• Jason Wessel's avatar
    mips,kgdb: fix recursive page fault with CONFIG_KPROBES · f0a996ee
    Jason Wessel authored
    This fault was detected using the kgdb test suite on boot and it
    crashes recursively due to the fact that CONFIG_KPROBES on mips adds
    an extra die notifier in the page fault handler.  The crash signature
    looks like this:
    
    kgdbts:RUN bad memory access test
    KGDB: re-enter exception: ALL breakpoints killed
    Call Trace:
    [<807b7548>] dump_stack+0x20/0x54
    [<807b7548>] dump_stack+0x20/0x54
    
    The fix for now is to have kgdb return immediately if the fault type
    is DIE_PAGE_FAULT and allow the kprobe code to decide what is supposed
    to happen.
    
    Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
    Cc: David S. Miller <davem@davemloft.net>
    Cc: <stable@vger.kernel.org>
    Signed-off-by: default avatarJason Wessel <jason.wessel@windriver.com>
    f0a996ee
kgdb.c 11.1 KB