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Commit 33974093c024f08caadd2fc71a83bd811ed1831d

Authored by Matt Fleming
Committed by Ingo Molnar
1 parent 84d88d5d4e
Exists in master and in 7 other branches imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

tracing: Fix infinite recursion in ftrace_update_pid_func() 

When CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST is enabled
__ftrace_trace_function contains the current trace function, not
ftrace_trace_function.

In ftrace_update_pid_func() we currently incorrectly assign the
value of ftrace_trace_function to __ftrace_trace_funcion before
returning.

Without this patch it is possible to execute an infinite recursion
whereby ftrace_test_stop_func() calls __ftrace_trace_function,
which was assigned ftrace_test_stop_func() in
ftrace_update_pid_func().

Signed-off-by: Matt Fleming <matthew.fleming@imgtec.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1254152581-18347-1-git-send-email-matt@console-pimps.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Showing 1 changed file with 4 additions and 0 deletions Side-by-side Diff

kernel/trace/ftrace.c
Diff comments   View file @ 3397409
... ... @@ -225,7 +225,11 @@
225 225 if (ftrace_trace_function == ftrace_stub)
226 226 return;
227 227  
  228 +#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
228 229 func = ftrace_trace_function;
  230 +#else
  231 + func = __ftrace_trace_function;
  232 +#endif
229 233  
230 234 if (ftrace_pid_trace) {
231 235 set_ftrace_pid_function(func);