Commit ad2d2344 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/64s: Make kuap_check_amr() and kuap_get_and_check_amr() generic 



In preparation of porting powerpc32 to C syscall entry/exit,
rename kuap_check_amr() and kuap_get_and_check_amr() as
kuap_assert_locked() and kuap_get_and_assert_locked(), and move in the
generic asm/kup.h the stub for when CONFIG_PPC_KUAP is not selected.

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: default avatarNicholas Piggin <npiggin@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f82614d9b17b83abd739aa18fc08811815d0c2e3.1615552867.git.christophe.leroy@csgroup.eu
parent b5efec00

arch/powerpc/include/asm/book3s/64/kup.h

+2 −22
Original line number Diff line number Diff line
@@ -287,7 +287,7 @@ static inline void kuap_kernel_restore(struct pt_regs *regs, 
	 */

}



static inline unsigned long kuap_get_and_check_amr(void)

static inline unsigned long kuap_get_and_assert_locked(void)

{

	if (mmu_has_feature(MMU_FTR_BOOK3S_KUAP)) {

		unsigned long amr = mfspr(SPRN_AMR);
@@ -298,27 +298,7 @@ static inline unsigned long kuap_get_and_check_amr(void) 
	return 0;

}



#else /* CONFIG_PPC_PKEY */



static inline void kuap_user_restore(struct pt_regs *regs)

{

}



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

{

}



static inline unsigned long kuap_get_and_check_amr(void)

{

	return 0;

}



#endif /* CONFIG_PPC_PKEY */





#ifdef CONFIG_PPC_KUAP



static inline void kuap_check_amr(void)

static inline void kuap_assert_locked(void)

{

	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && mmu_has_feature(MMU_FTR_BOOK3S_KUAP))

		WARN_ON_ONCE(mfspr(SPRN_AMR) != AMR_KUAP_BLOCKED);

arch/powerpc/include/asm/kup.h

+9 −1
Original line number Diff line number Diff line
@@ -74,7 +74,15 @@ bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write) 
	return false;

}



static inline void kuap_check_amr(void) { }

static inline void kuap_assert_locked(void) { }

static inline void kuap_save_and_lock(struct pt_regs *regs) { }

static inline void kuap_user_restore(struct pt_regs *regs) { }

static inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long amr) { }



static inline unsigned long kuap_get_and_assert_locked(void)

{

	return 0;

}



/*

 * book3s/64/kup-radix.h defines these functions for the !KUAP case to flush

arch/powerpc/kernel/interrupt.c

+6 −6
Original line number Diff line number Diff line
@@ -76,7 +76,7 @@ notrace long system_call_exception(long r3, long r4, long r5, 
	} else

#endif

#ifdef CONFIG_PPC64

		kuap_check_amr();

		kuap_assert_locked();

#endif



	booke_restore_dbcr0();
@@ -254,7 +254,7 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3, 
	CT_WARN_ON(ct_state() == CONTEXT_USER);



#ifdef CONFIG_PPC64

	kuap_check_amr();

	kuap_assert_locked();

#endif



	regs->result = r3;
@@ -380,7 +380,7 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned 
	 * AMR can only have been unlocked if we interrupted the kernel.

	 */

#ifdef CONFIG_PPC64

	kuap_check_amr();

	kuap_assert_locked();

#endif



	local_irq_save(flags);
@@ -451,7 +451,7 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsign 
	unsigned long flags;

	unsigned long ret = 0;

#ifdef CONFIG_PPC64

	unsigned long amr;

	unsigned long kuap;

#endif



	if (!IS_ENABLED(CONFIG_BOOKE) && !IS_ENABLED(CONFIG_40x) &&
@@ -467,7 +467,7 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsign 
		CT_WARN_ON(ct_state() == CONTEXT_USER);



#ifdef CONFIG_PPC64

	amr = kuap_get_and_check_amr();

	kuap = kuap_get_and_assert_locked();

#endif



	if (unlikely(current_thread_info()->flags & _TIF_EMULATE_STACK_STORE)) {
@@ -511,7 +511,7 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsign 
	 * value from the check above.

	 */

#ifdef CONFIG_PPC64

	kuap_kernel_restore(regs, amr);

	kuap_kernel_restore(regs, kuap);

#endif



	return ret;

arch/powerpc/kernel/irq.c

+1 −1
Original line number Diff line number Diff line
@@ -282,7 +282,7 @@ static inline void replay_soft_interrupts_irqrestore(void) 
	 * and re-locking AMR but we shouldn't get here in the first place,

	 * hence the warning.

	 */

	kuap_check_amr();

	kuap_assert_locked();



	if (kuap_state != AMR_KUAP_BLOCKED)

		set_kuap(AMR_KUAP_BLOCKED);