[PATCH 0/2] [GIT PULL] tracing: more updates for 2.6.36

[PATCH 0/2] [GIT PULL] tracing: more updates for 2.6.36

[Steven Rostedt]

Ingo,

These changes are on top of my previous pull request.

Also, I notice that a fix that did not make the 35-rc never got
into tip. This is the "FORMAT TOO BIG" that the scsi events output.
And I do not want another major release to have this bug in it.

Please pull the latest tip/perf/urgent-2 tree, which can be found at:

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git
tip/perf/urgent-2


Mike Frysinger (1):
      tracing: Extend recordmcount to better support Blackfin mcount

Steven Rostedt (1):
      tracing/events: Convert format output to seq_file

----
 kernel/trace/trace_events.c |  208 +++++++++++++++++++++++++++++--------------
 scripts/recordmcount.pl     |    7 ++-
 2 files changed, 147 insertions(+), 68 deletions(-)

[PATCH 1/2] tracing: Extend recordmcount to better support Blackfin mcount

[Steven Rostedt]

[-- Attachment #1: 0001-tracing-Extend-recordmcount-to-better-support-Blackf.patch --]
[-- Type: text/plain, Size: 2083 bytes --]

From: Mike Frysinger <vapier@gentoo.org>

The mcount call on Blackfin systems includes some stack manipulation
around the actual call site, so extend the build time perl script to
support this.  This way we can avoid doing the calculation at runtime.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
LKML-Reference: <1281079584-21205-1-git-send-email-vapier@gentoo.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 scripts/recordmcount.pl |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)

diff --git a/scripts/recordmcount.pl b/scripts/recordmcount.pl
index f3c9c0a..2c56539 100755
--- a/scripts/recordmcount.pl
+++ b/scripts/recordmcount.pl
@@ -159,6 +159,7 @@ my $section_regex;	# Find the start of a section
 my $function_regex;	# Find the name of a function
 			#    (return offset and func name)
 my $mcount_regex;	# Find the call site to mcount (return offset)
+my $mcount_adjust;	# Address adjustment to mcount offset
 my $alignment;		# The .align value to use for $mcount_section
 my $section_type;	# Section header plus possible alignment command
 my $can_use_local = 0; 	# If we can use local function references
@@ -213,6 +214,7 @@ $section_regex = "Disassembly of section\\s+(\\S+):";
 $function_regex = "^([0-9a-fA-F]+)\\s+<(.*?)>:";
 $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\smcount\$";
 $section_type = '@progbits';
+$mcount_adjust = 0;
 $type = ".long";
 
 if ($arch eq "x86_64") {
@@ -351,6 +353,9 @@ if ($arch eq "x86_64") {
 } elsif ($arch eq "microblaze") {
     # Microblaze calls '_mcount' instead of plain 'mcount'.
     $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s_mcount\$";
+} elsif ($arch eq "blackfin") {
+    $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s__mcount\$";
+    $mcount_adjust = -4;
 } else {
     die "Arch $arch is not supported with CONFIG_FTRACE_MCOUNT_RECORD";
 }
@@ -511,7 +516,7 @@ while (<IN>) {
     }
     # is this a call site to mcount? If so, record it to print later
     if ($text_found && /$mcount_regex/) {
-	push(@offsets, hex $1);
+	push(@offsets, (hex $1) + $mcount_adjust);
     }
 }
 
-- 
1.7.1

[PATCH 2/2] tracing/events: Convert format output to seq_file

[Steven Rostedt]

[-- Attachment #1: 0002-tracing-events-Convert-format-output-to-seq_file.patch --]
[-- Type: text/plain, Size: 7295 bytes --]

From: Steven Rostedt <srostedt@redhat.com>

Two new events were added that broke the current format output.

Both from the SCSI system: scsi_dispatch_cmd_done and scsi_dispatch_cmd_timeout

The reason is that their print_fmt exceeded a page size. Since the output
of the format used simple_read_from_buffer and trace_seq, it was limited
to a page size in output.

This patch converts the printing of the format of an event into seq_file,
which allows greater than a page size to be shown.

