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    Subject[PATCH 5.15 617/846] parisc: Avoid calling faulthandler_disabled() twice
    Date
    From: John David Anglin <dave.anglin@bell.net>

    [ Upstream commit 9e9d4b460f23bab61672eae397417d03917d116c ]

    In handle_interruption(), we call faulthandler_disabled() to check whether the
    fault handler is not disabled. If the fault handler is disabled, we immediately
    call do_page_fault(). It then calls faulthandler_disabled(). If disabled,
    do_page_fault() attempts to fixup the exception by jumping to no_context:

    no_context:

    if (!user_mode(regs) && fixup_exception(regs)) {
    return;
    }

    parisc_terminate("Bad Address (null pointer deref?)", regs, code, address);

    Apart from the error messages, the two blocks of code perform the same
    function.

    We can avoid two calls to faulthandler_disabled() by a simple revision
    to the code in handle_interruption().

    Note: I didn't try to fix the formatting of this code block.

    Signed-off-by: John David Anglin <dave.anglin@bell.net>
    Signed-off-by: Helge Deller <deller@gmx.de>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    arch/parisc/kernel/traps.c | 2 +-
    1 file changed, 1 insertion(+), 1 deletion(-)

    diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c
    index 197cb8480350c..afe8b902a8fc4 100644
    --- a/arch/parisc/kernel/traps.c
    +++ b/arch/parisc/kernel/traps.c
    @@ -784,7 +784,7 @@ void notrace handle_interruption(int code, struct pt_regs *regs)
    * unless pagefault_disable() was called before.
    */

    - if (fault_space == 0 && !faulthandler_disabled())
    + if (faulthandler_disabled() || fault_space == 0)
    {
    /* Clean up and return if in exception table. */
    if (fixup_exception(regs))
    --
    2.34.1


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