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Diffstat (limited to '')
-rw-r--r-- | arch/powerpc/include/asm/nohash/kup-booke.h | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/nohash/kup-booke.h b/arch/powerpc/include/asm/nohash/kup-booke.h new file mode 100644 index 0000000000..0c7c325813 --- /dev/null +++ b/arch/powerpc/include/asm/nohash/kup-booke.h @@ -0,0 +1,112 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_POWERPC_KUP_BOOKE_H_ +#define _ASM_POWERPC_KUP_BOOKE_H_ + +#include <asm/bug.h> +#include <asm/mmu.h> + +#ifdef CONFIG_PPC_KUAP + +#ifdef __ASSEMBLY__ + +.macro kuap_check_amr gpr1, gpr2 +.endm + +#else + +#include <linux/sched.h> + +#include <asm/reg.h> + +static __always_inline void __kuap_lock(void) +{ + mtspr(SPRN_PID, 0); + isync(); +} +#define __kuap_lock __kuap_lock + +static __always_inline void __kuap_save_and_lock(struct pt_regs *regs) +{ + regs->kuap = mfspr(SPRN_PID); + mtspr(SPRN_PID, 0); + isync(); +} +#define __kuap_save_and_lock __kuap_save_and_lock + +static __always_inline void kuap_user_restore(struct pt_regs *regs) +{ + if (kuap_is_disabled()) + return; + + mtspr(SPRN_PID, current->thread.pid); + + /* Context synchronisation is performed by rfi */ +} + +static __always_inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap) +{ + if (regs->kuap) + mtspr(SPRN_PID, current->thread.pid); + + /* Context synchronisation is performed by rfi */ +} + +#ifdef CONFIG_PPC_KUAP_DEBUG +static __always_inline unsigned long __kuap_get_and_assert_locked(void) +{ + WARN_ON_ONCE(mfspr(SPRN_PID)); + + return 0; +} +#define __kuap_get_and_assert_locked __kuap_get_and_assert_locked +#endif + +static __always_inline void uaccess_begin_booke(unsigned long val) +{ + asm(ASM_MMU_FTR_IFSET("mtspr %0, %1; isync", "", %2) : : + "i"(SPRN_PID), "r"(val), "i"(MMU_FTR_KUAP) : "memory"); +} + +static __always_inline void uaccess_end_booke(void) +{ + asm(ASM_MMU_FTR_IFSET("mtspr %0, %1; isync", "", %2) : : + "i"(SPRN_PID), "r"(0), "i"(MMU_FTR_KUAP) : "memory"); +} + +static __always_inline void allow_user_access(void __user *to, const void __user *from, + unsigned long size, unsigned long dir) +{ + uaccess_begin_booke(current->thread.pid); +} + +static __always_inline void prevent_user_access(unsigned long dir) +{ + uaccess_end_booke(); +} + +static __always_inline unsigned long prevent_user_access_return(void) +{ + unsigned long flags = mfspr(SPRN_PID); + + uaccess_end_booke(); + + return flags; +} + +static __always_inline void restore_user_access(unsigned long flags) +{ + if (flags) + uaccess_begin_booke(current->thread.pid); +} + +static __always_inline bool +__bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write) +{ + return !regs->kuap; +} + +#endif /* !__ASSEMBLY__ */ + +#endif /* CONFIG_PPC_KUAP */ + +#endif /* _ASM_POWERPC_KUP_BOOKE_H_ */ |