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-rw-r--r--arch/riscv/kernel/stacktrace.c146
1 files changed, 146 insertions, 0 deletions
diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c
new file mode 100644
index 000000000..17d7383f2
--- /dev/null
+++ b/arch/riscv/kernel/stacktrace.c
@@ -0,0 +1,146 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2008 ARM Limited
+ * Copyright (C) 2014 Regents of the University of California
+ */
+
+#include <linux/export.h>
+#include <linux/kallsyms.h>
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/task_stack.h>
+#include <linux/stacktrace.h>
+#include <linux/ftrace.h>
+
+#include <asm/stacktrace.h>
+
+#ifdef CONFIG_FRAME_POINTER
+
+void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
+ bool (*fn)(void *, unsigned long), void *arg)
+{
+ unsigned long fp, sp, pc;
+ int level = 0;
+
+ if (regs) {
+ fp = frame_pointer(regs);
+ sp = user_stack_pointer(regs);
+ pc = instruction_pointer(regs);
+ } else if (task == NULL || task == current) {
+ fp = (unsigned long)__builtin_frame_address(0);
+ sp = current_stack_pointer;
+ pc = (unsigned long)walk_stackframe;
+ level = -1;
+ } else {
+ /* task blocked in __switch_to */
+ fp = task->thread.s[0];
+ sp = task->thread.sp;
+ pc = task->thread.ra;
+ }
+
+ for (;;) {
+ unsigned long low, high;
+ struct stackframe *frame;
+
+ if (unlikely(!__kernel_text_address(pc) || (level++ >= 0 && !fn(arg, pc))))
+ break;
+
+ /* Validate frame pointer */
+ low = sp + sizeof(struct stackframe);
+ high = ALIGN(sp, THREAD_SIZE);
+ if (unlikely(fp < low || fp > high || fp & 0x7))
+ break;
+ /* Unwind stack frame */
+ frame = (struct stackframe *)fp - 1;
+ sp = fp;
+ if (regs && (regs->epc == pc) && (frame->fp & 0x7)) {
+ fp = frame->ra;
+ pc = regs->ra;
+ } else {
+ fp = frame->fp;
+ pc = ftrace_graph_ret_addr(current, NULL, frame->ra,
+ &frame->ra);
+ }
+
+ }
+}
+
+#else /* !CONFIG_FRAME_POINTER */
+
+void notrace walk_stackframe(struct task_struct *task,
+ struct pt_regs *regs, bool (*fn)(void *, unsigned long), void *arg)
+{
+ unsigned long sp, pc;
+ unsigned long *ksp;
+
+ if (regs) {
+ sp = user_stack_pointer(regs);
+ pc = instruction_pointer(regs);
+ } else if (task == NULL || task == current) {
+ sp = current_stack_pointer;
+ pc = (unsigned long)walk_stackframe;
+ } else {
+ /* task blocked in __switch_to */
+ sp = task->thread.sp;
+ pc = task->thread.ra;
+ }
+
+ if (unlikely(sp & 0x7))
+ return;
+
+ ksp = (unsigned long *)sp;
+ while (!kstack_end(ksp)) {
+ if (__kernel_text_address(pc) && unlikely(!fn(arg, pc)))
+ break;
+ pc = READ_ONCE_NOCHECK(*ksp++) - 0x4;
+ }
+}
+
+#endif /* CONFIG_FRAME_POINTER */
+
+static bool print_trace_address(void *arg, unsigned long pc)
+{
+ const char *loglvl = arg;
+
+ print_ip_sym(loglvl, pc);
+ return true;
+}
+
+noinline void dump_backtrace(struct pt_regs *regs, struct task_struct *task,
+ const char *loglvl)
+{
+ walk_stackframe(task, regs, print_trace_address, (void *)loglvl);
+}
+
+void show_stack(struct task_struct *task, unsigned long *sp, const char *loglvl)
+{
+ pr_cont("%sCall Trace:\n", loglvl);
+ dump_backtrace(NULL, task, loglvl);
+}
+
+static bool save_wchan(void *arg, unsigned long pc)
+{
+ if (!in_sched_functions(pc)) {
+ unsigned long *p = arg;
+ *p = pc;
+ return false;
+ }
+ return true;
+}
+
+unsigned long __get_wchan(struct task_struct *task)
+{
+ unsigned long pc = 0;
+
+ if (!try_get_task_stack(task))
+ return 0;
+ walk_stackframe(task, NULL, save_wchan, &pc);
+ put_task_stack(task);
+ return pc;
+}
+
+noinline void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
+ struct task_struct *task, struct pt_regs *regs)
+{
+ walk_stackframe(task, regs, consume_entry, cookie);
+}