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author | Jason Baron <jbaron@akamai.com> | 2017-11-13 22:48:47 +0100 |
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committer | Ingo Molnar <mingo@kernel.org> | 2017-11-14 08:41:41 +0100 |
commit | 92ee46efeb505ead3ab06d3c5ce695637ed5f152 (patch) | |
tree | 7e02f00739dd7beab0959a2bf0a370616be4e222 | |
parent | x86 / CPU: Avoid unnecessary IPIs in arch_freq_get_on_cpu() (diff) | |
download | linux-92ee46efeb505ead3ab06d3c5ce695637ed5f152.tar.xz linux-92ee46efeb505ead3ab06d3c5ce695637ed5f152.zip |
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greter than or equal to SYSTEM_RUNNING then __init sections are no longer
valid (since the assumption is that they have been freed).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 <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>
-rw-r--r-- | kernel/jump_label.c | 2 |
1 files changed, 1 insertions, 1 deletions
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 */ |