• Josh Poimboeuf's avatar
    jump_label: Disable jump labels in __exit code · 578ae447
    Josh Poimboeuf authored
    With the following commit:
      33352244 ("jump_label: Explicitly disable jump labels in __init code")
    ... we explicitly disabled jump labels in __init code, so they could be
    detected and not warned about in the following commit:
      dc1dd184 ("jump_label: Warn on failed jump_label patching attempt")
    In-kernel __exit code has the same issue.  It's never used, so it's
    freed along with the rest of initmem.  But jump label entries in __exit
    code aren't explicitly disabled, so we get the following warning when
    enabling pr_debug() in __exit code:
      can't patch jump_label at dmi_sysfs_exit+0x0/0x2d
      WARNING: CPU: 0 PID: 22572 at kernel/jump_label.c:376 __jump_label_update+0x9d/0xb0
    Fix the warning by disabling all jump labels in initmem (which includes
    both __init and __exit code).
    Reported-and-tested-by: default avatarLi Wang <liwang@redhat.com>
    Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
    Cc: Borislav Petkov <bp@suse.de>
    Cc: Jason Baron <jbaron@akamai.com>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Fixes: dc1dd184 ("jump_label: Warn on failed jump_label patching attempt")
    Link: http://lkml.kernel.org/r/7121e6e595374f06616c505b6e690e275c0054d1.1521483452.git.jpoimboe@redhat.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
jump_label.c 19.8 KB