[RFC PATCH 01/11] ARM: kprobes: directly modify code if kprobe is not initialized.

[Wang Nan]

If kprobe is optimized before kprobe is initialized, there should
be only one core, the probed instruction is not armed with breakpoint,
so simply patch text is okay.

Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
---
 arch/arm/probes/kprobes/opt-arm.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/arm/probes/kprobes/opt-arm.c b/arch/arm/probes/kprobes/opt-arm.c
index 15b37c0..a021474 100644
--- a/arch/arm/probes/kprobes/opt-arm.c
+++ b/arch/arm/probes/kprobes/opt-arm.c
@@ -325,8 +325,17 @@ void __kprobes arch_optimize_kprobes(struct list_head *oplist)
 		 * Similar to __arch_disarm_kprobe, operations which
 		 * removing breakpoints must be wrapped by stop_machine
 		 * to avoid racing.
+		 *
+		 * If this function is called before kprobes initialized,
+		 * the kprobe should be an early kprobe, the instruction
+		 * is not armed with breakpoint. There should be only
+		 * one core now, so directly __patch_text is enough.
 		 */
-		kprobes_remove_breakpoint(op->kp.addr, insn);
+		if (unlikely(!kprobes_initialized)) {
+			BUG_ON(!(op->kp.flags & KPROBE_FLAG_EARLY));
+			__patch_text(op->kp.addr, insn);
+		} else
+			kprobes_remove_breakpoint(op->kp.addr, insn);
 
 		list_del_init(&op->list);
 	}
-- 
1.8.4

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