1 files changed, 186 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..ad7e8c5ae
--- /dev/null
+++ b/arch/powerpc/include/asm/kup.h
@@ -0,0 +1,186 @@
+/* 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)
+
+#ifndef __ASSEMBLY__
+#include <linux/types.h>
+
+static __always_inline bool kuap_is_disabled(void);
+#endif
+
+#ifdef CONFIG_PPC_BOOK3S_64
+#include <asm/book3s/64/kup.h>
+#endif
+
+#ifdef CONFIG_PPC_8xx
+#include <asm/nohash/32/kup-8xx.h>
+#endif
+
+#ifdef CONFIG_BOOKE_OR_40x
+#include <asm/nohash/kup-booke.h>
+#endif
+
+#ifdef CONFIG_PPC_BOOK3S_32
+#include <asm/book3s/32/kup.h>
+#endif
+
+#ifdef __ASSEMBLY__
+#ifndef CONFIG_PPC_KUAP
+.macro kuap_check_amr	gpr1, gpr2
+.endm
+
+#endif
+
+#else /* !__ASSEMBLY__ */
+
+extern bool disable_kuep;
+extern bool disable_kuap;
+
+#include <linux/pgtable.h>
+
+void setup_kup(void);
+void setup_kuep(bool disabled);
+
+#ifdef CONFIG_PPC_KUAP
+void setup_kuap(bool disabled);
+
+static __always_inline bool kuap_is_disabled(void)
+{
+	return !mmu_has_feature(MMU_FTR_KUAP);
+}
+#else
+static inline void setup_kuap(bool disabled) { }
+
+static __always_inline bool kuap_is_disabled(void) { return true; }
+
+static __always_inline bool
+__bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+{
+	return false;
+}
+
+static __always_inline void kuap_user_restore(struct pt_regs *regs) { }
+static __always_inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long amr) { }
+
+/*
+ * 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 __always_inline void allow_user_access(void __user *to, const void __user *from,
+					      unsigned long size, unsigned long dir) { }
+static __always_inline void prevent_user_access(unsigned long dir) { }
+static __always_inline unsigned long prevent_user_access_return(void) { return 0UL; }
+static __always_inline void restore_user_access(unsigned long flags) { }
+#endif /* CONFIG_PPC_BOOK3S_64 */
+#endif /* CONFIG_PPC_KUAP */
+
+static __always_inline bool
+bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+{
+	if (kuap_is_disabled())
+		return false;
+
+	return __bad_kuap_fault(regs, address, is_write);
+}
+
+static __always_inline void kuap_lock(void)
+{
+#ifdef __kuap_lock
+	if (kuap_is_disabled())
+		return;
+
+	__kuap_lock();
+#endif
+}
+
+static __always_inline void kuap_save_and_lock(struct pt_regs *regs)
+{
+#ifdef __kuap_save_and_lock
+	if (kuap_is_disabled())
+		return;
+
+	__kuap_save_and_lock(regs);
+#endif
+}
+
+static __always_inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long amr)
+{
+	if (kuap_is_disabled())
+		return;
+
+	__kuap_kernel_restore(regs, amr);
+}
+
+static __always_inline unsigned long kuap_get_and_assert_locked(void)
+{
+#ifdef __kuap_get_and_assert_locked
+	if (!kuap_is_disabled())
+		return __kuap_get_and_assert_locked();
+#endif
+	return 0;
+}
+
+static __always_inline void kuap_assert_locked(void)
+{
+	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))
+		kuap_get_and_assert_locked();
+}
+
+static __always_inline void allow_read_from_user(const void __user *from, unsigned long size)
+{
+	barrier_nospec();
+	allow_user_access(NULL, from, size, KUAP_READ);
+}
+
+static __always_inline void allow_write_to_user(void __user *to, unsigned long size)
+{
+	allow_user_access(to, NULL, size, KUAP_WRITE);
+}
+
+static __always_inline void allow_read_write_user(void __user *to, const void __user *from,
+						  unsigned long size)
+{
+	barrier_nospec();
+	allow_user_access(to, from, size, KUAP_READ_WRITE);
+}
+
+static __always_inline void prevent_read_from_user(const void __user *from, unsigned long size)
+{
+	prevent_user_access(KUAP_READ);
+}
+
+static __always_inline void prevent_write_to_user(void __user *to, unsigned long size)
+{
+	prevent_user_access(KUAP_WRITE);
+}
+
+static __always_inline void prevent_read_write_user(void __user *to, const void __user *from,
+						    unsigned long size)
+{
+	prevent_user_access(KUAP_READ_WRITE);
+}
+
+static __always_inline void prevent_current_access_user(void)
+{
+	prevent_user_access(KUAP_READ_WRITE);
+}
+
+static __always_inline void prevent_current_read_from_user(void)
+{
+	prevent_user_access(KUAP_READ);
+}
+
+static __always_inline void prevent_current_write_to_user(void)
+{
+	prevent_user_access(KUAP_WRITE);
+}
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* _ASM_POWERPC_KUAP_H_ */