tracing: Have stack tracing set filtered functions at boot

Add stacktrace_filter= to the kernel command line that lets
the user pick specific functions to check the stack on.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index fd5c913c33c1..fde2ae06539a 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2435,6 +2435,14 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
         stacktrace      [FTRACE]
                         Enabled the stack tracer on boot up.
 
+        stacktrace_filter=[function-list]
+                        [FTRACE] Limit the functions that the stack tracer
+                        will trace at boot up. function-list is a comma separated
+                        list of functions. This list can be changed at run
+                        time by the stack_trace_filter file in the debugfs
+                        tracing directory. Note, this enables stack tracing
+                        and the stacktrace above is not needed.
+
         sti=            [PARISC,HW]
                         Format: <num>
                         Set the STI (builtin display/keyboard on the HP-PARISC