[for-next][PATCH 0/5] tracing: More updates for 3.13

[for-next][PATCH 0/5] tracing: More updates for 3.13

[Steven Rostedt]

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
for-next

Head SHA1: 20b72e76c42bc4f0dd091f9faee542ea45ad6b5e


Cody P Schafer (1):
      tracing: Open tracer when ftrace_dump_on_oops is used

Geyslan G. Bem (2):
      tracing: Add helper function tracing_is_disabled()
      tracing: Do not assign filp->private_data to freed memory

Steven Rostedt (1):
      Merge branch 'trace/ftrace/core' into trace/for-next

Steven Rostedt (Red Hat) (2):
      tracing: Remove unused function ftrace_off_permanent()
      tracing: Do not use signed enums with unsigned long long in fgragh output

----
 include/linux/kernel.h               |  2 --
 kernel/trace/trace.c                 | 31 ++++++++++++++++---------------
 kernel/trace/trace.h                 |  3 +++
 kernel/trace/trace_events.c          |  9 ++++++++-
 kernel/trace/trace_functions_graph.c | 22 +++++++++++-----------
 5 files changed, 38 insertions(+), 29 deletions(-)

[for-next][PATCH 1/5] tracing: Open tracer when ftrace_dump_on_oops is used

[Steven Rostedt]

[-- Attachment #1: 0001-tracing-Open-tracer-when-ftrace_dump_on_oops-is-used.patch --]
[-- Type: text/plain, Size: 1571 bytes --]

From: Cody P Schafer <cody@linux.vnet.ibm.com>

With ftrace_dump_on_oops, we previously did not open the tracer in
question, sometimes causing the trace output to be useless.

For example, the function_graph tracer with tracing_thresh set dumped via
ftrace_dump_on_oops would show a series of '}' indented at different levels,
but no function names.

call trace->open() (and do a few other fixups copied from the normal dump
path) to make the output more intelligible.

Link: http://lkml.kernel.org/r/1382554197-16961-1-git-send-email-cody@linux.vnet.ibm.com

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/trace.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index f9fa42b..eaacd3a 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -6276,6 +6276,17 @@ void trace_init_global_iter(struct trace_iterator *iter)
 	iter->trace = iter->tr->current_trace;
 	iter->cpu_file = RING_BUFFER_ALL_CPUS;
 	iter->trace_buffer = &global_trace.trace_buffer;
+
+	if (iter->trace && iter->trace->open)
+		iter->trace->open(iter);
+
+	/* Annotate start of buffers if we had overruns */
+	if (ring_buffer_overruns(iter->trace_buffer->buffer))
+		iter->iter_flags |= TRACE_FILE_ANNOTATE;
+
+	/* Output in nanoseconds only if we are using a clock in nanoseconds. */
+	if (trace_clocks[iter->tr->clock_id].in_ns)
+		iter->iter_flags |= TRACE_FILE_TIME_IN_NS;
 }
 
 void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
-- 
1.8.4.rc3

[for-next][PATCH 2/5] tracing: Add helper function tracing_is_disabled()

[Steven Rostedt]

[-- Attachment #1: 0002-tracing-Add-helper-function-tracing_is_disabled.patch --]
[-- Type: text/plain, Size: 1368 bytes --]

From: "Geyslan G. Bem" <geyslan@gmail.com>

This patch creates the function 'tracing_is_disabled', which
can be used outside of trace.c.

Link: http://lkml.kernel.org/r/1382141754-12155-1-git-send-email-geyslan@gmail.com

Signed-off-by: Geyslan G. Bem <geyslan@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/trace.c | 5 +++++
 kernel/trace/trace.h | 1 +
 2 files changed, 6 insertions(+)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index eaacd3a..2a595cf 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2987,6 +2987,11 @@ int tracing_open_generic(struct inode *inode, struct file *filp)
 	return 0;
 }
 
+bool tracing_is_disabled(void)
+{
+	return (tracing_disabled) ? true: false;
+}
+
 /*
  * Open and update trace_array ref count.
  * Must have the current trace_array passed to it.
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 9c27cda..4388e16 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -514,6 +514,7 @@ void tracing_reset_online_cpus(struct trace_buffer *buf);
 void tracing_reset_current(int cpu);
 void tracing_reset_all_online_cpus(void);
 int tracing_open_generic(struct inode *inode, struct file *filp);
+bool tracing_is_disabled(void);
 struct dentry *trace_create_file(const char *name,
 				 umode_t mode,
 				 struct dentry *parent,
-- 
1.8.4.rc3

