1 files changed, 126 insertions, 0 deletions
diff --git a/arch/x86/include/asm/unwind.h b/arch/x86/include/asm/unwind.h
new file mode 100644
index 000000000..70fc159eb
--- /dev/null
+++ b/arch/x86/include/asm/unwind.h
@@ -0,0 +1,126 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_UNWIND_H
+#define _ASM_X86_UNWIND_H
+
+#include <linux/sched.h>
+#include <linux/ftrace.h>
+#include <asm/ptrace.h>
+#include <asm/stacktrace.h>
+
+#define IRET_FRAME_OFFSET (offsetof(struct pt_regs, ip))
+#define IRET_FRAME_SIZE   (sizeof(struct pt_regs) - IRET_FRAME_OFFSET)
+
+struct unwind_state {
+	struct stack_info stack_info;
+	unsigned long stack_mask;
+	struct task_struct *task;
+	int graph_idx;
+	bool error;
+#if defined(CONFIG_UNWINDER_ORC)
+	bool signal, full_regs;
+	unsigned long sp, bp, ip;
+	struct pt_regs *regs, *prev_regs;
+#elif defined(CONFIG_UNWINDER_FRAME_POINTER)
+	bool got_irq;
+	unsigned long *bp, *orig_sp, ip;
+	/*
+	 * If non-NULL: The current frame is incomplete and doesn't contain a
+	 * valid BP. When looking for the next frame, use this instead of the
+	 * non-existent saved BP.
+	 */
+	unsigned long *next_bp;
+	struct pt_regs *regs;
+#else
+	unsigned long *sp;
+#endif
+};
+
+void __unwind_start(struct unwind_state *state, struct task_struct *task,
+		    struct pt_regs *regs, unsigned long *first_frame);
+bool unwind_next_frame(struct unwind_state *state);
+unsigned long unwind_get_return_address(struct unwind_state *state);
+unsigned long *unwind_get_return_address_ptr(struct unwind_state *state);
+
+static inline bool unwind_done(struct unwind_state *state)
+{
+	return state->stack_info.type == STACK_TYPE_UNKNOWN;
+}
+
+static inline bool unwind_error(struct unwind_state *state)
+{
+	return state->error;
+}
+
+static inline
+void unwind_start(struct unwind_state *state, struct task_struct *task,
+		  struct pt_regs *regs, unsigned long *first_frame)
+{
+	first_frame = first_frame ? : get_stack_pointer(task, regs);
+
+	__unwind_start(state, task, regs, first_frame);
+}
+
+#if defined(CONFIG_UNWINDER_ORC) || defined(CONFIG_UNWINDER_FRAME_POINTER)
+/*
+ * If 'partial' returns true, only the iret frame registers are valid.
+ */
+static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state,
+						    bool *partial)
+{
+	if (unwind_done(state))
+		return NULL;
+
+	if (partial) {
+#ifdef CONFIG_UNWINDER_ORC
+		*partial = !state->full_regs;
+#else
+		*partial = false;
+#endif
+	}
+
+	return state->regs;
+}
+#else
+static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state,
+						    bool *partial)
+{
+	return NULL;
+}
+#endif
+
+#ifdef CONFIG_UNWINDER_ORC
+void unwind_init(void);
+void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size,
+			void *orc, size_t orc_size);
+#else
+static inline void unwind_init(void) {}
+static inline
+void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size,
+			void *orc, size_t orc_size) {}
+#endif
+
+/*
+ * This disables KASAN checking when reading a value from another task's stack,
+ * since the other task could be running on another CPU and could have poisoned
+ * the stack in the meantime.
+ */
+#define READ_ONCE_TASK_STACK(task, x)			\
+({							\
+	unsigned long val;				\
+	if (task == current)				\
+		val = READ_ONCE(x);			\
+	else						\
+		val = READ_ONCE_NOCHECK(x);		\
+	val;						\
+})
+
+static inline bool task_on_another_cpu(struct task_struct *task)
+{
+#ifdef CONFIG_SMP
+	return task != current && task->on_cpu;
+#else
+	return false;
+#endif
+}
+
+#endif /* _ASM_X86_UNWIND_H */