This is a note to let you know that I've just added the patch titled jump_label: Invoke jump_label_test() via early_initcall() to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: jump_label-invoke-jump_label_test-via-early_initcall.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Tue Dec 12 13:26:17 CET 2017 From: Jason Baron <jbaron@xxxxxxxxxx> Date: Mon, 13 Nov 2017 16:48:47 -0500 Subject: jump_label: Invoke jump_label_test() via early_initcall() From: Jason Baron <jbaron@xxxxxxxxxx> [ Upstream commit 92ee46efeb505ead3ab06d3c5ce695637ed5f152 ] 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in turn assumes that if the system_state variable is greter than or equal to SYSTEM_RUNNING then __init sections are no longer valid (since the assumption is that they have been freed).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 <fengguang.wu@xxxxxxxxx> Signed-off-by: Jason Baron <jbaron@xxxxxxxxxx> Acked-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/1510609727-2238-1-git-send-email-jbaron@xxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/jump_label.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -612,7 +612,7 @@ 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 */ Patches currently in stable-queue which might be from jbaron@xxxxxxxxxx are queue-4.9/module-set-__jump_table-alignment-to-8.patch queue-4.9/jump_label-invoke-jump_label_test-via-early_initcall.patch queue-4.9/dynamic-debug-howto-fix-optional-omitted-ending-line-number-to-be-large-instead-of-0.patch