From 27646b2e02b096a6936b3e3b6ba334ae20763eab Mon Sep 17 00:00:00 2001 From: Benjamin Gray Date: Tue, 29 Aug 2023 16:34:57 +1000 Subject: [PATCH] powerpc/watchpoints: Annotate atomic context in more places 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 Signed-off-by: Michael Ellerman Link: https://msgid.link/20230829063457.54157-4-bgray@linux.ibm.com --- arch/powerpc/kernel/hw_breakpoint.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c index 2854376..a1318ce1 100644 --- a/arch/powerpc/kernel/hw_breakpoint.c +++ b/arch/powerpc/kernel/hw_breakpoint.c @@ -368,6 +368,11 @@ static void handle_p10dd1_spurious_exception(struct perf_event **bp, } } +/* + * Handle a DABR or DAWR exception. + * + * Called in atomic context. + */ int hw_breakpoint_handler(struct die_args *args) { bool err = false; @@ -495,6 +500,8 @@ 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) { @@ -546,6 +553,8 @@ 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) -- 2.7.4