powerpc/32s: Remove capability to disable KUEP at boottime

Disabling KUEP at boottime makes things unnecessarily complex.

Still allow disabling KUEP at build time, but when it's built-in
it is always there.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/96f583f82423a29a4205c60b9721079111b35567.1634627931.git.christophe.leroy@csgroup.eu

diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h
index 9f38040f0641dc1b87e036f77b961961b21eab80..fb6c39225dd19a0184cfcaa6ef25fb0a87484414 100644 (file)
--- a/arch/powerpc/include/asm/book3s/32/kup.h
+++ b/arch/powerpc/include/asm/book3s/32/kup.h
@@ -12,7 +12,6 @@
 #include <linux/jump_label.h>
 
 extern struct static_key_false disable_kuap_key;
-extern struct static_key_false disable_kuep_key;
 
 static __always_inline bool kuap_is_disabled(void)
 {
@@ -21,7 +20,7 @@ static __always_inline bool kuap_is_disabled(void)
 
 static __always_inline bool kuep_is_disabled(void)
 {
-       return !IS_ENABLED(CONFIG_PPC_KUEP) || static_branch_unlikely(&disable_kuep_key);
+       return !IS_ENABLED(CONFIG_PPC_KUEP);
 }
 
 static inline void kuep_lock(void)

diff --git a/arch/powerpc/mm/book3s32/kuep.c b/arch/powerpc/mm/book3s32/kuep.c
index c20733d6e02cb6013b847f2a7ba315b480984582..8474edce3df9a28d82d87da9658b3da1a14f61d6 100644 (file)
--- a/arch/powerpc/mm/book3s32/kuep.c
+++ b/arch/powerpc/mm/book3s32/kuep.c
@@ -3,18 +3,12 @@
 #include <asm/kup.h>
 #include <asm/smp.h>
 
-struct static_key_false disable_kuep_key;
-
 void setup_kuep(bool disabled)
 {
-       if (!disabled)
-               kuep_lock();
+       kuep_lock();
 
        if (smp_processor_id() != boot_cpuid)
                return;
 
-       if (disabled)
-               static_branch_enable(&disable_kuep_key);
-       else
-               pr_info("Activating Kernel Userspace Execution Prevention\n");
+       pr_info("Activating Kernel Userspace Execution Prevention\n");
 }