summaryrefslogtreecommitdiffstats
path: root/arch/loongarch/include/asm/unwind.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/loongarch/include/asm/unwind.h')
-rw-r--r--arch/loongarch/include/asm/unwind.h82
1 files changed, 82 insertions, 0 deletions
diff --git a/arch/loongarch/include/asm/unwind.h b/arch/loongarch/include/asm/unwind.h
new file mode 100644
index 0000000000..b9dce87afd
--- /dev/null
+++ b/arch/loongarch/include/asm/unwind.h
@@ -0,0 +1,82 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Most of this ideas comes from x86.
+ *
+ * Copyright (C) 2022 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_UNWIND_H
+#define _ASM_UNWIND_H
+
+#include <linux/sched.h>
+#include <linux/ftrace.h>
+
+#include <asm/ptrace.h>
+#include <asm/stacktrace.h>
+
+enum unwinder_type {
+ UNWINDER_GUESS,
+ UNWINDER_PROLOGUE,
+};
+
+struct unwind_state {
+ char type; /* UNWINDER_XXX */
+ struct stack_info stack_info;
+ struct task_struct *task;
+ bool first, error, reset;
+ int graph_idx;
+ unsigned long sp, pc, ra;
+};
+
+bool default_next_frame(struct unwind_state *state);
+
+void unwind_start(struct unwind_state *state,
+ struct task_struct *task, struct pt_regs *regs);
+bool unwind_next_frame(struct unwind_state *state);
+unsigned long unwind_get_return_address(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;
+}
+
+#define GRAPH_FAKE_OFFSET (sizeof(struct pt_regs) - offsetof(struct pt_regs, regs[1]))
+
+static inline unsigned long unwind_graph_addr(struct unwind_state *state,
+ unsigned long pc, unsigned long cfa)
+{
+ return ftrace_graph_ret_addr(state->task, &state->graph_idx,
+ pc, (unsigned long *)(cfa - GRAPH_FAKE_OFFSET));
+}
+
+static __always_inline void __unwind_start(struct unwind_state *state,
+ struct task_struct *task, struct pt_regs *regs)
+{
+ memset(state, 0, sizeof(*state));
+ if (regs) {
+ state->sp = regs->regs[3];
+ state->pc = regs->csr_era;
+ state->ra = regs->regs[1];
+ } else if (task && task != current) {
+ state->sp = thread_saved_fp(task);
+ state->pc = thread_saved_ra(task);
+ state->ra = 0;
+ } else {
+ state->sp = (unsigned long)__builtin_frame_address(0);
+ state->pc = (unsigned long)__builtin_return_address(0);
+ state->ra = 0;
+ }
+ state->task = task;
+ get_stack_info(state->sp, state->task, &state->stack_info);
+ state->pc = unwind_graph_addr(state, state->pc, state->sp);
+}
+
+static __always_inline unsigned long __unwind_get_return_address(struct unwind_state *state)
+{
+ return unwind_done(state) ? 0 : state->pc;
+}
+#endif /* _ASM_UNWIND_H */