[PATCH] ftrace: fix trace_marker output

[PATCH] ftrace: fix trace_marker output

[Carsten Emde]

When a string was written to <debugfs>/tracing/trace_marker, some
strange characters appeared in the trace output instead of the
string, since a vprint function erroneously called a vararg print
function with a va_list argument. This patch fixes the problem and
simplifies the related code.

Signed-off-by: Carsten Emde <C.Emde@osadl.org>

Index: linux-2.6.31.6-rt19/kernel/trace/trace.c
===================================================================
--- linux-2.6.31.6-rt19.orig/kernel/trace/trace.c
+++ linux-2.6.31.6-rt19/kernel/trace/trace.c
@@ -1376,10 +1376,11 @@ int trace_array_vprintk(struct trace_arr
 	pause_graph_tracing();
 	raw_local_irq_save(irq_flags);
 	__raw_spin_lock(&trace_buf_lock);
-	len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
-
-	len = min(len, TRACE_BUF_SIZE-1);
-	trace_buf[len] = 0;
+	if (args == NULL) {
+		strncpy(trace_buf, fmt, TRACE_BUF_SIZE);
+		len = strlen(trace_buf);
+	} else
+		len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
 
 	size = sizeof(*entry) + len + 1;
 	buffer = tr->buffer;
@@ -1388,10 +1389,10 @@ int trace_array_vprintk(struct trace_arr
 	if (!event)
 		goto out_unlock;
 	entry = ring_buffer_event_data(event);
-	entry->ip			= ip;
+	entry->ip = ip;
 
 	memcpy(&entry->buf, trace_buf, len);
-	entry->buf[len] = 0;
+	entry->buf[len] = '\0';
 	if (!filter_check_discard(call, entry, buffer, event))
 		ring_buffer_unlock_commit(buffer, event);
 
@@ -1408,7 +1409,7 @@ int trace_array_vprintk(struct trace_arr
 
 int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
 {
-	return trace_array_printk(&global_trace, ip, fmt, args);
+	return trace_array_vprintk(&global_trace, ip, fmt, args);
 }
 EXPORT_SYMBOL_GPL(trace_vprintk);
 
@@ -3336,22 +3337,11 @@ tracing_entries_write(struct file *filp,
 	return cnt;
 }
 
-static int mark_printk(const char *fmt, ...)
-{
-	int ret;
-	va_list args;
-	va_start(args, fmt);
-	ret = trace_vprintk(0, fmt, args);
-	va_end(args);
-	return ret;
-}
-
 static ssize_t
 tracing_mark_write(struct file *filp, const char __user *ubuf,
 					size_t cnt, loff_t *fpos)
 {
 	char *buf;
-	char *end;
 
 	if (tracing_disabled)
 		return -EINVAL;
@@ -3359,7 +3349,7 @@ tracing_mark_write(struct file *filp, co
 	if (cnt > TRACE_BUF_SIZE)
 		cnt = TRACE_BUF_SIZE;
 
-	buf = kmalloc(cnt + 1, GFP_KERNEL);
+	buf = kmalloc(cnt + 2, GFP_KERNEL);
 	if (buf == NULL)
 		return -ENOMEM;
 
@@ -3367,14 +3357,13 @@ tracing_mark_write(struct file *filp, co
 		kfree(buf);
 		return -EFAULT;
 	}
+	if (buf[cnt-1] != '\n') {
+		buf[cnt] = '\n';
+		buf[cnt+1] = '\0';
+	} else
+		buf[cnt] = '\0';
 
-	/* Cut from the first nil or newline. */
-	buf[cnt] = '\0';
-	end = strchr(buf, '\n');
-	if (end)
-		*end = '\0';
-
-	cnt = mark_printk("%s\n", buf);
+	cnt = trace_vprintk(0, buf, NULL);
 	kfree(buf);
 	*fpos += cnt;
 

Re: [PATCH] ftrace: fix trace_marker output

[Steven Rostedt]

On Mon, 2009-11-16 at 20:56 +0100, Carsten Emde wrote:
> When a string was written to <debugfs>/tracing/trace_marker, some
> strange characters appeared in the trace output instead of the
> string, since a vprint function erroneously called a vararg print
> function with a va_list argument. This patch fixes the problem and
> simplifies the related code.
> 
> Signed-off-by: Carsten Emde <C.Emde@osadl.org>

Thanks Carsten! I'll pull this in. Perhaps this should go into 32.

-- Steve

Re: [PATCH] ftrace: fix trace_marker output

[Steven Rostedt]

On Mon, 2009-11-16 at 20:56 +0100, Carsten Emde wrote:
>  
> @@ -1408,7 +1409,7 @@ int trace_array_vprintk(struct trace_arr
>  
>  int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
>  {
> -	return trace_array_printk(&global_trace, ip, fmt, args);
> +	return trace_array_vprintk(&global_trace, ip, fmt, args);
>  }
>  EXPORT_SYMBOL_GPL(trace_vprintk);

Applying the patch, I found that this part is already fixed upstream.
But I'll add the rest of your patch since it does have other fixes.

