191 lines
3.8 KiB
C
191 lines
3.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_POWERPC_BOOK3S_32_KUP_H
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#define _ASM_POWERPC_BOOK3S_32_KUP_H
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#include <asm/bug.h>
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#include <asm/book3s/32/mmu-hash.h>
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#include <asm/mmu.h>
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#include <asm/synch.h>
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#ifndef __ASSEMBLY__
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#include <linux/jump_label.h>
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extern struct static_key_false disable_kuap_key;
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static __always_inline bool kuep_is_disabled(void)
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{
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return !IS_ENABLED(CONFIG_PPC_KUEP);
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}
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#ifdef CONFIG_PPC_KUAP
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#include <linux/sched.h>
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#define KUAP_NONE (~0UL)
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#define KUAP_ALL (~1UL)
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static __always_inline bool kuap_is_disabled(void)
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{
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return static_branch_unlikely(&disable_kuap_key);
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}
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static inline void kuap_lock_one(unsigned long addr)
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{
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mtsr(mfsr(addr) | SR_KS, addr);
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isync(); /* Context sync required after mtsr() */
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}
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static inline void kuap_unlock_one(unsigned long addr)
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{
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mtsr(mfsr(addr) & ~SR_KS, addr);
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isync(); /* Context sync required after mtsr() */
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}
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static inline void kuap_lock_all(void)
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{
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update_user_segments(mfsr(0) | SR_KS);
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isync(); /* Context sync required after mtsr() */
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}
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static inline void kuap_unlock_all(void)
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{
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update_user_segments(mfsr(0) & ~SR_KS);
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isync(); /* Context sync required after mtsr() */
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}
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void kuap_lock_all_ool(void);
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void kuap_unlock_all_ool(void);
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static inline void kuap_lock_addr(unsigned long addr, bool ool)
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{
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if (likely(addr != KUAP_ALL))
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kuap_lock_one(addr);
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else if (!ool)
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kuap_lock_all();
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else
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kuap_lock_all_ool();
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}
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static inline void kuap_unlock(unsigned long addr, bool ool)
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{
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if (likely(addr != KUAP_ALL))
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kuap_unlock_one(addr);
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else if (!ool)
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kuap_unlock_all();
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else
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kuap_unlock_all_ool();
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}
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static inline void __kuap_lock(void)
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{
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}
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static inline void __kuap_save_and_lock(struct pt_regs *regs)
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{
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unsigned long kuap = current->thread.kuap;
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regs->kuap = kuap;
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if (unlikely(kuap == KUAP_NONE))
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return;
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current->thread.kuap = KUAP_NONE;
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kuap_lock_addr(kuap, false);
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}
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static inline void kuap_user_restore(struct pt_regs *regs)
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{
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}
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static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
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{
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if (unlikely(kuap != KUAP_NONE)) {
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current->thread.kuap = KUAP_NONE;
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kuap_lock_addr(kuap, false);
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}
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if (likely(regs->kuap == KUAP_NONE))
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return;
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current->thread.kuap = regs->kuap;
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kuap_unlock(regs->kuap, false);
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}
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static inline unsigned long __kuap_get_and_assert_locked(void)
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{
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unsigned long kuap = current->thread.kuap;
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WARN_ON_ONCE(IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && kuap != KUAP_NONE);
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return kuap;
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}
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static __always_inline void __allow_user_access(void __user *to, const void __user *from,
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u32 size, unsigned long dir)
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{
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BUILD_BUG_ON(!__builtin_constant_p(dir));
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if (!(dir & KUAP_WRITE))
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return;
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current->thread.kuap = (__force u32)to;
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kuap_unlock_one((__force u32)to);
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}
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static __always_inline void __prevent_user_access(unsigned long dir)
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{
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u32 kuap = current->thread.kuap;
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BUILD_BUG_ON(!__builtin_constant_p(dir));
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if (!(dir & KUAP_WRITE))
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return;
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current->thread.kuap = KUAP_NONE;
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kuap_lock_addr(kuap, true);
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}
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static inline unsigned long __prevent_user_access_return(void)
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{
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unsigned long flags = current->thread.kuap;
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if (flags != KUAP_NONE) {
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current->thread.kuap = KUAP_NONE;
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kuap_lock_addr(flags, true);
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}
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return flags;
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}
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static inline void __restore_user_access(unsigned long flags)
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{
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if (flags != KUAP_NONE) {
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current->thread.kuap = flags;
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kuap_unlock(flags, true);
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}
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}
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static inline bool
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__bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
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{
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unsigned long kuap = regs->kuap;
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if (!is_write || kuap == KUAP_ALL)
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return false;
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if (kuap == KUAP_NONE)
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return true;
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/* If faulting address doesn't match unlocked segment, unlock all */
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if ((kuap ^ address) & 0xf0000000)
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regs->kuap = KUAP_ALL;
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return false;
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}
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#endif /* CONFIG_PPC_KUAP */
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#endif /* __ASSEMBLY__ */
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#endif /* _ASM_POWERPC_BOOK3S_32_KUP_H */
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