diff options
Diffstat (limited to 'arch/powerpc/include/asm/book3s/64/kup-radix.h')
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/kup-radix.h | 66 |
1 files changed, 42 insertions, 24 deletions
diff --git a/arch/powerpc/include/asm/book3s/64/kup-radix.h b/arch/powerpc/include/asm/book3s/64/kup-radix.h index 3ee1ec60be84..28716e2f13e3 100644 --- a/arch/powerpc/include/asm/book3s/64/kup-radix.h +++ b/arch/powerpc/include/asm/book3s/64/kup-radix.h @@ -27,6 +27,7 @@ #endif .endm +#ifdef CONFIG_PPC_KUAP .macro kuap_check_amr gpr1, gpr2 #ifdef CONFIG_PPC_KUAP_DEBUG BEGIN_MMU_FTR_SECTION_NESTED(67) @@ -38,6 +39,7 @@ END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_RADIX_KUAP, 67) #endif .endm +#endif .macro kuap_save_amr_and_lock gpr1, gpr2, use_cr, msr_pr_cr #ifdef CONFIG_PPC_KUAP @@ -61,6 +63,8 @@ #else /* !__ASSEMBLY__ */ +DECLARE_STATIC_KEY_FALSE(uaccess_flush_key); + #ifdef CONFIG_PPC_KUAP #include <asm/mmu.h> @@ -103,8 +107,16 @@ static inline void kuap_check_amr(void) static inline unsigned long get_kuap(void) { + /* + * We return AMR_KUAP_BLOCKED when we don't support KUAP because + * prevent_user_access_return needs to return AMR_KUAP_BLOCKED to + * cause restore_user_access to do a flush. + * + * This has no effect in terms of actually blocking things on hash, + * so it doesn't break anything. + */ if (!early_mmu_has_feature(MMU_FTR_RADIX_KUAP)) - return 0; + return AMR_KUAP_BLOCKED; return mfspr(SPRN_AMR); } @@ -123,6 +135,29 @@ static inline void set_kuap(unsigned long value) isync(); } +static inline bool +bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write) +{ + return WARN(mmu_has_feature(MMU_FTR_RADIX_KUAP) && + (regs->kuap & (is_write ? AMR_KUAP_BLOCK_WRITE : AMR_KUAP_BLOCK_READ)), + "Bug: %s fault blocked by AMR!", is_write ? "Write" : "Read"); +} +#else /* CONFIG_PPC_KUAP */ +static inline void kuap_restore_amr(struct pt_regs *regs, unsigned long amr) { } + +static inline unsigned long kuap_get_and_check_amr(void) +{ + return 0UL; +} + +static inline unsigned long get_kuap(void) +{ + return AMR_KUAP_BLOCKED; +} + +static inline void set_kuap(unsigned long value) { } +#endif /* !CONFIG_PPC_KUAP */ + static __always_inline void allow_user_access(void __user *to, const void __user *from, unsigned long size, unsigned long dir) { @@ -142,6 +177,8 @@ static inline void prevent_user_access(void __user *to, const void __user *from, unsigned long size, unsigned long dir) { set_kuap(AMR_KUAP_BLOCKED); + if (static_branch_unlikely(&uaccess_flush_key)) + do_uaccess_flush(); } static inline unsigned long prevent_user_access_return(void) @@ -149,6 +186,8 @@ static inline unsigned long prevent_user_access_return(void) unsigned long flags = get_kuap(); set_kuap(AMR_KUAP_BLOCKED); + if (static_branch_unlikely(&uaccess_flush_key)) + do_uaccess_flush(); return flags; } @@ -156,30 +195,9 @@ static inline unsigned long prevent_user_access_return(void) static inline void restore_user_access(unsigned long flags) { set_kuap(flags); + if (static_branch_unlikely(&uaccess_flush_key) && flags == AMR_KUAP_BLOCKED) + do_uaccess_flush(); } - -static inline bool -bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write) -{ - return WARN(mmu_has_feature(MMU_FTR_RADIX_KUAP) && - (regs->kuap & (is_write ? AMR_KUAP_BLOCK_WRITE : AMR_KUAP_BLOCK_READ)), - "Bug: %s fault blocked by AMR!", is_write ? "Write" : "Read"); -} -#else /* CONFIG_PPC_KUAP */ -static inline void kuap_restore_amr(struct pt_regs *regs, unsigned long amr) -{ -} - -static inline void kuap_check_amr(void) -{ -} - -static inline unsigned long kuap_get_and_check_amr(void) -{ - return 0; -} -#endif /* CONFIG_PPC_KUAP */ - #endif /* __ASSEMBLY__ */ #endif /* _ASM_POWERPC_BOOK3S_64_KUP_RADIX_H */ |