I diffed all event formats comparing the output with and without this
patch. All matched except for the above two, which showed just:

  FORMAT TOO BIG

without this patch, but now properly displays the output with this patch.

v2: Remove updating *pos in seq start function.
   [ Thanks to Li Zefan for pointing that out ]

Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Kei Tokunaga <tokunaga.keiich@jp.fujitsu.com>
Cc: James Bottomley <James.Bottomley@suse.de>
Cc: Tomohiro Kusumi <kusumi.tomohiro@jp.fujitsu.com>
Cc: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/trace_events.c |  208 +++++++++++++++++++++++++++++--------------
 1 files changed, 141 insertions(+), 67 deletions(-)

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 53cffc0..45a8968 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -29,6 +29,8 @@ DEFINE_MUTEX(event_mutex);
 
 LIST_HEAD(ftrace_events);
 
+#define COMMON_FIELD_COUNT	5
+
 struct list_head *
 trace_get_fields(struct ftrace_event_call *event_call)
 {
@@ -544,85 +546,155 @@ out:
 	return ret;
 }
 
-static ssize_t
-event_format_read(struct file *filp, char __user *ubuf, size_t cnt,
-		  loff_t *ppos)
+enum {
+	FORMAT_HEADER		= 1,
+	FORMAT_PRINTFMT		= 2,
+};
+
+static void *f_next(struct seq_file *m, void *v, loff_t *pos)
 {
-	struct ftrace_event_call *call = filp->private_data;
+	struct ftrace_event_call *call = m->private;
 	struct ftrace_event_field *field;
 	struct list_head *head;
-	struct trace_seq *s;
-	int common_field_count = 5;
-	char *buf;
-	int r = 0;
-
-	if (*ppos)
-		return 0;
+	loff_t index = *pos;
 
-	s = kmalloc(sizeof(*s), GFP_KERNEL);
-	if (!s)
-		return -ENOMEM;
+	(*pos)++;
 
-	trace_seq_init(s);
+	head = trace_get_fields(call);
 
-	trace_seq_printf(s, "name: %s\n", call->name);
-	trace_seq_printf(s, "ID: %d\n", call->event.type);
-	trace_seq_printf(s, "format:\n");
+	switch ((unsigned long)v) {
+	case FORMAT_HEADER:
 
-	head = trace_get_fields(call);
-	list_for_each_entry_reverse(field, head, link) {
-		/*
-		 * Smartly shows the array type(except dynamic array).
-		 * Normal:
-		 *	field:TYPE VAR
-		 * If TYPE := TYPE[LEN], it is shown:
-		 *	field:TYPE VAR[LEN]
-		 */
-		const char *array_descriptor = strchr(field->type, '[');
-
-		if (!strncmp(field->type, "__data_loc", 10))
-			array_descriptor = NULL;
-
-		if (!array_descriptor) {
-			r = trace_seq_printf(s, "\tfield:%s %s;\toffset:%u;"
-					"\tsize:%u;\tsigned:%d;\n",
-					field->type, field->name, field->offset,
-					field->size, !!field->is_signed);
-		} else {
-			r = trace_seq_printf(s, "\tfield:%.*s %s%s;\toffset:%u;"
-					"\tsize:%u;\tsigned:%d;\n",
-					(int)(array_descriptor - field->type),
-					field->type, field->name,
-					array_descriptor, field->offset,
-					field->size, !!field->is_signed);
-		}
+		if (unlikely(list_empty(head)))
+			return NULL;
 
-		if (--common_field_count == 0)
-			r = trace_seq_printf(s, "\n");
+		field = list_entry(head->prev, struct ftrace_event_field, link);
+		return field;
 
-		if (!r)
-			break;
+	case FORMAT_PRINTFMT:
+		/* all done */
+		return NULL;
 	}
 
-	if (r)
-		r = trace_seq_printf(s, "\nprint fmt: %s\n",
-				call->print_fmt);
+	/*
+	 * To separate common fields from event fields, the
+	 * LSB is set on the first event field. Clear it in case.
+	 */
+	v = (void *)((unsigned long)v & ~1L);
 
