This is a note to let you know that I've just added the patch titled parisc: Avoid calling faulthandler_disabled() twice to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: parisc-avoid-calling-faulthandler_disabled-twice.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit fa2324b2cae276f52b2836c241ea56d03a82b0f2 Author: John David Anglin <dave.anglin@xxxxxxxx> Date: Wed Dec 22 16:52:26 2021 +0000 parisc: Avoid calling faulthandler_disabled() twice [ 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@xxxxxxxx> Signed-off-by: Helge Deller <deller@xxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> 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))