x86/kprobes: Fix __recover_optprobed_insn check optimizing logic

stable inclusion
from stable-v4.19.276
commit 4334c26f53585a45455af324c08a4b0036bfaa8d
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6TIG1
CVE: NA

--------------------------------

commit 868a6fc0 upstream.

Since the following commit:

  commit f66c0447 ("kprobes: Set unoptimized flag after unoptimizing code")

modified the update timing of the KPROBE_FLAG_OPTIMIZED, a optimized_kprobe
may be in the optimizing or unoptimizing state when op.kp->flags
has KPROBE_FLAG_OPTIMIZED and op->list is not empty.

The __recover_optprobed_insn check logic is incorrect, a kprobe in the
unoptimizing state may be incorrectly determined as unoptimizing.
As a result, incorrect instructions are copied.

The optprobe_queued_unopt function needs to be exported for invoking in
arch directory.

Link: https://lore.kernel.org/all/20230216034247.32348-2-yangjihong1@huawei.com/

Fixes: f66c0447 ("kprobes: Set unoptimized flag after unoptimizing code")
Cc: stable@vger.kernel.org
Signed-off-by: NYang Jihong <yangjihong1@huawei.com>
Acked-by: NMasami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: NMasami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYongqiang Liu <liuyongqiang13@huawei.com>

arch/x86/kernel/kprobes/opt.c

@@ -56,8 +56,8 @@ unsigned long __recover_optprobed_insn(kprobe_opcode_t *buf, unsigned long addr)
 		/* This function only handles jump-optimized kprobe */
 		if (kp && kprobe_optimized(kp)) {
 			op = container_of(kp, struct optimized_kprobe, kp);
-			/* If op->list is not empty, op is under optimizing */
-			if (list_empty(&op->list))
+			/* If op is optimized or under unoptimizing */
+			if (list_empty(&op->list) || optprobe_queued_unopt(op))
 				goto found;
 		}
 	}

include/linux/kprobes.h

@@ -329,6 +329,7 @@ extern int proc_kprobes_optimization_handler(struct ctl_table *table,
 					     size_t *length, loff_t *ppos);
 #endif
 extern void wait_for_kprobe_optimizer(void);
+bool optprobe_queued_unopt(struct optimized_kprobe *op);
 #else
 static inline void wait_for_kprobe_optimizer(void) { }
 #endif /* CONFIG_OPTPROBES */

kernel/kprobes.c

@@ -625,7 +625,7 @@ void wait_for_kprobe_optimizer(void)
 	mutex_unlock(&kprobe_mutex);
 }
 
-static bool optprobe_queued_unopt(struct optimized_kprobe *op)
+bool optprobe_queued_unopt(struct optimized_kprobe *op)
 {
 	struct optimized_kprobe *_op;