74 lines
1.6 KiB
C
74 lines
1.6 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2022 Loongson Technology Corporation Limited
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*/
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#include <linux/kernel.h>
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#include <asm/unwind.h>
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unsigned long unwind_get_return_address(struct unwind_state *state)
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{
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if (unwind_done(state))
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return 0;
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else if (state->first)
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return state->pc;
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return *(unsigned long *)(state->sp);
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}
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EXPORT_SYMBOL_GPL(unwind_get_return_address);
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void unwind_start(struct unwind_state *state, struct task_struct *task,
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struct pt_regs *regs)
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{
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memset(state, 0, sizeof(*state));
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if (regs) {
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state->sp = regs->regs[3];
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state->pc = regs->csr_era;
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} else if (task && task != current) {
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state->sp = thread_saved_fp(task);
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state->pc = thread_saved_ra(task);
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} else {
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state->sp = (unsigned long)__builtin_frame_address(0);
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state->pc = (unsigned long)__builtin_return_address(0);
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}
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state->task = task;
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state->first = true;
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get_stack_info(state->sp, state->task, &state->stack_info);
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if (!unwind_done(state) && !__kernel_text_address(state->pc))
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unwind_next_frame(state);
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}
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EXPORT_SYMBOL_GPL(unwind_start);
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bool unwind_next_frame(struct unwind_state *state)
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{
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struct stack_info *info = &state->stack_info;
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unsigned long addr;
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if (unwind_done(state))
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return false;
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if (state->first)
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state->first = false;
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do {
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for (state->sp += sizeof(unsigned long);
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state->sp < info->end;
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state->sp += sizeof(unsigned long)) {
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addr = *(unsigned long *)(state->sp);
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if (__kernel_text_address(addr))
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return true;
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}
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state->sp = info->next_sp;
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} while (!get_stack_info(state->sp, state->task, info));
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return false;
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}
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EXPORT_SYMBOL_GPL(unwind_next_frame);
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