[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 <redacted>
---
 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

On Thu, Jan 09, 2020 at 08:15:01AM +0000, Christophe Leroy wrote:

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 <redacted>

Oh, yes, I like this. Should the message include a hint to the config
name?

Regardless:

Acked-by: Kees Cook <redacted>

-Kees

-- 
Kees Cook