linux-kernel - [PATCH] init: fix misleading "This architecture does not have kernel memory protection" message

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Message-Id: <62477e446d9685459d4f27d193af6ff1bd69d55f.1578557581.git.christophe.leroy@c-s.fr>
Date:   Thu,  9 Jan 2020 08:15:01 +0000 (UTC)
From:   Christophe Leroy <christophe.leroy@....fr>
To:     Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Paul Mackerras <paulus@...ba.org>,
        Michael Ellerman <mpe@...erman.id.au>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Kees Cook <keescook@...omium.org>
Cc:     linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
        linux-mm@...ck.org
Subject: [PATCH] init: fix misleading "This architecture does not have kernel
 memory protection" message

This message leads to think that memory protection is not implemented
for the said architecture, whereas absence of CONFIG_STRICT_KERNEL_RWX
only means that memory protection has not been selected at
compile time.

Don't print this message when CONFIG_ARCH_HAS_STRICT_KERNEL_RWX is
selected by the architecture. Instead, print "Kernel memory protection
not selected by kernel config."

Signed-off-by: Christophe Leroy <christophe.leroy@....fr>
---
 init/main.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/init/main.c b/init/main.c
index 2cd736059416..fd31b15cc910 100644
--- a/init/main.c
+++ b/init/main.c
@@ -1090,6 +1090,11 @@ static void mark_readonly(void)
 	} else
 		pr_info("Kernel memory protection disabled.\n");
 }
+#elif defined(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)
+static inline void mark_readonly(void)
+{
+	pr_warn("Kernel memory protection not selected by kernel config.\n");
+}
 #else
 static inline void mark_readonly(void)
 {
-- 
2.13.3