Thanks,

-- Steve

[PATCH][GIT PULL][v2.6.32] tracing: Fix trace_marker output

[Steven Rostedt]

Ingo,

Think we may be able to slip this into 32?

Please pull the latest tip/tracing/urgent tree, which can be found at:

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


Carsten Emde (1):
      tracing: Fix trace_marker output

----
 kernel/trace/trace.c |   39 ++++++++++++++-------------------------
 1 files changed, 14 insertions(+), 25 deletions(-)
---------------------------
commit c13d2f7c3231e873f30db92b96c8caa48f100f33
Author: Carsten Emde <Carsten.Emde@osadl.org>
Date:   Mon Nov 16 20:56:13 2009 +0100

    tracing: Fix trace_marker output
    
    When a string was written to <debugfs>/tracing/trace_marker, some
    strange characters appeared in the trace output instead of the
    string, since a vprint function erroneously called a vararg print
    function with a va_list argument. This patch fixes the problem and
    simplifies the related code.
    
    Signed-off-by: Carsten Emde <C.Emde@osadl.org>
    LKML-Reference: <4B01AE5D.1010801@osadl.org>
    Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 03c7fd5..12b49ca 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1361,10 +1361,11 @@ int trace_array_vprintk(struct trace_array *tr,
 	pause_graph_tracing();
 	raw_local_irq_save(irq_flags);
 	__raw_spin_lock(&trace_buf_lock);
-	len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
-
-	len = min(len, TRACE_BUF_SIZE-1);
-	trace_buf[len] = 0;
+	if (args == NULL) {
+		strncpy(trace_buf, fmt, TRACE_BUF_SIZE);
+		len = strlen(trace_buf);
+	} else
+		len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
 
 	size = sizeof(*entry) + len + 1;
 	buffer = tr->buffer;
@@ -1373,10 +1374,10 @@ int trace_array_vprintk(struct trace_array *tr,
 	if (!event)
 		goto out_unlock;
 	entry = ring_buffer_event_data(event);
-	entry->ip			= ip;
+	entry->ip = ip;
 
 	memcpy(&entry->buf, trace_buf, len);
-	entry->buf[len] = 0;
+	entry->buf[len] = '\0';
 	if (!filter_check_discard(call, entry, buffer, event))
 		ring_buffer_unlock_commit(buffer, event);
 
@@ -3319,22 +3320,11 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 	return cnt;
 }
 
-static int mark_printk(const char *fmt, ...)
-{
-	int ret;
-	va_list args;
-	va_start(args, fmt);
-	ret = trace_vprintk(0, fmt, args);
-	va_end(args);
-	return ret;
-}
-
 static ssize_t
 tracing_mark_write(struct file *filp, const char __user *ubuf,
 					size_t cnt, loff_t *fpos)
 {
 	char *buf;
-	char *end;
 
 	if (tracing_disabled)
 		return -EINVAL;
@@ -3342,7 +3332,7 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
 	if (cnt > TRACE_BUF_SIZE)
 		cnt = TRACE_BUF_SIZE;
 
-	buf = kmalloc(cnt + 1, GFP_KERNEL);
+	buf = kmalloc(cnt + 2, GFP_KERNEL);
 	if (buf == NULL)
 		return -ENOMEM;
 
@@ -3350,14 +3340,13 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
 		kfree(buf);
 		return -EFAULT;
 	}
+	if (buf[cnt-1] != '\n') {
+		buf[cnt] = '\n';
+		buf[cnt+1] = '\0';
+	} else
+		buf[cnt] = '\0';
 
-	/* Cut from the first nil or newline. */
-	buf[cnt] = '\0';
-	end = strchr(buf, '\n');
-	if (end)
-		*end = '\0';
-
-	cnt = mark_printk("%s\n", buf);
+	cnt = trace_vprintk(0, buf, NULL);
 	kfree(buf);
 	*fpos += cnt;
 

[tip:tracing/urgent] tracing: Fix trace_marker output

[tip-bot for Carsten Emde]

Commit-ID:  c13d2f7c3231e873f30db92b96c8caa48f100f33
Gitweb:     http://git.kernel.org/tip/c13d2f7c3231e873f30db92b96c8caa48f100f33
Author:     Carsten Emde <Carsten.Emde@osadl.org>
AuthorDate: Mon, 16 Nov 2009 20:56:13 +0100
Committer:  Steven Rostedt <rostedt@goodmis.org>
CommitDate: Tue, 17 Nov 2009 09:19:06 -0500

tracing: Fix trace_marker output

When a string was written to <debugfs>/tracing/trace_marker, some
strange characters appeared in the trace output instead of the
string, since a vprint function erroneously called a vararg print
function with a va_list argument. This patch fixes the problem and
simplifies the related code.

