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tracing: Fix file mode of free_buffer

PATCH In review Wang YanQing 4 participants 5 messages May 26, 2013 – May 29, 2013 Tracing

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#0 lore raw

PATCH 1/1 tracing: Fix file mode of free_buffer

Commit 4f271a2a60c748599b30bb4dafff30d770439b96 (tracing: Add a proc file to stop tracing and free buffer) implement a method to free up ring buffer in kernel memory in the release code path of free_buffer's fd.

Then we don't need read/write support for free_buffer, indeed we just have a dummy write fop, and don't implement read fop.

So the 0200 is more reasonable file mode for free_buffer than the current file mode 0644.

---
 kernel/trace/trace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
kernel/trace/trace.c +1 -1
index ae6fa2d..02d9875 100644
@@ -5927,7 +5927,7 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
 	trace_create_file("buffer_total_size_kb", 0444, d_tracer,
 			  tr, &tracing_total_entries_fops);
 
-	trace_create_file("free_buffer", 0644, d_tracer,
+	trace_create_file("free_buffer", 0200, d_tracer,
 			  tr, &tracing_free_buffer_fops);
 
 	trace_create_file("trace_marker", 0220, d_tracer,
Signature · 1 line
1.7.12.4.dirty
maintainer
#1 lore raw

David, Vaibhav,

Any comments on this patch?

-- Steve

Quoted 29 lines · Wang YanQing

Commit 4f271a2a60c748599b30bb4dafff30d770439b96 (tracing: Add a proc file to stop tracing and free buffer) implement a method to free up ring buffer in kernel memory in the release code path of free_buffer's fd.

Then we don't need read/write support for free_buffer, indeed we just have a dummy write fop, and don't implement read fop.

So the 0200 is more reasonable file mode for free_buffer than the current file mode 0644.

---
 kernel/trace/trace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
kernel/trace/trace.c +1 -1
index ae6fa2d..02d9875 100644
@@ -5927,7 +5927,7 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
 	trace_create_file("buffer_total_size_kb", 0444, d_tracer,
 			  tr, &tracing_total_entries_fops);
 
-	trace_create_file("free_buffer", 0644, d_tracer,
+	trace_create_file("free_buffer", 0200, d_tracer,
 			  tr, &tracing_free_buffer_fops);
 
 	trace_create_file("trace_marker", 0220, d_tracer,
Acked-by on v1 1/1
#2 lore raw
In reply to Wang YanQing
Quoted 5 lines · Wang YanQing

Commit 4f271a2a60c748599b30bb4dafff30d770439b96 (tracing: Add a proc file to stop tracing and free buffer) implement a method to free up ring buffer in kernel memory in the release code path of free_buffer's fd.

Quoted 7 lines

Then we don't need read/write support for free_buffer, indeed we just have a dummy write fop, and don't implement read fop.

So the 0200 is more reasonable file mode for free_buffer than the current file mode 0644.

Vaibhav Nagarnaik

Quoted 19 lines
---
 kernel/trace/trace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
kernel/trace/trace.c +1 -2
index ae6fa2d..02d9875 100644
@@ -5927,7 +5927,7 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
        trace_create_file("buffer_total_size_kb", 0444, d_tracer,
                          tr, &tracing_total_entries_fops);
 
-       trace_create_file("free_buffer", 0644, d_tracer,
+       trace_create_file("free_buffer", 0200, d_tracer,
                          tr, &tracing_free_buffer_fops);
 
        trace_create_file("trace_marker", 0220, d_tracer,
--

1.7.12.4.dirty

Acked-by
#3 lore raw
Quoted 9 lines · Vaibhav Nagarnaik
Quoted 8 lines · Wang YanQing

Commit 4f271a2a60c748599b30bb4dafff30d770439b96 (tracing: Add a proc file to stop tracing and free buffer) implement a method to free up ring buffer in kernel memory in the release code path of free_buffer's fd.

Then we don't need read/write support for free_buffer, indeed we just have a dummy write fop, and don't implement read fop.

Quoted 6 lines
Quoted 4 lines

So the 0200 is more reasonable file mode for free_buffer than the current file mode 0644.

Quoted 28 lines

Vaibhav Nagarnaik

Quoted 18 lines
---
 kernel/trace/trace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
kernel/trace/trace.c +1 -2
index ae6fa2d..02d9875 100644
@@ -5927,7 +5927,7 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
        trace_create_file("buffer_total_size_kb", 0444, d_tracer,
                          tr, &tracing_total_entries_fops);
 
-       trace_create_file("free_buffer", 0644, d_tracer,
+       trace_create_file("free_buffer", 0200, d_tracer,
                          tr, &tracing_free_buffer_fops);
 
        trace_create_file("trace_marker", 0220, d_tracer,
--
Quoted 1 line

1.7.12.4.dirty

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maintainer
#4 lore raw
Quoted 11 lines · David Sharp
Quoted 9 lines · Vaibhav Nagarnaik
Quoted 8 lines · Wang YanQing

Commit 4f271a2a60c748599b30bb4dafff30d770439b96 (tracing: Add a proc file to stop tracing and free buffer) implement a method to free up ring buffer in kernel memory in the release code path of free_buffer's fd.

Then we don't need read/write support for free_buffer, indeed we just have a dummy write fop, and don't implement read fop.

Quoted 10 lines
Quoted 6 lines
Quoted 4 lines

So the 0200 is more reasonable file mode for free_buffer than the current file mode 0644.

Quoted 1 line

Thanks guys,

As this isn't that big of a deal, I'm going to just queue this for 3.11.

-- Steve