FAILED: patch "[PATCH] kprobes: Fix build errors with CONFIG_KRETPROBES=n" failed to apply to 5.15-stable tree

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 43994049180704fd1faf78623fabd9a5cd443708 Mon Sep 17 00:00:00 2001
From: Masami Hiramatsu <[email protected]>
Date: Wed, 4 May 2022 12:36:31 +0900
Subject: [PATCH] kprobes: Fix build errors with CONFIG_KRETPROBES=n
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Max Filippov reported:

When building kernel with CONFIG_KRETPROBES=n kernel/kprobes.c compilation fails with the following messages:

kernel/kprobes.c: In function ‘recycle_rp_inst’:
kernel/kprobes.c:1273:32: error: implicit declaration of function
‘get_kretprobe’

kernel/kprobes.c: In function ‘kprobe_flush_task’:
kernel/kprobes.c:1299:35: error: ‘struct task_struct’ has no member
named ‘kretprobe_instances’

This came from the commit d741bf41d7c7 ("kprobes: Remove kretprobe hash") which introduced get_kretprobe() and kretprobe_instances member in task_struct when CONFIG_KRETPROBES=y, but did not make recycle_rp_inst() and kprobe_flush_task() depending on CONFIG_KRETPORBES.

Since those functions are only used for kretprobe, move those functions into #ifdef CONFIG_KRETPROBE area.

index 157168769fc2..55041d2f884d 100644
@@ -424,7 +424,7 @@ void unregister_kretprobe(struct kretprobe *rp);
 int register_kretprobes(struct kretprobe **rps, int num);
 void unregister_kretprobes(struct kretprobe **rps, int num);
 
-#ifdef CONFIG_KRETPROBE_ON_RETHOOK
+#if defined(CONFIG_KRETPROBE_ON_RETHOOK) || !defined(CONFIG_KRETPROBES)
 #define kprobe_flush_task(tk)	do {} while (0)
 #else
 void kprobe_flush_task(struct task_struct *tk);