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[3/3] powerpc/watchpoints: Annotate atomic context in more places

Message ID 20230829063457.54157-4-bgray@linux.ibm.com (mailing list archive)
State Accepted
Commit 27646b2e02b096a6936b3e3b6ba334ae20763eab
Headers show
Series Fix preemption errors in watchpoints | expand

Commit Message

Benjamin Gray Aug. 29, 2023, 6:34 a.m. UTC 
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@linux.ibm.com>
---
 arch/powerpc/kernel/hw_breakpoint.c | 9 +++++++++
 1 file changed, 9 insertions(+)
diff mbox series

Patch

diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index 2854376870cf..a1318ce18d0e 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)