-	if (!r) {
-		/*
-		 * ug!  The format output is bigger than a PAGE!!
-		 */
-		buf = "FORMAT TOO BIG\n";
-		r = simple_read_from_buffer(ubuf, cnt, ppos,
-					      buf, strlen(buf));
-		goto out;
+	field = v;
+	if (field->link.prev == head)
+		return (void *)FORMAT_PRINTFMT;
+
+	field = list_entry(field->link.prev, struct ftrace_event_field, link);
+
+	/* Set the LSB to notify f_show to print an extra newline */
+	if (index == COMMON_FIELD_COUNT)
+		field = (struct ftrace_event_field *)
+			((unsigned long)field | 1);
+
+	return field;
+}
+
+static void *f_start(struct seq_file *m, loff_t *pos)
+{
+	loff_t l = 0;
+	void *p;
+
+	/* Start by showing the header */
+	if (!*pos)
+		return (void *)FORMAT_HEADER;
+
+	p = (void *)FORMAT_HEADER;
+	do {
+		p = f_next(m, p, &l);
+	} while (p && l < *pos);
+
+	return p;
+}
+
+static int f_show(struct seq_file *m, void *v)
+{
+	struct ftrace_event_call *call = m->private;
+	struct ftrace_event_field *field;
+	const char *array_descriptor;
+
+	switch ((unsigned long)v) {
+	case FORMAT_HEADER:
+		seq_printf(m, "name: %s\n", call->name);
+		seq_printf(m, "ID: %d\n", call->event.type);
+		seq_printf(m, "format:\n");
+		return 0;
+
+	case FORMAT_PRINTFMT:
+		seq_printf(m, "\nprint fmt: %s\n",
+			   call->print_fmt);
+		return 0;
 	}
 
-	r = simple_read_from_buffer(ubuf, cnt, ppos,
-				    s->buffer, s->len);
- out:
-	kfree(s);
-	return r;
+	/*
+	 * To separate common fields from event fields, the
+	 * LSB is set on the first event field. Clear it and
+	 * print a newline if it is set.
+	 */
+	if ((unsigned long)v & 1) {
+		seq_putc(m, '\n');
+		v = (void *)((unsigned long)v & ~1L);
+	}
+
+	field = v;
+
+	/*
+	 * Smartly shows the array type(except dynamic array).
+	 * Normal:
+	 *	field:TYPE VAR
+	 * If TYPE := TYPE[LEN], it is shown:
+	 *	field:TYPE VAR[LEN]
+	 */
+	array_descriptor = strchr(field->type, '[');
+
+	if (!strncmp(field->type, "__data_loc", 10))
+		array_descriptor = NULL;
+
+	if (!array_descriptor)
+		seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
+			   field->type, field->name, field->offset,
+			   field->size, !!field->is_signed);
+	else
+		seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
+			   (int)(array_descriptor - field->type),
+			   field->type, field->name,
+			   array_descriptor, field->offset,
+			   field->size, !!field->is_signed);
+
+	return 0;
+}
+
+static void f_stop(struct seq_file *m, void *p)
+{
+}
+
+static const struct seq_operations trace_format_seq_ops = {
+	.start		= f_start,
+	.next		= f_next,
+	.stop		= f_stop,
+	.show		= f_show,
+};
+
+static int trace_format_open(struct inode *inode, struct file *file)
+{
+	struct ftrace_event_call *call = inode->i_private;
+	struct seq_file *m;
+	int ret;
+
+	ret = seq_open(file, &trace_format_seq_ops);
+	if (ret < 0)
+		return ret;
+
+	m = file->private_data;
+	m->private = call;
+
+	return 0;
 }
 
 static ssize_t
@@ -820,8 +892,10 @@ static const struct file_operations ftrace_enable_fops = {
 };
 
 static const struct file_operations ftrace_event_format_fops = {
-	.open = tracing_open_generic,
-	.read = event_format_read,
+	.open = trace_format_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = seq_release,
 };
 
 static const struct file_operations ftrace_event_id_fops = {
-- 
1.7.1