From 9d77db3c730780c8ef5ccd4b66403ff5675cfe4e Mon Sep 17 00:00:00 2001 From: hc <hc@nodka.com> Date: Mon, 13 May 2024 10:30:14 +0000 Subject: [PATCH] modify sin led gpio --- kernel/Documentation/trace/ftrace-uses.rst | 22 +++++++++++++++------- 1 files changed, 15 insertions(+), 7 deletions(-) diff --git a/kernel/Documentation/trace/ftrace-uses.rst b/kernel/Documentation/trace/ftrace-uses.rst index 1fbc698..a4955f7 100644 --- a/kernel/Documentation/trace/ftrace-uses.rst +++ b/kernel/Documentation/trace/ftrace-uses.rst @@ -55,17 +55,17 @@ Both .flags and .private are optional. Only .func is required. -To enable tracing call: +To enable tracing call:: -.. c:function:: register_ftrace_function(&ops); + register_ftrace_function(&ops); -To disable tracing call: +To disable tracing call:: -.. c:function:: unregister_ftrace_function(&ops); + unregister_ftrace_function(&ops); -The above is defined by including the header: +The above is defined by including the header:: -.. c:function:: #include <linux/ftrace.h> + #include <linux/ftrace.h> The registered callback will start being called some time after the register_ftrace_function() is called and before it returns. The exact time @@ -146,7 +146,7 @@ itself or any nested functions that those functions call. If this flag is set, it is possible that the callback will also - be called with preemption enabled (when CONFIG_PREEMPT is set), + be called with preemption enabled (when CONFIG_PREEMPTION is set), but this is not guaranteed. FTRACE_OPS_FL_IPMODIFY @@ -170,6 +170,14 @@ a callback may be executed and RCU synchronization will not protect it. +FTRACE_OPS_FL_PERMANENT + If this is set on any ftrace ops, then the tracing cannot disabled by + writing 0 to the proc sysctl ftrace_enabled. Equally, a callback with + the flag set cannot be registered if ftrace_enabled is 0. + + Livepatch uses it not to lose the function redirection, so the system + stays protected. + Filtering which functions to trace ================================== -- Gitblit v1.6.2