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-rw-r--r--arch/powerpc/include/asm/nohash/kup-booke.h110
1 files changed, 110 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/nohash/kup-booke.h b/arch/powerpc/include/asm/nohash/kup-booke.h
new file mode 100644
index 000000000..49bb41ed0
--- /dev/null
+++ b/arch/powerpc/include/asm/nohash/kup-booke.h
@@ -0,0 +1,110 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_POWERPC_KUP_BOOKE_H_
+#define _ASM_POWERPC_KUP_BOOKE_H_
+
+#include <asm/bug.h>
+
+#ifdef CONFIG_PPC_KUAP
+
+#ifdef __ASSEMBLY__
+
+.macro kuap_check_amr gpr1, gpr2
+.endm
+
+#else
+
+#include <linux/jump_label.h>
+#include <linux/sched.h>
+
+#include <asm/reg.h>
+
+extern struct static_key_false disable_kuap_key;
+
+static __always_inline bool kuap_is_disabled(void)
+{
+ return static_branch_unlikely(&disable_kuap_key);
+}
+
+static inline void __kuap_lock(void)
+{
+ mtspr(SPRN_PID, 0);
+ isync();
+}
+
+static inline void __kuap_save_and_lock(struct pt_regs *regs)
+{
+ regs->kuap = mfspr(SPRN_PID);
+ mtspr(SPRN_PID, 0);
+ isync();
+}
+
+static inline void kuap_user_restore(struct pt_regs *regs)
+{
+ if (kuap_is_disabled())
+ return;
+
+ mtspr(SPRN_PID, current->thread.pid);
+
+ /* Context synchronisation is performed by rfi */
+}
+
+static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
+{
+ if (regs->kuap)
+ mtspr(SPRN_PID, current->thread.pid);
+
+ /* Context synchronisation is performed by rfi */
+}
+
+static inline unsigned long __kuap_get_and_assert_locked(void)
+{
+ unsigned long kuap = mfspr(SPRN_PID);
+
+ if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))
+ WARN_ON_ONCE(kuap);
+
+ return kuap;
+}
+
+static inline void __allow_user_access(void __user *to, const void __user *from,
+ unsigned long size, unsigned long dir)
+{
+ mtspr(SPRN_PID, current->thread.pid);
+ isync();
+}
+
+static inline void __prevent_user_access(unsigned long dir)
+{
+ mtspr(SPRN_PID, 0);
+ isync();
+}
+
+static inline unsigned long __prevent_user_access_return(void)
+{
+ unsigned long flags = mfspr(SPRN_PID);
+
+ mtspr(SPRN_PID, 0);
+ isync();
+
+ return flags;
+}
+
+static inline void __restore_user_access(unsigned long flags)
+{
+ if (flags) {
+ mtspr(SPRN_PID, current->thread.pid);
+ isync();
+ }
+}
+
+static inline bool
+__bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+{
+ return !regs->kuap;
+}
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* CONFIG_PPC_KUAP */
+
+#endif /* _ASM_POWERPC_KUP_BOOKE_H_ */