Signed-off-by: Carsten Emde <C.Emde@osadl.org>
LKML-Reference: <4B01AE5D.1010801@osadl.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/trace.c |   39 ++++++++++++++-------------------------
 1 files changed, 14 insertions(+), 25 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 03c7fd5..12b49ca 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1361,10 +1361,11 @@ int trace_array_vprintk(struct trace_array *tr,
 	pause_graph_tracing();
 	raw_local_irq_save(irq_flags);
 	__raw_spin_lock(&trace_buf_lock);
-	len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
-
-	len = min(len, TRACE_BUF_SIZE-1);
-	trace_buf[len] = 0;
+	if (args == NULL) {
+		strncpy(trace_buf, fmt, TRACE_BUF_SIZE);
+		len = strlen(trace_buf);
+	} else
+		len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
 
 	size = sizeof(*entry) + len + 1;
 	buffer = tr->buffer;
@@ -1373,10 +1374,10 @@ int trace_array_vprintk(struct trace_array *tr,
 	if (!event)
 		goto out_unlock;
 	entry = ring_buffer_event_data(event);
-	entry->ip			= ip;
+	entry->ip = ip;
 
 	memcpy(&entry->buf, trace_buf, len);
-	entry->buf[len] = 0;
+	entry->buf[len] = '\0';
 	if (!filter_check_discard(call, entry, buffer, event))
 		ring_buffer_unlock_commit(buffer, event);
 
@@ -3319,22 +3320,11 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 	return cnt;
 }
 
-static int mark_printk(const char *fmt, ...)
-{
-	int ret;
-	va_list args;
-	va_start(args, fmt);
-	ret = trace_vprintk(0, fmt, args);
-	va_end(args);
-	return ret;
-}
-
 static ssize_t
 tracing_mark_write(struct file *filp, const char __user *ubuf,
 					size_t cnt, loff_t *fpos)
 {
 	char *buf;
-	char *end;
 
 	if (tracing_disabled)
 		return -EINVAL;
@@ -3342,7 +3332,7 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
 	if (cnt > TRACE_BUF_SIZE)
 		cnt = TRACE_BUF_SIZE;
 
-	buf = kmalloc(cnt + 1, GFP_KERNEL);
+	buf = kmalloc(cnt + 2, GFP_KERNEL);
 	if (buf == NULL)
 		return -ENOMEM;
 
@@ -3350,14 +3340,13 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
 		kfree(buf);
 		return -EFAULT;
 	}
+	if (buf[cnt-1] != '\n') {
+		buf[cnt] = '\n';
+		buf[cnt+1] = '\0';
+	} else
+		buf[cnt] = '\0';
 
-	/* Cut from the first nil or newline. */
-	buf[cnt] = '\0';
-	end = strchr(buf, '\n');
-	if (end)
-		*end = '\0';
-
-	cnt = mark_printk("%s\n", buf);
+	cnt = trace_vprintk(0, buf, NULL);
 	kfree(buf);
 	*fpos += cnt;
 

Re: [tip:tracing/urgent] tracing: Fix trace_marker output

[Olof Johansson]

Hi,

On Sun, Nov 22, 2009 at 10:24:48AM +0000, tip-bot for Carsten Emde wrote:
> Commit-ID:  c13d2f7c3231e873f30db92b96c8caa48f100f33
> Gitweb:     http://git.kernel.org/tip/c13d2f7c3231e873f30db92b96c8caa48f100f33
> Author:     Carsten Emde <Carsten.Emde@osadl.org>
> AuthorDate: Mon, 16 Nov 2009 20:56:13 +0100
> Committer:  Steven Rostedt <rostedt@goodmis.org>
> CommitDate: Tue, 17 Nov 2009 09:19:06 -0500
> 
> tracing: Fix trace_marker output
> 
> When a string was written to <debugfs>/tracing/trace_marker, some
> strange characters appeared in the trace output instead of the
> string, since a vprint function erroneously called a vararg print
> function with a va_list argument. This patch fixes the problem and
> simplifies the related code.

[...]

> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index 03c7fd5..12b49ca 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -1361,10 +1361,11 @@ int trace_array_vprintk(struct trace_array *tr,
>  	pause_graph_tracing();
>  	raw_local_irq_save(irq_flags);
>  	__raw_spin_lock(&trace_buf_lock);
> -	len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
> -
> -	len = min(len, TRACE_BUF_SIZE-1);
> -	trace_buf[len] = 0;
> +	if (args == NULL) {
> +		strncpy(trace_buf, fmt, TRACE_BUF_SIZE);
> +		len = strlen(trace_buf);
> +	} else
> +		len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);


Comparing a va_list with NULL is bogus. It's supposed to be treated like
an opaque type and only be manipulated with va_* accessors.

