From: Jason Baron Date: Mon, 13 Nov 2017 21:48:47 +0000 (-0500) Subject: jump_label: Invoke jump_label_test() via early_initcall() X-Git-Tag: v4.15-rc1~6^2 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=92ee46efeb505ead3ab06d3c5ce695637ed5f152;p=users%2Fhch%2Fmisc.git 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in turn assumes that if the system_state variable is greter than or equal to SYSTEM_RUNNING then __init sections are no longer valid (since the assumption is that they have been freed).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: Fengguang Wu Signed-off-by: Jason Baron Acked-by: Paul E. McKenney Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1510609727-2238-1-git-send-email-jbaron@akamai.com Signed-off-by: Ingo Molnar --- diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 8ff4ca4665ff..8594d24e4adc 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -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 */