From 0b45359aa2df7b761817a9664cfb53ea3070c390 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Fri, 12 Mar 2021 12:50:50 +0000 Subject: [PATCH] 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: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/156a7c4b669d26785391422a5581a1d919544c9a.1615552867.git.christophe.leroy@csgroup.eu --- arch/powerpc/include/asm/nohash/32/kup-8xx.h | 31 ++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/arch/powerpc/include/asm/nohash/32/kup-8xx.h b/arch/powerpc/include/asm/nohash/32/kup-8xx.h index 17a4a616436f..e6b5ebca47e5 100644 --- a/arch/powerpc/include/asm/nohash/32/kup-8xx.h +++ b/arch/powerpc/include/asm/nohash/32/kup-8xx.h @@ -34,6 +34,37 @@ #include +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) {