[for-next][PATCH 3/5] tracing: Do not assign filp->private_data to freed memory

[Steven Rostedt]

[-- Attachment #1: 0003-tracing-Do-not-assign-filp-private_data-to-freed-mem.patch --]
[-- Type: text/plain, Size: 1789 bytes --]

From: "Geyslan G. Bem" <geyslan@gmail.com>

In system_tr_open(), the filp->private_data can be assigned the 'dir'
variable even if it was freed. This is on the error path, and is
harmless because the error return code will prevent filp->private_data
from being used. But for correctness, we should not assign it to
a recently freed variable, as that can cause static tools to give
false warnings.

Also have both subsystem_open() and system_tr_open() return -ENODEV
if tracing has been disabled.

Link: http://lkml.kernel.org/r/1383764571-7318-1-git-send-email-geyslan@gmail.com

Signed-off-by: Geyslan G. Bem <geyslan@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/trace_events.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 043f833..f919a2e 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1062,6 +1062,9 @@ static int subsystem_open(struct inode *inode, struct file *filp)
 	struct trace_array *tr;
 	int ret;
 
+	if (tracing_is_disabled())
+		return -ENODEV;
+
 	/* Make sure the system still exists */
 	mutex_lock(&trace_types_lock);
 	mutex_lock(&event_mutex);
@@ -1108,6 +1111,9 @@ static int system_tr_open(struct inode *inode, struct file *filp)
 	struct trace_array *tr = inode->i_private;
 	int ret;
 
+	if (tracing_is_disabled())
+		return -ENODEV;
+
 	if (trace_array_get(tr) < 0)
 		return -ENODEV;
 
@@ -1124,11 +1130,12 @@ static int system_tr_open(struct inode *inode, struct file *filp)
 	if (ret < 0) {
 		trace_array_put(tr);
 		kfree(dir);
+		return ret;
 	}
 
 	filp->private_data = dir;
 
-	return ret;
+	return 0;
 }
 
 static int subsystem_release(struct inode *inode, struct file *file)
-- 
1.8.4.rc3

[for-next][PATCH 4/5] tracing: Remove unused function ftrace_off_permanent()

[Steven Rostedt]

[-- Attachment #1: 0004-tracing-Remove-unused-function-ftrace_off_permanent.patch --]
[-- Type: text/plain, Size: 1934 bytes --]

From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>

In the past, ftrace_off_permanent() was called if something
strange was detected. But the ftrace_bug() now handles all the
anomolies that can happen with ftrace (function tracing), and there
are no uses of ftrace_off_permanent(). Get rid of it.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 include/linux/kernel.h |  2 --
 kernel/trace/trace.c   | 15 ---------------
 2 files changed, 17 deletions(-)

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 672ddc4..d4e98d1 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -501,7 +501,6 @@ void tracing_snapshot_alloc(void);
 
 extern void tracing_start(void);
 extern void tracing_stop(void);
-extern void ftrace_off_permanent(void);
 
 static inline __printf(1, 2)
 void ____trace_printk_check_format(const char *fmt, ...)
@@ -639,7 +638,6 @@ extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
 #else
 static inline void tracing_start(void) { }
 static inline void tracing_stop(void) { }
-static inline void ftrace_off_permanent(void) { }
 static inline void trace_dump_stack(int skip) { }
 
 static inline void tracing_on(void) { }
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 2a595cf..d72a15c 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1284,21 +1284,6 @@ int is_tracing_stopped(void)
 }
 
 /**
- * ftrace_off_permanent - disable all ftrace code permanently
- *
- * This should only be called when a serious anomally has
- * been detected.  This will turn off the function tracing,
- * ring buffers, and other tracing utilites. It takes no
- * locks and can be called from any context.
- */
-void ftrace_off_permanent(void)
-{
-	tracing_disabled = 1;
-	ftrace_stop();
-	tracing_off_permanent();
-}
-
-/**
  * tracing_start - quick start of the tracer
  *
  * If tracing is enabled but was stopped by tracing_stop,
-- 
1.8.4.rc3

[for-next][PATCH 5/5] tracing: Do not use signed enums with unsigned long long in fgragh output

