[PATCH v2 1/2] livepatch: Add comment to clarify klp_add_nops()

From: Yafang Shao
Date: Sun Feb 23 2025 - 01:21:18 EST


Add detailed comments to clarify the purpose of klp_add_nops() function.
These comments are based on Petr's explanation[0].

Link: https://lore.kernel.org/all/Z6XUA7D0eU_YDMVp@xxxxxxxxxxxxxxx/ [0]
Suggested-by: Petr Mladek <pmladek@xxxxxxxx>
Suggested-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
---
kernel/livepatch/core.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 0cd39954d5a1..4a0fb7978d0d 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -601,9 +601,12 @@ static int klp_add_object_nops(struct klp_patch *patch,
}

/*
- * Add 'nop' functions which simply return to the caller to run
- * the original function. The 'nop' functions are added to a
- * patch to facilitate a 'replace' mode.
+ * Add 'nop' functions which simply return to the caller to run the
+ * original function.
+ *
+ * They are added only when the atomic replace mode is used and only for
+ * functions which are currently livepatched but are no longer included
+ * in the new livepatch.
*/
static int klp_add_nops(struct klp_patch *patch)
{
--
2.43.5