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 | 205 |
1 files changed, 0 insertions, 205 deletions
diff --git a/arch/powerpc/include/asm/book3s/64/kup-radix.h b/arch/powerpc/include/asm/book3s/64/kup-radix.h deleted file mode 100644 index a39e2d193fdc..000000000000 --- a/arch/powerpc/include/asm/book3s/64/kup-radix.h +++ /dev/null @@ -1,205 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _ASM_POWERPC_BOOK3S_64_KUP_RADIX_H -#define _ASM_POWERPC_BOOK3S_64_KUP_RADIX_H - -#include <linux/const.h> -#include <asm/reg.h> - -#define AMR_KUAP_BLOCK_READ UL(0x4000000000000000) -#define AMR_KUAP_BLOCK_WRITE UL(0x8000000000000000) -#define AMR_KUAP_BLOCKED (AMR_KUAP_BLOCK_READ | AMR_KUAP_BLOCK_WRITE) -#define AMR_KUAP_SHIFT 62 - -#ifdef __ASSEMBLY__ - -.macro kuap_restore_amr gpr1, gpr2 -#ifdef CONFIG_PPC_KUAP - BEGIN_MMU_FTR_SECTION_NESTED(67) - mfspr \gpr1, SPRN_AMR - ld \gpr2, STACK_REGS_KUAP(r1) - cmpd \gpr1, \gpr2 - beq 998f - isync - mtspr SPRN_AMR, \gpr2 - /* No isync required, see kuap_restore_amr() */ -998: - END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_RADIX_KUAP, 67) -#endif -.endm - -#ifdef CONFIG_PPC_KUAP -.macro kuap_check_amr gpr1, gpr2 -#ifdef CONFIG_PPC_KUAP_DEBUG - BEGIN_MMU_FTR_SECTION_NESTED(67) - mfspr \gpr1, SPRN_AMR - li \gpr2, (AMR_KUAP_BLOCKED >> AMR_KUAP_SHIFT) - sldi \gpr2, \gpr2, AMR_KUAP_SHIFT -999: tdne \gpr1, \gpr2 - EMIT_BUG_ENTRY 999b, __FILE__, __LINE__, (BUGFLAG_WARNING | BUGFLAG_ONCE) - 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 - BEGIN_MMU_FTR_SECTION_NESTED(67) - .ifnb \msr_pr_cr - bne \msr_pr_cr, 99f - .endif - mfspr \gpr1, SPRN_AMR - std \gpr1, STACK_REGS_KUAP(r1) - li \gpr2, (AMR_KUAP_BLOCKED >> AMR_KUAP_SHIFT) - sldi \gpr2, \gpr2, AMR_KUAP_SHIFT - cmpd \use_cr, \gpr1, \gpr2 - beq \use_cr, 99f - // We don't isync here because we very recently entered via rfid - mtspr SPRN_AMR, \gpr2 - isync -99: - END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_RADIX_KUAP, 67) -#endif -.endm - -#else /* !__ASSEMBLY__ */ - -#include <linux/jump_label.h> - -DECLARE_STATIC_KEY_FALSE(uaccess_flush_key); - -#ifdef CONFIG_PPC_KUAP - -#include <asm/mmu.h> -#include <asm/ptrace.h> - -static inline void kuap_restore_amr(struct pt_regs *regs, unsigned long amr) -{ - if (mmu_has_feature(MMU_FTR_RADIX_KUAP) && unlikely(regs->kuap != amr)) { - isync(); - mtspr(SPRN_AMR, regs->kuap); - /* - * No isync required here because we are about to RFI back to - * previous context before any user accesses would be made, - * which is a CSI. - */ - } -} - -static inline unsigned long kuap_get_and_check_amr(void) -{ - if (mmu_has_feature(MMU_FTR_RADIX_KUAP)) { - unsigned long amr = mfspr(SPRN_AMR); - if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG)) /* kuap_check_amr() */ - WARN_ON_ONCE(amr != AMR_KUAP_BLOCKED); - return amr; - } - return 0; -} - -static inline void kuap_check_amr(void) -{ - if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && mmu_has_feature(MMU_FTR_RADIX_KUAP)) - WARN_ON_ONCE(mfspr(SPRN_AMR) != AMR_KUAP_BLOCKED); -} - -/* - * 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. - */ - -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 AMR_KUAP_BLOCKED; - - return mfspr(SPRN_AMR); -} - -static inline void set_kuap(unsigned long value) -{ - if (!early_mmu_has_feature(MMU_FTR_RADIX_KUAP)) - return; - - /* - * ISA v3.0B says we need a CSI (Context Synchronising Instruction) both - * before and after the move to AMR. See table 6 on page 1134. - */ - isync(); - mtspr(SPRN_AMR, 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) -{ - // This is written so we can resolve to a single case at build time - BUILD_BUG_ON(!__builtin_constant_p(dir)); - if (dir == KUAP_READ) - set_kuap(AMR_KUAP_BLOCK_WRITE); - else if (dir == KUAP_WRITE) - set_kuap(AMR_KUAP_BLOCK_READ); - else if (dir == KUAP_READ_WRITE) - set_kuap(0); - else - BUILD_BUG(); -} - -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) -{ - unsigned long flags = get_kuap(); - - set_kuap(AMR_KUAP_BLOCKED); - if (static_branch_unlikely(&uaccess_flush_key)) - do_uaccess_flush(); - - return flags; -} - -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(); -} -#endif /* __ASSEMBLY__ */ - -#endif /* _ASM_POWERPC_BOOK3S_64_KUP_RADIX_H */ |