I wouldn't really care much, but it broke builds on some ARM platforms:

kernel/trace/trace.c: In function 'trace_array_vprintk':
kernel/trace/trace.c:1364: error: invalid operands to binary == (have 'va_list' and 'void *')
kernel/trace/trace.c: In function 'tracing_mark_write':
kernel/trace/trace.c:3349: error: incompatible type for argument 3 of 'trace_vprintk'

I see no real graceful way of solving this. What is really needed is a
trace_puts to output a string without applying format parsing to it.

I am going to do the lazy thing here, define a trace_puts() and call the
vprintk innards with it instead of duplicating code. It's probably not
the most graceful solution to the problem, but reporting a bug with a
bad patch tends to be better than reporting it without one at all. Better
suggestions are appreciated.

Oh, and I haven't had a chance to actually test and make sure it does
what is expected, since I don't have a testcase for it.


Signed-off-by: Olof Johansson <olof@lixom.net>

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 874f289..9b5bb4c 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1361,11 +1361,7 @@ int trace_array_vprintk(struct trace_array *tr,
 	pause_graph_tracing();
 	raw_local_irq_save(irq_flags);
 	__raw_spin_lock(&trace_buf_lock);
-	if (args == NULL) {
-		strncpy(trace_buf, fmt, TRACE_BUF_SIZE);
-		len = strlen(trace_buf);
-	} else
-		len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
+	len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
 
 	size = sizeof(*entry) + len + 1;
 	buffer = tr->buffer;
@@ -1398,6 +1394,22 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
 }
 EXPORT_SYMBOL_GPL(trace_vprintk);
 
+static int __trace_puts(unsigned long ip, ...)
+{
+	va_list ap;
+	int ret;
+
+	va_start(ap, ip);
+	ret = trace_vprintk(ip, "%s", ap);
+	va_end(ap);
+	return ret;
+}
+
+static int trace_puts(unsigned long ip, const char *str)
+{
+	return __trace_puts(ip, str);
+}
+
 enum trace_file_type {
 	TRACE_FILE_LAT_FMT	= 1,
 	TRACE_FILE_ANNOTATE	= 2,
@@ -3346,7 +3358,7 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
 	} else
 		buf[cnt] = '\0';
 
-	cnt = trace_vprintk(0, buf, NULL);
+	cnt = trace_puts(0, buf);
 	kfree(buf);
 	*fpos += cnt;
 

Re: [tip:tracing/urgent] tracing: Fix trace_marker output

[Carsten Emde]

Olof,

> On Sun, Nov 22, 2009 at 10:24:48AM +0000, tip-bot for Carsten Emde wrote:
>> Commit-ID:  c13d2f7c3231e873f30db92b96c8caa48f100f33
>> Gitweb:     http://git.kernel.org/tip/c13d2f7c3231e873f30db92b96c8caa48f100f33
>> Author:     Carsten Emde<Carsten.Emde@osadl.org>
>> AuthorDate: Mon, 16 Nov 2009 20:56:13 +0100
>> Committer:  Steven Rostedt<rostedt@goodmis.org>
>> CommitDate: Tue, 17 Nov 2009 09:19:06 -0500
>> tracing: Fix trace_marker output
>> When a string was written to<debugfs>/tracing/trace_marker, some
>> strange characters appeared in the trace output instead of the
>> string, since a vprint function erroneously called a vararg print
>> function with a va_list argument. This patch fixes the problem and
>> simplifies the related code.
>
> [...]
>
>> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
>> index 03c7fd5..12b49ca 100644
>> --- a/kernel/trace/trace.c
>> +++ b/kernel/trace/trace.c
>> @@ -1361,10 +1361,11 @@ int trace_array_vprintk(struct trace_array *tr,
>>   	pause_graph_tracing();
>>   	raw_local_irq_save(irq_flags);
>>   	__raw_spin_lock(&trace_buf_lock);
>> -	len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
>> -
>> -	len = min(len, TRACE_BUF_SIZE-1);
>> -	trace_buf[len] = 0;
>> +	if (args == NULL) {
>> +		strncpy(trace_buf, fmt, TRACE_BUF_SIZE);
>> +		len = strlen(trace_buf);
>> +	} else
>> +		len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
> Comparing a va_list with NULL is bogus. It's supposed to be treated like
> an opaque type and only be manipulated with va_* accessors.
>
> I wouldn't really care much, but it broke builds on some ARM platforms:
>
> kernel/trace/trace.c: In function 'trace_array_vprintk':
> kernel/trace/trace.c:1364: error: invalid operands to binary == (have 'va_list' and 'void *')
> kernel/trace/trace.c: In function 'tracing_mark_write':
> kernel/trace/trace.c:3349: error: incompatible type for argument 3 of 'trace_vprintk'
Oops, sorry. Didn't know that the gcc warn/error level is so much 
different across platforms.

