Commit 42e03bc5 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/kuap: Prepare for supporting KUAP on BOOK3E/64 



Also call kuap_lock() and kuap_save_and_lock() from
interrupt functions with CONFIG_PPC64.

For book3s/64 we keep them empty as it is done in assembly.

Also do the locked assert when switching task unless it is
book3s/64.

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/1cbf94e26e6d6e2e028fd687588a7e6622d454a6.1634627931.git.christophe.leroy@csgroup.eu
parent 047a6fd4

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

+9 −0
Original line number Diff line number Diff line
@@ -298,6 +298,15 @@ static inline unsigned long __kuap_get_and_assert_locked(void) 
	return amr;

}



/* Do nothing, book3s/64 does that in ASM */

static inline void __kuap_lock(void)

{

}



static inline void __kuap_save_and_lock(struct pt_regs *regs)

{

}



/*

 * We support individually allowing read or write, but we don't support nesting

 * because that would require an expensive read/modify write of the AMR.

arch/powerpc/include/asm/interrupt.h

+2 −0
Original line number Diff line number Diff line
@@ -154,12 +154,14 @@ static inline void interrupt_enter_prepare(struct pt_regs *regs, struct interrup 
	local_paca->irq_happened |= PACA_IRQ_HARD_DIS;



	if (user_mode(regs)) {

		kuap_lock();

		CT_WARN_ON(ct_state() != CONTEXT_USER);

		user_exit_irqoff();



		account_cpu_user_entry();

		account_stolen_time();

	} else {

		kuap_save_and_lock(regs);

		/*

		 * CT_WARN_ON comes here via program_check_exception,

		 * so avoid recursion.

arch/powerpc/include/asm/kup.h

+0 −2
Original line number Diff line number Diff line
@@ -91,7 +91,6 @@ static __always_inline void kuap_assert_locked(void) 
		__kuap_get_and_assert_locked();

}



#ifdef CONFIG_PPC32

static __always_inline void kuap_lock(void)

{

	if (kuap_is_disabled())
@@ -107,7 +106,6 @@ static __always_inline void kuap_save_and_lock(struct pt_regs *regs) 


	__kuap_save_and_lock(regs);

}

#endif



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

{

arch/powerpc/kernel/process.c

+3 −3
Original line number Diff line number Diff line
@@ -1315,9 +1315,9 @@ struct task_struct *__switch_to(struct task_struct *prev, 


	set_return_regs_changed(); /* _switch changes stack (and regs) */



#ifdef CONFIG_PPC32

	if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64))

		kuap_assert_locked();

#endif



	last = _switch(old_thread, new_thread);



	/*