// SPDX-License-Identifier: GPL-2.0
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/*
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* Stack trace management functions
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*
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* Copyright IBM Corp. 2006
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* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
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*/
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#include <linux/stacktrace.h>
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#include <asm/stacktrace.h>
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#include <asm/unwind.h>
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#include <asm/kprobes.h>
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void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
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struct task_struct *task, struct pt_regs *regs)
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{
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struct unwind_state state;
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unsigned long addr;
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unwind_for_each_frame(&state, task, regs, 0) {
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addr = unwind_get_return_address(&state);
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if (!addr || !consume_entry(cookie, addr))
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break;
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}
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}
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/*
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* This function returns an error if it detects any unreliable features of the
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* stack. Otherwise it guarantees that the stack trace is reliable.
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*
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* If the task is not 'current', the caller *must* ensure the task is inactive.
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*/
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int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry,
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void *cookie, struct task_struct *task)
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{
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struct unwind_state state;
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unsigned long addr;
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unwind_for_each_frame(&state, task, NULL, 0) {
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if (state.stack_info.type != STACK_TYPE_TASK)
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return -EINVAL;
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if (state.regs)
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return -EINVAL;
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addr = unwind_get_return_address(&state);
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if (!addr)
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return -EINVAL;
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#ifdef CONFIG_KPROBES
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/*
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* Mark stacktraces with kretprobed functions on them
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* as unreliable.
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*/
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if (state.ip == (unsigned long)kretprobe_trampoline)
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return -EINVAL;
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#endif
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if (!consume_entry(cookie, addr))
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return -EINVAL;
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}
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/* Check for stack corruption */
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if (unwind_error(&state))
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return -EINVAL;
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return 0;
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}
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