>[..]
> Oh, and I haven't had a chance to actually test and make sure it does
> what is expected, since I don't have a testcase for it.
The testcase is:
# cd /sys/kernel/debug/tracing/
[root@deliv1 tracing]# echo "I am a marker" >trace_marker
[root@deliv1 tracing]# tail -1 trace
             bash-6347  [002] 303160.793532: 0: I am a marker

> +	ret = trace_vprintk(ip, "%s", ap);
This prevents the '%' character to be used in an output string. If used, 
it may horribly crash the kernel.

I'll investigate the situation further and try to come back with a 
better solution.

	Carsten.

Re: [tip:tracing/urgent] tracing: Fix trace_marker output

[Carsten Emde]

Olof,

> On Sun, Nov 22, 2009 at 10:24:48AM +0000, tip-bot for Carsten Emde wrote:
>> Commit-ID:  c13d2f7c3231e873f30db92b96c8caa48f100f33
>> Gitweb:     http://git.kernel.org/tip/c13d2f7c3231e873f30db92b96c8caa48f100f33
>> Author:     Carsten Emde <Carsten.Emde@osadl.org>
>> AuthorDate: Mon, 16 Nov 2009 20:56:13 +0100
>> Committer:  Steven Rostedt <rostedt@goodmis.org>
>> CommitDate: Tue, 17 Nov 2009 09:19:06 -0500
>>
>> tracing: Fix trace_marker output
>>
>> When a string was written to <debugfs>/tracing/trace_marker, some
>> strange characters appeared in the trace output instead of the
>> string, since a vprint function erroneously called a vararg print
>> function with a va_list argument. This patch fixes the problem and
>> simplifies the related code.
> 
> [...]
> 
>> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
>> index 03c7fd5..12b49ca 100644
>> --- a/kernel/trace/trace.c
>> +++ b/kernel/trace/trace.c
>> @@ -1361,10 +1361,11 @@ int trace_array_vprintk(struct trace_array *tr,
>>  	pause_graph_tracing();
>>  	raw_local_irq_save(irq_flags);
>>  	__raw_spin_lock(&trace_buf_lock);
>> -	len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
>> -
>> -	len = min(len, TRACE_BUF_SIZE-1);
>> -	trace_buf[len] = 0;
>> +	if (args == NULL) {
>> +		strncpy(trace_buf, fmt, TRACE_BUF_SIZE);
>> +		len = strlen(trace_buf);
>> +	} else
>> +		len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
> 
> 
> Comparing a va_list with NULL is bogus. It's supposed to be treated like
> an opaque type and only be manipulated with va_* accessors.
> 
> I wouldn't really care much, but it broke builds on some ARM platforms:
> 
> kernel/trace/trace.c: In function 'trace_array_vprintk':
> kernel/trace/trace.c:1364: error: invalid operands to binary == (have 'va_list' and 'void *')
> kernel/trace/trace.c: In function 'tracing_mark_write':
> kernel/trace/trace.c:3349: error: incompatible type for argument 3 of 'trace_vprintk'
Having looked at other possible solutions, I find that the best thing to do
is to revert this part of the patch. Sorry that I didn't check it on ARM
platforms.

	Carsten.

-=-

This patch partly reverts c13d2f7c3231e873f30db92b96c8caa48f100f33 and
re-installs Steven's original mark_printk() mechanism.

Signed-off-by: Carsten Emde <C.Emde@osadl.org>

Index: linux-2.6-tip/kernel/trace/trace.c
===================================================================
--- linux-2.6-tip.orig/kernel/trace/trace.c
+++ linux-2.6-tip/kernel/trace/trace.c
@@ -1361,11 +1361,7 @@ int trace_array_vprintk(struct trace_arr
 	pause_graph_tracing();
 	raw_local_irq_save(irq_flags);
 	__raw_spin_lock(&trace_buf_lock);
-	if (args == NULL) {
-		strncpy(trace_buf, fmt, TRACE_BUF_SIZE);
-		len = strlen(trace_buf);
-	} else
-		len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
+	len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
 
 	size = sizeof(*entry) + len + 1;
 	buffer = tr->buffer;
@@ -3320,6 +3316,16 @@ tracing_entries_write(struct file *filp,
 	return cnt;
 }
 
