linux-kernel - Fix MAX_STACK_ENTRIES from 100 to 32

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Message-ID: <931aaecf-66b1-469a-8bc3-7126871a8464.ydzhang@linux.alibaba.com>
Date:   Sat, 08 Jul 2023 09:56:34 +0800
From:   "wardenjohn" <ydzhang@...ux.alibaba.com>
To:     "jpoimboe" <jpoimboe@...nel.org>
Cc:     "jikos" <jikos@...nel.org>, "mbenes" <mbenes@...e.cz>,
        "pmladek" <pmladek@...e.com>,
        "joe.lawrence" <joe.lawrence@...hat.com>,
        "live-patching" <live-patching@...r.kernel.org>,
        "linux-kernel" <linux-kernel@...r.kernel.org>
Subject: Fix MAX_STACK_ENTRIES from 100 to 32

Thanks for reading my suggestion. I found that the array for task stack entries when
doing livepatch function check is too large which seems to be unnecessary. Therefore,
I suggest to fix the MAX_STACK_ENTRIES from 100 to 32.

The patch is as follows:

From ee27da5e64daced159257f54170a31141e943710 Mon Sep 17 00:00:00 2001
From: Yongde Zhang <ydzhang@...ux.alibaba.com>
Date: Sat, 8 Jul 2023 09:40:50 +0800
Subject: [PATCH] Fix MAX_STACK_ENTRIES to 32

When checking the task stack, using an stack array of size 100 
seems to be to large for a task stack. Therefore, I suggest to
change the stack size from 100 to 32. 

Signed-off-by: Yongde Zhang <ydzhang@...ux.alibaba.com>
---
 kernel/livepatch/transition.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c
index e54c3d60a904..8d61c62b0c27 100644
--- a/kernel/livepatch/transition.c
+++ b/kernel/livepatch/transition.c
@@ -14,7 +14,7 @@
 #include "patch.h"
 #include "transition.h"
 
-#define MAX_STACK_ENTRIES  100
+#define MAX_STACK_ENTRIES  32
 static DEFINE_PER_CPU(unsigned long[MAX_STACK_ENTRIES], klp_stack_entries);
 
 #define STACK_ERR_BUF_SIZE 128 
-- 
2.37.3