[PATCH] tracing: fix file mode of trace and README

[PATCH] tracing: fix file mode of trace and README

[Li Zefan]

trace is read-write and README is read-only.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---
 kernel/trace/trace.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 031c46f..f681f64 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4002,7 +4002,7 @@ static __init int tracer_init_debugfs(void)
 	trace_create_file("available_tracers", 0444, d_tracer,
 			&global_trace, &show_traces_fops);
 
-	trace_create_file("current_tracer", 0444, d_tracer,
+	trace_create_file("current_tracer", 0644, d_tracer,
 			&global_trace, &set_tracer_fops);
 
 	trace_create_file("tracing_max_latency", 0644, d_tracer,
@@ -4011,7 +4011,7 @@ static __init int tracer_init_debugfs(void)
 	trace_create_file("tracing_thresh", 0644, d_tracer,
 			&tracing_thresh, &tracing_max_lat_fops);
 
-	trace_create_file("README", 0644, d_tracer,
+	trace_create_file("README", 0444, d_tracer,
 			NULL, &tracing_readme_fops);
 
 	trace_create_file("trace_pipe", 0444, d_tracer,
-- 
1.5.4.rc3

Re: [PATCH] tracing: fix file mode of trace and README

[Frederic Weisbecker]

On Fri, Apr 17, 2009 at 10:34:30AM +0800, Li Zefan wrote:
> trace is read-write and README is read-only.
> 
> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
> ---
>  kernel/trace/trace.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index 031c46f..f681f64 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -4002,7 +4002,7 @@ static __init int tracer_init_debugfs(void)
>  	trace_create_file("available_tracers", 0444, d_tracer,
>  			&global_trace, &show_traces_fops);
>  
> -	trace_create_file("current_tracer", 0444, d_tracer,
> +	trace_create_file("current_tracer", 0644, d_tracer,
>  			&global_trace, &set_tracer_fops);



Oh!
I wonder how much time we ran with this false permission.
It clearly shows a bug in debugfs permission (or something
near this this layer), we have be running with this file
for a while and I've never seen any issue while writing into it.

And we have seen several patches with 0444 permissions for the
tracing tree containing writeable files, showing that the authors
ran them whithout problems.

Adding Greg in Cc.



>  
>  	trace_create_file("tracing_max_latency", 0644, d_tracer,
> @@ -4011,7 +4011,7 @@ static __init int tracer_init_debugfs(void)
>  	trace_create_file("tracing_thresh", 0644, d_tracer,
>  			&tracing_thresh, &tracing_max_lat_fops);
>  
> -	trace_create_file("README", 0644, d_tracer,
> +	trace_create_file("README", 0444, d_tracer,
>  			NULL, &tracing_readme_fops);



At least this one was harmless, but still it fixes the correctness.

Thanks,
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>



>  	trace_create_file("trace_pipe", 0444, d_tracer,
> -- 
> 1.5.4.rc3
> 

Re: [PATCH] tracing: fix file mode of trace and README

[Li Zefan]

>> -	trace_create_file("current_tracer", 0444, d_tracer,
>> +	trace_create_file("current_tracer", 0644, d_tracer,
>>  			&global_trace, &set_tracer_fops);
> 
> 
> 
> Oh!
> I wonder how much time we ran with this false permission.
> It clearly shows a bug in debugfs permission (or something
> near this this layer), we have be running with this file
> for a while and I've never seen any issue while writing into it.
> 
> And we have seen several patches with 0444 permissions for the
> tracing tree containing writeable files, showing that the authors
> ran them whithout problems.
> 

It's not a bug in debugfs or vfs. It's just because root can
do anything. ;)

> Adding Greg in Cc.
> 

[tip:tracing/core] tracing: fix file mode of trace and README

[tip-bot for Li Zefan]

Commit-ID:  339ae5d3c3fc2025e3657637921495fd600027c7
Gitweb:     http://git.kernel.org/tip/339ae5d3c3fc2025e3657637921495fd600027c7
Author:     Li Zefan <lizf@cn.fujitsu.com>
AuthorDate: Fri, 17 Apr 2009 10:34:30 +0800
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Fri, 17 Apr 2009 18:04:36 +0200

tracing: fix file mode of trace and README

trace is read-write and README is read-only.

[ Impact: fix /debug/tracing/ file permissions. ]

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <49E7EAB6.4070605@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>


---
 kernel/trace/trace.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 031c46f..f681f64 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4002,7 +4002,7 @@ static __init int tracer_init_debugfs(void)
 	trace_create_file("available_tracers", 0444, d_tracer,
 			&global_trace, &show_traces_fops);
 
-	trace_create_file("current_tracer", 0444, d_tracer,
+	trace_create_file("current_tracer", 0644, d_tracer,
 			&global_trace, &set_tracer_fops);
 
 	trace_create_file("tracing_max_latency", 0644, d_tracer,
@@ -4011,7 +4011,7 @@ static __init int tracer_init_debugfs(void)
 	trace_create_file("tracing_thresh", 0644, d_tracer,
 			&tracing_thresh, &tracing_max_lat_fops);
 
-	trace_create_file("README", 0644, d_tracer,
+	trace_create_file("README", 0444, d_tracer,
 			NULL, &tracing_readme_fops);
 
 	trace_create_file("trace_pipe", 0444, d_tracer,