Commit 21eb58ae authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/32s: 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 book3s/32.

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/2be8fb729da4a0f9863b25e1b9d547174fcd5056.1615552867.git.christophe.leroy@csgroup.eu
parent ad2d2344

arch/powerpc/include/asm/book3s/32/kup.h

+45 −0
Original line number Diff line number Diff line
@@ -72,6 +72,51 @@ static inline void kuap_update_sr(u32 sr, u32 addr, u32 end) 
	isync();	/* Context sync required after mtsr() */

}



static inline void kuap_save_and_lock(struct pt_regs *regs)

{

	unsigned long kuap = current->thread.kuap;

	u32 addr = kuap & 0xf0000000;

	u32 end = kuap << 28;



	regs->kuap = kuap;

	if (unlikely(!kuap))

		return;



	current->thread.kuap = 0;

	kuap_update_sr(mfsr(addr) | SR_KS, addr, end);	/* Set Ks */

}



static inline void kuap_user_restore(struct pt_regs *regs)

{

}



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

{

	u32 addr = regs->kuap & 0xf0000000;

	u32 end = regs->kuap << 28;



	current->thread.kuap = regs->kuap;



	if (unlikely(regs->kuap == kuap))

		return;



	kuap_update_sr(mfsr(addr) & ~SR_KS, addr, end);	/* Clear Ks */

}



static inline unsigned long kuap_get_and_assert_locked(void)

{

	unsigned long kuap = current->thread.kuap;



	WARN_ON_ONCE(IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && kuap != 0);



	return kuap;

}



static inline void kuap_assert_locked(void)

{

	kuap_get_and_assert_locked();

}



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

					      u32 size, unsigned long dir)

{