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    modules: Fix module_bug_list list corruption race · 5336377d
    Linus Torvalds 提交于
    With all the recent module loading cleanups, we've minimized the code
    that sits under module_mutex, fixing various deadlocks and making it
    possible to do most of the module loading in parallel.
    
    However, that whole conversion totally missed the rather obscure code
    that adds a new module to the list for BUG() handling.  That code was
    doubly obscure because (a) the code itself lives in lib/bugs.c (for
    dubious reasons) and (b) it gets called from the architecture-specific
    "module_finalize()" rather than from generic code.
    
    Calling it from arch-specific code makes no sense what-so-ever to begin
    with, and is now actively wrong since that code isn't protected by the
    module loading lock any more.
    
    So this commit moves the "module_bug_{finalize,cleanup}()" calls away
    from the arch-specific code, and into the generic code - and in the
    process protects it with the module_mutex so that the list operations
    are now safe.
    
    Future fixups:
     - move the module list handling code into kernel/module.c where it
       belongs.
     - get rid of 'module_bug_list' and just use the regular list of modules
       (called 'modules' - imagine that) that we already create and maintain
       for other reasons.
    Reported-and-tested-by: NThomas Gleixner <tglx@linutronix.de>
    Cc: Rusty Russell <rusty@rustcorp.com.au>
    Cc: Adrian Bunk <bunk@kernel.org>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Cc: stable@kernel.org
    Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
    5336377d
module.c 82.3 KB