1 files changed, 54 insertions, 69 deletions

diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h
index 678f9c9d89b6..4e14a5427a63 100644
--- a/arch/powerpc/include/asm/book3s/32/kup.h
+++ b/arch/powerpc/include/asm/book3s/32/kup.h
@@ -9,79 +9,53 @@
 
 #ifndef __ASSEMBLY__
 
-#include <linux/jump_label.h>
-
-extern struct static_key_false disable_kuap_key;
-
-static __always_inline bool kuep_is_disabled(void)
-{
-	return !IS_ENABLED(CONFIG_PPC_KUEP);
-}
-
 #ifdef CONFIG_PPC_KUAP
 
 #include <linux/sched.h>
 
 #define KUAP_NONE	(~0UL)
-#define KUAP_ALL	(~1UL)
 
-static __always_inline bool kuap_is_disabled(void)
-{
-	return static_branch_unlikely(&disable_kuap_key);
-}
-
-static inline void kuap_lock_one(unsigned long addr)
+static __always_inline void kuap_lock_one(unsigned long addr)
 {
 	mtsr(mfsr(addr) | SR_KS, addr);
 	isync();	/* Context sync required after mtsr() */
 }
 
-static inline void kuap_unlock_one(unsigned long addr)
+static __always_inline void kuap_unlock_one(unsigned long addr)
 {
 	mtsr(mfsr(addr) & ~SR_KS, addr);
 	isync();	/* Context sync required after mtsr() */
 }
 
-static inline void kuap_lock_all(void)
+static __always_inline void uaccess_begin_32s(unsigned long addr)
 {
-	update_user_segments(mfsr(0) | SR_KS);
-	isync();	/* Context sync required after mtsr() */
-}
+	unsigned long tmp;
 
-static inline void kuap_unlock_all(void)
-{
-	update_user_segments(mfsr(0) & ~SR_KS);
-	isync();	/* Context sync required after mtsr() */
+	asm volatile(ASM_MMU_FTR_IFSET(
+		"mfsrin %0, %1;"
+		"rlwinm %0, %0, 0, %2;"
+		"mtsrin %0, %1;"
+		"isync", "", %3)
+		: "=&r"(tmp)
+		: "r"(addr), "i"(~SR_KS), "i"(MMU_FTR_KUAP)
+		: "memory");
 }
 
-void kuap_lock_all_ool(void);
-void kuap_unlock_all_ool(void);
-
-static inline void kuap_lock_addr(unsigned long addr, bool ool)
+static __always_inline void uaccess_end_32s(unsigned long addr)
 {
-	if (likely(addr != KUAP_ALL))
-		kuap_lock_one(addr);
-	else if (!ool)
-		kuap_lock_all();
-	else
-		kuap_lock_all_ool();
-}
+	unsigned long tmp;
 
-static inline void kuap_unlock(unsigned long addr, bool ool)
-{
-	if (likely(addr != KUAP_ALL))
-		kuap_unlock_one(addr);
-	else if (!ool)
-		kuap_unlock_all();
-	else
-		kuap_unlock_all_ool();
+	asm volatile(ASM_MMU_FTR_IFSET(
+		"mfsrin %0, %1;"
+		"oris %0, %0, %2;"
+		"mtsrin %0, %1;"
+		"isync", "", %3)
+		: "=&r"(tmp)
+		: "r"(addr), "i"(SR_KS >> 16), "i"(MMU_FTR_KUAP)
+		: "memory");
 }
 
-static inline void __kuap_lock(void)
-{
-}
-
-static inline void __kuap_save_and_lock(struct pt_regs *regs)
+static __always_inline void __kuap_save_and_lock(struct pt_regs *regs)
 {
 	unsigned long kuap = current->thread.kuap;
 
@@ -90,18 +64,19 @@ static inline void __kuap_save_and_lock(struct pt_regs *regs)
 		return;
 
 	current->thread.kuap = KUAP_NONE;
-	kuap_lock_addr(kuap, false);
+	kuap_lock_one(kuap);
 }
+#define __kuap_save_and_lock __kuap_save_and_lock
 
