This is a note to let you know that I've just added the patch titled
powerpc/watchpoints: Annotate atomic context in more places
to the 5.4-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:
powerpc-watchpoints-annotate-atomic-context-in-more-.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 111666998d83c7e4c6fdf61badcff34a680b8fcb
Author: Benjamin Gray <bgray@xxxxxxxxxxxxx>
Date: Tue Aug 29 16:34:57 2023 +1000
powerpc/watchpoints: Annotate atomic context in more places
[ Upstream commit 27646b2e02b096a6936b3e3b6ba334ae20763eab ]
It can be easy to miss that the notifier mechanism invokes the callbacks
in an atomic context, so add some comments to that effect on the two
handlers we register here.
Signed-off-by: Benjamin Gray <bgray@xxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://msgid.link/20230829063457.54157-4-bgray@xxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index 1007ec36b4cb9..fb736fdb4193f 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -247,6 +247,11 @@ static bool stepping_handler(struct pt_regs *regs, struct perf_event *bp,
return false;
}
+/*
+ * Handle a DABR or DAWR exception.
+ *
+ * Called in atomic context.
+ */
int hw_breakpoint_handler(struct die_args *args)
{
int rc = NOTIFY_STOP;
@@ -315,6 +320,8 @@ NOKPROBE_SYMBOL(hw_breakpoint_handler);
/*
* Handle single-step exceptions following a DABR hit.
+ *
+ * Called in atomic context.
*/
static int single_step_dabr_instruction(struct die_args *args)
{
@@ -355,6 +362,8 @@ NOKPROBE_SYMBOL(single_step_dabr_instruction);
/*
* Handle debug exception notifications.
+ *
+ * Called in atomic context.
*/
int hw_breakpoint_exceptions_notify(
struct notifier_block *unused, unsigned long val, void *data)
