Commit 92ee46ef authored by Jason Baron's avatar Jason Baron Committed by Ingo Molnar

jump_label: Invoke jump_label_test() via early_initcall()

Fengguang Wu reported that running the rcuperf test during boot can cause
the jump_label_test() to hit a WARN_ON(). The issue is that the core jump
label code relies on kernel_text_address() to detect when it can no longer
update branches that may be contained in __init sections. The
kernel_text_address() in turn assumes that if the system_state variable is
greter than or equal to SYSTEM_RUNNING then __init sections are no longer
valid (since the assumption is that they have been freed). However, when
rcuperf is setup to run in early boot it can call kernel_power_off() which
sets the system_state to SYSTEM_POWER_OFF.

Since rcuperf initialization is invoked via a module_init(), we can make
the dependency of jump_label_test() needing to complete before rcuperf
explicit by calling it via early_initcall().
Reported-by: default avatarFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: default avatarJason Baron <jbaron@akamai.com>
Acked-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1510609727-2238-1-git-send-email-jbaron@akamai.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent b29c6ef7
......@@ -769,7 +769,7 @@ static __init int jump_label_test(void)
return 0;
}
late_initcall(jump_label_test);
early_initcall(jump_label_test);
#endif /* STATIC_KEYS_SELFTEST */
#endif /* HAVE_JUMP_LABEL */
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