-static inline void kuap_user_restore(struct pt_regs *regs)
+static __always_inline void kuap_user_restore(struct pt_regs *regs)
 {
 }
 
-static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
+static __always_inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
 {
 	if (unlikely(kuap != KUAP_NONE)) {
 		current->thread.kuap = KUAP_NONE;
-		kuap_lock_addr(kuap, false);
+		kuap_lock_one(kuap);
 	}
 
 	if (likely(regs->kuap == KUAP_NONE))
@@ -109,10 +84,10 @@ static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kua
 
 	current->thread.kuap = regs->kuap;
 
-	kuap_unlock(regs->kuap, false);
+	kuap_unlock_one(regs->kuap);
 }
 
-static inline unsigned long __kuap_get_and_assert_locked(void)
+static __always_inline unsigned long __kuap_get_and_assert_locked(void)
 {
 	unsigned long kuap = current->thread.kuap;
 
@@ -120,9 +95,10 @@ static inline unsigned long __kuap_get_and_assert_locked(void)
 
 	return kuap;
 }
+#define __kuap_get_and_assert_locked __kuap_get_and_assert_locked
 
-static __always_inline void __allow_user_access(void __user *to, const void __user *from,
-						u32 size, unsigned long dir)
+static __always_inline void allow_user_access(void __user *to, const void __user *from,
+					      u32 size, unsigned long dir)
 {
 	BUILD_BUG_ON(!__builtin_constant_p(dir));
 
@@ -130,10 +106,10 @@ static __always_inline void __allow_user_access(void __user *to, const void __us
 		return;
 
 	current->thread.kuap = (__force u32)to;
-	kuap_unlock_one((__force u32)to);
+	uaccess_begin_32s((__force u32)to);
 }
 
-static __always_inline void __prevent_user_access(unsigned long dir)
+static __always_inline void prevent_user_access(unsigned long dir)
 {
 	u32 kuap = current->thread.kuap;
 
@@ -143,42 +119,51 @@ static __always_inline void __prevent_user_access(unsigned long dir)
 		return;
 
 	current->thread.kuap = KUAP_NONE;
-	kuap_lock_addr(kuap, true);
+	uaccess_end_32s(kuap);
 }
 
-static inline unsigned long __prevent_user_access_return(void)
+static __always_inline unsigned long prevent_user_access_return(void)
 {
 	unsigned long flags = current->thread.kuap;
 
 	if (flags != KUAP_NONE) {
 		current->thread.kuap = KUAP_NONE;
-		kuap_lock_addr(flags, true);
+		uaccess_end_32s(flags);
 	}
 
 	return flags;
 }
 
-static inline void __restore_user_access(unsigned long flags)
+static __always_inline void restore_user_access(unsigned long flags)
 {
 	if (flags != KUAP_NONE) {
 		current->thread.kuap = flags;
-		kuap_unlock(flags, true);
+		uaccess_begin_32s(flags);
 	}
 }
 
-static inline bool
+static __always_inline bool
 __bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 {
 	unsigned long kuap = regs->kuap;
 
-	if (!is_write || kuap == KUAP_ALL)
+	if (!is_write)
 		return false;
 	if (kuap == KUAP_NONE)
 		return true;
 
-	/* If faulting address doesn't match unlocked segment, unlock all */
-	if ((kuap ^ address) & 0xf0000000)
-		regs->kuap = KUAP_ALL;
+	/*
+	 * If faulting address doesn't match unlocked segment, change segment.
+	 * In case of unaligned store crossing two segments, emulate store.
+	 */
+	if ((kuap ^ address) & 0xf0000000) {
+		if (!(kuap & 0x0fffffff) && address > kuap - 4 && fix_alignment(regs)) {
+			regs_add_return_ip(regs, 4);
+			emulate_single_step(regs);
+		} else {
+			regs->kuap = address;
+		}
+	}
 
 	return false;
 }