Messages in this thread Patch in this message | | | From | Jason Baron <> | Subject | [PATCH] jump_label: invoke jump_label_test() via early_initcall() | Date | Mon, 13 Nov 2017 16:48:47 -0500 |
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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in turn assumes that if the system_state variable is greter than or equal to SYSTEM_RUNNING then __init sections are no longer valid (since the assumption is that they have been freed).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> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Jason Baron <jbaron@akamai.com> --- kernel/jump_label.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 0bf2e8f5..7c3774a 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 */ -- 2.6.1
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