1 files changed, 132 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
new file mode 100644
index 000000000..0d93331d0
--- /dev/null
+++ b/arch/powerpc/include/asm/kup.h
@@ -0,0 +1,132 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_POWERPC_KUP_H_
+#define _ASM_POWERPC_KUP_H_
+
+#define KUAP_READ	1
+#define KUAP_WRITE	2
+#define KUAP_READ_WRITE	(KUAP_READ | KUAP_WRITE)
+/*
+ * For prevent_user_access() only.
+ * Use the current saved situation instead of the to/from/size params.
+ * Used on book3s/32
+ */
+#define KUAP_CURRENT_READ	4
+#define KUAP_CURRENT_WRITE	8
+#define KUAP_CURRENT		(KUAP_CURRENT_READ | KUAP_CURRENT_WRITE)
+
+#ifdef CONFIG_PPC_BOOK3S_64
+#include <asm/book3s/64/kup-radix.h>
+#endif
+#ifdef CONFIG_PPC_8xx
+#include <asm/nohash/32/kup-8xx.h>
+#endif
+#ifdef CONFIG_PPC_BOOK3S_32
+#include <asm/book3s/32/kup.h>
+#endif
+
+#ifdef __ASSEMBLY__
+#ifndef CONFIG_PPC_KUAP
+.macro kuap_save_and_lock	sp, thread, gpr1, gpr2, gpr3
+.endm
+
+.macro kuap_restore	sp, current, gpr1, gpr2, gpr3
+.endm
+
+.macro kuap_check	current, gpr
+.endm
+
+.macro kuap_check_amr	gpr1, gpr2
+.endm
+
+#endif
+
+#else /* !__ASSEMBLY__ */
+
+#include <linux/pgtable.h>
+
+void setup_kup(void);
+
+#ifdef CONFIG_PPC_KUEP
+void setup_kuep(bool disabled);
+#else
+static inline void setup_kuep(bool disabled) { }
+#endif /* CONFIG_PPC_KUEP */
+
+#ifdef CONFIG_PPC_KUAP
+void setup_kuap(bool disabled);
+#else
+static inline void setup_kuap(bool disabled) { }
+
+static inline bool
+bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+{
+	return false;
+}
+
+static inline void kuap_check_amr(void) { }
+
+/*
+ * book3s/64/kup-radix.h defines these functions for the !KUAP case to flush
+ * the L1D cache after user accesses. Only include the empty stubs for other
+ * platforms.
+ */
+#ifndef CONFIG_PPC_BOOK3S_64
+static inline void allow_user_access(void __user *to, const void __user *from,
+				     unsigned long size, unsigned long dir) { }
+static inline void prevent_user_access(void __user *to, const void __user *from,
+				       unsigned long size, unsigned long dir) { }
+static inline unsigned long prevent_user_access_return(void) { return 0UL; }
+static inline void restore_user_access(unsigned long flags) { }
+#endif /* CONFIG_PPC_BOOK3S_64 */
+#endif /* CONFIG_PPC_KUAP */
+
+static inline void allow_read_from_user(const void __user *from, unsigned long size)
+{
+	allow_user_access(NULL, from, size, KUAP_READ);
+}
+
+static inline void allow_write_to_user(void __user *to, unsigned long size)
+{
+	allow_user_access(to, NULL, size, KUAP_WRITE);
+}
+
+static inline void allow_read_write_user(void __user *to, const void __user *from,
+					 unsigned long size)
+{
+	allow_user_access(to, from, size, KUAP_READ_WRITE);
+}
+
+static inline void prevent_read_from_user(const void __user *from, unsigned long size)
+{
+	prevent_user_access(NULL, from, size, KUAP_READ);
+}
+
+static inline void prevent_write_to_user(void __user *to, unsigned long size)
+{
+	prevent_user_access(to, NULL, size, KUAP_WRITE);
+}
+
+static inline void prevent_read_write_user(void __user *to, const void __user *from,
+					   unsigned long size)
+{
+	prevent_user_access(to, from, size, KUAP_READ_WRITE);
+}
+
+static inline void prevent_current_access_user(void)
+{
+	prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT);
+}
+
+static inline void prevent_current_read_from_user(void)
+{
+	prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT_READ);
+}
+
+static inline void prevent_current_write_to_user(void)
+{
+	prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT_WRITE);
+}
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* _ASM_POWERPC_KUAP_H_ */