modify sin led gpio

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2024-05-13 9d77db3c730780c8ef5ccd4b66403ff5675cfe4e

 kernel/Documentation/trace/ftrace-uses.rst
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@@ -55,17 +55,17 @@
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 Both .flags and .private are optional. Only .func is required.
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-To enable tracing call:
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+To enable tracing call::
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-.. c:function::  register_ftrace_function(&ops);
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+    register_ftrace_function(&ops);
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-To disable tracing call:
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+To disable tracing call::
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-.. c:function::  unregister_ftrace_function(&ops);
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+    unregister_ftrace_function(&ops);
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-The above is defined by including the header:
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+The above is defined by including the header::
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-.. c:function:: #include <linux/ftrace.h>
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+    #include <linux/ftrace.h>
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 The registered callback will start being called some time after the
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 register_ftrace_function() is called and before it returns. The exact time
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@@ -146,7 +146,7 @@
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 	itself or any nested functions that those functions call.
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 	If this flag is set, it is possible that the callback will also
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-	be called with preemption enabled (when CONFIG_PREEMPT is set),
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+	be called with preemption enabled (when CONFIG_PREEMPTION is set),
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 	but this is not guaranteed.
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 FTRACE_OPS_FL_IPMODIFY
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@@ -170,6 +170,14 @@
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 	a callback may be executed and RCU synchronization will not protect
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 	it.
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+FTRACE_OPS_FL_PERMANENT
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+        If this is set on any ftrace ops, then the tracing cannot disabled by
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+        writing 0 to the proc sysctl ftrace_enabled. Equally, a callback with
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+        the flag set cannot be registered if ftrace_enabled is 0.
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+
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+        Livepatch uses it not to lose the function redirection, so the system
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+        stays protected.
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+
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 Filtering which functions to trace
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 ==================================