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 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: jump_label-invoke-jump_label_test-via-early_initcall.patch and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Tue Dec 12 13:38:50 CET 2017
From: Jason Baron jbaron@akamai.com Date: Mon, 13 Nov 2017 16:48:47 -0500 Subject: jump_label: Invoke jump_label_test() via early_initcall()
From: Jason Baron jbaron@akamai.com
[ 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in turn assumes that if the system_state variable is greter than or equal to SYSTEM_RUNNING then __init sections are no longer valid (since the assumption is that they have been freed).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@intel.com Signed-off-by: Jason Baron jbaron@akamai.com Acked-by: Paul 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.com Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/jump_label.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -553,7 +553,7 @@ 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@akamai.com are
queue-4.4/module-set-__jump_table-alignment-to-8.patch queue-4.4/jump_label-invoke-jump_label_test-via-early_initcall.patch queue-4.4/dynamic-debug-howto-fix-optional-omitted-ending-line-number-to-be-large-instead-of-0.patch