Messages in this thread | | | From | "Zhengyuan Liu" <> | Subject | Re: [PATCH] ftrace: fix the file mode of graph tracer and stacktracer | Date | Fri, 9 Feb 2018 10:33:31 +0800 |
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2018-02-08 23:21 GMT+08:00 Steven Rostedt <rostedt@goodmis.org>: > On Thu, 8 Feb 2018 09:41:53 +0800 > Zhengyuan Liu <liuzhengyuan@kylinos.cn> wrote: > >> It's something looks weird that those files could be written by root >> but shows with no write permission by ll command. >> Chen LinX <linx.z.chen@intel.com> has sent a similar patch to fix >> graph function file mode in 2000, I didn't get the reason why that >> patch wasn't applied so I resend it. >> >> Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn> >> --- >> kernel/trace/ftrace.c | 4 ++-- >> kernel/trace/trace_stack.c | 2 +- >> 2 files changed, 3 insertions(+), 3 deletions(-) >> >> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c >> index ccdf366..fe903dc8 100644 >> --- a/kernel/trace/ftrace.c >> +++ b/kernel/trace/ftrace.c >> @@ -5513,10 +5513,10 @@ static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer) >> ftrace_create_filter_files(&global_ops, d_tracer); >> >> #ifdef CONFIG_FUNCTION_GRAPH_TRACER >> - trace_create_file("set_graph_function", 0444, d_tracer, >> + trace_create_file("set_graph_function", 0644, d_tracer, > > Thanks for resending the patch. > > What's interesting is that this doesn't seem to affect whether or not > root can write to the file. I wonder if that's a bug itself. > > -- Steve
Hi, Steve, Thanks for reply.
It doesn't affect root writing to those files as root is a super user and can access to any write-only files. I just want to make those writable file to look consistent with others, seeing bellow:
-rw-r--r-- 1 root root set_event_pid -rw-r--r-- 1 root root set_ftrace_filter -rw-r--r-- 1 root root set_ftrace_notrace -rw-r--r-- 1 root root set_ftrace_pid -r--r--r-- 1 root root set_graph_function -r--r--r-- 1 root root set_graph_notrace
If this patch makes no sense, just ignore it!
>> NULL, >> &ftrace_graph_fops); >> - trace_create_file("set_graph_notrace", 0444, d_tracer, >> + trace_create_file("set_graph_notrace", 0644, d_tracer, >> NULL, >> &ftrace_graph_notrace_fops); >> #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ >> diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c >> index 734accc..4356f14 100644 >> --- a/kernel/trace/trace_stack.c >> +++ b/kernel/trace/trace_stack.c >> @@ -468,7 +468,7 @@ static __init int stack_trace_init(void) >> NULL, &stack_trace_fops); >> >> #ifdef CONFIG_DYNAMIC_FTRACE >> - trace_create_file("stack_trace_filter", 0444, d_tracer, >> + trace_create_file("stack_trace_filter", 0644, d_tracer, >> &trace_ops, &stack_trace_filter_fops); >> #endif >> > | |