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-rw-r--r--arch/loongarch/kernel/stacktrace.c78
1 files changed, 78 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/stacktrace.c b/arch/loongarch/kernel/stacktrace.c
new file mode 100644
index 000000000..3a690f96f
--- /dev/null
+++ b/arch/loongarch/kernel/stacktrace.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Stack trace management functions
+ *
+ * Copyright (C) 2022 Loongson Technology Corporation Limited
+ */
+#include <linux/sched.h>
+#include <linux/stacktrace.h>
+#include <linux/uaccess.h>
+
+#include <asm/stacktrace.h>
+#include <asm/unwind.h>
+
+void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
+ struct task_struct *task, struct pt_regs *regs)
+{
+ unsigned long addr;
+ struct pt_regs dummyregs;
+ struct unwind_state state;
+
+ regs = &dummyregs;
+
+ if (task == current) {
+ regs->regs[3] = (unsigned long)__builtin_frame_address(0);
+ regs->csr_era = (unsigned long)__builtin_return_address(0);
+ } else {
+ regs->regs[3] = thread_saved_fp(task);
+ regs->csr_era = thread_saved_ra(task);
+ }
+
+ regs->regs[1] = 0;
+ for (unwind_start(&state, task, regs);
+ !unwind_done(&state); unwind_next_frame(&state)) {
+ addr = unwind_get_return_address(&state);
+ if (!addr || !consume_entry(cookie, addr))
+ break;
+ }
+}
+
+static int
+copy_stack_frame(unsigned long fp, struct stack_frame *frame)
+{
+ int ret = 1;
+ unsigned long err;
+ unsigned long __user *user_frame_tail;
+
+ user_frame_tail = (unsigned long *)(fp - sizeof(struct stack_frame));
+ if (!access_ok(user_frame_tail, sizeof(*frame)))
+ return 0;
+
+ pagefault_disable();
+ err = (__copy_from_user_inatomic(frame, user_frame_tail, sizeof(*frame)));
+ if (err || (unsigned long)user_frame_tail >= frame->fp)
+ ret = 0;
+ pagefault_enable();
+
+ return ret;
+}
+
+void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie,
+ const struct pt_regs *regs)
+{
+ unsigned long fp = regs->regs[22];
+
+ while (fp && !((unsigned long)fp & 0xf)) {
+ struct stack_frame frame;
+
+ frame.fp = 0;
+ frame.ra = 0;
+ if (!copy_stack_frame(fp, &frame))
+ break;
+ if (!frame.ra)
+ break;
+ if (!consume_entry(cookie, frame.ra))
+ break;
+ fp = frame.fp;
+ }
+}