+static int mark_printk(const char *fmt, ...)
+{
+	int ret;
+	va_list args;
+	va_start(args, fmt);
+	ret = trace_vprintk(0, fmt, args);
+	va_end(args);
+	return ret;
+}
+
 static ssize_t
 tracing_mark_write(struct file *filp, const char __user *ubuf,
 					size_t cnt, loff_t *fpos)
@@ -3346,7 +3352,7 @@ tracing_mark_write(struct file *filp, co
 	} else
 		buf[cnt] = '\0';
 
-	cnt = trace_vprintk(0, buf, NULL);
+	cnt = mark_printk("%s", buf);
 	kfree(buf);
 	*fpos += cnt;
 

Re: [tip:tracing/urgent] tracing: Fix trace_marker output

[Olof Johansson]

On Sun, Dec 06, 2009 at 02:02:44PM +0100, Carsten Emde wrote:
> Olof,
> 
[...]
> Having looked at other possible solutions, I find that the best thing to do
> is to revert this part of the patch. Sorry that I didn't check it on ARM
> platforms.

Thanks, no worries. I figured there was a better way to fix it but
including a bad patch tends to be better than not including one :)


-Olof

[PATCH][GIT PULL][v2.6.33] tracing: Remove comparing of NULL to va_list in trace_array_vprintk()

[Steven Rostedt]

Hi Ingo,

This is an urgent fix that fixes a ARM build breakage. It is based on
the last pull request I had that fixes the function graph tracer output.


Ingo,

Please pull the latest tip/tracing/core2 tree, which can be found at:

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git
tip/tracing/core2


Carsten Emde (1):
      tracing: Remove comparing of NULL to va_list in trace_array_vprintk()

----
 kernel/trace/trace.c |   18 ++++++++++++------
 1 files changed, 12 insertions(+), 6 deletions(-)
---------------------------
commit efcf61abeb355273bc8933faf426adc366b23153
Author: Carsten Emde <Carsten.Emde@osadl.org>
Date:   Sun Dec 6 14:02:44 2009 +0100

    tracing: Remove comparing of NULL to va_list in trace_array_vprintk()
    
    Olof Johansson stated the following:
    
      Comparing a va_list with NULL is bogus. It's supposed to be treated like
      an opaque type and only be manipulated with va_* accessors.
    
    Olof noticed that this code broke the ARM builds:
    
        kernel/trace/trace.c: In function 'trace_array_vprintk':
        kernel/trace/trace.c:1364: error: invalid operands to binary == (have 'va_list' and 'void *')
        kernel/trace/trace.c: In function 'tracing_mark_write':
        kernel/trace/trace.c:3349: error: incompatible type for argument 3 of 'trace_vprintk'
    
    This patch partly reverts c13d2f7c3231e873f30db92b96c8caa48f100f33 and
    re-installs the original mark_printk() mechanism.
    
    Reported-by: Olof Johansson <olof@lixom.net>
    Signed-off-by: Carsten Emde <C.Emde@osadl.org>
    LKML-Reference: <4B1BAB74.104@osadl.org>
    Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 596dcf2..bf84e1a 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1361,11 +1361,7 @@ int trace_array_vprintk(struct trace_array *tr,
 	pause_graph_tracing();
 	raw_local_irq_save(irq_flags);
 	__raw_spin_lock(&trace_buf_lock);
-	if (args == NULL) {
-		strncpy(trace_buf, fmt, TRACE_BUF_SIZE);
-		len = strlen(trace_buf);
-	} else
-		len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
+	len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
 
 	size = sizeof(*entry) + len + 1;
 	buffer = tr->buffer;
@@ -3353,6 +3349,16 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 	return cnt;
 }
 
+static int mark_printk(const char *fmt, ...)
+{
+	int ret;
+	va_list args;
+	va_start(args, fmt);
+	ret = trace_vprintk(0, fmt, args);
+	va_end(args);
+	return ret;
+}
+
 static ssize_t
 tracing_mark_write(struct file *filp, const char __user *ubuf,
 					size_t cnt, loff_t *fpos)
@@ -3379,7 +3385,7 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
 	} else
 		buf[cnt] = '\0';
 
-	cnt = trace_vprintk(0, buf, NULL);
+	cnt = mark_printk("%s", buf);
 	kfree(buf);
 	*fpos += cnt;
 

Re: [PATCH][GIT PULL][v2.6.33] tracing: Remove comparing of NULL to va_list in trace_array_vprintk()

[Ingo Molnar]

* Steven Rostedt <rostedt@goodmis.org> wrote:

> Hi Ingo,
> 
> This is an urgent fix that fixes a ARM build breakage. It is based on
> the last pull request I had that fixes the function graph tracer output.
> 
> 
> Ingo,
> 
> Please pull the latest tip/tracing/core2 tree, which can be found at:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git
> tip/tracing/core2
> 
> 
> Carsten Emde (1):
>       tracing: Remove comparing of NULL to va_list in trace_array_vprintk()
> 
> ----
>  kernel/trace/trace.c |   18 ++++++++++++------
>  1 files changed, 12 insertions(+), 6 deletions(-)

Pulled, thanks Steve!

