Commit 0b45359a authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/8xx: Create C version of kuap save/restore/check helpers 



In preparation of porting PPC32 to C syscall entry/exit,
create C version of kuap_save_and_lock() and kuap_user_restore() and
kuap_kernel_restore() and kuap_assert_locked() and
kuap_get_and_assert_locked() on 8xx.

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156a7c4b669d26785391422a5581a1d919544c9a.1615552867.git.christophe.leroy@csgroup.eu
parent 21eb58ae

arch/powerpc/include/asm/nohash/32/kup-8xx.h

+31 −0
Original line number Diff line number Diff line
@@ -34,6 +34,37 @@ 


#include <asm/reg.h>



static inline void kuap_save_and_lock(struct pt_regs *regs)

{

	regs->kuap = mfspr(SPRN_MD_AP);

	mtspr(SPRN_MD_AP, MD_APG_KUAP);

}



static inline void kuap_user_restore(struct pt_regs *regs)

{

}



static inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)

{

	mtspr(SPRN_MD_AP, regs->kuap);

}



static inline unsigned long kuap_get_and_assert_locked(void)

{

	unsigned long kuap = mfspr(SPRN_MD_AP);



	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))

		WARN_ON_ONCE(kuap >> 16 != MD_APG_KUAP >> 16);



	return kuap;

}



static inline void kuap_assert_locked(void)

{

	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))

		kuap_get_and_assert_locked();

}



static inline void allow_user_access(void __user *to, const void __user *from,

				     unsigned long size, unsigned long dir)

{