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  • Jason Baron's avatar
    jump_label: Invoke jump_label_test() via early_initcall() · 74b470ce
    Jason Baron authored
    
    [ Upstream commit 92ee46ef
    
     ]
    
    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    greter than or equal to SYSTEM_RUNNING then __init sections are no longer
    valid (since the assumption is that they have been freed).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: default avatarFengguang Wu <fengguang.wu@intel.com>
    Signed-off-by: Jason Baron <jbar...
    74b470ce