	Ingo

Re: [PATCH][GIT PULL][v2.6.33] tracing: Remove comparing of NULL to va_list in trace_array_vprintk()

[Ingo Molnar]

-tip testing found that the Alpha defconfig fails to build. (error log 
attached below)

To fix this bug i have unpulled this commit for now:

 efcf61a: tracing: Remove comparing of NULL to va_list in trace_array_vprintk()

Thanks,

	Ingo

---------------->
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/init/noinitramfs.c:23:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/init/main.c:16:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
cc1: warnings being treated as errors
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/arch/alpha/kernel/osf_sys.c:20:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: error: no return statement in function returning non-void
cc1: warnings being treated as errors
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/arch/alpha/kernel/alpha_ksyms.c:15:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: error: no return statement in function returning non-void
make[2]: *** [arch/alpha/kernel/alpha_ksyms.o] Error 1
make[2]: *** Waiting for unfinished jobs....
cc1: warnings being treated as errors
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/arch/alpha/kernel/signal.c:22:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: error: no return statement in function returning non-void
make[2]: *** [arch/alpha/kernel/osf_sys.o] Error 1
make[2]: *** [arch/alpha/kernel/signal.o] Error 1
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/init/do_mounts.h:4,
                 from /home/mingo/tip/init/do_mounts.c:23:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/kernel/exec_domain.c:18:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/kernel/sched.c:62:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/kernel/fork.c:38:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/kernel/printk.c:34:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/kernel/itimer.c:11:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/mm/fadvise.c:19:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
make[1]: *** [arch/alpha/kernel] Error 2
make[1]: *** Waiting for unfinished jobs....
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/kernel/exit.c:36:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/kernel/capability.c:15:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/mm/filemap.c:32:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/kernel/sysctl.c:45:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/kernel/ptrace.c:23:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/kernel/timer.c:36:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/mm/page-writeback.c:34:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/kernel/signal.c:21:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/kernel/kmod.c:23:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/open.c:28:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/kernel/sysctl_binary.c:7:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/read_write.c:16:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/kernel/pid.c:38:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/super.c:33:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/stat.c:15:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/kernel/posix-timers.c:45:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/fcntl.c:7:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/exec.c:49:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/pipe.c:20:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/ioctl.c:7:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/namei.c:28:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/select.c:19:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/readdir.c:17:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/mm/fremap.c:17:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/kernel/hrtimer.c:39:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/mm/madvise.c:10:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/mm/mincore.c:14:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/dcache.c:17:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/mm/mmap.c:16:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/mm/mlock.c:15:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/mm/mremap.c:21:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/mm/mprotect.c:21:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/mm/msync.c:14:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/namespace.c:11:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/kernel/groups.c:8:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/filesystems.c:9:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/kernel/futex.c:56:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
/home/mingo/tip/kernel/irq/handle.c:437:3: warning: #warning __do_IRQ is deprecated. Please convert to proper flow handlers
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/xattr.c:17:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/kernel/module.c:21:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/mm/swapfile.c:30:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/splice.c:30:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/sync.c:11:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/utimes.c:10:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/kernel/time.c:35:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/buffer.c:22:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/ioprio.c:26:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/notify/inotify/inotify_user.c:38:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/eventpoll.c:28:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/signalfd.c:30:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/timerfd.c:23:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/eventfd.c:17:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/locks.c:126:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/aio.c:17:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
                 from /home/mingo/tip/include/trace/syscall.h:6,
                 from /home/mingo/tip/include/linux/syscalls.h:71,
                 from /home/mingo/tip/fs/nfsctl.c:18:
/home/mingo/tip/include/linux/trace_seq.h: In function 'trace_print_seq':
/home/mingo/tip/include/linux/trace_seq.h:62: warning: no return statement in function returning non-void
make[1]: *** wait: No child processes.  Stop.
make: *** [sub-make] Error 2

Re: [PATCH][GIT PULL][v2.6.33] tracing: Remove comparing of NULL to va_list in trace_array_vprintk()

[Ingo Molnar]

* Ingo Molnar <mingo@elte.hu> wrote:

>  efcf61a: tracing: Remove comparing of NULL to va_list in trace_array_vprintk()

the real culprit was:

  6e0573f: tracing: Buffer the output of seq_file in case of filled buffer

so i kept this commit:

  c521efd: tracing: Add pipe_close interface

and skipped the rest for now - please resend if this is fixed.