[Steven Rostedt]

[-- Attachment #1: 0005-tracing-Do-not-use-signed-enums-with-unsigned-long-l.patch --]
[-- Type: text/plain, Size: 4055 bytes --]

From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>

The duration field of print_graph_duration() can also be used
to do the space filling by passing an enum in it:

  DURATION_FILL_FULL
  DURATION_FILL_START
  DURATION_FILL_END

The problem is that these are enums and defined as negative,
but the duration field is unsigned long long. Most archs are
fine with this but blackfin fails to compile because of it:

kernel/built-in.o: In function `print_graph_duration':
kernel/trace/trace_functions_graph.c:782: undefined reference to `__ucmpdi2'

Overloading a unsigned long long with an signed enum is just
bad in principle. We can accomplish the same thing by using
part of the flags field instead.

Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/trace.h                 |  2 ++
 kernel/trace/trace_functions_graph.c | 22 +++++++++++-----------
 2 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 4388e16..11a04d6 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -712,6 +712,8 @@ extern unsigned long trace_flags;
 #define TRACE_GRAPH_PRINT_PROC          0x8
 #define TRACE_GRAPH_PRINT_DURATION      0x10
 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
+#define TRACE_GRAPH_PRINT_FILL_SHIFT	28
+#define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
 
 extern enum print_line_t
 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 80387d1..0b99120 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -82,9 +82,9 @@ static struct trace_array *graph_array;
  * to fill in space into DURATION column.
  */
 enum {
-	DURATION_FILL_FULL  = -1,
-	DURATION_FILL_START = -2,
-	DURATION_FILL_END   = -3,
+	FLAGS_FILL_FULL  = 1 << TRACE_GRAPH_PRINT_FILL_SHIFT,
+	FLAGS_FILL_START = 2 << TRACE_GRAPH_PRINT_FILL_SHIFT,
+	FLAGS_FILL_END   = 3 << TRACE_GRAPH_PRINT_FILL_SHIFT,
 };
 
 static enum print_line_t
@@ -702,7 +702,7 @@ print_graph_irq(struct trace_iterator *iter, unsigned long addr,
 	}
 
 	/* No overhead */
-	ret = print_graph_duration(DURATION_FILL_START, s, flags);
+	ret = print_graph_duration(0, s, flags | FLAGS_FILL_START);
 	if (ret != TRACE_TYPE_HANDLED)
 		return ret;
 
@@ -714,7 +714,7 @@ print_graph_irq(struct trace_iterator *iter, unsigned long addr,
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
-	ret = print_graph_duration(DURATION_FILL_END, s, flags);
+	ret = print_graph_duration(0, s, flags | FLAGS_FILL_END);
 	if (ret != TRACE_TYPE_HANDLED)
 		return ret;
 
@@ -779,14 +779,14 @@ print_graph_duration(unsigned long long duration, struct trace_seq *s,
 			return TRACE_TYPE_HANDLED;
 
 	/* No real adata, just filling the column with spaces */
-	switch (duration) {
-	case DURATION_FILL_FULL:
+	switch (flags & TRACE_GRAPH_PRINT_FILL_MASK) {
+	case FLAGS_FILL_FULL:
 		ret = trace_seq_puts(s, "              |  ");
 		return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
-	case DURATION_FILL_START:
+	case FLAGS_FILL_START:
 		ret = trace_seq_puts(s, "  ");
 		return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
-	case DURATION_FILL_END:
+	case FLAGS_FILL_END:
 		ret = trace_seq_puts(s, " |");
 		return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
 	}
@@ -902,7 +902,7 @@ print_graph_entry_nested(struct trace_iterator *iter,
 	}
 
 	/* No time */
-	ret = print_graph_duration(DURATION_FILL_FULL, s, flags);
+	ret = print_graph_duration(0, s, flags | FLAGS_FILL_FULL);
 	if (ret != TRACE_TYPE_HANDLED)
 		return ret;
 
@@ -1222,7 +1222,7 @@ print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
 		return TRACE_TYPE_PARTIAL_LINE;
 
 	/* No time */
-	ret = print_graph_duration(DURATION_FILL_FULL, s, flags);
+	ret = print_graph_duration(0, s, flags | FLAGS_FILL_FULL);
 	if (ret != TRACE_TYPE_HANDLED)
 		return ret;
 
-- 
1.8.4.rc3