlate (existing) printk debugging with other tracing.

Link http://lkml.kernel.org/r/[email protected] open here

Acked-by Frederic Weisbecker <[email protected]>

Cc Christoph Hellwig <[email protected]>

Cc Ingo Molnar <[email protected]>

Acked-by Peter Zijlstra <[email protected]>

Acked-by Thomas Gleixner <[email protected]>

Signed-off-by Johannes Berg <[email protected]>

Signed-off-by Steven Rostedt <[email protected]>

---
 include/trace/events/printk.h |   41 +++++++++++++++++++++++++++++++++++++++++
 kernel/printk.c               |    5 +++++
 2 files changed, 46 insertions(+), 0 deletions(-)
 create mode 100644 include/trace/events/printk.h

include/trace/events/printk.h new file +41 -0

new file mode 100644
index 0000000..94ec79c
@@ -0,0 +1,41 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM printk
+
+#if !defined(_TRACE_PRINTK_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_PRINTK_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT_CONDITION(console,
+	TP_PROTO(const char *log_buf, unsigned start, unsigned end,
+		 unsigned log_buf_len),
+
+	TP_ARGS(log_buf, start, end, log_buf_len),
+
+	TP_CONDITION(start != end),
+
+	TP_STRUCT__entry(
+		__dynamic_array(char, msg, end - start + 1)
+	),
+
+	TP_fast_assign(
+		if ((start & (log_buf_len - 1)) > (end & (log_buf_len - 1))) {
+			memcpy(__get_dynamic_array(msg),
+			       log_buf + (start & (log_buf_len - 1)),
+			       log_buf_len - (start & (log_buf_len - 1)));
+			memcpy((char *)__get_dynamic_array(msg) +
+			       log_buf_len - (start & (log_buf_len - 1)),
+			       log_buf, end & (log_buf_len - 1));
+		} else
+			memcpy(__get_dynamic_array(msg),
+			       log_buf + (start & (log_buf_len - 1)),
+			       end - start);
+		((char *)__get_dynamic_array(msg))[end - start] = 0;
+	),
+
+	TP_printk("%s", __get_str(msg))
+);
+#endif /* _TRACE_PRINTK_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>

kernel/printk.c +5 -0

index 13c0a11..cb8a6bd 100644
@@ -44,6 +44,9 @@
 
 #include <asm/uaccess.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/printk.h>
+
 /*
  * Architectures can override it:
  */

@@ -542,6 +545,8 @@ MODULE_PARM_DESC(ignore_loglevel, "ignore loglevel setting, to"
 static void _call_console_drivers(unsigned start,
 				unsigned end, int msg_log_level)
 {
+	trace_console(&LOG_BUF(0), start, end, log_buf_len);
+
 	if ((msg_log_level < console_loglevel || ignore_loglevel) &&
 			console_drivers && start != end) {
 		if ((start & LOG_BUF_MASK) > (end & LOG_BUF_MASK)) {

Signature · 1 line

1.7.8.3

Steven Rostedt

author maintainer

2012-02-14 03:41 UTC #9 lore raw

PATCH 9/9 tracing/trivial: Use kcalloc instead of kzalloc to allocate array

In reply to Steven Rostedt

From: Thomas Meyer <[email protected]>

The advantage of kcalloc is, that will prevent integer overflows which could result from the multiplication of number of elements and size and it is also a bit nicer to read.

The semantic patch that makes this change is available in https://lkml.org/lkml/2011/11/25/107

Link http://lkml.kernel.org/r/[email protected] open here

Signed-off-by Thomas Meyer <[email protected]>

Signed-off-by Steven Rostedt <[email protected]>

---
 kernel/trace/ftrace.c              |    2 +-
 kernel/trace/trace_events_filter.c |    7 +++----
 kernel/trace/trace_syscalls.c      |    4 ++--
 3 files changed, 6 insertions(+), 7 deletions(-)

kernel/trace/ftrace.c +1 -1

index e2e0597..d1499e9 100644
@@ -1129,7 +1129,7 @@ static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
 		return NULL;
 
 	size = 1 << size_bits;
-	hash->buckets = kzalloc(sizeof(*hash->buckets) * size, GFP_KERNEL);
+	hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
 
 	if (!hash->buckets) {
 		kfree(hash);

kernel/trace/trace_events_filter.c +3 -4

index 24aee71..76afaee 100644
@@ -685,7 +685,7 @@ find_event_field(struct ftrace_event_call *call, char *name)
 
 static int __alloc_pred_stack(struct pred_stack *stack, int n_preds)
 {
-	stack->preds = kzalloc(sizeof(*stack->preds)*(n_preds + 1), GFP_KERNEL);
+	stack->preds = kcalloc(n_preds + 1, sizeof(*stack->preds), GFP_KERNEL);
 	if (!stack->preds)
 		return -ENOMEM;
 	stack->index = n_preds;

@@ -826,8 +826,7 @@ static int __alloc_preds(struct event_filter *filter, int n_preds)
 	if (filter->preds)
 		__free_preds(filter);
 
-	filter->preds =
-		kzalloc(sizeof(*filter->preds) * n_preds, GFP_KERNEL);
+	filter->preds = kcalloc(n_preds, sizeof(*filter->preds), GFP_KERNEL);
 
 	if (!filter->preds)
 		return -ENOMEM;

@@ -1486,7 +1485,7 @@ static int fold_pred(struct filter_pred *preds, struct filter_pred *root)
 	children = count_leafs(preds, &preds[root->left]);
 	children += count_leafs(preds, &preds[root->right]);
 
-	root->ops = kzalloc(sizeof(*root->ops) * children, GFP_KERNEL);
+	root->ops = kcalloc(children, sizeof(*root->ops), GFP_KERNEL);
 	if (!root->ops)
 		return -ENOMEM;

kernel/trace/trace_syscalls.c +2 -2

index cb65454..4350015 100644
@@ -468,8 +468,8 @@ int __init init_ftrace_syscalls(void)
 	unsigned long addr;
 	int i;
 
-	syscalls_metadata = kzalloc(sizeof(*syscalls_metadata) *
-					NR_syscalls, GFP_KERNEL);
+	syscalls_metadata = kcalloc(NR_syscalls, sizeof(*syscalls_metadata),
+				    GFP_KERNEL);
 	if (!syscalls_metadata) {
 		WARN_ON(1);
 		return -ENOMEM;

Signature · 1 line

1.7.8.3