	Ingo

Re: [PATCH][GIT PULL][v2.6.33] tracing: Remove comparing of NULL to va_list in trace_array_vprintk()

[Steven Rostedt]

On Wed, 2009-12-09 at 07:15 +0100, Ingo Molnar wrote:
> * Ingo Molnar <mingo@elte.hu> wrote:
> 
> >  efcf61a: tracing: Remove comparing of NULL to va_list in trace_array_vprintk()
> 
> the real culprit was:
> 
>   6e0573f: tracing: Buffer the output of seq_file in case of filled buffer
> 
> so i kept this commit:
> 
>   c521efd: tracing: Add pipe_close interface
> 
> and skipped the rest for now - please resend if this is fixed.
> 

I'll get this fixed today.

Thanks!

-- Steve

Re: [PATCH][GIT PULL][v2.6.33] tracing: Remove comparing of NULL to va_list in trace_array_vprintk()

[Steven Rostedt]

On Wed, 2009-12-09 at 07:11 +0100, Ingo Molnar wrote:
> -tip testing found that the Alpha defconfig fails to build. (error log 
> attached below)
> 
> To fix this bug i have unpulled this commit for now:
> 
>  efcf61a: tracing: Remove comparing of NULL to va_list in trace_array_vprintk()
> 
> Thanks,
> 
> 	Ingo
> 
> ---------------->
> In file included from /home/mingo/tip/include/linux/ftrace_event.h:5,
>                  from /home/mingo/tip/include/trace/syscall.h:6,
>                  from /home/mingo/tip/include/linux/syscalls.h:71,
>                  from /home/mingo/tip/init/noinitramfs.c:23:

Ah, this was caused by the !CONFIG_TRACING path:

-static inline void trace_print_seq(struct seq_file *m, struct trace_seq *s)
+static inline int trace_print_seq(struct seq_file *m, struct trace_seq *s)
{
}

Will fix.

Thanks,

-- Steve

[tip:tracing/core] tracing: Remove comparing of NULL to va_list in trace_array_vprintk()

[tip-bot for Carsten Emde]

Commit-ID:  f2942487ffb0c0a80b2312f667ea30dd55a24bb0
Gitweb:     http://git.kernel.org/tip/f2942487ffb0c0a80b2312f667ea30dd55a24bb0
Author:     Carsten Emde <Carsten.Emde@osadl.org>
AuthorDate: Sun, 6 Dec 2009 14:02:44 +0100
Committer:  Steven Rostedt <rostedt@goodmis.org>
CommitDate: Wed, 9 Dec 2009 14:20:08 -0500

tracing: Remove comparing of NULL to va_list in trace_array_vprintk()

Olof Johansson stated the following:

  Comparing a va_list with NULL is bogus. It's supposed to be treated like
  an opaque type and only be manipulated with va_* accessors.

Olof noticed that this code broke the ARM builds:

    kernel/trace/trace.c: In function 'trace_array_vprintk':
    kernel/trace/trace.c:1364: error: invalid operands to binary == (have 'va_list' and 'void *')
    kernel/trace/trace.c: In function 'tracing_mark_write':
    kernel/trace/trace.c:3349: error: incompatible type for argument 3 of 'trace_vprintk'

This patch partly reverts c13d2f7c3231e873f30db92b96c8caa48f100f33 and
re-installs the original mark_printk() mechanism.

Reported-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Carsten Emde <C.Emde@osadl.org>
LKML-Reference: <4B1BAB74.104@osadl.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/trace.c |   18 ++++++++++++------
 1 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 484114d..88bd9ae 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1361,11 +1361,7 @@ int trace_array_vprintk(struct trace_array *tr,
 	pause_graph_tracing();
 	raw_local_irq_save(irq_flags);
 	__raw_spin_lock(&trace_buf_lock);
-	if (args == NULL) {
-		strncpy(trace_buf, fmt, TRACE_BUF_SIZE);
-		len = strlen(trace_buf);
-	} else
-		len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
+	len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
 
 	size = sizeof(*entry) + len + 1;
 	buffer = tr->buffer;
@@ -3353,6 +3349,16 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 	return cnt;
 }
 
+static int mark_printk(const char *fmt, ...)
+{
+	int ret;
+	va_list args;
+	va_start(args, fmt);
+	ret = trace_vprintk(0, fmt, args);
+	va_end(args);
+	return ret;
+}
+
 static ssize_t
 tracing_mark_write(struct file *filp, const char __user *ubuf,
 					size_t cnt, loff_t *fpos)
@@ -3379,7 +3385,7 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
 	} else
 		buf[cnt] = '\0';
 
-	cnt = trace_vprintk(0, buf, NULL);
+	cnt = mark_printk("%s", buf);
 	kfree(buf);
 	*fpos += cnt;