When registering early kprobes, SMP should has not been enabled, so
doesn't require synchronization in text_poke_bp(). Simply memcpy is
enough.

Signed-off-by: Wang Nan <[email protected]>
---
 arch/x86/kernel/kprobes/opt.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
index 0dd8d08..21847ab 100644
--- a/arch/x86/kernel/kprobes/opt.c
+++ b/arch/x86/kernel/kprobes/opt.c
@@ -36,6 +36,7 @@
 #include <asm/alternative.h>
 #include <asm/insn.h>
 #include <asm/debugreg.h>
+#include <asm/tlbflush.h>
 
 #include "common.h"
 
@@ -397,8 +398,15 @@ void arch_optimize_kprobes(struct list_head *oplist)
                insn_buf[0] = RELATIVEJUMP_OPCODE;
                *(s32 *)(&insn_buf[1]) = rel;
 
-               text_poke_bp(op->kp.addr, insn_buf, RELATIVEJUMP_SIZE,
-                            op->optinsn.insn);
+               if (unlikely(kprobes_is_early())) {
+                       BUG_ON(!(op->kp.flags & KPROBE_FLAG_EARLY));
+                       memcpy(op->kp.addr, insn_buf, RELATIVEJUMP_SIZE);
+                       local_flush_tlb();
+                       sync_core();
+               } else {
+                       text_poke_bp(op->kp.addr, insn_buf, RELATIVEJUMP_SIZE,
+                                    op->optinsn.insn);
+               }
 
                list_del_init(&op->list);
        }
-- 
1.8.4

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