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))
